Diagnosis of Trypanosoma brucei rhodesiense human African trypanosomiasis requires demonstration of parasites in body fluids by microscopy. The microscopy methods that are routinely used are difficult to deploy in res...Diagnosis of Trypanosoma brucei rhodesiense human African trypanosomiasis requires demonstration of parasites in body fluids by microscopy. The microscopy methods that are routinely used are difficult to deploy in resource-limited settings due to practical challenges, including lengthy and tedious procedures, and the need for specific equipment to centrifuge samples in glass capillary tubes. We report here on a study that was conducted in a rural region of eastern Uganda to evaluate new methods that take advantage of a field-deployable LED fluorescence microscope. Examination of acridine orange-stained blood smears by LED fluorescence microscopy resulted in a diagnostic accuracy that was similar to that of routine methods, while the time needed to identify parasites was shortened significantly. These findings make these new microscopy methods attractive alternatives to procedures that are currently used for diagnosis of T. b. rhodesiense human African trypanosomiasis.展开更多
Human African trypanosomiasis (HAT) affects up to half a million people every year in sub-Saharan Africa. Interruption of transmission of the disease by early diagnosis and treatment is core to the control and eventua...Human African trypanosomiasis (HAT) affects up to half a million people every year in sub-Saharan Africa. Interruption of transmission of the disease by early diagnosis and treatment is core to the control and eventual elimination of HAT. The routine diagnostic method for HAT is light microscopy of blood samples. The present study sought to evaluate the potential of TbgI2 and TbgI17 tandem repeat antigens as candidates for the diagnosis of Trypanosoma brucei rhodesiense. The expressed proteins were purified and the antigenic reactivity evaluation was done using multiplex assay using sera obtained from HAT patients. Receiver operating characteristic analysis showed that recombinant antigen, TbgI2 had high sensitivity for sera from patients infected with T. b. rhodesiense with the area under the curve being 0.577 and a sensitivity of 0.641 and specificity 0.650. The results suggest that TbgI2 is a potential biomarker for T. b. rhodesiense HAT serodiagnostic tests.展开更多
Background:Uganda has suffered from a series of epidemics of Human African Trypanosomiasis(HAT),a tsetse transmitted disease,also known as sleeping sickness.The area affected by acute Trypanosoma brucei rhodesiense HA...Background:Uganda has suffered from a series of epidemics of Human African Trypanosomiasis(HAT),a tsetse transmitted disease,also known as sleeping sickness.The area affected by acute Trypanosoma brucei rhodesiense HAT(rHAT)has been expanding,driven by importation of infected cattle into regions previously free of the disease.These regions are also affected by African Animal Trypanosomiasis(AAT)demanding a strategy for integrated disease control.Methods:In 2008,the Public Private Partnership,Stamp Out Sleeping Sickness(SOS)administered a single dose of trypanocide to 31486 head of cattle in 29 parishes in Dokolo and Kaberamaido districts.This study examines the impact of this intervention on the prevalence of rHAT and AAT trypanosomes in cattle from villages that had(HAT^(+ve))or had not(HAT^(-ve))experienced a recent case of rHAT.Cattle herds from 20 villages were sampled and screened by PCR,pre-intervention and 6-months post-intervention,for the presence or absence of:Trypanosoma brucei s.l.;human infective T.b.rhodesiense;Trypanosoma vivax;and Trypanosoma congolense savannah.Results:Post-intervention,there was a significant decrease in the prevalence of T.brucei s.l.and the human infective sub-species T.b.rhodesiense in village cattle across all 20 villages.The prevalence of T.b.rhodesiense was reduced from 2.4%to 0.74%(P<0.0001),with the intervention showing greater impact in HAT^(-ve) villages.The number of villages containing cattle harbouring human infective parasites decreased from 15/20 to 8/20,with T.b.rhodesiense infection mainly persisting within cattle in HAT^(+ve) villages(six/eight).The proportion of T.brucei s.l.infections identified as human infective T.b.rhodesiense decreased after the intervention from 8.3%(95%CI=11.1-5.9%)to 4.1%(95%CI=6.8-2.3%).Villages that had experienced a recent human case(HAT^(+ve) villages)showed a significantly higher prevalence for AAT both pre-and post-intervention.For AAT the prevalence of T.vivax was significantly reduced from 5.9%to 0.05%post-intervention while the prevalence of T.congolense increased from 8.0%to 12.2%.Conclusions:The intervention resulted in a significant decrease in the prevalence of T.brucei s.l.,human infective T.b.rhodesiense and T.vivax infection in village cattle herds.The proportion of T.brucei s.l.that were human infective,decreased from 1:12 T.brucei s.l.infections before the intervention to 1:33 post-intervention.It is clearly more difficult to eliminate T.b.rhodesiense from cattle in villages that have experienced a human case.Evidence of elevated levels of AAT in livestock within village herds is a useful indicator of risk for rHAT in Uganda.Integrated veterinary and medical surveillance is key to successful control of zoonotic rHAT.展开更多
Background:Human African trypanosomiasis(HAT)is one of the most complex parasitic diseases known to humankind.It usually occurs in endemic areas in Africa,but is occasionally detected in returning travelers and migran...Background:Human African trypanosomiasis(HAT)is one of the most complex parasitic diseases known to humankind.It usually occurs in endemic areas in Africa,but is occasionally detected in returning travelers and migrants in non-endemic countries.Case presentation:In August 2017,a case of HAT was diagnosed in China in a traveler returning from the Masai Mara area in Kenya and the Serengeti area in Tanzania.The traveler visited Africa from 23 July to 5 August,2017.Upon return to China,she developed a fever(on 8 August),and Trypanosoma brucei rhodesiense infection was confirmed by laboratory tests(on 14 August)including observation of parasites in blood films and by polymerase chain reaction.She was treated with pentamidine followed by suramin,and recovered 1 month later.Conclusions:This is the first imported rhodesiense HAT case reported in China.This case alerts clinical and public health workers to be aware of HAT in travelers,and expatriates and migrants who have visited at-risk areas in Africa.展开更多
Objective:To establish the modulatory effects of coenzyme Q_(10)on experimental trypanosome infections in mice and evaluate the risk of occurrence and severity of melarsoprol-induced post treatment reactive encephalop...Objective:To establish the modulatory effects of coenzyme Q_(10)on experimental trypanosome infections in mice and evaluate the risk of occurrence and severity of melarsoprol-induced post treatment reactive encephalopathy(PTRE).Methods:Female Swiss white mice were orally administered with 200 mg/kg of coenzyme Q_(10)after which they were intraperitoneally inoculated with Trypanasoma brucei rhodesiense(T.b.rhodesiense).The resultant infection was allowed to develop and simulate all phases of human African trypanosomiasis and PTRE.Parasitaemia development,packed cell volume,haematological and pathological changes were determined.Results:A histological study in the brain tissue of T.b.rhodesiense infected mice demonstrated neuroinflammatory pathology which was highly amplified in the PTRE-induced groups.A prominent reduction in the severity of the neuroinflammatory response was detected when coenzyme-Q_(10)was administered.Furthermore,the mean tissue weight of spleen to body ratio in coenzyme Q_(10)supplemented group was significantly(P<0.05)different compared to un-supplemented groups,and clearly indicated that coenzyme Q_(10)prevented full blown splenomegaly pathogenesis by T.b.rhodesiense.A significant(P<0.05)increase in hemoglobin levels and red blood cells was observed in coenzyme Q_(10)mice compared to those infected and un-supplemented with coenzyme Q_(10).Conclusions:The capacity of coenzyme Q_(10)to alter the pathogenesis of T.b.rhodesiense infection in mice and following treatment with melarsoprol,may find application by rendering humans and animals less susceptible to deleterious effects of trypanosome infection such as splenomegaly and melarsoprol-induced PTRE and neurotoxicity.展开更多
Background:Acute human African trypanosomiasis(rHAT)caused by Trypanosoma brucei rhodesiense is associated with high mortality and is fatal if left untreated.Only a few studies have examined the psychological,social a...Background:Acute human African trypanosomiasis(rHAT)caused by Trypanosoma brucei rhodesiense is associated with high mortality and is fatal if left untreated.Only a few studies have examined the psychological,social and economic impacts of rHAT.In this study,mixed qualitative and quantitative research methods were used to evaluate the socio-economic impacts of rHAT in Mambwe,Rufunsa,Mpika and Chama Districts of Zambia.Methods:Individuals diagnosed with rHAT from 2004 to 2014 were traced using hospital records and discussions with communities.Either they,or their families,were interviewed using a structured questionnaire and focus group discussions were conducted with affected communities.The burden of the disease was investigated using disability adjusted life years(DALYs),with and without discounting and age-weighting.The impact of long-term disabilities on the rHAT burden was also investigated.Results:Sixty four cases were identified in the study.The majority were identified in second stage,and the mortality rate was high(12.5%).The total number of DALYs was 285 without discounting or age-weighting.When long-term disabilities were included this estimate increased by 50%to 462.The proportion of years lived with disability(YLD)increased from 6.4%to 37%of the undiscounted and un-age-weighted DALY total.When a more active surveillance method was applied in 2013-2014 the cases identified increased dramatically,suggesting a high level of under-reporting.Similarly,the proportion of females increased substantially,indicating that passive surveillance may be especially failing this group.An average of 4.9 months of productive time was lost per patient as a consequence of infection.The health consequences included pain,amnesia and physical disability.The social consequences included stigma,dropping out of education,loss of friends and self-esteem.Results obtained from focus group discussions revealed misconceptions among community members which could be attributed to lack of knowledge about rHAT.Conclusions:The social and economic impact of rHAT on rural households and communities is substantial.Improved surveillance and strengthening of local medical services are needed for early and accurate diagnosis.Disease prevention should be prioritised in communities at risk of rHAT,and interventions put in place to prevent zoonotic disease spill over from domestic animals and wildlife.Supportive measures to mitigate the long-term effects of disability due to rHAT are needed.展开更多
文摘Diagnosis of Trypanosoma brucei rhodesiense human African trypanosomiasis requires demonstration of parasites in body fluids by microscopy. The microscopy methods that are routinely used are difficult to deploy in resource-limited settings due to practical challenges, including lengthy and tedious procedures, and the need for specific equipment to centrifuge samples in glass capillary tubes. We report here on a study that was conducted in a rural region of eastern Uganda to evaluate new methods that take advantage of a field-deployable LED fluorescence microscope. Examination of acridine orange-stained blood smears by LED fluorescence microscopy resulted in a diagnostic accuracy that was similar to that of routine methods, while the time needed to identify parasites was shortened significantly. These findings make these new microscopy methods attractive alternatives to procedures that are currently used for diagnosis of T. b. rhodesiense human African trypanosomiasis.
文摘Human African trypanosomiasis (HAT) affects up to half a million people every year in sub-Saharan Africa. Interruption of transmission of the disease by early diagnosis and treatment is core to the control and eventual elimination of HAT. The routine diagnostic method for HAT is light microscopy of blood samples. The present study sought to evaluate the potential of TbgI2 and TbgI17 tandem repeat antigens as candidates for the diagnosis of Trypanosoma brucei rhodesiense. The expressed proteins were purified and the antigenic reactivity evaluation was done using multiplex assay using sera obtained from HAT patients. Receiver operating characteristic analysis showed that recombinant antigen, TbgI2 had high sensitivity for sera from patients infected with T. b. rhodesiense with the area under the curve being 0.577 and a sensitivity of 0.641 and specificity 0.650. The results suggest that TbgI2 is a potential biomarker for T. b. rhodesiense HAT serodiagnostic tests.
基金This study was funded with UK aid from the UK government’under the DfID Research into Use Programme(SCW,LH,KP,KP,KLB,CW,JDK)and from the European Union’s Seventh Framework Program(FP7/2007-2014)under grant agreement n°221948 Integrated Control of Neglected Zoonoses(ICONZ)(SCW,KP,KLB,CW,JDK)Treatment of village cattle was undertaken under the Stamp Out Sleeping Sickness Programme supported by IKARE and Ceva Sante AnimaleThe funders had no role in study design,data collection and analysis,decision to publish,or preparation of the manuscript.
文摘Background:Uganda has suffered from a series of epidemics of Human African Trypanosomiasis(HAT),a tsetse transmitted disease,also known as sleeping sickness.The area affected by acute Trypanosoma brucei rhodesiense HAT(rHAT)has been expanding,driven by importation of infected cattle into regions previously free of the disease.These regions are also affected by African Animal Trypanosomiasis(AAT)demanding a strategy for integrated disease control.Methods:In 2008,the Public Private Partnership,Stamp Out Sleeping Sickness(SOS)administered a single dose of trypanocide to 31486 head of cattle in 29 parishes in Dokolo and Kaberamaido districts.This study examines the impact of this intervention on the prevalence of rHAT and AAT trypanosomes in cattle from villages that had(HAT^(+ve))or had not(HAT^(-ve))experienced a recent case of rHAT.Cattle herds from 20 villages were sampled and screened by PCR,pre-intervention and 6-months post-intervention,for the presence or absence of:Trypanosoma brucei s.l.;human infective T.b.rhodesiense;Trypanosoma vivax;and Trypanosoma congolense savannah.Results:Post-intervention,there was a significant decrease in the prevalence of T.brucei s.l.and the human infective sub-species T.b.rhodesiense in village cattle across all 20 villages.The prevalence of T.b.rhodesiense was reduced from 2.4%to 0.74%(P<0.0001),with the intervention showing greater impact in HAT^(-ve) villages.The number of villages containing cattle harbouring human infective parasites decreased from 15/20 to 8/20,with T.b.rhodesiense infection mainly persisting within cattle in HAT^(+ve) villages(six/eight).The proportion of T.brucei s.l.infections identified as human infective T.b.rhodesiense decreased after the intervention from 8.3%(95%CI=11.1-5.9%)to 4.1%(95%CI=6.8-2.3%).Villages that had experienced a recent human case(HAT^(+ve) villages)showed a significantly higher prevalence for AAT both pre-and post-intervention.For AAT the prevalence of T.vivax was significantly reduced from 5.9%to 0.05%post-intervention while the prevalence of T.congolense increased from 8.0%to 12.2%.Conclusions:The intervention resulted in a significant decrease in the prevalence of T.brucei s.l.,human infective T.b.rhodesiense and T.vivax infection in village cattle herds.The proportion of T.brucei s.l.that were human infective,decreased from 1:12 T.brucei s.l.infections before the intervention to 1:33 post-intervention.It is clearly more difficult to eliminate T.b.rhodesiense from cattle in villages that have experienced a human case.Evidence of elevated levels of AAT in livestock within village herds is a useful indicator of risk for rHAT in Uganda.Integrated veterinary and medical surveillance is key to successful control of zoonotic rHAT.
基金This work was supported by the National Key Research and Development Program of China(Grant Nos.2016YFC1202000,2016YFC1202002)by the International Development Research Center(IDRC),Canada(grant No.108100–001).
文摘Background:Human African trypanosomiasis(HAT)is one of the most complex parasitic diseases known to humankind.It usually occurs in endemic areas in Africa,but is occasionally detected in returning travelers and migrants in non-endemic countries.Case presentation:In August 2017,a case of HAT was diagnosed in China in a traveler returning from the Masai Mara area in Kenya and the Serengeti area in Tanzania.The traveler visited Africa from 23 July to 5 August,2017.Upon return to China,she developed a fever(on 8 August),and Trypanosoma brucei rhodesiense infection was confirmed by laboratory tests(on 14 August)including observation of parasites in blood films and by polymerase chain reaction.She was treated with pentamidine followed by suramin,and recovered 1 month later.Conclusions:This is the first imported rhodesiense HAT case reported in China.This case alerts clinical and public health workers to be aware of HAT in travelers,and expatriates and migrants who have visited at-risk areas in Africa.
基金Supported by a grant from graduate school(GSEU 20RR0234/2011),Egerton University Faculty Research Committee.
文摘Objective:To establish the modulatory effects of coenzyme Q_(10)on experimental trypanosome infections in mice and evaluate the risk of occurrence and severity of melarsoprol-induced post treatment reactive encephalopathy(PTRE).Methods:Female Swiss white mice were orally administered with 200 mg/kg of coenzyme Q_(10)after which they were intraperitoneally inoculated with Trypanasoma brucei rhodesiense(T.b.rhodesiense).The resultant infection was allowed to develop and simulate all phases of human African trypanosomiasis and PTRE.Parasitaemia development,packed cell volume,haematological and pathological changes were determined.Results:A histological study in the brain tissue of T.b.rhodesiense infected mice demonstrated neuroinflammatory pathology which was highly amplified in the PTRE-induced groups.A prominent reduction in the severity of the neuroinflammatory response was detected when coenzyme-Q_(10)was administered.Furthermore,the mean tissue weight of spleen to body ratio in coenzyme Q_(10)supplemented group was significantly(P<0.05)different compared to un-supplemented groups,and clearly indicated that coenzyme Q_(10)prevented full blown splenomegaly pathogenesis by T.b.rhodesiense.A significant(P<0.05)increase in hemoglobin levels and red blood cells was observed in coenzyme Q_(10)mice compared to those infected and un-supplemented with coenzyme Q_(10).Conclusions:The capacity of coenzyme Q_(10)to alter the pathogenesis of T.b.rhodesiense infection in mice and following treatment with melarsoprol,may find application by rendering humans and animals less susceptible to deleterious effects of trypanosome infection such as splenomegaly and melarsoprol-induced PTRE and neurotoxicity.
基金This work was part of the Dynamic Drivers of Disease in Africa Consortium,NERC project no.NE/J000701/1was funded with support from the Ecosystem Services for Poverty Alleviation Programme(ESPA)+1 种基金The ESPA programme is funded by the Department for International Development(DFID)the Economic and Social Research Council(ESRC)and the Natural Environment Research Council(NERC).
文摘Background:Acute human African trypanosomiasis(rHAT)caused by Trypanosoma brucei rhodesiense is associated with high mortality and is fatal if left untreated.Only a few studies have examined the psychological,social and economic impacts of rHAT.In this study,mixed qualitative and quantitative research methods were used to evaluate the socio-economic impacts of rHAT in Mambwe,Rufunsa,Mpika and Chama Districts of Zambia.Methods:Individuals diagnosed with rHAT from 2004 to 2014 were traced using hospital records and discussions with communities.Either they,or their families,were interviewed using a structured questionnaire and focus group discussions were conducted with affected communities.The burden of the disease was investigated using disability adjusted life years(DALYs),with and without discounting and age-weighting.The impact of long-term disabilities on the rHAT burden was also investigated.Results:Sixty four cases were identified in the study.The majority were identified in second stage,and the mortality rate was high(12.5%).The total number of DALYs was 285 without discounting or age-weighting.When long-term disabilities were included this estimate increased by 50%to 462.The proportion of years lived with disability(YLD)increased from 6.4%to 37%of the undiscounted and un-age-weighted DALY total.When a more active surveillance method was applied in 2013-2014 the cases identified increased dramatically,suggesting a high level of under-reporting.Similarly,the proportion of females increased substantially,indicating that passive surveillance may be especially failing this group.An average of 4.9 months of productive time was lost per patient as a consequence of infection.The health consequences included pain,amnesia and physical disability.The social consequences included stigma,dropping out of education,loss of friends and self-esteem.Results obtained from focus group discussions revealed misconceptions among community members which could be attributed to lack of knowledge about rHAT.Conclusions:The social and economic impact of rHAT on rural households and communities is substantial.Improved surveillance and strengthening of local medical services are needed for early and accurate diagnosis.Disease prevention should be prioritised in communities at risk of rHAT,and interventions put in place to prevent zoonotic disease spill over from domestic animals and wildlife.Supportive measures to mitigate the long-term effects of disability due to rHAT are needed.
