Background: Diarrheal diseases have globally decreased over the past few decades, yet they remain one of the top three causes of mortality in children under five years, especially in sub-Saharan Africa and Nigeria. Se...Background: Diarrheal diseases have globally decreased over the past few decades, yet they remain one of the top three causes of mortality in children under five years, especially in sub-Saharan Africa and Nigeria. Seasonal peaks of diarrheal episodes continue to contribute significantly to childhood mortality in these regions. One of the notable causes of diarrhea in children is parasitic infections, particularly Cryptosporidium, which poses a serious health risk. In Nigeria, the burden of Cryptosporidium diarrhea is under-researched, making it imperative to investigate its prevalence and associated risk factors. Study Objectives: The study aims to determine the prevalence and risk factors associated with Cryptosporidium diarrhea among children aged five years and below in selected health institutions in Abakaliki, South-East Nigeria. Methodology: This cross-sectional study was conducted from January to May 2017, recruiting 200 children under five years with diarrhea from health institutions in Abakaliki. Fecal specimens were analyzed for Cryptosporidium oocysts using light microscopy with modified Ziehl-Neelsen staining and immunofluorescent antibody test (IFAT). Deoxyribonucleic acid (DNA) was extracted from positive samples using QIAmp® DNA stool kit, followed by Polymerase Chain Reaction (PCR) and molecular genotyping. Results: Cryptosporidium was detected in 0.5% (1/200) of children via light microscopy and 6.5% (13/200) via IFAT. All positive samples were confirmed as Cryptosporidium hominis by PCR. The prevalence of infection was significantly higher in children from institutionalized homes (50.0%) compared to monogamous homes (6.2%) (p Conclusion: Cryptosporidium hominis is a notable cause of diarrhea among children in Abakaliki, primarily transmitted through human-to-human contact. The study underscores the need for targeted interventions in childcare institutions to prevent outbreaks. Health authorities should promote breastfeeding and enhance education on hygiene practices in vulnerable populations.展开更多
Objective Cryptosporidium spp. are prevalent globally and sheep are an important zoonotic reservoir. Little data regarding the rates of Cryptosporidium infections in ovines in China are available. This study assessed ...Objective Cryptosporidium spp. are prevalent globally and sheep are an important zoonotic reservoir. Little data regarding the rates of Cryptosporidium infections in ovines in China are available. This study assessed the prevalence of Cryptosporidium spp. in pre-weaned ovines from Aba Tibetan and Qiang Autonomous Prefecture in the Sichuan province of China. Methods A total of 213 fecal samples were collected from pre-weaned ovines and were examined microscopically （following modified acid fast staining）. In addition, 18S rRNA genetic sequences were amplified from fecal samples by nested PCR and phylogenetically analyzed. Results The prevalence of Cryptosporidium in the collected samples was at 14.6% （31/213） and four isolates identified by PCR belonged to the Cryptosporidium cervine genotype （Cryptosporidium ubiquiturn） demonstrating that this species was the primary sheep species found in sheep in China. Conclusion The present study suggested that the high incidence of Cryptosporidium in sheep poses a significant public health threat and that surveillance practices must be established to prevent zoonotic disease of humans.展开更多
Objective Pigs, as hosts of zoonotic Cryptosporidium species/genotypes, are domestic animals with public health significance. The present study was to characterize the infection rate and species/genotype of Cryptospor...Objective Pigs, as hosts of zoonotic Cryptosporidium species/genotypes, are domestic animals with public health significance. The present study was to characterize the infection rate and species/genotype of Cryptosporidium in pre-weaned and post-weaned pigs from Shanghai and Shaoxing, China. Methods A total of 208 fecal samples （42 from pre-weaned piglets, and 166 from post-weaned pigs） were examined by nested PCR of the 185 rRNA gene and analyzed by phylogenetic DNA fragment sequencing of secondary PCR products. Results Infection was detected in 79 samples （19/42 pre-weaned piglets, and 60/166 post-weaned pigs）. C. suis （14/79） and Cryptosporidium pig genotype II （65/79） were identified; piglets were more susceptible to the former （13/14） and post-weaned pigs to the latter （59/65）. Conclusion Infection of Cryptosporidium spp. in pigs was age-specific; piglets were more susceptible to C. suis while pigs were more susceptible to Cryptosporidium pig genotype II. These findings combined with the isolation of the two Cryptosporidium from water suggest that pigs may be a source of zoonotic Cryptosporidium water pollution. Improvements in pig feeding practices, sewage discharge, feces disposal and field worker protection are therefore important to prevent potential public health problems.展开更多
[Objective] To clone the actin gene of Cryptosporidium andersoni, and to study its eukaryotic expression in Hela cells. [Methed] Specific primers were designed for the partial encoding sequence of actin, which were ob...[Objective] To clone the actin gene of Cryptosporidium andersoni, and to study its eukaryotic expression in Hela cells. [Methed] Specific primers were designed for the partial encoding sequence of actin, which were obtained by screening the T7 phage display library of Cryptosporidium andersoni, and the actin gene CA42 was amplified by PCR. Recombinant eukaryotic expression plasmid pVAX1-CA42 was constructed and transfected to Hela cells with lipofection strategy. Indirect im- munofluorescence staining, SDS-PAGE and Western blotting analysis were used to detect the expression of recombinant protein in Hela cells. [Result] CA42 protein was successfully expressed in Hela cells, and the expression products had reactogenicity. [Conclusion] The partial encoding sequence of actin from Cryptosporidium andersoni has been successfully cloned, and it can be stably expressed in Hela Cells展开更多
The fluorescence staining method and scanning electron microscopy （SEM） were used to study the effect of ozone （O3） inactivating Cryptosporidium in water and cell ultrastructures variation to shed light on the mec...The fluorescence staining method and scanning electron microscopy （SEM） were used to study the effect of ozone （O3） inactivating Cryptosporidium in water and cell ultrastructures variation to shed light on the mechanism of inactivation preliminarily. Results indicated that O3 had a stronger inactivating capability. When the concentration of O3 was above 3.0 mg/L and the contact time was up to 7 min, a significant inactivating effect could be achieved. The turbidity on inactivation effects was also found to be statistically significant in artificial water. With increases in turbidity, the inactivating effect decreased. Inactivation rate improved with a temperature increase from 5 to 25℃, but decreased beyond this. The inactivating capability of O3 was found to be stronger under acidic than that under alkalic conditions. When the concentration of organic matter in the reaction system was increased, the competition between Cryptosporidium and organics with O3 probably took place, thereby reducing the inactivation rate. In addition, the cellular morphology of Cryptosporidium varied with different contact times. At zero contact time, cells were rotundity and sphericity, at 60 sec they became folded, underwent emboly, and burst at 480 sec, the cell membrane of Cryptosporidium shrinked and collapsed completely.展开更多
Objective:To evaluate the presence of gastrointestinal parasites on cattle in Indonesia because the prevalence of parasites varies between counlries depending on the terrain surrounding livestock farms and investigati...Objective:To evaluate the presence of gastrointestinal parasites on cattle in Indonesia because the prevalence of parasites varies between counlries depending on the terrain surrounding livestock farms and investigations in Indonesia have never been performed.Methods:Fecal samples from cattle at 35 farms in 7 districts in West Java,Indonesia,has been examined using the floatation or sedimentation methods,and a immunofluorescence assay and experimentally inoculation to mice for Cryptosporidium or Giardia spp.Results:153 of 394 examined cattle(38.8%)were infected with gastrointestinal parasites.The prevalence of Eimeria spp.,Nematoda spp.(including Oesophagustomum and Bunostomum-like),Fasciola gigantica and Paramphistomum spp.was 22.4%,11.2%,12.5%and 3.8%,respectively.Cryptosporidium andersoni(C.andersoni)was also found in two samples.One isolate of this parasite was confirmed to be transmitted to mice,in contrast to the isolates from other countries.Conclusions:although this survey is preliminary,the results shows that the infection of gastrointestinal parasites in Indonesia was not high,but these infected cattle could be as a potential source leading to economic losses in livestock production.展开更多
Cryptosporidiosis is an important zoonosis caused by the Cryptosporidium species. To develop a PCR diagnostic kit for molecular detection and differential diagnosis of Cryptosporidium spp., a portion of ITS-1 sequence...Cryptosporidiosis is an important zoonosis caused by the Cryptosporidium species. To develop a PCR diagnostic kit for molecular detection and differential diagnosis of Cryptosporidium spp., a portion of ITS-1 sequence of Cryptosporidium. andersoni was chosen as the target DNA for designing the species-specific primers （ZRQF/ZR）. The kit components were determined after the PCR amplification conditions were serially optimized. A series of tests were conducted in the specificity, sensitivity, stability, reproducibility, and stored period of the kit, respectively. The results showed that only C. andersoni were amplified specific band of about 500 bp, while Cryptosporidium. parvum, Cryptosporidium. baileyi, Eimeria sp of dairy cow, Toxoplasma gondii, Eimeria sp of pig, Ascaris suum, Cyclospora sp, and E. coli could not be amplified. 254 oocysts of C. andersoni was the lowest number that could be detected using the kit. The kit worked well after being stored at room temperature, 4 and -20℃ for nine months. Fecal specimens, which were collected from a total of 243 calves on four different dairy farms in Guangdong Province, China, and one dairy farm in Henan Province, China, were examined using the kit; the positive rate of the kit was 2-13% higher than that of the routine methods. The results indicated that the kit can detect fecal samples faster, more sensitively, and conveniently, and can provide a useful tool for the identification and differentiation of C. andersoni from the other Cryptosporidium species; it also has implications for further studies on molecular epidemiology and differential diagnostics of cryptosporidiosis in animals.展开更多
Diarrhea is a common complication in solid organ transplant(SOT) recipients and may be attributed to immunosuppressive drugs or infectious organisms such as bacteria, viruses or parasites. Cryptosporidium usually caus...Diarrhea is a common complication in solid organ transplant(SOT) recipients and may be attributed to immunosuppressive drugs or infectious organisms such as bacteria, viruses or parasites. Cryptosporidium usually causes self-limited diarrhea in immunocompetent hosts. Although it is estimated that cryptosporidium is involved in about 12% of cases of infectious diarrhea in developing countries and causes approximately 748000 cases each year in the United States, it is still an under recognized and important cause of infectious diarrhea in SOT recipients. It may run a protracted course with severe diarrhea, fluid and electrolyte depletion and potential for organ failure. Although diagnostic methodologies have improved significantly, allowing for fast and accurate identification of the parasite, treatment of the disease is difficult because antiparasitic drugs have modest activity at best. Current management includes fluid and electrolyte replacement, reduction of immunosuppression and single therapy with Nitazoxanide or combination therapy with Nitazoxanide and other drugs. Future drug and vaccine development may add to the currently poor armamentarium to manage the disease. The current review highlights key epidemiological, diagnostic and management issues in the SOT population.展开更多
Objective:To investigate the prevalence of Cryptosporidium spp.in goat kids in selected areas of Bangladesh and to elucidate the potential zoonotic hazards.Methods:In the present study,we have used Ziehl-Neelsen stain...Objective:To investigate the prevalence of Cryptosporidium spp.in goat kids in selected areas of Bangladesh and to elucidate the potential zoonotic hazards.Methods:In the present study,we have used Ziehl-Neelsen staining and nested PCR approach to identify and characterize the Cryptosporidium sp.from diarrhoeic feces of goat kids.A total of 100 diarrhoeic feces samples were collected from Chittagong region in Southern Bangladesh.For nested PCR analysis,specific primers for amplification of 581 base pair fragments of 18 S rRNA gene were used.Results:A total of 15%and 3%samples were found positive in microscopic study and in nested PCR analysis respectively.Phylogenetic analysis of sequence data showed similarity with that of Cryptosporidium xiaoi recorded from sheep and goat.Conclusions:To our knowledge,this is the first report of Cryptosporidium xiaoi responsible for diarrhoea in goat kids in Bangladesh.Further study can highlight their zoonotic significance along with genetic diversity in other host species inside the country.展开更多
Objective:To identify the genotypes of prevalent Cryptosporidia in broiler chickens in Lorestan province,Iran.Methods:A total of 1 000 fecal and 1 000 trachea samples were collected from chickens.Smears from both feca...Objective:To identify the genotypes of prevalent Cryptosporidia in broiler chickens in Lorestan province,Iran.Methods:A total of 1 000 fecal and 1 000 trachea samples were collected from chickens.Smears from both fecal and tracheal samples were stained with modified ZiehlNeelsen method and nested PCR-RFTP according to amplification of 18S rRNA gene using Ssp1 and Vsp 1 restriction enzymes and DNA sequencing.Results:From the examined chickens0.7%was positive for Cryptosporidium,Infection was present in 0.3%fecal samples and also in0.5%trachea.Only 0.3%of simultaneous infections in fecal and tracheal samples were observed.Nested PCR of our isolates demonstrated Cryptosporidium baileyi.Conclusions:In our work,low rate of Cryptosporidium baileyi infection was detected,but in critical situations and our poor management circumstances,cryptosporidiosis occurs in serious feature especially in immune suppressed individuals.展开更多
Objective:To identify the prevalence of Cryptosporidium from goats in three types of farm management systems in Terengganu,Malaysia and to determine the Cryptosporidium species infecting goats by using 18 S r RNA.Meth...Objective:To identify the prevalence of Cryptosporidium from goats in three types of farm management systems in Terengganu,Malaysia and to determine the Cryptosporidium species infecting goats by using 18 S r RNA.Methods:A total of 478 fecal samples were randomly collected from goats in three farms;199 samples were collected from intensive farm,179 samples from semi-intensive farm and 100 samples from extensive farm.The samples were processed by using formolether concentration technique and stained by using modified Ziehl–Neelsen.Positive samples were performed by using nested PCR analysis by using 18 S r RNA.Results:Out of 478 goats,207(43.3%) were found to be infected with Cryptosporidium.Goats reared under the intensive farm management system reported the highest prevalence of infection(49.7%),followed by intensive farm management system(41%) and the lowest prevalence was reported in the goats reared under semi-intensive management system(37.4%).Conclusions:The identified species found in goat was Cryptosporidium parvum.Future study on the zoonotic transmission of Cryptosporidium parvum in goats needs to be done in order to find the source of transmission of this parasite.展开更多
Objective:To identify the serological epidemiology of Cryptosporidium infections and to follow up on the changes in the infection profile in Southern Egypt in order to establish a suitable scheme for control and preve...Objective:To identify the serological epidemiology of Cryptosporidium infections and to follow up on the changes in the infection profile in Southern Egypt in order to establish a suitable scheme for control and prevention of cryptosporidiosis.Methods:A total of 1912(960 from human and 952 from animals)stool specimens and sera were screened for Cryptosporidium species using modified Ziehl Neelsen technique and a newly-developed enzyme-linked immunosorbent assay(ELISA).Environmental risk factors and socioeconomic data were surveyed by questionnaire between September 2016 and December 2017.Results:Totally,20.83%of the human subjects were positive for Cryptosporidium infection tested by ELISA.The seropositivity was positively correlated with age.The prevalence of Cryptosporidium infections in females was significantly higher than in males(P<0.05).The sensitivity and specificity of ELISA for Cryptosporidium were 99.06%and 88.88%,respectively.Furthermore,a high prevalence of Cryptosporidium in domestic animals(42.20%).Conclusions:The study observed that Cryptosporidium infections are common in the study area,with water sanitation,socioeconomic level;eating habits and hygienic status are considered the main risk factors for cryptosporidiosis.Therefore,environmental sanitation and health education will be useful in reducing the prevalence of infection.展开更多
Diarrheal disease is a chronic public health problem in Chobe District, Botswana. Acute diarrheal outbreaks occur annually with a bimodal seasonal pattern coinciding with major hydrological phenomena. Information is l...Diarrheal disease is a chronic public health problem in Chobe District, Botswana. Acute diarrheal outbreaks occur annually with a bimodal seasonal pattern coinciding with major hydrological phenomena. Information is lacking regarding the etiology of reoccurring outbreaks. Cryptosporidium and Giardia are recognized as important waterborne causes of diarrheal disease with Cryptosporidium transmission potentially involving zoonotic reservoirs. In Chobe District, municipal water is obtained from the Chobe River after it exits the Chobe National Park where high concentrations of wildlife occur. Using the Giardia/Cryptosporidium QUIK CHEK rapid antigen cartridge test, we evaluate the occurrence of Giardia and Cryptosporidium among patients (n = 153) presenting to medical facilities in Chobe District with diarrhea (August 2011-July 2012). Cryptosporidium was only identified in children less than two years of age (10%, n = 42, 95% CI 3% - 23%), with positive cases occurring during diarrheal outbreak periods. Infections were not identified in adults despite the high level of human immunodeficiency virus infection/acquired immunodeficiency syndrome (HIV/AIDS) in the region (n = 117). Although not significant, cases were predominately identified in the wet season outbreak (p = 0.94, 25%, n = 12, 95% CI 5% - 57%, dry season outbreaks 3%, n = 30, CI 95% 0% - 17%). Giardia infections occurred across age groups and seasons (7%, n = 153, 95% CI 4% - 10%). This is the first published report of human infections with Cryptosporidium and Giardia in this area of Africa. This study suggests that Cryptosporidium may be a potentially important cause of diarrheal disease in children less than 2 years of age in this region. Further research is required to identify pathogen transmission and persistence dynamics and public health implications, particularly the role of HIV/AIDS and vulnerability to waterborne disease.展开更多
<i><span style="font-family:Verdana;">Cryptosporidium</span></i><span style="font-family:;" "=""><span style="font-family:Verdana;"> inf...<i><span style="font-family:Verdana;">Cryptosporidium</span></i><span style="font-family:;" "=""><span style="font-family:Verdana;"> infection is estimated to cause 2.9 million diarrheal cases yearly among children aged under 24 months in sub-Saharan Africa. Studies have shown long-term climatic variations can affect infectious diseases. The burden of cryptosporidiosis in rural areas of sub-Saharan Africa is well characterized. However, the trend of </span><i><span style="font-family:Verdana;">Cryptosporidium</span></i><span style="font-family:Verdana;"> infection is not known, especially in informal urban settings. This study therefore sought to determine cryptosporidiosis trends, and further explore the association between year and </span><i><span style="font-family:Verdana;">Cryptosporidium</span></i><span style="font-family:Verdana;"> infection among children below 24 months in Kibera urban informal settlement in Kenya. Data collected by the Kenya Medical Research Institute longitudinal study in Tabitha clinic in Kibera from 2009 to 2015 were used. At least 3000 children aged < 24 months receive free health care at the clinic. In the longitudinal study</span></span><span style="font-family:Verdana;">,</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> children presenting with diarrhea were eligible for stool sample collection (</span><i><span style="font-family:Verdana;">n</span></i><span style="font-family:Verdana;"> = 477), out of which 421 stool samples were tested using TaqMan</span><span style="font-family:Verdana;"><span style="white-space:nowrap;">™</span></span><span style="font-family:Verdana;"> Array Card (TAC) polymerase chain reaction panel that included a target for </span><i><span style="font-family:Verdana;">Cryptosporidium</span></i><span style="font-family:Verdana;"> genus. Data for the 421 children were included in the analysis. Logistic regression was used to explore the difference between the seven years and cryptosporidiosis. Overall, the pooled data indicated that 23.5% of the children who were tested had </span><i><span style="font-family:Verdana;">Cryptosporidium</span></i><span style="font-family:Verdana;"> infection, with the highest proportions of </span><i><span style="font-family:Verdana;">Cryptosporidium-</span></i><span style="font-family:Verdana;">positive cases observed in 2015 (45.2%). The logistic regression results also indicated that children who were tested in the year 2015 were more likely to have </span><i><span style="font-family:Verdana;">Cryptosporidium</span></i><span style="font-family:Verdana;"> infection (OR = 3.39;95% CI: 1.44 - 7.96;</span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;"> = 0.005) than those in 2009. Watery stool was also found to be an important symptom of cryptosporidiosis. There was a high prevalence of </span><i><span style="font-family:Verdana;">Cryptosporidium</span></i><span style="font-family:Verdana;"> infection among young children, especially in the most recent year. Routine testing of </span><i><span style="font-family:Verdana;">Cryptosporidium</span></i><span style="font-family:Verdana;"> infection using molecular methods, constant monitoring and identification of the infection sources is therefore necessary towards reducing the disease burden in the low resource settings.</span></span>展开更多
Objective: To determine the ability of oysters to trap and maintain viable Cryptosporidium oocysts, and the feasibility of Cryptosporidium multiplication in oysters’ organs. Methods: Seventy oysters were raised in ex...Objective: To determine the ability of oysters to trap and maintain viable Cryptosporidium oocysts, and the feasibility of Cryptosporidium multiplication in oysters’ organs. Methods: Seventy oysters were raised in experimentally seeded natural seawater for up to 3 months, with weekly oocysts inoculations. Cryptosporidium oocysts, viable and non-viable, as well as other stages were detected using two immunofluorescence vital staining techniques(SporoGlo and Merifluor~) with confocal microscopy. Viability rate at various times after inoculations were calculated. Results: Cryptosporidium oocysts were found most concentrated in oysters’ digestive organs than in gill and water inside the oysters. Oocysts numbers were 857.33 at 24 h after inoculation and strikingly decreased to 243.00 and 126.67 oocysts at 72 h and 7 days, respectively. The oocysts in oyster were also less viable over time; 70%, 60% and 30% viable at 24 hrs, 72 hrs and 7days after inoculation, respectively. At 77 days, the number of oocysts was very low and none was found at 84 days onwards. Although some oocysts were ruptured with released sporozoites, there was no evidence throughout the study of sporozoites multiplication to indicate that oyster is a biological host. Despite the significant reduction in oocysts number after 7 days of inoculation, the remained viable oocysts can still cause cryptosporidiosis. Conclusion: The findings confirm that Cryptosporidium parvum does not multiply in oyster, and is therefore not a biological host. Nevertheless, the results suggest that oyster can be an effective transmission vehicle for Cryptosporidium oocysts, especially within 24-72 h of contamination, with viable oocysts present at up to 7 days post infection. Unless consuming well-cooked oyster dishes, eating raw oyster remains a public health concern and at least 3 days of depuration in clean sea water prior to consumption is recommended.展开更多
Three isolates of the genus Cryptosporidium, namely, Guangdong isolate, Anhui isolate and Jiangsu isolate from MainlandChina, were identified and characterized genetically utilizing nuclear DNA regions of the small su...Three isolates of the genus Cryptosporidium, namely, Guangdong isolate, Anhui isolate and Jiangsu isolate from MainlandChina, were identified and characterized genetically utilizing nuclear DNA regions of the small subunit of ribosomal RNA(SSU rRNA) and heat shock protein 70 gene (HSP70) as genetic markers. These two regions were amplified by PCR fromDNA extracted from oocysts and amplicons of approximately 290 bp and 450 bp were produced, respectively. The ampliconswere purified, cloned and sequenced. Sequences of 446 bp and 290-292 bp were obtained for the SSU rRNA and HSP70regions, respectively. The obtained SSU rRNA and HSP70 sequences representing the three Cryptosporidium isolateswere compared with those retrieved from the DNA database. Genetic analyses using either DNA region revealed thatmembers of Cryptosporidium formed two clusters, with C. parvum, C. wariri, C. felis and C. meleagridis clusteredtogether, while C. andersoni, C. muris and C. serpentis belong to the other cluster. Based on SSU rRNA and HSP70sequences, both Guangdong and Anhui isolates of Cryptosporidium were identified as C. muris of the calf genotype (i.e., C. andersoni), whereas the Jiangsu isolate was identified as C. parvum of the calf genotype. The findings of thepresent study should have important implications for the diagnosis and control of Cryptosporidium infections in bothhumans and animals in China.展开更多
The CP15/60 gene encoding the CP15/60 surface protein of sporozoites in Cryptosporidiumparvum was obtained by PCR so as to research the nucleic vaccine against C.parvum. Theeukaryotic expressing vector pcDNA3-15/60 wa...The CP15/60 gene encoding the CP15/60 surface protein of sporozoites in Cryptosporidiumparvum was obtained by PCR so as to research the nucleic vaccine against C.parvum. Theeukaryotic expressing vector pcDNA3-15/60 was constructed by inserting CP15/60 gene intopcDNA3 (+) in XhoⅠand EcoRⅠ. A vaccination protocol was the adult pregnant goatsinoculated intranasally with the pcDNA3-15/60 plasmid and their offspring were infectedwith C.parvum oocysts. The results showed that the pcDNA3-15/60 plasmid can induce theimmune response of goats and the vaccinated goats can transfer the immunity to offspringconferring protection against C.parvum infection. These suggested that the recombinantplasmid could be a DNA vaccine candidate.展开更多
Recent Cryptosporidium outbreaks have highlighted concerns about filter efficiency and in particular particle breakthrough. It is essential to ascertain the causes of Cryptosporidium sized particle breakthrough for Cr...Recent Cryptosporidium outbreaks have highlighted concerns about filter efficiency and in particular particle breakthrough. It is essential to ascertain the causes of Cryptosporidium sized particle breakthrough for Cryptosporidium cannot be destroyed by conventional chlorine disinfection. This research tried to investigate the influence of temperature, flow rate and chemical dosing on particle breakthrough during filtration. The results showed that higher temperatures and coagulant doses could reduce particle breakthrough. The increase of filtration rate made the residual particle counts become larger. There was an optimal dose in filtration and was well correlated to ζ potential.展开更多
文摘Background: Diarrheal diseases have globally decreased over the past few decades, yet they remain one of the top three causes of mortality in children under five years, especially in sub-Saharan Africa and Nigeria. Seasonal peaks of diarrheal episodes continue to contribute significantly to childhood mortality in these regions. One of the notable causes of diarrhea in children is parasitic infections, particularly Cryptosporidium, which poses a serious health risk. In Nigeria, the burden of Cryptosporidium diarrhea is under-researched, making it imperative to investigate its prevalence and associated risk factors. Study Objectives: The study aims to determine the prevalence and risk factors associated with Cryptosporidium diarrhea among children aged five years and below in selected health institutions in Abakaliki, South-East Nigeria. Methodology: This cross-sectional study was conducted from January to May 2017, recruiting 200 children under five years with diarrhea from health institutions in Abakaliki. Fecal specimens were analyzed for Cryptosporidium oocysts using light microscopy with modified Ziehl-Neelsen staining and immunofluorescent antibody test (IFAT). Deoxyribonucleic acid (DNA) was extracted from positive samples using QIAmp® DNA stool kit, followed by Polymerase Chain Reaction (PCR) and molecular genotyping. Results: Cryptosporidium was detected in 0.5% (1/200) of children via light microscopy and 6.5% (13/200) via IFAT. All positive samples were confirmed as Cryptosporidium hominis by PCR. The prevalence of infection was significantly higher in children from institutionalized homes (50.0%) compared to monogamous homes (6.2%) (p Conclusion: Cryptosporidium hominis is a notable cause of diarrhea among children in Abakaliki, primarily transmitted through human-to-human contact. The study underscores the need for targeted interventions in childcare institutions to prevent outbreaks. Health authorities should promote breastfeeding and enhance education on hygiene practices in vulnerable populations.
基金supported by grants from the Chinese Special Program for Scientific Research of Public Health (200802012)Chinese National Key Program for Infectious Diseases of China (2009ZX10004‐201, and 2008ZX10004‐002)
文摘Objective Cryptosporidium spp. are prevalent globally and sheep are an important zoonotic reservoir. Little data regarding the rates of Cryptosporidium infections in ovines in China are available. This study assessed the prevalence of Cryptosporidium spp. in pre-weaned ovines from Aba Tibetan and Qiang Autonomous Prefecture in the Sichuan province of China. Methods A total of 213 fecal samples were collected from pre-weaned ovines and were examined microscopically （following modified acid fast staining）. In addition, 18S rRNA genetic sequences were amplified from fecal samples by nested PCR and phylogenetically analyzed. Results The prevalence of Cryptosporidium in the collected samples was at 14.6% （31/213） and four isolates identified by PCR belonged to the Cryptosporidium cervine genotype （Cryptosporidium ubiquiturn） demonstrating that this species was the primary sheep species found in sheep in China. Conclusion The present study suggested that the high incidence of Cryptosporidium in sheep poses a significant public health threat and that surveillance practices must be established to prevent zoonotic disease of humans.
基金supported by grants from the Chinese Special Program for Scientific Research of Public Health (No.200802012)the National S&T Major Program of China (No.2009ZX10004-201 and No.2012ZX10004-201)
文摘Objective Pigs, as hosts of zoonotic Cryptosporidium species/genotypes, are domestic animals with public health significance. The present study was to characterize the infection rate and species/genotype of Cryptosporidium in pre-weaned and post-weaned pigs from Shanghai and Shaoxing, China. Methods A total of 208 fecal samples （42 from pre-weaned piglets, and 166 from post-weaned pigs） were examined by nested PCR of the 185 rRNA gene and analyzed by phylogenetic DNA fragment sequencing of secondary PCR products. Results Infection was detected in 79 samples （19/42 pre-weaned piglets, and 60/166 post-weaned pigs）. C. suis （14/79） and Cryptosporidium pig genotype II （65/79） were identified; piglets were more susceptible to the former （13/14） and post-weaned pigs to the latter （59/65）. Conclusion Infection of Cryptosporidium spp. in pigs was age-specific; piglets were more susceptible to C. suis while pigs were more susceptible to Cryptosporidium pig genotype II. These findings combined with the isolation of the two Cryptosporidium from water suggest that pigs may be a source of zoonotic Cryptosporidium water pollution. Improvements in pig feeding practices, sewage discharge, feces disposal and field worker protection are therefore important to prevent potential public health problems.
基金Supported by the National Key Technology R & D Program (2007BAD40B05),Chinathe National High Technology Research and Development Program of China(2006AA10A207)~~
文摘[Objective] To clone the actin gene of Cryptosporidium andersoni, and to study its eukaryotic expression in Hela cells. [Methed] Specific primers were designed for the partial encoding sequence of actin, which were obtained by screening the T7 phage display library of Cryptosporidium andersoni, and the actin gene CA42 was amplified by PCR. Recombinant eukaryotic expression plasmid pVAX1-CA42 was constructed and transfected to Hela cells with lipofection strategy. Indirect im- munofluorescence staining, SDS-PAGE and Western blotting analysis were used to detect the expression of recombinant protein in Hela cells. [Result] CA42 protein was successfully expressed in Hela cells, and the expression products had reactogenicity. [Conclusion] The partial encoding sequence of actin from Cryptosporidium andersoni has been successfully cloned, and it can be stably expressed in Hela Cells
基金supported by the National High Technology Research and Development Program (863) of China(No. 2006AAZ309)
文摘The fluorescence staining method and scanning electron microscopy （SEM） were used to study the effect of ozone （O3） inactivating Cryptosporidium in water and cell ultrastructures variation to shed light on the mechanism of inactivation preliminarily. Results indicated that O3 had a stronger inactivating capability. When the concentration of O3 was above 3.0 mg/L and the contact time was up to 7 min, a significant inactivating effect could be achieved. The turbidity on inactivation effects was also found to be statistically significant in artificial water. With increases in turbidity, the inactivating effect decreased. Inactivation rate improved with a temperature increase from 5 to 25℃, but decreased beyond this. The inactivating capability of O3 was found to be stronger under acidic than that under alkalic conditions. When the concentration of organic matter in the reaction system was increased, the competition between Cryptosporidium and organics with O3 probably took place, thereby reducing the inactivation rate. In addition, the cellular morphology of Cryptosporidium varied with different contact times. At zero contact time, cells were rotundity and sphericity, at 60 sec they became folded, underwent emboly, and burst at 480 sec, the cell membrane of Cryptosporidium shrinked and collapsed completely.
基金partly supported by the JICA Project of Capacity Development of Animal Health Laboratory and Grants-in-Aid for Scientifie Research from the Ministry of Education.Culture.Sports.Science and Technology.Japan(No.22700773 to M.M.)
文摘Objective:To evaluate the presence of gastrointestinal parasites on cattle in Indonesia because the prevalence of parasites varies between counlries depending on the terrain surrounding livestock farms and investigations in Indonesia have never been performed.Methods:Fecal samples from cattle at 35 farms in 7 districts in West Java,Indonesia,has been examined using the floatation or sedimentation methods,and a immunofluorescence assay and experimentally inoculation to mice for Cryptosporidium or Giardia spp.Results:153 of 394 examined cattle(38.8%)were infected with gastrointestinal parasites.The prevalence of Eimeria spp.,Nematoda spp.(including Oesophagustomum and Bunostomum-like),Fasciola gigantica and Paramphistomum spp.was 22.4%,11.2%,12.5%and 3.8%,respectively.Cryptosporidium andersoni(C.andersoni)was also found in two samples.One isolate of this parasite was confirmed to be transmitted to mice,in contrast to the isolates from other countries.Conclusions:although this survey is preliminary,the results shows that the infection of gastrointestinal parasites in Indonesia was not high,but these infected cattle could be as a potential source leading to economic losses in livestock production.
文摘Cryptosporidiosis is an important zoonosis caused by the Cryptosporidium species. To develop a PCR diagnostic kit for molecular detection and differential diagnosis of Cryptosporidium spp., a portion of ITS-1 sequence of Cryptosporidium. andersoni was chosen as the target DNA for designing the species-specific primers （ZRQF/ZR）. The kit components were determined after the PCR amplification conditions were serially optimized. A series of tests were conducted in the specificity, sensitivity, stability, reproducibility, and stored period of the kit, respectively. The results showed that only C. andersoni were amplified specific band of about 500 bp, while Cryptosporidium. parvum, Cryptosporidium. baileyi, Eimeria sp of dairy cow, Toxoplasma gondii, Eimeria sp of pig, Ascaris suum, Cyclospora sp, and E. coli could not be amplified. 254 oocysts of C. andersoni was the lowest number that could be detected using the kit. The kit worked well after being stored at room temperature, 4 and -20℃ for nine months. Fecal specimens, which were collected from a total of 243 calves on four different dairy farms in Guangdong Province, China, and one dairy farm in Henan Province, China, were examined using the kit; the positive rate of the kit was 2-13% higher than that of the routine methods. The results indicated that the kit can detect fecal samples faster, more sensitively, and conveniently, and can provide a useful tool for the identification and differentiation of C. andersoni from the other Cryptosporidium species; it also has implications for further studies on molecular epidemiology and differential diagnostics of cryptosporidiosis in animals.
文摘Diarrhea is a common complication in solid organ transplant(SOT) recipients and may be attributed to immunosuppressive drugs or infectious organisms such as bacteria, viruses or parasites. Cryptosporidium usually causes self-limited diarrhea in immunocompetent hosts. Although it is estimated that cryptosporidium is involved in about 12% of cases of infectious diarrhea in developing countries and causes approximately 748000 cases each year in the United States, it is still an under recognized and important cause of infectious diarrhea in SOT recipients. It may run a protracted course with severe diarrhea, fluid and electrolyte depletion and potential for organ failure. Although diagnostic methodologies have improved significantly, allowing for fast and accurate identification of the parasite, treatment of the disease is difficult because antiparasitic drugs have modest activity at best. Current management includes fluid and electrolyte replacement, reduction of immunosuppression and single therapy with Nitazoxanide or combination therapy with Nitazoxanide and other drugs. Future drug and vaccine development may add to the currently poor armamentarium to manage the disease. The current review highlights key epidemiological, diagnostic and management issues in the SOT population.
基金Supported by two grants(No.-09-148 RG/BIO/AS_G and No.-10-087 RG/ITC/AS_C)from the Academy of Science for the developing World(TWAS)
文摘Objective:To investigate the prevalence of Cryptosporidium spp.in goat kids in selected areas of Bangladesh and to elucidate the potential zoonotic hazards.Methods:In the present study,we have used Ziehl-Neelsen staining and nested PCR approach to identify and characterize the Cryptosporidium sp.from diarrhoeic feces of goat kids.A total of 100 diarrhoeic feces samples were collected from Chittagong region in Southern Bangladesh.For nested PCR analysis,specific primers for amplification of 581 base pair fragments of 18 S rRNA gene were used.Results:A total of 15%and 3%samples were found positive in microscopic study and in nested PCR analysis respectively.Phylogenetic analysis of sequence data showed similarity with that of Cryptosporidium xiaoi recorded from sheep and goat.Conclusions:To our knowledge,this is the first report of Cryptosporidium xiaoi responsible for diarrhoea in goat kids in Bangladesh.Further study can highlight their zoonotic significance along with genetic diversity in other host species inside the country.
基金supported by Shahid Chamran University of Alivaz,Iran
文摘Objective:To identify the genotypes of prevalent Cryptosporidia in broiler chickens in Lorestan province,Iran.Methods:A total of 1 000 fecal and 1 000 trachea samples were collected from chickens.Smears from both fecal and tracheal samples were stained with modified ZiehlNeelsen method and nested PCR-RFTP according to amplification of 18S rRNA gene using Ssp1 and Vsp 1 restriction enzymes and DNA sequencing.Results:From the examined chickens0.7%was positive for Cryptosporidium,Infection was present in 0.3%fecal samples and also in0.5%trachea.Only 0.3%of simultaneous infections in fecal and tracheal samples were observed.Nested PCR of our isolates demonstrated Cryptosporidium baileyi.Conclusions:In our work,low rate of Cryptosporidium baileyi infection was detected,but in critical situations and our poor management circumstances,cryptosporidiosis occurs in serious feature especially in immune suppressed individuals.
基金Supported by IIUM Research Initiative Grant,RIGS grant no.16-301-0465
文摘Objective:To identify the prevalence of Cryptosporidium from goats in three types of farm management systems in Terengganu,Malaysia and to determine the Cryptosporidium species infecting goats by using 18 S r RNA.Methods:A total of 478 fecal samples were randomly collected from goats in three farms;199 samples were collected from intensive farm,179 samples from semi-intensive farm and 100 samples from extensive farm.The samples were processed by using formolether concentration technique and stained by using modified Ziehl–Neelsen.Positive samples were performed by using nested PCR analysis by using 18 S r RNA.Results:Out of 478 goats,207(43.3%) were found to be infected with Cryptosporidium.Goats reared under the intensive farm management system reported the highest prevalence of infection(49.7%),followed by intensive farm management system(41%) and the lowest prevalence was reported in the goats reared under semi-intensive management system(37.4%).Conclusions:The identified species found in goat was Cryptosporidium parvum.Future study on the zoonotic transmission of Cryptosporidium parvum in goats needs to be done in order to find the source of transmission of this parasite.
文摘Objective:To identify the serological epidemiology of Cryptosporidium infections and to follow up on the changes in the infection profile in Southern Egypt in order to establish a suitable scheme for control and prevention of cryptosporidiosis.Methods:A total of 1912(960 from human and 952 from animals)stool specimens and sera were screened for Cryptosporidium species using modified Ziehl Neelsen technique and a newly-developed enzyme-linked immunosorbent assay(ELISA).Environmental risk factors and socioeconomic data were surveyed by questionnaire between September 2016 and December 2017.Results:Totally,20.83%of the human subjects were positive for Cryptosporidium infection tested by ELISA.The seropositivity was positively correlated with age.The prevalence of Cryptosporidium infections in females was significantly higher than in males(P<0.05).The sensitivity and specificity of ELISA for Cryptosporidium were 99.06%and 88.88%,respectively.Furthermore,a high prevalence of Cryptosporidium in domestic animals(42.20%).Conclusions:The study observed that Cryptosporidium infections are common in the study area,with water sanitation,socioeconomic level;eating habits and hygienic status are considered the main risk factors for cryptosporidiosis.Therefore,environmental sanitation and health education will be useful in reducing the prevalence of infection.
文摘Diarrheal disease is a chronic public health problem in Chobe District, Botswana. Acute diarrheal outbreaks occur annually with a bimodal seasonal pattern coinciding with major hydrological phenomena. Information is lacking regarding the etiology of reoccurring outbreaks. Cryptosporidium and Giardia are recognized as important waterborne causes of diarrheal disease with Cryptosporidium transmission potentially involving zoonotic reservoirs. In Chobe District, municipal water is obtained from the Chobe River after it exits the Chobe National Park where high concentrations of wildlife occur. Using the Giardia/Cryptosporidium QUIK CHEK rapid antigen cartridge test, we evaluate the occurrence of Giardia and Cryptosporidium among patients (n = 153) presenting to medical facilities in Chobe District with diarrhea (August 2011-July 2012). Cryptosporidium was only identified in children less than two years of age (10%, n = 42, 95% CI 3% - 23%), with positive cases occurring during diarrheal outbreak periods. Infections were not identified in adults despite the high level of human immunodeficiency virus infection/acquired immunodeficiency syndrome (HIV/AIDS) in the region (n = 117). Although not significant, cases were predominately identified in the wet season outbreak (p = 0.94, 25%, n = 12, 95% CI 5% - 57%, dry season outbreaks 3%, n = 30, CI 95% 0% - 17%). Giardia infections occurred across age groups and seasons (7%, n = 153, 95% CI 4% - 10%). This is the first published report of human infections with Cryptosporidium and Giardia in this area of Africa. This study suggests that Cryptosporidium may be a potentially important cause of diarrheal disease in children less than 2 years of age in this region. Further research is required to identify pathogen transmission and persistence dynamics and public health implications, particularly the role of HIV/AIDS and vulnerability to waterborne disease.
文摘<i><span style="font-family:Verdana;">Cryptosporidium</span></i><span style="font-family:;" "=""><span style="font-family:Verdana;"> infection is estimated to cause 2.9 million diarrheal cases yearly among children aged under 24 months in sub-Saharan Africa. Studies have shown long-term climatic variations can affect infectious diseases. The burden of cryptosporidiosis in rural areas of sub-Saharan Africa is well characterized. However, the trend of </span><i><span style="font-family:Verdana;">Cryptosporidium</span></i><span style="font-family:Verdana;"> infection is not known, especially in informal urban settings. This study therefore sought to determine cryptosporidiosis trends, and further explore the association between year and </span><i><span style="font-family:Verdana;">Cryptosporidium</span></i><span style="font-family:Verdana;"> infection among children below 24 months in Kibera urban informal settlement in Kenya. Data collected by the Kenya Medical Research Institute longitudinal study in Tabitha clinic in Kibera from 2009 to 2015 were used. At least 3000 children aged < 24 months receive free health care at the clinic. In the longitudinal study</span></span><span style="font-family:Verdana;">,</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> children presenting with diarrhea were eligible for stool sample collection (</span><i><span style="font-family:Verdana;">n</span></i><span style="font-family:Verdana;"> = 477), out of which 421 stool samples were tested using TaqMan</span><span style="font-family:Verdana;"><span style="white-space:nowrap;">™</span></span><span style="font-family:Verdana;"> Array Card (TAC) polymerase chain reaction panel that included a target for </span><i><span style="font-family:Verdana;">Cryptosporidium</span></i><span style="font-family:Verdana;"> genus. Data for the 421 children were included in the analysis. Logistic regression was used to explore the difference between the seven years and cryptosporidiosis. Overall, the pooled data indicated that 23.5% of the children who were tested had </span><i><span style="font-family:Verdana;">Cryptosporidium</span></i><span style="font-family:Verdana;"> infection, with the highest proportions of </span><i><span style="font-family:Verdana;">Cryptosporidium-</span></i><span style="font-family:Verdana;">positive cases observed in 2015 (45.2%). The logistic regression results also indicated that children who were tested in the year 2015 were more likely to have </span><i><span style="font-family:Verdana;">Cryptosporidium</span></i><span style="font-family:Verdana;"> infection (OR = 3.39;95% CI: 1.44 - 7.96;</span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;"> = 0.005) than those in 2009. Watery stool was also found to be an important symptom of cryptosporidiosis. There was a high prevalence of </span><i><span style="font-family:Verdana;">Cryptosporidium</span></i><span style="font-family:Verdana;"> infection among young children, especially in the most recent year. Routine testing of </span><i><span style="font-family:Verdana;">Cryptosporidium</span></i><span style="font-family:Verdana;"> infection using molecular methods, constant monitoring and identification of the infection sources is therefore necessary towards reducing the disease burden in the low resource settings.</span></span>
基金partially funded by Research Assistantships 2012,Mahidol University
文摘Objective: To determine the ability of oysters to trap and maintain viable Cryptosporidium oocysts, and the feasibility of Cryptosporidium multiplication in oysters’ organs. Methods: Seventy oysters were raised in experimentally seeded natural seawater for up to 3 months, with weekly oocysts inoculations. Cryptosporidium oocysts, viable and non-viable, as well as other stages were detected using two immunofluorescence vital staining techniques(SporoGlo and Merifluor~) with confocal microscopy. Viability rate at various times after inoculations were calculated. Results: Cryptosporidium oocysts were found most concentrated in oysters’ digestive organs than in gill and water inside the oysters. Oocysts numbers were 857.33 at 24 h after inoculation and strikingly decreased to 243.00 and 126.67 oocysts at 72 h and 7 days, respectively. The oocysts in oyster were also less viable over time; 70%, 60% and 30% viable at 24 hrs, 72 hrs and 7days after inoculation, respectively. At 77 days, the number of oocysts was very low and none was found at 84 days onwards. Although some oocysts were ruptured with released sporozoites, there was no evidence throughout the study of sporozoites multiplication to indicate that oyster is a biological host. Despite the significant reduction in oocysts number after 7 days of inoculation, the remained viable oocysts can still cause cryptosporidiosis. Conclusion: The findings confirm that Cryptosporidium parvum does not multiply in oyster, and is therefore not a biological host. Nevertheless, the results suggest that oyster can be an effective transmission vehicle for Cryptosporidium oocysts, especially within 24-72 h of contamination, with viable oocysts present at up to 7 days post infection. Unless consuming well-cooked oyster dishes, eating raw oyster remains a public health concern and at least 3 days of depuration in clean sea water prior to consumption is recommended.
基金Financial support was provided by the Natural Science Foundation of Guangdong Province(010354,32286)China and National Natural Science Foundation of China(30371082).
文摘Three isolates of the genus Cryptosporidium, namely, Guangdong isolate, Anhui isolate and Jiangsu isolate from MainlandChina, were identified and characterized genetically utilizing nuclear DNA regions of the small subunit of ribosomal RNA(SSU rRNA) and heat shock protein 70 gene (HSP70) as genetic markers. These two regions were amplified by PCR fromDNA extracted from oocysts and amplicons of approximately 290 bp and 450 bp were produced, respectively. The ampliconswere purified, cloned and sequenced. Sequences of 446 bp and 290-292 bp were obtained for the SSU rRNA and HSP70regions, respectively. The obtained SSU rRNA and HSP70 sequences representing the three Cryptosporidium isolateswere compared with those retrieved from the DNA database. Genetic analyses using either DNA region revealed thatmembers of Cryptosporidium formed two clusters, with C. parvum, C. wariri, C. felis and C. meleagridis clusteredtogether, while C. andersoni, C. muris and C. serpentis belong to the other cluster. Based on SSU rRNA and HSP70sequences, both Guangdong and Anhui isolates of Cryptosporidium were identified as C. muris of the calf genotype (i.e., C. andersoni), whereas the Jiangsu isolate was identified as C. parvum of the calf genotype. The findings of thepresent study should have important implications for the diagnosis and control of Cryptosporidium infections in bothhumans and animals in China.
基金supported by Natural Science Foundation of Jilin Province for Outstanding Young scientists Award,China(2002).
文摘The CP15/60 gene encoding the CP15/60 surface protein of sporozoites in Cryptosporidiumparvum was obtained by PCR so as to research the nucleic vaccine against C.parvum. Theeukaryotic expressing vector pcDNA3-15/60 was constructed by inserting CP15/60 gene intopcDNA3 (+) in XhoⅠand EcoRⅠ. A vaccination protocol was the adult pregnant goatsinoculated intranasally with the pcDNA3-15/60 plasmid and their offspring were infectedwith C.parvum oocysts. The results showed that the pcDNA3-15/60 plasmid can induce theimmune response of goats and the vaccinated goats can transfer the immunity to offspringconferring protection against C.parvum infection. These suggested that the recombinantplasmid could be a DNA vaccine candidate.
文摘Recent Cryptosporidium outbreaks have highlighted concerns about filter efficiency and in particular particle breakthrough. It is essential to ascertain the causes of Cryptosporidium sized particle breakthrough for Cryptosporidium cannot be destroyed by conventional chlorine disinfection. This research tried to investigate the influence of temperature, flow rate and chemical dosing on particle breakthrough during filtration. The results showed that higher temperatures and coagulant doses could reduce particle breakthrough. The increase of filtration rate made the residual particle counts become larger. There was an optimal dose in filtration and was well correlated to ζ potential.
