Background: Varicella is a contagious illness, caused by varicella zoster virus (VZV). It is transmitted via the respiratory route and through contact with the infected person. Fourteen cases of varicella from a board...Background: Varicella is a contagious illness, caused by varicella zoster virus (VZV). It is transmitted via the respiratory route and through contact with the infected person. Fourteen cases of varicella from a boarding school in Chikomba District, Zimbabwe were reported on 14 February 2019. We investigated the outbreak to determine its scope, identify risk factors for transmission and recommend evidence-based control measures. Methods: A 1:2 unmatched case-control study was conducted. A case was a form one student at a boarding school in Chikomba District who developed acute onset of diffuse maculopapulovesicular rash without other apparent cause from 22 January 2019 to 24 February 2019. A control was a form one student at the same boarding school who did not develop the signs and symptoms of varicella during the same period. The diagnosis was based on clinical signs and symptoms. An interviewer-administered questionnaire was used to collect data. Epi info 7<sup>TM</sup> was used to calculate frequencies, odds ratios and perform logistic regression to control for confounding variables. Results: We recruited 31 cases and 62 controls. Independent risk factors for contracting varicella were classmate contact [AOR 24;(95% CI 4.4 - 83), p Conclusion: A perfect setting for the spread of infection was available in the form of students in a naive community living in close proximity both at class and at dormitories, which lead to the rapid transmission of the virus. Screening and isolation of the infected students controlled the outbreak.展开更多
Community health workers (CHWs) have long played an important role in the management of complex health problems, especially in resource-poor settings. Although there is a large literature regarding the use of CHWs aro...Community health workers (CHWs) have long played an important role in the management of complex health problems, especially in resource-poor settings. Although there is a large literature regarding the use of CHWs around the world, there is little detail about how these workers are selected, trained and utilized in the field. Lesotho has one of the highest rates of HIV in the world, with an estimated 25% of the general population infected with the disease;at the same time, there is a significant health human resources shortage in Lesotho with an estimated 60% of health posts left vacant. Community health workers have the potential to play a major role in HIV treatment scale-up in the country, and in 2006, a CWH-based project called 'The Rural Initiative' was started in the remote mountain regions of the country. More than 1000 CHWs were trained and employed through this program between June 2006 and December 2008. This paper will review the CHW program in detail, with a focus on recruitment, training, ongoing supervision and support, and the larger public health implications of the CHW program in Lesotho. It is hoped this program can serve as a practical model for other programs working with or in need of CHWs.展开更多
The worldwide distribution and extensive genetic diversity of the whitefly,Bemisia tabaci,has long been recognized.However,the levels of separation within B.tabaci and the nomenclature of the various genetic groups ha...The worldwide distribution and extensive genetic diversity of the whitefly,Bemisia tabaci,has long been recognized.However,the levels of separation within B.tabaci and the nomenclature of the various genetic groups have been a subject of debate.Recent phylogenetic analyses indicate that B.tabaci is a complex composed of 28 morphologically indistinguishable species.In this article,we first review the debate and difficulties associated with B.tabaci＇s taxonomy and systematics,and argue for the need to apply the biological species concept in order to elucidate B.tabaci＇s systematics.We summarize the accumulated genetic and behavioural data on reproductive incompatibilities evident amongst phylogenetic mtCOI groups of B.tabaci.Crossing studies have been conducted with 14 of the 28 putative species covering 54 reciprocal inter-species pairs,and observations on mating behaviour have been conducted for seven species pairs.Data from both crossing trials and behavioural observations indicate a consistent pattern of reproductive isolation among the putative species.We then discuss the technical and conceptual complexities associated with crossing experiments and behavioural observations designed to reveal reproductive incompatibility.Finally,we elaborate on a strategy for further clarifying the pattern of reproductive isolation between B.tabaci groups and propose future research directions on the systematics of this complex.展开更多
A programme of functional genomics research is underway at the University of Greenwich,UK,to develop and apply genomics technologies to characterise an economically-important but under-researched Bemisia tabaci（Hemip...A programme of functional genomics research is underway at the University of Greenwich,UK,to develop and apply genomics technologies to characterise an economically-important but under-researched Bemisia tabaci（Hemiptera：Aleyrodidae）,the Asia 1 mtCOI phylogenetic group.A comparison of this putative species from India with other important B.tabaci populations and insect species may provide targets for the development of more effective whitefly control strategies.As a first step,next-generation sequencing（NGS）has been used to survey the transcriptome of adult female whitefly,with high quality RNA preparations being used to generate cDNA libraries for NGS using the Roche 454 Titanium DNA sequencing platform.Contig assemblies constructed from the resultant sequences（301 094 reads）using the software program CLC Genomics Workbench generated 3 821 core contigs.Comparison of a selection of these contigs with related sequences from other B.tabaci genetic groups has revealed good alignment for some genes（e.g.,HSP90）but misassemblies in other datasets（e.g.,the vitellogenin gene family）,highlighting the need for manual curation as well as collaborative international efforts to obtain accurate assemblies from the existing next generation sequence datasets.Nevertheless,data emerging from the NGS has facilitated the development of accurate and reliable methods for analysing gene expression based on quantitative real-time RT-PCR,illustrating the power of this approach to enable rapid expression analyses in an organism for which a complete genome sequence is currently lacking.展开更多
Bemisia tabaci adults from various host-plant species were collected from 31 regions across India.266 B.tabaci samples were first screened by RAPD-PCR to examine molecular variability and to select individuals with di...Bemisia tabaci adults from various host-plant species were collected from 31 regions across India.266 B.tabaci samples were first screened by RAPD-PCR to examine molecular variability and to select individuals with different fingerprints.Host-plant and region of collection were then used to select 25 individuals for PCR amplification and sequencing of their partial mitochondrial cytochrome oxidase subunit one（mtCOI）genes.Pairwise comparisons with mtCOI consensus sequences showed that the majority of these samples had 〈3.5% sequence divergence from groups currently termed Asia I,Asia II-5,Asia II-7,and Asia II-8.The biotype-B B.tabaci from India clustered into the Middle East-Asia Minor 1 group.A new group of B.tabaci from Coimbatore,collected from pumpkin,was related most closely to the Asia I group（6.2% sequence divergence from the consensus Asia I sequence）.To increase our understanding of the epidemiology of tomato leaf curl disease（ToLCD）and the key B.tabaci genetic groups involved in virus spread,the indigenous Asia I and the exotic biotype-B population from South India were used to carry out transmission experiments using Tomato leaf curl Bangalore virus（ToLCBV）.The acquisition access periods（AAP）,inoculation access periods（IAP）,latent periods（LP）,and ToLCBV transmission efficiencies of the two populations were compared and the biotype-B had the more efficient transmission characteristics.These results are discussed in relation to recent changes in the epidemiology of tomato leaf curl disease in South India.展开更多
Objective:To assess the profile of TB/multidrug-resistant TB(MDR-TB) among household contacts of MDR-TB patients.Methods:Close contacts of MDR-TB patients were traced in the cross-sectional study.Different clinical,ra...Objective:To assess the profile of TB/multidrug-resistant TB(MDR-TB) among household contacts of MDR-TB patients.Methods:Close contacts of MDR-TB patients were traced in the cross-sectional study.Different clinical,radiological and bacteriological were performed to rule out the evidence of TB/MDR-TB.Results:Between January 2012 and December 2012,a total of 200 index MDR-TB patients were initiated on MDR-TB treatment,out of which home visit and contacts screening were conducted for 154 index cases.Of 610 contacts who could be studied,41(17.4%) were diagnosed with MDR-TB and 10(4.2%) had TB.The most common symptoms observed were cough,chest pain and fever.Conclusions:The high incidence of MDR-TB among close contacts emphasize the need for effective contact screening programme of index MDR-TB cases in order to cut the chain of transmission of this disease.展开更多
Background: Zimbabwe recorded a 55% increase in HIV testing from 2011 to 2018 but with decreasing HIV-testing yields from 20% to 6% respectively as we aim to identify the narrowing gap of undiagnosed people living wit...Background: Zimbabwe recorded a 55% increase in HIV testing from 2011 to 2018 but with decreasing HIV-testing yields from 20% to 6% respectively as we aim to identify the narrowing gap of undiagnosed people living with HIV. As such adoption of screening tools during targeted HIV testing services improves efficiency by identifying individuals who are likely to test positive. Effective utilization of screening tools requires an understanding of health care worker perception and willingness to use the tools. Methods: We conducted a qualitative study among healthcare workers at 8 selected primary healthcare facilities in Zimbabwe. Interviewer-guided, in-depth interviews were conducted with healthcare workers and their immediate supervisors. Thematic analysis was performed following a framework built around the grounded theory model to describe perspectives that influence the utilization of HIV screening tools and suggestions for improved eligibility screening. Results: Behavioural factors facilitating the utilisation of the screening tool included motivation to adhere to standard practice, awareness of screening in targeting testing, and its ability to manage workload through screening out ineligible clients. This was evident across service delivery levels. Barriers included limited healthcare capacity, confidentiality space, multiple screening tools and opaque screening in/out criteria and the potential of clients not responding to screening questions truthfully. Conclusions: Across geographical and service delivery levels, placing screening tools at HIV testing entry points, healthcare worker knowledge on screening in/out criteria emerged as enablers for correct and consistent utilization. Further, standardizing the tools and adopting a decision aid algorithm would improve the accurate utilisation of screening tools.展开更多
<strong>Background:</strong> Low level of transfusion transmissible infections (TTIs) is an indicator of a well-performing blood donor program. <strong>Aim:</strong> The study was designed to e...<strong>Background:</strong> Low level of transfusion transmissible infections (TTIs) is an indicator of a well-performing blood donor program. <strong>Aim:</strong> The study was designed to estimate the prevalence of TTIs and to evaluate the demographic characteristics of reactive and non-reactive blood donors in Zimbabwe in 2018. <strong>Methods:</strong> A cross-sectional study was conducted using routinely available data from January to December 2018 in five branches of National Blood Service Zimbabwe (NBSZ). After initial screening for high-risk behavior with a questionnaire, weight, blood pressure and hemoglobin level, eligible donors were invited for blood donation. The following laboratory tests for TTIs were done: antibodies and antigen tests for human immunodeficiency virus 1 and 2 (HIV 1/2), tests for the surface antigen of hepatitis B virus (HBV), testing for hepatitis C virus (HCV) antibody and antibodies for treponema pallidum. Information on age, gender, NBSZ branch, marital status, occupation, donor type (first time/repeat) and TTIs test results were extracted from the NBSZ electronic database (e-Delphyn blood bank software).<strong> Results:</strong> Out of a sample of 1586 blood donors, thirteen (0.81%) were reactive to at least one TTI marker;five (0.32%) were reactive for human immunodeficiency virus, seven (0.44%) for hepatitis B and one (0.06%) for syphilis. There were no samples with co-infection and hepatitis C virus markers. The prevalence of TTIs was highest in the 31 - 45 years age group (2.3%) and among first-time blood donors (4.7%). The prevalence of all TTI was low with the highest prevalence of 0.44% for the hepatitis B virus. <strong>Conclusion:</strong> Continued concerted efforts will help to maintain satisfactory blood safety in Zimbabwe.展开更多
Research carried out to assess the impact of open-pollinated Tomato leaf curl virus（ToLCV）-resistant tomatoes and hybrids on the livelihoods of resource-poor farmers in Southern India is described and discussed.Thre...Research carried out to assess the impact of open-pollinated Tomato leaf curl virus（ToLCV）-resistant tomatoes and hybrids on the livelihoods of resource-poor farmers in Southern India is described and discussed.Three high-yielding ToLCV-resistant tomato varieties were developed initially using conventional breeding and screening techniques involving inoculation by ToLCV-viruliferous whitefly,Bemisia tabaci.In 2003 and 2004,respectively,these varieties were released officially by the Karnataka State Seed Committee and the Indian Ministry of Agriculture through notification in the Gazette of India.From 2003 to 2005,eleven seed companies bought breeder seed of the ToLCV-resistant varieties and used them to begin breeding F1 hybrids from them.Socio-economic studies carried out to assess the benefits obtained from growing the ToLCV-resistant varieties found that farmers could gain up to 10 times the profit by growing the ToLCV-resistant varieties compared to the pre-existing ToLCV-susceptible varieties.Adoption of ToLCV-resistant tomatoes was also associated with reduced pesticide use.Extra income from tomato sales was prioritised by farmers to pay for children＇s education,better nutrition and medicines.In a joint effort with the commercial seed sector in India,a promotional field day was organised in 2007.As well as the three ToLCV-resistant varieties,62 ToLCV-resistant hybrid tomatoes were exhibited during a farmer-field day by 17 commercial seed companies and several public institutes.Tomatoes with ToLCV-resistance are now grown widely in South India and seeds of the three open-pollinated varieties have been distributed to more than 12 countries.In 2007,a conservative estimate of the financial-benefit to cost of the research ratio was already more than 837：1.展开更多
Background: Human Immuno-Deficiency Virus Self-Testing (HIVST) is a process where an individual who wants to know their HIV status collects a specimen, performs a test and interprets the result by themselves. HIVST da...Background: Human Immuno-Deficiency Virus Self-Testing (HIVST) is a process where an individual who wants to know their HIV status collects a specimen, performs a test and interprets the result by themselves. HIVST data from the Zimbabwe AIDS and TB Program (ATP) directorate showed that between 2019-2020, only 31% of the target HIVST kits were distributed in the country. Mashonaland West Province was one of the least performing provinces in meeting targets for HIVST kits distribution. Gaps in the implementation of the HIVST in the province ultimately affect the nationwide scaleup of targeted testing, a key enabler in achieving HIV epidemic control. We analyzed HIVST trends in Mashonaland West Province to inform HIV testing services programming. Methods: We conducted a cross-sectional study using HIVST secondary data obtained from the District Health Information Software 2 (DHIS2) electronic database. We conducted regression analysis for trends using Epi Info 7.2 and tables, bar graphs, pie charts and linear graphs were used for data presentation. Results: A total of 31,070 clients accessed HIVST kits in Mashonaland West Province from 2019-2020. A slightly higher proportion (50.4% and 51.7%) of females as compared to males accessed HIVST kits in 2019 and 2020 respectively. Overall, an increase in the trend of HIVST kits uptake was recorded (males R<sup>2</sup> = 0.3945, p-value = 0.003 and females R<sup>2</sup> = 0.4739, p-value = 0.001). There was generally a decline in the trend of community-based distribution of HIVST kits from the third quarter of 2019 throughout 2020 (R<sup>2</sup> = 0.2441, p-value = 0.006). Primary distribution of HIVST kits remained the dominant method of distribution, constituting more than half of the kits distributed in both 2019 (67%) and 2020 (86%). Conclusion: Mashonaland West Province was mainly utilising facility-based distribution model for HIVST over the community-based distribution model. We recommended training more community-based distribution agents to increase community distribution of HIVST kits.展开更多
Long chain polyunsaturated fatty acids are essential macronutrients that have several benefits which have been described for children’s health. Omega 3 LCPUFA metabolism has been reported to be altered in under-nouri...Long chain polyunsaturated fatty acids are essential macronutrients that have several benefits which have been described for children’s health. Omega 3 LCPUFA metabolism has been reported to be altered in under-nourished and in HIV infected children. Therefore, we describe Eicosapentaenoic acid, Docosapentaenoic acid and Docosahexaenoic acid levels of HIV infected, HIV exposed uninfected and HIV unexposed uninfected school aged children from a low income country with a high burden of HIV infection and under-nutrition. This cross-sectional study recruited children 7 to 10 years old. Capillary blood was collected on filter paper and whole blood fatty acid analysis done using automated gas liquid chromatography. Kruskal Wallis and Median tests were used to compare the distribution and medians of the Omega 3 LCPUFA among the children according to HIV status, gender, age and nutritional status. A total of 318 children were recruited with 21 (7%) being HIV infected and 116 (37%) being HIV exposed uninfected. Chronic malnutrition was present in 12% of the children. The omega 3 fatty acids were expressed as percent weight of total fatty acids. The medians (interquartile range) for EPA, DPA and DHA for all the children were 0.19 (0.09), 0.79 (0.19) and 2.14 (0.54) %wt/wt respectively. EPA, DPA and DHA levels were not associated with the HIV status of the children. EPA levels were much lower in the 7-year-age group compared with the 8 and 9 - 10-year-age groups. Further studies assessing LCPUFA levels that include larger sample size, children from both urban and rural areas are recommended as this may assist in clearly defining the association of LCPUFA with HIV status in children from low income countries with high burden of under-nutrition.展开更多
The investigation of the long-term performance of solidified/stabilized （S/S） contaminated soils was carried out in a trial site in southeast UK. The soils were exposed to the maximum natural weathering for four yea...The investigation of the long-term performance of solidified/stabilized （S/S） contaminated soils was carried out in a trial site in southeast UK. The soils were exposed to the maximum natural weathering for four years and sampled at various depths in a controlled manner. The chemical properties （e.g., degree of carbonation （DOC）, pH, electrical conductivity （EC）） and physical properties （e.g., moisture content （MC）, liquid limit CLL）, plastic limit （PL）, plasticity index （PI）） of the samples untreated and treated with the traditional and accelerated carbonated S/S processes were analyzed. Their variations on the depths of the soils were also studied. The result showed that the broad geotechnical properties of the soils, manifested in their PIs, were related to the concentration of the water soluble ions and in particular the free calcium ions. The samples treated with the accelerated carbonation technology （ACT）, and the untreated samples contained limited number of free calcium ions in solutions and consequently interacted with waters in a similar way. Compared with the traditional cement-based S/S technology, e.g., treatment with ordinary portland cement （OPC） or EnvirOceM, ACT caused the increase of the PI of the treated soil and made it more stable during long-term weathering. The PI values for the four soils ascended according to the order： the EnvirOceM soil, the OPC soil, the ACT soil, and the untreated soil while their pH and EC values descended according to the same order.展开更多
Background: Persons with HIV and severe mental illness face numerous barriers in antiretroviral treatment adherence. More information is needed on reasons for loss of follow-up in this population. Methods: A retrospec...Background: Persons with HIV and severe mental illness face numerous barriers in antiretroviral treatment adherence. More information is needed on reasons for loss of follow-up in this population. Methods: A retrospective analysis was conducted on adult HIV patients with a history of mental illness enrolled at an urban HIV clinic in Johannesburg, South Africa who discontinued care. Results: 24.8% of adult patients in the clinic discontinued follow-up during the study period. Of those discontinuing follow-up, 48 were successfully traced by home visits. Among this group, 21 (43.8%) were not engaged in care, 12 (25.0%) had transferred care, 9 (18.8%) were deceased, 3 (6.2%) had relocated, and 3 (6.2%) were missing. Transportation costs and distance, conflicts with work/school schedule, and confusion regarding when to return were the most frequently cited reasons for discontinuing follow-up. Conclusions: Although almost 25% of patients were lost to follow up, overall rates of retention in care for these patients were similar to those seen in other HIV-infected populations and higher than those seen among patients with psychiatric disease. Tracing patients through home visits proved to be an effective means to confirm the magnitude of patients lost to follow up, ascertain their outcomes, and elucidate the reasons for discontinuing care.展开更多
Background:Since 2005,the Myanmar National Tuberculosis Programme(NTP)has been implementing active case finding(ACF)activities involving mobile teams in hard-to-reach areas.This study revealed the contribution of mobi...Background:Since 2005,the Myanmar National Tuberculosis Programme(NTP)has been implementing active case finding(ACF)activities involving mobile teams in hard-to-reach areas.This study revealed the contribution of mobile team activities to total tuberculosis(TB)case detection,characteristics of TB patients detected by mobile teams and their treatment outcomes.Methods:This was a descriptive study using routine programme data between October 2014 and December 2014.Mobile team activities were a one-stop service and included portable digital chest radiography(CXR)and microscopy of two sputum samples.The algorithm of the case detection included screening patients by symptoms,then by CXR followed by sputum microscopy for confirmation.Diagnosed patients were started on treatment and followed until a final outcome was ascertained.Results:A total of 9349 people with symptoms suggestive of TB were screened by CXR,with an uptake of 96.6%.Of those who were meant to undergo sputum smear microscopy,51.4%had sputum examinations.Finally,504 TB patients were identified by the mobile teams and the overall contribution to total TB case detection in the respective townships was 25.3%.Among total cases examined by microscopy,6.4%were sputum smear positive TB.Treatment success rate was high as 91.8%in study townships compared to national rate 85%(2014 cohort).Conclusions:This study confirmed the feasibility and acceptability of ACF by mobile teams in hard-to-reach contexts,especially when equipped with portable,digital CXR machines that provided immediate results.However,the follow-up process of sputum examination created a significant barrier to confirmation of the diagnosis.In order to optimize the ACF through mobile team activity,future ACF activities were needed to be strengthened one stop service including molecular diagnostics or provision of sputum cups to all presumptive TB cases prior to CXR and testing if CXR suggestive of TB.展开更多
文摘Background: Varicella is a contagious illness, caused by varicella zoster virus (VZV). It is transmitted via the respiratory route and through contact with the infected person. Fourteen cases of varicella from a boarding school in Chikomba District, Zimbabwe were reported on 14 February 2019. We investigated the outbreak to determine its scope, identify risk factors for transmission and recommend evidence-based control measures. Methods: A 1:2 unmatched case-control study was conducted. A case was a form one student at a boarding school in Chikomba District who developed acute onset of diffuse maculopapulovesicular rash without other apparent cause from 22 January 2019 to 24 February 2019. A control was a form one student at the same boarding school who did not develop the signs and symptoms of varicella during the same period. The diagnosis was based on clinical signs and symptoms. An interviewer-administered questionnaire was used to collect data. Epi info 7<sup>TM</sup> was used to calculate frequencies, odds ratios and perform logistic regression to control for confounding variables. Results: We recruited 31 cases and 62 controls. Independent risk factors for contracting varicella were classmate contact [AOR 24;(95% CI 4.4 - 83), p Conclusion: A perfect setting for the spread of infection was available in the form of students in a naive community living in close proximity both at class and at dormitories, which lead to the rapid transmission of the virus. Screening and isolation of the infected students controlled the outbreak.
文摘Community health workers (CHWs) have long played an important role in the management of complex health problems, especially in resource-poor settings. Although there is a large literature regarding the use of CHWs around the world, there is little detail about how these workers are selected, trained and utilized in the field. Lesotho has one of the highest rates of HIV in the world, with an estimated 25% of the general population infected with the disease;at the same time, there is a significant health human resources shortage in Lesotho with an estimated 60% of health posts left vacant. Community health workers have the potential to play a major role in HIV treatment scale-up in the country, and in 2006, a CWH-based project called 'The Rural Initiative' was started in the remote mountain regions of the country. More than 1000 CHWs were trained and employed through this program between June 2006 and December 2008. This paper will review the CHW program in detail, with a focus on recruitment, training, ongoing supervision and support, and the larger public health implications of the CHW program in Lesotho. It is hoped this program can serve as a practical model for other programs working with or in need of CHWs.
基金funded by the National Basic Research Program of China(2009CB119203)the National NaturalScience Foundation of China(30730061)the ChinaAgriculture Research System(CARS-25-B-08)
文摘The worldwide distribution and extensive genetic diversity of the whitefly,Bemisia tabaci,has long been recognized.However,the levels of separation within B.tabaci and the nomenclature of the various genetic groups have been a subject of debate.Recent phylogenetic analyses indicate that B.tabaci is a complex composed of 28 morphologically indistinguishable species.In this article,we first review the debate and difficulties associated with B.tabaci＇s taxonomy and systematics,and argue for the need to apply the biological species concept in order to elucidate B.tabaci＇s systematics.We summarize the accumulated genetic and behavioural data on reproductive incompatibilities evident amongst phylogenetic mtCOI groups of B.tabaci.Crossing studies have been conducted with 14 of the 28 putative species covering 54 reciprocal inter-species pairs,and observations on mating behaviour have been conducted for seven species pairs.Data from both crossing trials and behavioural observations indicate a consistent pattern of reproductive isolation among the putative species.We then discuss the technical and conceptual complexities associated with crossing experiments and behavioural observations designed to reveal reproductive incompatibility.Finally,we elaborate on a strategy for further clarifying the pattern of reproductive isolation between B.tabaci groups and propose future research directions on the systematics of this complex.
基金Funding for the studies described was provided by the University of Greenwich Proof of Concept and Research Funds,UK(E0162/RAE-NRI-009/09and K0070)
文摘A programme of functional genomics research is underway at the University of Greenwich,UK,to develop and apply genomics technologies to characterise an economically-important but under-researched Bemisia tabaci（Hemiptera：Aleyrodidae）,the Asia 1 mtCOI phylogenetic group.A comparison of this putative species from India with other important B.tabaci populations and insect species may provide targets for the development of more effective whitefly control strategies.As a first step,next-generation sequencing（NGS）has been used to survey the transcriptome of adult female whitefly,with high quality RNA preparations being used to generate cDNA libraries for NGS using the Roche 454 Titanium DNA sequencing platform.Contig assemblies constructed from the resultant sequences（301 094 reads）using the software program CLC Genomics Workbench generated 3 821 core contigs.Comparison of a selection of these contigs with related sequences from other B.tabaci genetic groups has revealed good alignment for some genes（e.g.,HSP90）but misassemblies in other datasets（e.g.,the vitellogenin gene family）,highlighting the need for manual curation as well as collaborative international efforts to obtain accurate assemblies from the existing next generation sequence datasets.Nevertheless,data emerging from the NGS has facilitated the development of accurate and reliable methods for analysing gene expression based on quantitative real-time RT-PCR,illustrating the power of this approach to enable rapid expression analyses in an organism for which a complete genome sequence is currently lacking.
基金R.V.Chowda-Reddy(HEFCE fellowship)and Kiran Kumar,from the research projects funded by the University of Greenwich,together with the Department for International Development,UK(DFID project code R8247,Crop Protection Programme)
文摘Bemisia tabaci adults from various host-plant species were collected from 31 regions across India.266 B.tabaci samples were first screened by RAPD-PCR to examine molecular variability and to select individuals with different fingerprints.Host-plant and region of collection were then used to select 25 individuals for PCR amplification and sequencing of their partial mitochondrial cytochrome oxidase subunit one（mtCOI）genes.Pairwise comparisons with mtCOI consensus sequences showed that the majority of these samples had 〈3.5% sequence divergence from groups currently termed Asia I,Asia II-5,Asia II-7,and Asia II-8.The biotype-B B.tabaci from India clustered into the Middle East-Asia Minor 1 group.A new group of B.tabaci from Coimbatore,collected from pumpkin,was related most closely to the Asia I group（6.2% sequence divergence from the consensus Asia I sequence）.To increase our understanding of the epidemiology of tomato leaf curl disease（ToLCD）and the key B.tabaci genetic groups involved in virus spread,the indigenous Asia I and the exotic biotype-B population from South India were used to carry out transmission experiments using Tomato leaf curl Bangalore virus（ToLCBV）.The acquisition access periods（AAP）,inoculation access periods（IAP）,latent periods（LP）,and ToLCBV transmission efficiencies of the two populations were compared and the biotype-B had the more efficient transmission characteristics.These results are discussed in relation to recent changes in the epidemiology of tomato leaf curl disease in South India.
文摘Objective:To assess the profile of TB/multidrug-resistant TB(MDR-TB) among household contacts of MDR-TB patients.Methods:Close contacts of MDR-TB patients were traced in the cross-sectional study.Different clinical,radiological and bacteriological were performed to rule out the evidence of TB/MDR-TB.Results:Between January 2012 and December 2012,a total of 200 index MDR-TB patients were initiated on MDR-TB treatment,out of which home visit and contacts screening were conducted for 154 index cases.Of 610 contacts who could be studied,41(17.4%) were diagnosed with MDR-TB and 10(4.2%) had TB.The most common symptoms observed were cough,chest pain and fever.Conclusions:The high incidence of MDR-TB among close contacts emphasize the need for effective contact screening programme of index MDR-TB cases in order to cut the chain of transmission of this disease.
文摘Background: Zimbabwe recorded a 55% increase in HIV testing from 2011 to 2018 but with decreasing HIV-testing yields from 20% to 6% respectively as we aim to identify the narrowing gap of undiagnosed people living with HIV. As such adoption of screening tools during targeted HIV testing services improves efficiency by identifying individuals who are likely to test positive. Effective utilization of screening tools requires an understanding of health care worker perception and willingness to use the tools. Methods: We conducted a qualitative study among healthcare workers at 8 selected primary healthcare facilities in Zimbabwe. Interviewer-guided, in-depth interviews were conducted with healthcare workers and their immediate supervisors. Thematic analysis was performed following a framework built around the grounded theory model to describe perspectives that influence the utilization of HIV screening tools and suggestions for improved eligibility screening. Results: Behavioural factors facilitating the utilisation of the screening tool included motivation to adhere to standard practice, awareness of screening in targeting testing, and its ability to manage workload through screening out ineligible clients. This was evident across service delivery levels. Barriers included limited healthcare capacity, confidentiality space, multiple screening tools and opaque screening in/out criteria and the potential of clients not responding to screening questions truthfully. Conclusions: Across geographical and service delivery levels, placing screening tools at HIV testing entry points, healthcare worker knowledge on screening in/out criteria emerged as enablers for correct and consistent utilization. Further, standardizing the tools and adopting a decision aid algorithm would improve the accurate utilisation of screening tools.
文摘<strong>Background:</strong> Low level of transfusion transmissible infections (TTIs) is an indicator of a well-performing blood donor program. <strong>Aim:</strong> The study was designed to estimate the prevalence of TTIs and to evaluate the demographic characteristics of reactive and non-reactive blood donors in Zimbabwe in 2018. <strong>Methods:</strong> A cross-sectional study was conducted using routinely available data from January to December 2018 in five branches of National Blood Service Zimbabwe (NBSZ). After initial screening for high-risk behavior with a questionnaire, weight, blood pressure and hemoglobin level, eligible donors were invited for blood donation. The following laboratory tests for TTIs were done: antibodies and antigen tests for human immunodeficiency virus 1 and 2 (HIV 1/2), tests for the surface antigen of hepatitis B virus (HBV), testing for hepatitis C virus (HCV) antibody and antibodies for treponema pallidum. Information on age, gender, NBSZ branch, marital status, occupation, donor type (first time/repeat) and TTIs test results were extracted from the NBSZ electronic database (e-Delphyn blood bank software).<strong> Results:</strong> Out of a sample of 1586 blood donors, thirteen (0.81%) were reactive to at least one TTI marker;five (0.32%) were reactive for human immunodeficiency virus, seven (0.44%) for hepatitis B and one (0.06%) for syphilis. There were no samples with co-infection and hepatitis C virus markers. The prevalence of TTIs was highest in the 31 - 45 years age group (2.3%) and among first-time blood donors (4.7%). The prevalence of all TTI was low with the highest prevalence of 0.44% for the hepatitis B virus. <strong>Conclusion:</strong> Continued concerted efforts will help to maintain satisfactory blood safety in Zimbabwe.
基金funded by the Department for Interna-tional Development,UK(DFID project codes R6627,R7460,R8247(Crop Protection Programme)and Phase Ⅲ of the International Whitefly Project)
文摘Research carried out to assess the impact of open-pollinated Tomato leaf curl virus（ToLCV）-resistant tomatoes and hybrids on the livelihoods of resource-poor farmers in Southern India is described and discussed.Three high-yielding ToLCV-resistant tomato varieties were developed initially using conventional breeding and screening techniques involving inoculation by ToLCV-viruliferous whitefly,Bemisia tabaci.In 2003 and 2004,respectively,these varieties were released officially by the Karnataka State Seed Committee and the Indian Ministry of Agriculture through notification in the Gazette of India.From 2003 to 2005,eleven seed companies bought breeder seed of the ToLCV-resistant varieties and used them to begin breeding F1 hybrids from them.Socio-economic studies carried out to assess the benefits obtained from growing the ToLCV-resistant varieties found that farmers could gain up to 10 times the profit by growing the ToLCV-resistant varieties compared to the pre-existing ToLCV-susceptible varieties.Adoption of ToLCV-resistant tomatoes was also associated with reduced pesticide use.Extra income from tomato sales was prioritised by farmers to pay for children＇s education,better nutrition and medicines.In a joint effort with the commercial seed sector in India,a promotional field day was organised in 2007.As well as the three ToLCV-resistant varieties,62 ToLCV-resistant hybrid tomatoes were exhibited during a farmer-field day by 17 commercial seed companies and several public institutes.Tomatoes with ToLCV-resistance are now grown widely in South India and seeds of the three open-pollinated varieties have been distributed to more than 12 countries.In 2007,a conservative estimate of the financial-benefit to cost of the research ratio was already more than 837：1.
文摘Background: Human Immuno-Deficiency Virus Self-Testing (HIVST) is a process where an individual who wants to know their HIV status collects a specimen, performs a test and interprets the result by themselves. HIVST data from the Zimbabwe AIDS and TB Program (ATP) directorate showed that between 2019-2020, only 31% of the target HIVST kits were distributed in the country. Mashonaland West Province was one of the least performing provinces in meeting targets for HIVST kits distribution. Gaps in the implementation of the HIVST in the province ultimately affect the nationwide scaleup of targeted testing, a key enabler in achieving HIV epidemic control. We analyzed HIVST trends in Mashonaland West Province to inform HIV testing services programming. Methods: We conducted a cross-sectional study using HIVST secondary data obtained from the District Health Information Software 2 (DHIS2) electronic database. We conducted regression analysis for trends using Epi Info 7.2 and tables, bar graphs, pie charts and linear graphs were used for data presentation. Results: A total of 31,070 clients accessed HIVST kits in Mashonaland West Province from 2019-2020. A slightly higher proportion (50.4% and 51.7%) of females as compared to males accessed HIVST kits in 2019 and 2020 respectively. Overall, an increase in the trend of HIVST kits uptake was recorded (males R<sup>2</sup> = 0.3945, p-value = 0.003 and females R<sup>2</sup> = 0.4739, p-value = 0.001). There was generally a decline in the trend of community-based distribution of HIVST kits from the third quarter of 2019 throughout 2020 (R<sup>2</sup> = 0.2441, p-value = 0.006). Primary distribution of HIVST kits remained the dominant method of distribution, constituting more than half of the kits distributed in both 2019 (67%) and 2020 (86%). Conclusion: Mashonaland West Province was mainly utilising facility-based distribution model for HIVST over the community-based distribution model. We recommended training more community-based distribution agents to increase community distribution of HIVST kits.
文摘Long chain polyunsaturated fatty acids are essential macronutrients that have several benefits which have been described for children’s health. Omega 3 LCPUFA metabolism has been reported to be altered in under-nourished and in HIV infected children. Therefore, we describe Eicosapentaenoic acid, Docosapentaenoic acid and Docosahexaenoic acid levels of HIV infected, HIV exposed uninfected and HIV unexposed uninfected school aged children from a low income country with a high burden of HIV infection and under-nutrition. This cross-sectional study recruited children 7 to 10 years old. Capillary blood was collected on filter paper and whole blood fatty acid analysis done using automated gas liquid chromatography. Kruskal Wallis and Median tests were used to compare the distribution and medians of the Omega 3 LCPUFA among the children according to HIV status, gender, age and nutritional status. A total of 318 children were recruited with 21 (7%) being HIV infected and 116 (37%) being HIV exposed uninfected. Chronic malnutrition was present in 12% of the children. The omega 3 fatty acids were expressed as percent weight of total fatty acids. The medians (interquartile range) for EPA, DPA and DHA for all the children were 0.19 (0.09), 0.79 (0.19) and 2.14 (0.54) %wt/wt respectively. EPA, DPA and DHA levels were not associated with the HIV status of the children. EPA levels were much lower in the 7-year-age group compared with the 8 and 9 - 10-year-age groups. Further studies assessing LCPUFA levels that include larger sample size, children from both urban and rural areas are recommended as this may assist in clearly defining the association of LCPUFA with HIV status in children from low income countries with high burden of under-nutrition.
文摘The investigation of the long-term performance of solidified/stabilized （S/S） contaminated soils was carried out in a trial site in southeast UK. The soils were exposed to the maximum natural weathering for four years and sampled at various depths in a controlled manner. The chemical properties （e.g., degree of carbonation （DOC）, pH, electrical conductivity （EC）） and physical properties （e.g., moisture content （MC）, liquid limit CLL）, plastic limit （PL）, plasticity index （PI）） of the samples untreated and treated with the traditional and accelerated carbonated S/S processes were analyzed. Their variations on the depths of the soils were also studied. The result showed that the broad geotechnical properties of the soils, manifested in their PIs, were related to the concentration of the water soluble ions and in particular the free calcium ions. The samples treated with the accelerated carbonation technology （ACT）, and the untreated samples contained limited number of free calcium ions in solutions and consequently interacted with waters in a similar way. Compared with the traditional cement-based S/S technology, e.g., treatment with ordinary portland cement （OPC） or EnvirOceM, ACT caused the increase of the PI of the treated soil and made it more stable during long-term weathering. The PI values for the four soils ascended according to the order： the EnvirOceM soil, the OPC soil, the ACT soil, and the untreated soil while their pH and EC values descended according to the same order.
文摘Background: Persons with HIV and severe mental illness face numerous barriers in antiretroviral treatment adherence. More information is needed on reasons for loss of follow-up in this population. Methods: A retrospective analysis was conducted on adult HIV patients with a history of mental illness enrolled at an urban HIV clinic in Johannesburg, South Africa who discontinued care. Results: 24.8% of adult patients in the clinic discontinued follow-up during the study period. Of those discontinuing follow-up, 48 were successfully traced by home visits. Among this group, 21 (43.8%) were not engaged in care, 12 (25.0%) had transferred care, 9 (18.8%) were deceased, 3 (6.2%) had relocated, and 3 (6.2%) were missing. Transportation costs and distance, conflicts with work/school schedule, and confusion regarding when to return were the most frequently cited reasons for discontinuing follow-up. Conclusions: Although almost 25% of patients were lost to follow up, overall rates of retention in care for these patients were similar to those seen in other HIV-infected populations and higher than those seen among patients with psychiatric disease. Tracing patients through home visits proved to be an effective means to confirm the magnitude of patients lost to follow up, ascertain their outcomes, and elucidate the reasons for discontinuing care.
基金The program was funded by WHO/TDR Impact grant to two TDR alumni from DMRThe funders had no role in study design,data collection and analysis,decision to publish,or preparation of the manuscript。
文摘Background:Since 2005,the Myanmar National Tuberculosis Programme(NTP)has been implementing active case finding(ACF)activities involving mobile teams in hard-to-reach areas.This study revealed the contribution of mobile team activities to total tuberculosis(TB)case detection,characteristics of TB patients detected by mobile teams and their treatment outcomes.Methods:This was a descriptive study using routine programme data between October 2014 and December 2014.Mobile team activities were a one-stop service and included portable digital chest radiography(CXR)and microscopy of two sputum samples.The algorithm of the case detection included screening patients by symptoms,then by CXR followed by sputum microscopy for confirmation.Diagnosed patients were started on treatment and followed until a final outcome was ascertained.Results:A total of 9349 people with symptoms suggestive of TB were screened by CXR,with an uptake of 96.6%.Of those who were meant to undergo sputum smear microscopy,51.4%had sputum examinations.Finally,504 TB patients were identified by the mobile teams and the overall contribution to total TB case detection in the respective townships was 25.3%.Among total cases examined by microscopy,6.4%were sputum smear positive TB.Treatment success rate was high as 91.8%in study townships compared to national rate 85%(2014 cohort).Conclusions:This study confirmed the feasibility and acceptability of ACF by mobile teams in hard-to-reach contexts,especially when equipped with portable,digital CXR machines that provided immediate results.However,the follow-up process of sputum examination created a significant barrier to confirmation of the diagnosis.In order to optimize the ACF through mobile team activity,future ACF activities were needed to be strengthened one stop service including molecular diagnostics or provision of sputum cups to all presumptive TB cases prior to CXR and testing if CXR suggestive of TB.
