American trypanosomiasis,commonly known as Chagas disease,is caused by the flagellate protozoan parasite Trypanosoma cruzi.An estimated eight million people infected with T.cruzi currently reside in the endemic region...American trypanosomiasis,commonly known as Chagas disease,is caused by the flagellate protozoan parasite Trypanosoma cruzi.An estimated eight million people infected with T.cruzi currently reside in the endemic regions of Latin America.However,as the disease has now been imported into many non-endemic countries outside of Latin America,it has become a global health issue.We reviewed the transmission patterns and current status of disease spread pertaining to American trypanosomiasis at the global level,as well as recent advances in research.Based on an analysis of the gaps in American trypanosomiasis control,we put forward future research priorities that must be implemented to stop the global spread of the disease.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
Trypanosoma evansi is the causative agent of the animal trypanosomiasis surra, a disease with serious economic burden worldwide. The availability of the genome of its closely related parasite Trypanosoma brucei allows...Trypanosoma evansi is the causative agent of the animal trypanosomiasis surra, a disease with serious economic burden worldwide. The availability of the genome of its closely related parasite Trypanosoma brucei allows us to compare their genetic and evolutionarily shared and distinct biological features. The complete genomic sequence of the T. evansi YNB strain was obtained using a combination of genomic and transcriptomic sequencing, de novo assembly, and bioinformatic analysis. The genome size of the T. evansi YNB strain was 35.2 Mb, showing 96.59% similarity in sequence and 88.97% in scaffold alignment with T. brucei. A total of 8,617 protein-coding genes, accounting for 31% of the genome, were predicted. Approximately 1,641 alternative splicing events of 820 genes were identified, with a majority mediated by intron retention, which represented a major difference in post-transcriptional regulation between T. evansi and T. brucei. Disparities in gene copy number of the variant surface glycoprotein, expression site-associated genes, microRNAs, and RNA-binding protein were clearly observed between the two parasites. The results revealed the genomic determinants of T. evansi, which encoded specific biological characteristics that distinguished them from other related trypanosome species.展开更多
Vector-borne protozoan diseases represent a serious public health challenge,especially in the tropics where poverty together with vector-favorable climates are the aggravating factors.Each of the various strategies cu...Vector-borne protozoan diseases represent a serious public health challenge,especially in the tropics where poverty together with vector-favorable climates are the aggravating factors.Each of the various strategies currently employed to face these scourges is seriously inadequate.Despite enormous efforts,vaccines-which represent the ideal weapon against these parasitic diseases—are yet to be sufficiently developed and implemented.Chemotherapy and vector control are therefore the sole effective attempts to minimize the disease burden.Nowadays,both strategies are also highly challenged by the phenomenon of drug and insecticide resistance,which affects virtually all interventions currently used.The recently growing support from international organizations and governments of some endemic countries is warmly welcome,and should be optimally exploited in the various approaches to drug and insecticide research and development to overcome the burden of these prevalent diseases,especially malaria,leishmaniasis,Human African Trypanosomiasis(HAT),and Chagas disease.展开更多
Background Serological screening tests play a crucial role to diagnose gambiense human African trypanosomiasis(gHAT).Presently,they preselect individuals for microscopic confrmation,but in future"screen and treat...Background Serological screening tests play a crucial role to diagnose gambiense human African trypanosomiasis(gHAT).Presently,they preselect individuals for microscopic confrmation,but in future"screen and treat"strategies they willidentify individuals for treatment.Variability in reported specificities,the development of new rapid diagnos-tic tests(RDT)and the hypothesis that malaria infection may decrease RDT specificity led us to evaluate the specificity of 5 gHAT screening tests.Methods During active screening,venous blood samples from 1095 individuals from Cote d'ivoire and Guinea were tested consecutively with commercial(CATT,HAT Sero-K-SeT,Abbott Bioline HAT 2.0)and prototype(DCN HAT RDT,HAT Sero-K-SeT 2.0)gHAT screening tests and with a malaria RDT.Individuals with≥1 positive gHAT screening test underwent microscopy and further immunological(trypanolysis with T.b.gambiense LiTat 1.3,1.5 and 1.6;indirect ELISA/Tb.gambiense;T.b.gambiense inhibition ELISA with T.b.gambiense LiTat 1.3 and 1.5 VSG)and molecular reference laboratory tests(PCR TBRN3,18S and TgsGP;SHERLOCK 18S Tids,7SL Zoon,and TgsGP;Trypanozoon S2-RT-qPCR 18S2,177T,GPl-PLC and TgsGP in multiplex;RT-qPCR DT8,DT9 and TgsGP in multiplex).Microscopic trypanosome detection confrmed gHAT,while other individuals were considered gHAT free.Differences in fractions between groups were assessed by Chi square and differences in specificity between 2 tests on the same individuals by McNemar.Results One gHAT case was diagnosed.Overall test specificities(n=1094)were:CATT 98.9%(95%CI:98.1-99.4%);HAT Sero-K-SeT 86.7%(95%CI:84.5-88.5%);Bioline HAT 2.082.1%(95%CI:79.7-84.2%);DCN HAT RDT 78.2%(95%CI:75.7-80.6%);and HAT Sero-K-SeT 2.078.4%(95%CI:75.9-80.8%).In malaria positives,gHAT screening tests appeared less specific,but the difference Was significant only in Guinea for Abbott Bioline HAT 2.0(P=0.03)and HAT Sero-K-Set 2.0(P=0.0006).The specificities of immunological and molecular laboratory tests in gHAT seropositives were 98.7-100%(n=399)and 93.0-100%(n=302)展开更多
Trypanosoma cruzi is the etiologic agent of Chagas disease.This flagellated protozoan is transmitted to humans as well as different species of domestic and wild animals via vectors from the Reduviidae family(known as&...Trypanosoma cruzi is the etiologic agent of Chagas disease.This flagellated protozoan is transmitted to humans as well as different species of domestic and wild animals via vectors from the Reduviidae family(known as"kissing bugs").Despite the fact that hundreds of species of wild mammals are part of the reservoir system,the morphologi-cal changes and clinical manifestations resulting from the pathogenesis of the infection have been largely neglected.The aim of this review is to systematically compile the available information regarding clinicopathological altera-tions in wild mammals due to natural infection by T.cruzi.Information was obtained from six online bibliographic data search platforms,resulting in the identification of 29 publications that met the inclusion criteria.Mortality was the most common clinical manifestation,cardiac damage was the main finding at necropsy,and lymphoplas-macytic inflammation was the most frequent microscopic injury.Thus,regardless of its role as a reservoir,T.cruzi has the potential to affect the health status of wild mammals,a situation that highlights the need for further research to analyze,measure,and compare its effects at both the individual and population levels.展开更多
Background: Confirmatory diagnosis of Trypanosoma brucei gambiense human African trypanosomiasis (HAT) is based on demonstration of parasites by microscopy. However, the sensitivity of routine microscopy methods is ve...Background: Confirmatory diagnosis of Trypanosoma brucei gambiense human African trypanosomiasis (HAT) is based on demonstration of parasites by microscopy. However, the sensitivity of routine microscopy methods is very low, and many cases are missed and left untreated. A clinical study was conducted in the Democratic Republic of the Congo to evaluate the accuracy of improved microscopy methods in diagnosis of HAT. These included examination by fluorescence microscopy (FM) of acridine orange (AO) stained smears of whole blood and smears made following a new procedure for concentrating trypanosomes by selective lysis of red blood cells (RBC). Methodology/Principal Findings: Venous blood was collected from 213 HAT cases, 101 HAT suspects and 95 controls and used to determine the accuracy of four microscopy methods: bright field microscopy of Giemsa-stained thick blood smears, FM of AO-stained thick blood smears, FM of AO-stained thick blood smears prepared after RBC lysis and concentration, and FM of AO-stained thin blood smears prepared after RBC lysis and concentration. The sensitivity of FM using thick blood smears stained with AO was 3 times higher than bright field microscopy using Giemsa-stained thick blood smears [19.7% (95% CI: 14.9% - 25.6%) versus 6.1% (95% CI: 3.6% - 10.2%)]. When the RBC lysis and concentration procedure was included, sensitivity of the test was further enhanced to 23.0% (95% CI: 17.9% - 29.1%) with thick blood smears and 34.3% (95% CI: 28.2% - 40.9%) with thin blood smears. Specificity of all four microscopy methods was 100% (95% CI: 96.1% - 100.0%). However, the miniature anion exchange chromatography technique (mAECT) and capillary tube centrifugation (CTC) method remained more sensitive. Conclusions: These new methods have practical advantages, including shorter staining time, ease of demonstration of parasites, and the possibility of archiving slides. They could, therefore, be alternative methods to improve case detection where concentration procedures such as mAECT or CTC are not 展开更多
Human African trypanosomiasis (HAT) commonly known as sleeping sickness occurs in about 36 countries in sub-Saharan Africa and results in a large number of deaths and considerable illness. The drugs used in the treatm...Human African trypanosomiasis (HAT) commonly known as sleeping sickness occurs in about 36 countries in sub-Saharan Africa and results in a large number of deaths and considerable illness. The drugs used in the treatment of HAT are very toxic and therefore might not be safe in pregnancy. Few published data exist on the treatment of HAT in pregnancy. We describe a case of T. brucei gambiense infection occurring in a pregnant woman that was successfully treated with Melarsoprol with no toxic effect to mother and the baby after 2 years of follow-up.展开更多
Human African Trypanosomiasis (HAT) or sleeping thickness is a forest and rural disease;where agriculture is the main activity. It is a chronic and lethal disease without treatment. HAT is caused by two parasites;Tryp...Human African Trypanosomiasis (HAT) or sleeping thickness is a forest and rural disease;where agriculture is the main activity. It is a chronic and lethal disease without treatment. HAT is caused by two parasites;Trypanosoma Brucei Gambiense (gTB) and Trypanosoma Brucei Rhodesiense (rTB) transmitted to humans by the tsetse fly. It is endemic condition in Africa between the 15° north latitude and the 20° south latitude. It is reported outside this area in travelers who stayed in endemic zone. Infection by gTB is wider and more frequent (98%) than that by rTB (2%). The Democratic Republic of Congo is the most affected country with more than 75% of reported cases. The geographical distribution is not homogeneous. There are more affected regions in a zone called “foci” which represents areas favorable to the development of the vector. Its diagnosis and treatment are very important because of its social and economic impact at both the individual and community levels. Promising molecules including fexinidazole are currently undergoing testing. Nowadays populations move more and more easily but the discovery of this disease in daily neuroradiological practice is exceptional. We propose in this paper through two observations, reminders on epidemiological, clinical and MRI features of HAT. It typically performs the edematous, bilateral and diffuse encephalitis. It is important to distinguish these aspects from the arsenic-induced encephalitis that may occur during treatment. Only vector control allows eradicating this disease. WHO has set targets elimination of HAT as a public health problem for 2020 deadline.展开更多
Human African trypanosomiasis (HAT), commonly known as sleeping sickness is one of the neglected tropical diseases (NTDs), which is fatal if left untreated. Its diagnosis is a challenge since the signs and symptoms of...Human African trypanosomiasis (HAT), commonly known as sleeping sickness is one of the neglected tropical diseases (NTDs), which is fatal if left untreated. Its diagnosis is a challenge since the signs and symptoms of the primary phase are not specific, the existing diagnostic methods have low sensitivity and specificity, and the available drugs have some toxicity. New, robust, and cost-effective techniques are needed for the early identification of parasites. This study aimed to assess the sensitivity and specificity of two different types of polyclonal antibodies against T. b. gambiense using antigen detection ELISA. Polyclonal antibodies against the expressed proteins Tbg I2 and Tbg I17 were produced using New Zealand white rabbits. The antibody titer measured was greater than 32 g/L after the 3<sup>rd</sup> immunization for the expressed protein Tbg I2. For the expressed protein Tbg I17, the antibody titer measured was greater than 32 g/L after the 4<sup>th</sup> immunization. The sensitivity and specificity of the Tbg I2 polyclonal antibody confirmed with Polymerase Chain Reaction (PCR) as gold standard were respectively 89.5% and 80.6%, while for the Tbg I17 polyclonal antibody, the sensitivity and specificity were respectively 92.1% and 88.9%. The area under the curve for the Tbg I2 polyclonal antibody was 0.90 ± 0.032, while for the Tbg I17 polyclonal antibody, the area under the curve was 0.92 ± 0.0. The Tbg I17 polyclonal antibody produced in New Zealand white rabbits has good sensitivity and good specificity;it can be successfully used in the diagnosis of HAT.展开更多
Protozoan diseases such as Visceral Leishmaniasis (VL) have re-emerged in Northern Brazil and cases of Chagas Disease also occur. This VL increase leads to early therapy for the public. Confirmatory parasitological di...Protozoan diseases such as Visceral Leishmaniasis (VL) have re-emerged in Northern Brazil and cases of Chagas Disease also occur. This VL increase leads to early therapy for the public. Confirmatory parasitological diagnoses in VL are performed by bone marrow or spleen aspiration, but ELISA, IFA or immunochromatographic tests for antibody detection are easily performed and can be used in the presence of clinical signs as confirmatory for specific therapy. This approach is successful in providing therapy and prevention of death in VL, but there is a chance of confusion with the emerging disease, Chagas Disease (CD), due to cross-reacting and similar clinical pictures, as in this case. Both VL and CD presented many asymptomatic or oligosymptomatic cases, complicating the picture. Our case report emphasizes these aspects. Positive serology, with an IIF titer of 1/160, and epidemiological correlation, suggests the diagnosis of VL and imposes antimony therapy. Despite the unfavorable evolution and signs of cardiac involvement, the presence of pericarditis and cardiac tamponade confirmed by the echocardiogram suggests CD. We reassessed the profiles of a suggested CD serology, the diagnosis was corrected and treatment with CD specific benznidazole. The good evolution started with benznidazole corroborates the diagnosis of CD and discards the hypothesis of double infection.展开更多
A cross-sectional study was carried out aimed to estimate sero-prevalence of camel trypanosomiasis and to investigate the related risk factors of the disease in Four Selected Villages of Galkayo, Mudug region from 14t...A cross-sectional study was carried out aimed to estimate sero-prevalence of camel trypanosomiasis and to investigate the related risk factors of the disease in Four Selected Villages of Galkayo, Mudug region from 14th March 2016 up to 20th April 2016. Blood samples were collected from 69 randomly selected camels of the four study villages, and samples were allowed to clot at room temper to detect the sero-prevalence of trypanosome using Card Agglutination Test for Trypanosomiasis (CATT). The results indicated that the overall sero-prevalence of trypanosomiasis in camels that 15.9% (11) samples were positive for trypanosome evansi (T. evansi) was recorded. Higher infection was found in female (19.4) as compared to male (11.1). However, there is no statistically significant difference in sero-prevalence between sex categories (P > 0.05). High Test infection of sero-prevalence was noted 20% in young age (10), and there was statistically significant difference (P < 0.05) in susceptibility among age groups. These results seem to indicate that T. evansi infection is high in the study area. There is need of further control of camel trypanosomiasis through the uses of curative and prophylactic drugs to avoid the various problems.展开更多
The Education for Health at PET Work Program (PET-Health) is focused on education as a pre-supposition. Actions are directed towards to the integration of service-learning and community. Interdisciplinary principle is...The Education for Health at PET Work Program (PET-Health) is focused on education as a pre-supposition. Actions are directed towards to the integration of service-learning and community. Interdisciplinary principle is directed from fusion of work of graduate students, academics and professionals of health services for the benefit of strengthening primary care and health surveillance. This work aimed to carry out educational activities with Community Health Agents (ACS) of the health facilities of PET-health, with the theme of Chagas disease. This descriptive cross-sectional study was carried out from January to May 2013, and the sample consisted of 25 active ACS in six Basic Health Units in the city of Petrolina, Brazil. In spite of actuation of ACS in primary care for over 10 years, a limited knowledge has been developed about this pathology. The health education workshops developed by the PET group clarified the ACS on Chagas disease allowing them to have an expansion of knowledge about the vector, habitat Barber, transmission, clinical manifestations… After the workshop, it was found that the ACS expanded their knowledge about the disease cycle, expanding the possibilities for action in the prevention of this pathology in their respective coverage areas. This work shows an important form of integration between education, service and community that can govern the new direction of health education.展开更多
Objective:To investigated the prevalence of human African trypanosomiasis(HAT),a neglected tropical disease caused by Trypanosoma brucei gambiens in an endemic focus of Nigeria,as it relates to age,sex and occupationa...Objective:To investigated the prevalence of human African trypanosomiasis(HAT),a neglected tropical disease caused by Trypanosoma brucei gambiens in an endemic focus of Nigeria,as it relates to age,sex and occupational differences.Methods:A total of 474 human subjects were screened using card agglutination test for trypanosomiasis kit.Positive samples were further investigated for parasite positivity in blood/serum and cerebrospinal fluid(CSF).Results:Of the 474 screened,44(9.3%) were seropositive with seroprevalence of 22(9.6%) in Urhouka,14(9.5%) in Umeghe and 8(7.9%) for Ugonu.The number of seropositives,observed for weakly,moderately and strongly positives for the three communities were 4,7 and 11 in Urhouka,4,5 and 5 in Umeghe and 3,2 and 3 in Ugonu respectively.Among the 16 volunteers with detected parasite in their blood,4 of them were weakly positive,5 of them were moderately positive and 7 of them strongly positive.4 volunteers from Urhouka community were found parasites in their CSF and they were all strongly positive.The difference between the seroprevalence of males and females was not statistically significant(OR=1.14,95%CI=0.37-3.4,P】0.05).The prevalence difference between age group 21-30 years old and the youngest and oldest age groups was statistically significant(OR=3.5,95%CI= 1.08-12.57,P【0.05) but not significant for other age categories (P】0.05),It was observed that farmers had significantly higher prevalence of HAT infection as well as greater risk of Trypanosoma brucei gambiense infection than inhabitants with other occupations (OR=3.25,95%CI=0.99-11.79,P【0.05).Conclusions:Human activities such as farming and visits to the river have been identified as major risk factors to HAT.Also the breakdown of HAT control program has been advanced for the rise in HAT in Abraka,an endemic focus in Nigeria.展开更多
Objective:To explore some Fumaria species which were recorded to be traditionally used against malaria and other protozoal diseases.Methods:Consequently,in the current study,antiprotozoal effect of the ethanol extract...Objective:To explore some Fumaria species which were recorded to be traditionally used against malaria and other protozoal diseases.Methods:Consequently,in the current study,antiprotozoal effect of the ethanol extracts obtained from five Fumaria species(Fumaria densiflora,Fumaria cilicica,Fumaria rostellata,Fumaria kralikii,and Fumaria parviflora)was investigated against the parasites;Plasmodium falciparum(malaria)and Trypanosoma bruceirhodesiense(human African trypanosomiasis)at 0.81 and 4.85μg/mL concentrations.Results:Among them,Fumaria densiflora extract exerted the highest antiplasmodial(93.80%)and antitrypanasomal effect(55.40%),while the ethanol extracts of Fumaria kralikii(43.45%)and Fumaria rostellata(41.65%)showed moderate activity against Plasmodium falciparum.Besides,phenolic acid contents of the extracts were analyzed using high performance liquid chromatography(HPLC)and trans-cinnamic(4.32 mg/g)and caffeic(3.71 mg/g)acids were found to be the dominant phenolic acids in Fumaria densiflora.Conclusions:According to our results,Fumaria densiflora deserve further study for its promising antiprotozoal activity.展开更多
Parasitic meningoencephalitis presents several etiologies which sometimes depend on their geographical location. They require thorough blood and cerebrospinal fluid check-up for directing an efficient treatment. Clini...Parasitic meningoencephalitis presents several etiologies which sometimes depend on their geographical location. They require thorough blood and cerebrospinal fluid check-up for directing an efficient treatment. Clinicians and radiologists are constantly looking for specific signs that could point to a particular etiology. The meningoencephalitis caused by Human African Trypanosomiasis (HAT) due to Trypanosoma brucei gambiense (TG) is a rare disease characterized by a slow progression, over years sometimes. Its non-specific presentation either clinically or in imaging can lead to misdiagnosis and thus, delay the treatment. However, involvement of the optic tracts seems to be characteristic of this condition, on old data from animal experimentation and recent high-field MRI data. MRI is the best current technique to explore the brain, cranial nerves, and visual pathways. In this article, we are going to present two observations of meningoencephalitis caused by HAT and then discuss some specific aspects of this neglected and re-emerging disease.展开更多
Human African trypanosomiasis (HAT), or sleeping sickness, caused by Trypanosoma brucei gambiense, is associated with diverse clinical outcomes. Host’s genetic factors involved in immunity are potential factors that ...Human African trypanosomiasis (HAT), or sleeping sickness, caused by Trypanosoma brucei gambiense, is associated with diverse clinical outcomes. Host’s genetic factors involved in immunity are potential factors that can regulate infection. Genetic polymorphisms within HLA-G could influence the level of HLA-G expression and therefore play a critical role in infection outcomes. The goal of our study was to investigate the association of 14 bp Indel HLA-G polymorphism with the susceptibility/resistance to HAT. DNA samples were collected from 119 cases, 221 controls and 43 seropositive individuals living in Ivorian HAT foci. The 14 bp Indel polymorphism was determined by PCR. Homozygous individuals for 14 bp insertion had a lower risk of progressing to active HAT (p = 0.012, OR = 0.27, 95% CI: 0.09 - 0.8). Moreover, the frequency of 14 bp insertion homozygous genotype was higher in the seropositive group (11%) than in the HAT cases group (3%) (p = 0.043, OR = 0.27, 95% CI: 0.07 - 0.99), which suggested a protective effect of 14 bp insertion homozygous genotype. Genetic polymorphisms in HLA-G may be associated with a variable risk to develop HAT. The 14 bp insertion appears to favour the occurrence of long-lasting T. b. gambiense latent infections.展开更多
基金This work was supported by the National S&T Major Programme(grant no.2012ZX10004220)Many thanks for Dr.Peiling Yap for her constructive comments on the manuscript.Many thanks also to Mr.Xue Jingbo and Mr.Shen Haimo for their help in drawing the figures.
文摘American trypanosomiasis,commonly known as Chagas disease,is caused by the flagellate protozoan parasite Trypanosoma cruzi.An estimated eight million people infected with T.cruzi currently reside in the endemic regions of Latin America.However,as the disease has now been imported into many non-endemic countries outside of Latin America,it has become a global health issue.We reviewed the transmission patterns and current status of disease spread pertaining to American trypanosomiasis at the global level,as well as recent advances in research.Based on an analysis of the gaps in American trypanosomiasis control,we put forward future research priorities that must be implemented to stop the global spread of the disease.
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 grants of the National Key Research and Development Program of China (2017YFD0500400 and 2017YFD0501200)the National Natural Science Foundation of China (81420108023 and 81772219)distinguished scientist grant from Shenyang Agricultural University
文摘Trypanosoma evansi is the causative agent of the animal trypanosomiasis surra, a disease with serious economic burden worldwide. The availability of the genome of its closely related parasite Trypanosoma brucei allows us to compare their genetic and evolutionarily shared and distinct biological features. The complete genomic sequence of the T. evansi YNB strain was obtained using a combination of genomic and transcriptomic sequencing, de novo assembly, and bioinformatic analysis. The genome size of the T. evansi YNB strain was 35.2 Mb, showing 96.59% similarity in sequence and 88.97% in scaffold alignment with T. brucei. A total of 8,617 protein-coding genes, accounting for 31% of the genome, were predicted. Approximately 1,641 alternative splicing events of 820 genes were identified, with a majority mediated by intron retention, which represented a major difference in post-transcriptional regulation between T. evansi and T. brucei. Disparities in gene copy number of the variant surface glycoprotein, expression site-associated genes, microRNAs, and RNA-binding protein were clearly observed between the two parasites. The results revealed the genomic determinants of T. evansi, which encoded specific biological characteristics that distinguished them from other related trypanosome species.
基金The present work was supported by a research grant awarded to Dr.Denis Zofou by the International Foundation for Science(IFS),Stockholm,Swedenthe Organization for the Prohibition of Chemical Weapons,The Hague,Netherlands(IFS-OPCW,Grant No F/5122-1).
文摘Vector-borne protozoan diseases represent a serious public health challenge,especially in the tropics where poverty together with vector-favorable climates are the aggravating factors.Each of the various strategies currently employed to face these scourges is seriously inadequate.Despite enormous efforts,vaccines-which represent the ideal weapon against these parasitic diseases—are yet to be sufficiently developed and implemented.Chemotherapy and vector control are therefore the sole effective attempts to minimize the disease burden.Nowadays,both strategies are also highly challenged by the phenomenon of drug and insecticide resistance,which affects virtually all interventions currently used.The recently growing support from international organizations and governments of some endemic countries is warmly welcome,and should be optimally exploited in the various approaches to drug and insecticide research and development to overcome the burden of these prevalent diseases,especially malaria,leishmaniasis,Human African Trypanosomiasis(HAT),and Chagas disease.
基金This work was supported by the Swiss Agency for Development and Cooperation(grant nr.81071426,7F-08866.03.01)the Bill and Melinda Gates Foundation(www.gatesfoundation.org)through the Trypa-NO!Project(grants number INV-001785,OPP1033712,OPP1154033)the'Development and integration of serological and molecular diagnostics in view of interruption of transmission of gambiense-HAT'project(grant number INV-031353).
文摘Background Serological screening tests play a crucial role to diagnose gambiense human African trypanosomiasis(gHAT).Presently,they preselect individuals for microscopic confrmation,but in future"screen and treat"strategies they willidentify individuals for treatment.Variability in reported specificities,the development of new rapid diagnos-tic tests(RDT)and the hypothesis that malaria infection may decrease RDT specificity led us to evaluate the specificity of 5 gHAT screening tests.Methods During active screening,venous blood samples from 1095 individuals from Cote d'ivoire and Guinea were tested consecutively with commercial(CATT,HAT Sero-K-SeT,Abbott Bioline HAT 2.0)and prototype(DCN HAT RDT,HAT Sero-K-SeT 2.0)gHAT screening tests and with a malaria RDT.Individuals with≥1 positive gHAT screening test underwent microscopy and further immunological(trypanolysis with T.b.gambiense LiTat 1.3,1.5 and 1.6;indirect ELISA/Tb.gambiense;T.b.gambiense inhibition ELISA with T.b.gambiense LiTat 1.3 and 1.5 VSG)and molecular reference laboratory tests(PCR TBRN3,18S and TgsGP;SHERLOCK 18S Tids,7SL Zoon,and TgsGP;Trypanozoon S2-RT-qPCR 18S2,177T,GPl-PLC and TgsGP in multiplex;RT-qPCR DT8,DT9 and TgsGP in multiplex).Microscopic trypanosome detection confrmed gHAT,while other individuals were considered gHAT free.Differences in fractions between groups were assessed by Chi square and differences in specificity between 2 tests on the same individuals by McNemar.Results One gHAT case was diagnosed.Overall test specificities(n=1094)were:CATT 98.9%(95%CI:98.1-99.4%);HAT Sero-K-SeT 86.7%(95%CI:84.5-88.5%);Bioline HAT 2.082.1%(95%CI:79.7-84.2%);DCN HAT RDT 78.2%(95%CI:75.7-80.6%);and HAT Sero-K-SeT 2.078.4%(95%CI:75.9-80.8%).In malaria positives,gHAT screening tests appeared less specific,but the difference Was significant only in Guinea for Abbott Bioline HAT 2.0(P=0.03)and HAT Sero-K-Set 2.0(P=0.0006).The specificities of immunological and molecular laboratory tests in gHAT seropositives were 98.7-100%(n=399)and 93.0-100%(n=302)
文摘Trypanosoma cruzi is the etiologic agent of Chagas disease.This flagellated protozoan is transmitted to humans as well as different species of domestic and wild animals via vectors from the Reduviidae family(known as"kissing bugs").Despite the fact that hundreds of species of wild mammals are part of the reservoir system,the morphologi-cal changes and clinical manifestations resulting from the pathogenesis of the infection have been largely neglected.The aim of this review is to systematically compile the available information regarding clinicopathological altera-tions in wild mammals due to natural infection by T.cruzi.Information was obtained from six online bibliographic data search platforms,resulting in the identification of 29 publications that met the inclusion criteria.Mortality was the most common clinical manifestation,cardiac damage was the main finding at necropsy,and lymphoplas-macytic inflammation was the most frequent microscopic injury.Thus,regardless of its role as a reservoir,T.cruzi has the potential to affect the health status of wild mammals,a situation that highlights the need for further research to analyze,measure,and compare its effects at both the individual and population levels.
文摘Background: Confirmatory diagnosis of Trypanosoma brucei gambiense human African trypanosomiasis (HAT) is based on demonstration of parasites by microscopy. However, the sensitivity of routine microscopy methods is very low, and many cases are missed and left untreated. A clinical study was conducted in the Democratic Republic of the Congo to evaluate the accuracy of improved microscopy methods in diagnosis of HAT. These included examination by fluorescence microscopy (FM) of acridine orange (AO) stained smears of whole blood and smears made following a new procedure for concentrating trypanosomes by selective lysis of red blood cells (RBC). Methodology/Principal Findings: Venous blood was collected from 213 HAT cases, 101 HAT suspects and 95 controls and used to determine the accuracy of four microscopy methods: bright field microscopy of Giemsa-stained thick blood smears, FM of AO-stained thick blood smears, FM of AO-stained thick blood smears prepared after RBC lysis and concentration, and FM of AO-stained thin blood smears prepared after RBC lysis and concentration. The sensitivity of FM using thick blood smears stained with AO was 3 times higher than bright field microscopy using Giemsa-stained thick blood smears [19.7% (95% CI: 14.9% - 25.6%) versus 6.1% (95% CI: 3.6% - 10.2%)]. When the RBC lysis and concentration procedure was included, sensitivity of the test was further enhanced to 23.0% (95% CI: 17.9% - 29.1%) with thick blood smears and 34.3% (95% CI: 28.2% - 40.9%) with thin blood smears. Specificity of all four microscopy methods was 100% (95% CI: 96.1% - 100.0%). However, the miniature anion exchange chromatography technique (mAECT) and capillary tube centrifugation (CTC) method remained more sensitive. Conclusions: These new methods have practical advantages, including shorter staining time, ease of demonstration of parasites, and the possibility of archiving slides. They could, therefore, be alternative methods to improve case detection where concentration procedures such as mAECT or CTC are not
文摘Human African trypanosomiasis (HAT) commonly known as sleeping sickness occurs in about 36 countries in sub-Saharan Africa and results in a large number of deaths and considerable illness. The drugs used in the treatment of HAT are very toxic and therefore might not be safe in pregnancy. Few published data exist on the treatment of HAT in pregnancy. We describe a case of T. brucei gambiense infection occurring in a pregnant woman that was successfully treated with Melarsoprol with no toxic effect to mother and the baby after 2 years of follow-up.
文摘Human African Trypanosomiasis (HAT) or sleeping thickness is a forest and rural disease;where agriculture is the main activity. It is a chronic and lethal disease without treatment. HAT is caused by two parasites;Trypanosoma Brucei Gambiense (gTB) and Trypanosoma Brucei Rhodesiense (rTB) transmitted to humans by the tsetse fly. It is endemic condition in Africa between the 15° north latitude and the 20° south latitude. It is reported outside this area in travelers who stayed in endemic zone. Infection by gTB is wider and more frequent (98%) than that by rTB (2%). The Democratic Republic of Congo is the most affected country with more than 75% of reported cases. The geographical distribution is not homogeneous. There are more affected regions in a zone called “foci” which represents areas favorable to the development of the vector. Its diagnosis and treatment are very important because of its social and economic impact at both the individual and community levels. Promising molecules including fexinidazole are currently undergoing testing. Nowadays populations move more and more easily but the discovery of this disease in daily neuroradiological practice is exceptional. We propose in this paper through two observations, reminders on epidemiological, clinical and MRI features of HAT. It typically performs the edematous, bilateral and diffuse encephalitis. It is important to distinguish these aspects from the arsenic-induced encephalitis that may occur during treatment. Only vector control allows eradicating this disease. WHO has set targets elimination of HAT as a public health problem for 2020 deadline.
文摘Human African trypanosomiasis (HAT), commonly known as sleeping sickness is one of the neglected tropical diseases (NTDs), which is fatal if left untreated. Its diagnosis is a challenge since the signs and symptoms of the primary phase are not specific, the existing diagnostic methods have low sensitivity and specificity, and the available drugs have some toxicity. New, robust, and cost-effective techniques are needed for the early identification of parasites. This study aimed to assess the sensitivity and specificity of two different types of polyclonal antibodies against T. b. gambiense using antigen detection ELISA. Polyclonal antibodies against the expressed proteins Tbg I2 and Tbg I17 were produced using New Zealand white rabbits. The antibody titer measured was greater than 32 g/L after the 3<sup>rd</sup> immunization for the expressed protein Tbg I2. For the expressed protein Tbg I17, the antibody titer measured was greater than 32 g/L after the 4<sup>th</sup> immunization. The sensitivity and specificity of the Tbg I2 polyclonal antibody confirmed with Polymerase Chain Reaction (PCR) as gold standard were respectively 89.5% and 80.6%, while for the Tbg I17 polyclonal antibody, the sensitivity and specificity were respectively 92.1% and 88.9%. The area under the curve for the Tbg I2 polyclonal antibody was 0.90 ± 0.032, while for the Tbg I17 polyclonal antibody, the area under the curve was 0.92 ± 0.0. The Tbg I17 polyclonal antibody produced in New Zealand white rabbits has good sensitivity and good specificity;it can be successfully used in the diagnosis of HAT.
文摘Protozoan diseases such as Visceral Leishmaniasis (VL) have re-emerged in Northern Brazil and cases of Chagas Disease also occur. This VL increase leads to early therapy for the public. Confirmatory parasitological diagnoses in VL are performed by bone marrow or spleen aspiration, but ELISA, IFA or immunochromatographic tests for antibody detection are easily performed and can be used in the presence of clinical signs as confirmatory for specific therapy. This approach is successful in providing therapy and prevention of death in VL, but there is a chance of confusion with the emerging disease, Chagas Disease (CD), due to cross-reacting and similar clinical pictures, as in this case. Both VL and CD presented many asymptomatic or oligosymptomatic cases, complicating the picture. Our case report emphasizes these aspects. Positive serology, with an IIF titer of 1/160, and epidemiological correlation, suggests the diagnosis of VL and imposes antimony therapy. Despite the unfavorable evolution and signs of cardiac involvement, the presence of pericarditis and cardiac tamponade confirmed by the echocardiogram suggests CD. We reassessed the profiles of a suggested CD serology, the diagnosis was corrected and treatment with CD specific benznidazole. The good evolution started with benznidazole corroborates the diagnosis of CD and discards the hypothesis of double infection.
文摘A cross-sectional study was carried out aimed to estimate sero-prevalence of camel trypanosomiasis and to investigate the related risk factors of the disease in Four Selected Villages of Galkayo, Mudug region from 14th March 2016 up to 20th April 2016. Blood samples were collected from 69 randomly selected camels of the four study villages, and samples were allowed to clot at room temper to detect the sero-prevalence of trypanosome using Card Agglutination Test for Trypanosomiasis (CATT). The results indicated that the overall sero-prevalence of trypanosomiasis in camels that 15.9% (11) samples were positive for trypanosome evansi (T. evansi) was recorded. Higher infection was found in female (19.4) as compared to male (11.1). However, there is no statistically significant difference in sero-prevalence between sex categories (P > 0.05). High Test infection of sero-prevalence was noted 20% in young age (10), and there was statistically significant difference (P < 0.05) in susceptibility among age groups. These results seem to indicate that T. evansi infection is high in the study area. There is need of further control of camel trypanosomiasis through the uses of curative and prophylactic drugs to avoid the various problems.
文摘The Education for Health at PET Work Program (PET-Health) is focused on education as a pre-supposition. Actions are directed towards to the integration of service-learning and community. Interdisciplinary principle is directed from fusion of work of graduate students, academics and professionals of health services for the benefit of strengthening primary care and health surveillance. This work aimed to carry out educational activities with Community Health Agents (ACS) of the health facilities of PET-health, with the theme of Chagas disease. This descriptive cross-sectional study was carried out from January to May 2013, and the sample consisted of 25 active ACS in six Basic Health Units in the city of Petrolina, Brazil. In spite of actuation of ACS in primary care for over 10 years, a limited knowledge has been developed about this pathology. The health education workshops developed by the PET group clarified the ACS on Chagas disease allowing them to have an expansion of knowledge about the vector, habitat Barber, transmission, clinical manifestations… After the workshop, it was found that the ACS expanded their knowledge about the disease cycle, expanding the possibilities for action in the prevention of this pathology in their respective coverage areas. This work shows an important form of integration between education, service and community that can govern the new direction of health education.
文摘Objective:To investigated the prevalence of human African trypanosomiasis(HAT),a neglected tropical disease caused by Trypanosoma brucei gambiens in an endemic focus of Nigeria,as it relates to age,sex and occupational differences.Methods:A total of 474 human subjects were screened using card agglutination test for trypanosomiasis kit.Positive samples were further investigated for parasite positivity in blood/serum and cerebrospinal fluid(CSF).Results:Of the 474 screened,44(9.3%) were seropositive with seroprevalence of 22(9.6%) in Urhouka,14(9.5%) in Umeghe and 8(7.9%) for Ugonu.The number of seropositives,observed for weakly,moderately and strongly positives for the three communities were 4,7 and 11 in Urhouka,4,5 and 5 in Umeghe and 3,2 and 3 in Ugonu respectively.Among the 16 volunteers with detected parasite in their blood,4 of them were weakly positive,5 of them were moderately positive and 7 of them strongly positive.4 volunteers from Urhouka community were found parasites in their CSF and they were all strongly positive.The difference between the seroprevalence of males and females was not statistically significant(OR=1.14,95%CI=0.37-3.4,P】0.05).The prevalence difference between age group 21-30 years old and the youngest and oldest age groups was statistically significant(OR=3.5,95%CI= 1.08-12.57,P【0.05) but not significant for other age categories (P】0.05),It was observed that farmers had significantly higher prevalence of HAT infection as well as greater risk of Trypanosoma brucei gambiense infection than inhabitants with other occupations (OR=3.25,95%CI=0.99-11.79,P【0.05).Conclusions:Human activities such as farming and visits to the river have been identified as major risk factors to HAT.Also the breakdown of HAT control program has been advanced for the rise in HAT in Abraka,an endemic focus in Nigeria.
文摘Objective:To explore some Fumaria species which were recorded to be traditionally used against malaria and other protozoal diseases.Methods:Consequently,in the current study,antiprotozoal effect of the ethanol extracts obtained from five Fumaria species(Fumaria densiflora,Fumaria cilicica,Fumaria rostellata,Fumaria kralikii,and Fumaria parviflora)was investigated against the parasites;Plasmodium falciparum(malaria)and Trypanosoma bruceirhodesiense(human African trypanosomiasis)at 0.81 and 4.85μg/mL concentrations.Results:Among them,Fumaria densiflora extract exerted the highest antiplasmodial(93.80%)and antitrypanasomal effect(55.40%),while the ethanol extracts of Fumaria kralikii(43.45%)and Fumaria rostellata(41.65%)showed moderate activity against Plasmodium falciparum.Besides,phenolic acid contents of the extracts were analyzed using high performance liquid chromatography(HPLC)and trans-cinnamic(4.32 mg/g)and caffeic(3.71 mg/g)acids were found to be the dominant phenolic acids in Fumaria densiflora.Conclusions:According to our results,Fumaria densiflora deserve further study for its promising antiprotozoal activity.
文摘Parasitic meningoencephalitis presents several etiologies which sometimes depend on their geographical location. They require thorough blood and cerebrospinal fluid check-up for directing an efficient treatment. Clinicians and radiologists are constantly looking for specific signs that could point to a particular etiology. The meningoencephalitis caused by Human African Trypanosomiasis (HAT) due to Trypanosoma brucei gambiense (TG) is a rare disease characterized by a slow progression, over years sometimes. Its non-specific presentation either clinically or in imaging can lead to misdiagnosis and thus, delay the treatment. However, involvement of the optic tracts seems to be characteristic of this condition, on old data from animal experimentation and recent high-field MRI data. MRI is the best current technique to explore the brain, cranial nerves, and visual pathways. In this article, we are going to present two observations of meningoencephalitis caused by HAT and then discuss some specific aspects of this neglected and re-emerging disease.
文摘Human African trypanosomiasis (HAT), or sleeping sickness, caused by Trypanosoma brucei gambiense, is associated with diverse clinical outcomes. Host’s genetic factors involved in immunity are potential factors that can regulate infection. Genetic polymorphisms within HLA-G could influence the level of HLA-G expression and therefore play a critical role in infection outcomes. The goal of our study was to investigate the association of 14 bp Indel HLA-G polymorphism with the susceptibility/resistance to HAT. DNA samples were collected from 119 cases, 221 controls and 43 seropositive individuals living in Ivorian HAT foci. The 14 bp Indel polymorphism was determined by PCR. Homozygous individuals for 14 bp insertion had a lower risk of progressing to active HAT (p = 0.012, OR = 0.27, 95% CI: 0.09 - 0.8). Moreover, the frequency of 14 bp insertion homozygous genotype was higher in the seropositive group (11%) than in the HAT cases group (3%) (p = 0.043, OR = 0.27, 95% CI: 0.07 - 0.99), which suggested a protective effect of 14 bp insertion homozygous genotype. Genetic polymorphisms in HLA-G may be associated with a variable risk to develop HAT. The 14 bp insertion appears to favour the occurrence of long-lasting T. b. gambiense latent infections.
