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1.
Infect Dis Poverty ; 11(1): 29, 2022 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-35287726

RESUMO

BACKGROUND: While malaria morbidity and mortality have declined since 2000, viral central nervous system infections appear to be an important, underestimated cause of coma in malaria-endemic Eastern Africa. We aimed to describe the etiology of non-traumatic comas in young children in Benin, as well as their management and early outcomes, and to identify factors associated with death. METHODS: From March to November 2018, we enrolled all HIV-negative children aged between 2 and 6 years, with a Blantyre Coma Score ≤ 2, in this prospective observational study. Children were screened for malaria severity signs and assessed using a systematic diagnostic protocol, including blood cultures, malaria diagnostics, and cerebrospinal fluid analysis using multiplex PCR. To determine factors associated with death, univariate and multivariate analyses were performed. RESULTS: From 3244 admissions, 84 children were included: malaria was diagnosed in 78, eight of whom had a viral or bacterial co-infection. Six children had a non-malarial infection or no identified cause. The mortality rate was 29.8% (25/84), with 20 children dying in the first 24 h. Co-infected children appeared to have a poorer prognosis. Of the 76 children who consulted a healthcare professional before admission, only 5 were prescribed adequate antimalarial oral therapy. Predictors of early death were jaundice or increased bilirubin [odd ratio (OR)= 8.6; 95% confidential interval (CI): 2.03-36.1] and lactate > 5 mmol/L (OR = 5.1; 95% CI: 1.49-17.30). Antibiotic use before admission (OR = 0.1; 95% CI: 0.02-0.85) and vaccination against yellow fever (OR = 0.2, 95% CI: 0.05-0.79) protected against mortality. CONCLUSIONS: Infections were found in all children who died, and cerebral malaria was by far the most common cause of non-traumatic coma. Missed opportunities to receive early effective antimalarial treatment were common. Other central nervous system infections must be considered in their management. Some factors that proved to be protective against early death were unexpected.


Assuntos
Infecções Bacterianas , Malária Cerebral , Benin/epidemiologia , Criança , Pré-Escolar , Humanos , Malária Cerebral/complicações , Malária Cerebral/epidemiologia , Razão de Chances , Estudos Prospectivos
3.
PLoS Negl Trop Dis ; 15(6): e0009430, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34143783

RESUMO

BACKGROUND: The term Nodding Syndrome (NS) refers to an atypical and severe form of childhood epilepsy characterized by a repetitive head nodding (HN). The disease has been for a long time limited to East Africa, and the cause is still unknown. The objective of this study was to confirm the existence of NS cases in Central African Republic (CAR). METHODOLOGY/PRINCIPAL FINDINGS: This was a cross-sectional descriptive study in the general population. The identification of NS cases was conducted through a door-to-door survey in a village near Bangui along the Ubangui River. Based on Winkler's 2008 and the World Health Organization (WHO)'s 2012 classifications, the confirmation of cases was done by a neurologist who also performed the electroencephalograms. No laboratory tests were done during this investigation. Treatment was offered to all patients. A total of 6,175 individuals was surveyed in 799 households. After reviewing the cases, we identified 5 NS cases in girls aged between 8 and 16. The age of onset of the seizures was between 5 and 12 years of age. Two cases were classified as "HN plus" according to Winkler's 2008 classification. Four NS cases were classified as probable and one as confirmed according to the WHO's 2012 classification. Three of them presented with developmental delay and cognitive decline, and one had an abnormally low height-for-age z-score. Electroencephalographic abnormalities were found in four patients. CONCLUSIONS/SIGNIFICANCE: Nodding Syndrome cases were described in CAR for the first time. Despite certain peculiarities, these cases are similar to those described elsewhere. Given that only a small part of the affected area was investigated, the study area along the Ubangui River needs to be expanded in order to investigate the association between Onchocerca volvulus and NS and also evaluate the real burden of NS in CAR.


Assuntos
Síndrome do Cabeceio/diagnóstico , Síndrome do Cabeceio/epidemiologia , Adolescente , República Centro-Africana/epidemiologia , Criança , Estudos Transversais , Feminino , Humanos , Fatores Socioeconômicos
4.
J Neurol Sci ; 421: 117314, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33493958

RESUMO

BACKGROUND: Onchocerciasis is a serious problem in tropical areas. The role of the parasite as a factor associated with neurological diseases needs to be addressed because it might involve a reduction of the risk via elimination strategies. We performed a systematic scoping review to identify available studies on this association and put into perspective the different methodological approaches for interpreting the evidence. METHODOLOGY: A literature search was conducted using MEDLINE (Pubmed) through October 1, 2020. We included all the studies evaluating the association between onchocerciasis and four neurological diseases (epilepsy, nodding syndrome, Nakalanga syndrome, and encephalitis) in tropical countries. A descriptive and critical summary of the results was conducted to provide an overview of the findings. RESULTS: Overall, 161 articles were identified in the literature search. After full-length examination, we included twelve articles for epilepsy and three for nodding syndrome. Two meta-analyses of case-control studies found a modest strength of the association between O. volvulus and epilepsy. Recent meta-analyses and original studies support a significant association. Epidemiological studies suggest an association between onchocerciasis and nodding syndrome, however, the level of evidence from case-control studies was relatively low. No measure of association was reported for Nakalanga syndrome. There was no specific study on the association between O. volvulus and encephalitis. CONCLUSION: The association between onchocerciasis and epilepsy seems increasingly likely. However, there are still many unanswered questions about the different clinical presentations of this epilepsy. Strong international collaboration is essential to improve our understanding of risk factors and physiopathological mechanisms of these intriguing conditions.


Assuntos
Epilepsia , Neurologia , Síndrome do Cabeceio , Oncocercose , Estudos de Casos e Controles , Epilepsia/epidemiologia , Humanos , Oncocercose/complicações , Oncocercose/epidemiologia
5.
Clin Infect Dis ; 72(9): 1557-1565, 2021 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-32412062

RESUMO

BACKGROUND: During 2017, in response to a physician's report, the Wisconsin Department of Health Services, Division of Public Health, began investigating an outbreak of febrile illness among attendees of a retreat where never frozen, intentionally undercooked, locally harvested venison was served. Preliminary testing tentatively identified the illness as toxoplasmosis. METHODS: Confirmatory human serology panels and testing of the venison to confirm and categorize the presence and type of Toxoplasma gondii were completed by French and American national reference laboratories. All 12 retreat attendees were interviewed; medical records were reviewed. RESULTS: All attendees were male; median age was 51 years (range: 22-75). After a median incubation period of 7 days, 9 (82%) of 11 exposed persons experienced illness lasting a median of 12 days. All 9 sought outpatient healthcare for symptoms including fever, chills, sweats, and headache (100%) and ocular disturbances (33%). Testing confirmed the illness as toxoplasmosis and venison as the infection source. Multiple laboratory results were atypical for toxoplasmosis, including transaminitis (86%), lymphocytopenia (88%), thrombocytopenia (38%), and leukopenia (63%). One exposed but asymptomatic person was seronegative; the other had immunity from prior infection. The T. gondii strain was identified as closely related to an atypical genotype (haplogroup 12, polymerase chain reaction restriction fragment length polymorphism genotype 5) common in North American wildlife but with previously uncharacterized human clinical manifestations. CONCLUSIONS: The T. gondii strain contaminating the venison might explain the unusual clinical presentations. In North America, clinicians and venison consumers should be aware of risk for severe or unusual presentations of acute toxoplasmosis after consuming undercooked game meat.


Assuntos
Toxoplasma , Toxoplasmose Animal , Animais , Surtos de Doenças , Feminino , Genótipo , Humanos , Incidência , Masculino , Carne , Pessoa de Meia-Idade , América do Norte , Polimorfismo de Fragmento de Restrição , Toxoplasma/genética , Toxoplasmose Animal/epidemiologia , Wisconsin
6.
Pathogens ; 9(5)2020 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-32365847

RESUMO

Recently, there were anecdotal reports of a high number of persons with epilepsy, including children with nodding seizures in the Landja Mboko area located about 9 km from the capital city Bangui, Central African Republic. We suspected the area to be endemic for onchocerciasis, and that the alleged increase in the number of epilepsy cases was due to ongoing Onchocerca volvulus transmission. However, ivermectin mass drug distribution (MDA) had never been implemented in the area. Therefore we performed an Ov16 antibody prevalence study among children, aged 6-9 years, using the biplex rapid diagnostic test (SD Bioline Oncho/LF biplex IgG4 RDT). The overall Ov16 seroprevalence was 8.9%, and that of lymphatic filariasis (LF) was 1.9%. Ov16 seropositivity was highest in Kodjo (20.0%), a village close to rapids on the river. Our study shows that there is ongoing O. volvulus transmission in the Landja Mboko area. We recommend that the extent of this onchocerciasis focus should be mapped, and the introduction of ivermectin MDA should be considered in these communities.

7.
PLoS Negl Trop Dis ; 13(7): e0007435, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31295245

RESUMO

Toxoplasma gondii is a zoonotic protozoan with a worldwide occurrence, but the determinants of the current pattern in the geographical distribution of T. gondii lineages and strains remain poorly understood. To test the influence of human trade on T. gondii populations, we conducted a population genetic study of 72 T. gondii animal isolates from Senegal, a West African country in which the ongoing inland progress of invasive murine hosts (introduced in port cities of Senegal since the 16th century by European sailors) is well described. Isolates were mainly collected on free-range poultry, which are considered as relevant bioindicators of T. gondii strain diversity in the domestic environment. Sampling was conducted in two port cities of Senegal (Dakar and Saint-Louis) and in one inland region (Kedougou). Population genetic analyses using 15 microsatellite markers revealed different patterns between port cities where lineages non-virulent for mice (type II, type III, and Africa 4) were predominant, and Kedougou where the mouse-virulent Africa 1 lineage was the most common. By considering the current spatial pattern in the inland progress of invasive rodents in Senegal, our results suggest that the invasive house mouse Mus musculus domesticus counter-selects the Africa 1 lineage in the invaded areas. The comparison of the microsatellite alleles of type II strains from Senegal to type II strains from other areas in Africa and Western Europe, using discriminant analysis of principal components and Network analysis, point to a mainly Western European origin of the type II lineage in Senegal. Collectively, these findings suggest that human-mediated intercontinental migrations of murine hosts are important vectors of T. gondii strains. Differential susceptibility of endemic and introduced murine hosts to various T. gondii strains probably determines the persistence of these strains in the environment, and therefore their availability for human and animal infection.


Assuntos
Comércio , Variação Genética , Doenças das Aves Domésticas/transmissão , Toxoplasma/genética , Toxoplasmose Animal/epidemiologia , Toxoplasmose Animal/transmissão , África Ocidental/epidemiologia , Alelos , Animais , Galinhas/parasitologia , Reservatórios de Doenças/parasitologia , Europa (Continente)/epidemiologia , Genética Populacional , Genótipo , Geografia , Humanos , Camundongos/parasitologia , Repetições de Microssatélites , Filogenia , Filogeografia , Polimorfismo de Fragmento de Restrição , Doenças das Aves Domésticas/parasitologia , Virulência
8.
BMJ Open ; 9(5): e027378, 2019 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-31142528

RESUMO

INTRODUCTION: In 2016, an estimated 216 million cases and 445 000 deaths of malaria occurred worldwide, in 91 countries. In Benin, malaria causes 26.8% of consultation and hospitalisation motif in the general population and 20.9% in children under 5 years old.The goal of the NeuroCM project is to identify the causative factors of neuroinflammation in the context of cerebral malaria. There are currently very few systematic data from West Africa on the aetiologies and management of non-malarial non-traumatic coma in small children, and NeuroCM will help to fill this gap. We postulate that an accurate understanding of molecular and cellular mechanisms involved in neuroinflammation may help to define efficient strategies to prevent and manage cerebral malaria. METHODS AND ANALYSIS: This is a prospective, case-control study comparing cerebral malaria to uncomplicated malaria and non-malarial non-traumatic coma. This study takes place in Benin, precisely in Cotonou for children with coma and in Sô-Ava district for children with uncomplicated malaria. We aim to include 300 children aged between 24 and 71 months and divided in three different clinical groups during 12 months (from December 2017 to November 2018) with a 21 to 28 days follow-up for coma. Study data, including clinical, biological and research results will be collected and managed using CSOnline-Ennov Clinical. ETHICS AND DISSEMINATION: Ethics approval for the NeuroCM study has been obtained from Comité National d'Ethique pour la Recherche en santé of Benin (n°67/MS/DC/SGM/DRFMT/CNERS/SA; 10/17/2017). NeuroCM study has also been approved by Comité consultatif de déontologie et d'éthique of Institut de Recherche pour le Développement (IRD; 10/24/2017). The study results will be disseminated through the direct consultations with the WHO's Multilateral Initiative on Malaria (TDR-MIM) and Roll Back Malaria programme, through scientific meetings and peer-reviewed publications in scientific or medical journals, and through guidelines and booklets.


Assuntos
Malária Cerebral/patologia , Malária Falciparum/patologia , Plasmodium falciparum/isolamento & purificação , Plasmodium falciparum/patogenicidade , Projetos de Pesquisa , Benin , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Estudos Prospectivos
9.
Int J Parasitol ; 49(3-4): 267-275, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30578812

RESUMO

Commensal rodent species are key reservoirs for Toxoplasma gondii in the domestic environment. In rodents, different T. gondii strains show variable patterns of virulence according to host species. Toxoplasma gondii strains causing non-lethal chronic infections in local hosts will be more likely to persist in a given environment, but few studies have addressed the possible role of these interactions in shaping the T. gondii population structure. In addition, the absence of validated techniques for upstream detection of T. gondii chronic infection in wild rodents hinders exploration of this issue under natural conditions. In this study, we took advantage of an extensive survey of commensal small mammals in three coastal localities of Senegal, with a species assemblage constituted of both native African species and invasive species. We tested 828 individuals for T. gondii chronic infection using the modified agglutination test for antibody detection in serum samples and a quantitative PCR assay for detection of T. gondii DNA in brain samples. The infecting T. gondii strains were genotyped whenever possible by the analysis of 15 microsatellite markers. We found (i) a very poor concordance between molecular detection and serology in the invasive house mouse, (ii) significantly different levels of prevalence by species and (iii) the autochthonous T. gondii Africa 1 lineage strains, which are lethal for laboratory mice, only in the native African species of commensal small mammals. Overall, this study highlights the need to reconsider the use of MAT serology in natural populations of house mice and provides the first known data about T. gondii genetic diversity in invasive and native species of small mammals from Africa. In light of these results, we discuss the role of invasive and native species, with their variable adaptations to different T. gondii strains, in shaping the spatial structure of T. gondii genetic diversity in Africa.


Assuntos
Biota , Variação Genética , Genótipo , Doenças dos Roedores/parasitologia , Toxoplasma/classificação , Toxoplasma/isolamento & purificação , Toxoplasmose Animal/parasitologia , Animais , Técnicas de Genotipagem , Repetições de Microssatélites , Prevalência , Roedores , Senegal , Toxoplasma/genética , Toxoplasmose Animal/epidemiologia
10.
J Infect Dis ; 218(11): 1783-1791, 2018 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-29982713

RESUMO

Background: Whereas in Europe most of Toxoplasma gondii genotypes belong to the type II lineage, in Latin America, type II is rare and atypical strains predominate. In North America, data on T. gondii genotypes in humans are scarce. Methods: In this study, T. gondii DNA samples from 67 patients with diagnosed toxoplasmosis in the United States were available for genotyping. Discriminant analysis of principal components was used to infer each atypical genotype to a geographic area where patients were probably infected. Associations between genotype, disease severity, immune status, and geographic region were also estimated. Results: Of 67 DNA samples, 41 were successfully genotyped: 18 (43.9%) and 5 (12.2%) were characterized as types II and III, respectively. The remaining 18 genotypes (43.9%) were atypical and were assigned to a geographic area. Ten genotypes originated from Latin America, 7 from North America, and 1 from Asia (China). In North America, unlike in Europe, T. gondii atypical genotypes are common in humans and, unlike in Latin America, type II strains are still present with significant frequency. Conclusions: Clinicians should be aware that atypical genotypes are common in North America and have been associated with severe ocular and systemic disease and unusual presentations of toxoplasmosis in immunocompetent patients.


Assuntos
Toxoplasma/genética , Toxoplasmose/epidemiologia , Toxoplasmose/parasitologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Análise por Conglomerados , Estudos de Coortes , DNA de Protozoário/análise , DNA de Protozoário/genética , Genótipo , Técnicas de Genotipagem , Humanos , Pessoa de Meia-Idade , Prevalência , Estados Unidos/epidemiologia , Adulto Jovem
11.
Proc Natl Acad Sci U S A ; 115(29): E6956-E6963, 2018 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-29967142

RESUMO

A majority of emerging infectious diseases in humans are zoonoses. Understanding factors that influence the emergence and transmission of zoonoses is pivotal for their prevention and control. Toxoplasma gondii is one of the most widespread zoonotic pathogens known today. Whereas only a few genotypes of T. gondii dominate in the Northern Hemisphere, many genotypes coexist in South America. Furthermore, T. gondii strains from South America are more likely to be virulent than those from the Northern Hemisphere. However, it is not clear what factor(s) shaped modern-day genetic diversity and virulence of T. gondii Here, our analysis suggests that the rise and expansion of farming in the past 11,000 years established the domestic cat/mouse transmission cycle for T. gondii, which has undoubtedly played a significant role in the selection of certain linages of T. gondii Our mathematical simulations showed that within the domestic transmission cycle, intermediately mouse-virulent T. gondii genotypes have an adaptive advantage and eventually become dominant due to a balance between lower host mortality and the ability to superinfect mice previously infected with a less virulent T. gondii strain. Our analysis of the global type II lineage of T. gondii suggests its Old World origin but recent expansion in North America, which is likely the consequence of global human migration and trading. These results have significant implications concerning transmission and evolution of zoonotic pathogens in the rapidly expanding anthropized environment demanded by rapid growth of the human population and intensive international trading at present and in the future.


Assuntos
Toxoplasma/genética , Toxoplasma/patogenicidade , Toxoplasmose/genética , Toxoplasmose/transmissão , Zoonoses/genética , Zoonoses/transmissão , Animais , Gatos , Migração Humana , Humanos , Camundongos , América do Sul , Toxoplasmose/mortalidade , Zoonoses/mortalidade
12.
Trends Parasitol ; 34(2): 140-154, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29174610

RESUMO

Exploring the genetic diversity of Toxoplasma gondii is essential for an understanding of its worldwide distribution and the determinants of its evolution. Africa remains one of the least studied areas of the world regarding T. gondii genetic diversity. This review has compiled published data on T. gondii strains from Africa to generate a comprehensive map of their continent-wide geographical distribution. The emerging picture about T. gondii strain distribution in Africa suggests a geographical separation of the parasite populations across the continent. We discuss the potential role of a number of factors in shaping this structure. We finally suggest the next steps towards a better understanding of Toxoplasma epidemiology in Africa in light of the strains circulating on this continent.


Assuntos
Variação Genética , Toxoplasma/genética , África/epidemiologia , Animais , Demografia , Toxoplasma/classificação , Toxoplasmose/epidemiologia , Toxoplasmose/parasitologia
13.
Rev Bras Parasitol Vet ; 26(2): 152-158, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28746445

RESUMO

Trypanosoma comprises flagellates able to infect several mammalian species and is transmitted by several groups of invertebrates. The order Chiroptera can be infected by the subgenera Herpetosoma, Schizotrypanum, Megatrypanum and Trypanozoon. In this study, we described the diversity of bat trypanosomes and inferred phylogenetic relationships among the trypanosomes from bats caught in Tapajós-Arapiuns Extractive Reserve (Resex) in Pará state. Trypanosomes from bats were isolated by means of hemoculture, and the molecular phylogeny was based on the trypanosome barcode (SSUrDNA V7V8 variable region). A total of 111 bats were caught in the area, belonging to three families (Emballonuridae, Molossidae and Phyllostomidae) and 12 species. The bat trypanosome prevalence, as evaluated through hemoculture, was 9% all positive cultures were cryopreserve (100% of isolation success). Phylogenetic trees grouped nine isolates in T. cruzi marinkellei branch and only one in T. dionisii branch. Studies on bat trypanosome diversity are important for identifying pathogenic species and for generating support for control measures, especially in such areas where humans inhabit the forest with close contact with bat species. In addition, this is the first study in Resex Tapajós-Arapiuns extractive reserve and further studies should be conducted to elucidate the role of these parasites as environmental degradation biomarkers.


Assuntos
Quirópteros/parasitologia , Trypanosoma/isolamento & purificação , Animais , Brasil , DNA de Protozoário/análise , Filogenia , Análise de Sequência de DNA , Trypanosoma/classificação
14.
Rev. bras. parasitol. vet ; 26(2): 152-158, Apr.-June 2017. tab, graf
Artigo em Inglês | LILACS | ID: biblio-899276

RESUMO

Abstract Trypanosoma comprises flagellates able to infect several mammalian species and is transmitted by several groups of invertebrates. The order Chiroptera can be infected by the subgenera Herpetosoma, Schizotrypanum, Megatrypanum and Trypanozoon. In this study, we described the diversity of bat trypanosomes and inferred phylogenetic relationships among the trypanosomes from bats caught in Tapajós-Arapiuns Extractive Reserve (Resex) in Pará state. Trypanosomes from bats were isolated by means of hemoculture, and the molecular phylogeny was based on the trypanosome barcode (SSUrDNA V7V8 variable region). A total of 111 bats were caught in the area, belonging to three families (Emballonuridae, Molossidae and Phyllostomidae) and 12 species. The bat trypanosome prevalence, as evaluated through hemoculture, was 9% all positive cultures were cryopreserve (100% of isolation success). Phylogenetic trees grouped nine isolates in T. cruzi marinkellei branch and only one in T. dionisii branch. Studies on bat trypanosome diversity are important for identifying pathogenic species and for generating support for control measures, especially in such areas where humans inhabit the forest with close contact with bat species. In addition, this is the first study in Resex Tapajós-Arapiuns extractive reserve and further studies should be conducted to elucidate the role of these parasites as environmental degradation biomarkers.


Resumo Trypanosoma compreende flagelados capazes de infectar diversas espécies de mamíferos e são transmitidos por diferentes grupos de invertebrados. A ordem Chiroptera pode ser parasitada pelos subgêneros Herpetosoma, Schizotrypanum, Megatrypanum e Trypanozoon. Neste estudo é descrita a diversidade de tripanossomas de morcegos capturados na Reserva Extrativista Tapajós-Arapiuns, no Estado do Pará. Os tripanossomas de morcegos foram isolados através de hemocultura e os estudos filogenéticos baseados na região de barcode de tripanossomas (SSUrDNA V7V8 região variável). Foram capturados 111 morcegos pertencentes a três famílias (Emballonuridae, Molossidae e Phyllostomidae) e 12 espécies. A prevalência dos tripanossomas de morcegos, avaliada por hemocultura, foi de 9% para as culturas positivas e todas foram criopreservadas (100% de eficiência no isolamento). As árvores filogenéticas agruparam nove isolados no ramo de T. cruzi marinkellei e um único isolado de T. dionisii. Estudos sobre a diversidade de tripanossomas de morcegos são importantes para identificar espécies patogênicas e gerar suporte para medidas de controle, principalmente em áreas silvestres com contato entre as populações humanas e de morcegos. Além disso, este foi o primeiro estudo realizado na Resex Tapajós-Arapiuns e novos estudos devem ser conduzidos para elucidar o papel destes parasitas como marcadores de degradação ambiental.


Assuntos
Animais , Trypanosoma/isolamento & purificação , Quirópteros/parasitologia , Filogenia , Trypanosoma/classificação , Brasil , DNA de Protozoário/análise , Análise de Sequência de DNA
15.
Parasit Vectors ; 10(1): 220, 2017 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-28468666

RESUMO

BACKGROUND: In Brazil, studies on animals and humans in mainland areas have shown that most strains of Toxoplasma gondii are pathogenic to mice and exhibit great genetic variability. RESULTS: In this study, using a set of 11 PCR-RFLP and 15 microsatellite markers, we isolated and genetically characterised T. gondii strains from one cat and three rats on Fernando de Noronha Island. The cat had antibodies to T. gondii, which were revealed using a modified agglutination test (MAT, cut-off 1:25) and the seroprevalence among the 46 rodents was 15.2%. Viable T. gondii was isolated from one cat (TgCatBrFN1), two brown rats (TgRatnoBrFN1 and TgRatnoBrFN2) and one black rat (TgRatraBrFN1). Unlike the strains from mainland Brazil, these isolates were not pathogenic to outbred mice. The genotypes of these strains were compared with strains previously isolated on the island and in mainland Brazil. The analysis based on microsatellite data showed a limited genetic diversity of T. gondii on Fernando de Noronha Island with the majority of strains clustered into the following three groups: type II, III, and Caribbean 1. CONCLUSIONS: There was little variation among strains within the same group, suggesting that the majority of strains circulating on Fernando de Noronha are derived from only a few strains that were recently introduced to the island, likely from imported cats. Except for the strain belonging to the Caribbean 1 group that originates from northeast Brazil, there was little evidence that strains from the other groups were introduced to Fernando de Noronha via mainland Brazil.


Assuntos
Doenças do Gato/parasitologia , Variação Genética , Doenças dos Roedores/parasitologia , Toxoplasma/genética , Toxoplasma/isolamento & purificação , Toxoplasmose Animal/parasitologia , Testes de Aglutinação , Animais , Animais Selvagens , Anticorpos Antiprotozoários/sangue , Brasil/epidemiologia , Gatos/parasitologia , Genótipo , Humanos , Ilhas , Camundongos , Repetições de Microssatélites , Reação em Cadeia da Polimerase/veterinária , Polimorfismo de Fragmento de Restrição , Ratos , Roedores/parasitologia , Estudos Soroepidemiológicos , Toxoplasma/imunologia , Toxoplasma/patogenicidade , Toxoplasmose Animal/epidemiologia , Toxoplasmose Animal/imunologia , Toxoplasmose Animal/transmissão
17.
Infect Genet Evol ; 48: 150-155, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28028000

RESUMO

Toxoplasma gondii, a protozoan found ubiquitously in mammals and birds, is the etiologic agent of toxoplasmosis, a disease causing substantial public health burden worldwide, including about 200,000 new cases of congenital toxoplasmosis each year. Clinical severity has been shown to vary across geographical regions, with South America exhibiting the highest burden. Unfortunately, the drivers of these heterogeneities are still poorly understood, and the geographical origin and historical spread of the pathogen worldwide are currently uncertain. A worldwide sample of 168 T. gondii isolates gathered in 13 populations was sequenced for five fragments of genes (140 single nucleotide polymorphisms from 3153bp per isolate). Phylogeny based on Maximum likelihood methods with estimation of the time to the most recent common ancestor (TMRCA) and geostatistical analyses were performed for inferring the putative origin of T. gondii. We show that extant strains of the pathogen likely evolved from a South American ancestor, around 1.5 million years ago, and reconstruct the subsequent spread of the pathogen worldwide. This emergence is much more recent than the appearance of ancestral T. gondii, believed to have taken place about 11 My ago, and follows the arrival of felids in this part of the world. We posit that an ancestral lineage of T. gondii likely arrived in South America with felids and that the evolution of oral infectivity through carnivorism and the radiation of felids in this region enabled a new strain to outcompete the ancestral lineage and undergo a pandemic radiation.


Assuntos
Doenças do Gato/parasitologia , Toxoplasma/genética , Toxoplasmose Animal/parasitologia , Animais , Doenças do Gato/epidemiologia , Gatos , Evolução Molecular , Genes de Protozoários , Especiação Genética , Variação Genética , Humanos , Filogenia , Filogeografia , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA , América do Sul/epidemiologia , Toxoplasmose/epidemiologia , Toxoplasmose/parasitologia , Toxoplasmose Animal/epidemiologia
18.
PLoS Negl Trop Dis ; 10(6): e0004790, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27355620

RESUMO

BACKGROUND: Toxoplasmic encephalitis in patients with AIDS is a life-threatening disease mostly due to reactivation of Toxoplasma gondii cysts in the brain. The main objective of this study was to evaluate the performance of real-time PCR assay in peripheral blood samples for the diagnosis of toxoplasmic encephalitis in AIDS patients in the French West Indies and Guiana. METHODOLOGY/PRINCIPAL FINDINGS: Adult patients with HIV and suspicion of toxoplasmic encephalitis with start of specific antitoxoplasmic therapy were included in this study during 40 months. The real-time PCR assay targeting the 529 bp repeat region of T. gondii was performed in two different centers for all blood samples. A Neighbor-Joining tree was reconstructed from microsatellite data to examine the relationships between strains from human cases of toxoplasmosis in South America and the Caribbean. A total of 44 cases were validated by a committee of experts, including 36 cases with toxoplasmic encephalitis. The specificity of the PCR assay in blood samples was 100% but the sensitivity was only 25% with moderate agreement between the two centers. Altered level of consciousness and being born in the French West Indies and Guiana were the only two variables that were associated with significantly decreased risk of false negative results with the PCR assay. CONCLUSION/SIGNIFICANCE: Our results showed that PCR sensitivity in blood samples increased with severity of toxoplasmic encephalitis in AIDS patients. Geographic origin of patients was likely to influence PCR sensitivity but there was little evidence that it was caused by differences in T. gondii strains. TRIAL REGISTRATION: ClinicalTrials.gov NCT00803621.


Assuntos
Síndrome da Imunodeficiência Adquirida/complicações , Variação Genética , Reação em Cadeia da Polimerase/métodos , Toxoplasma/genética , Toxoplasmose Cerebral/complicações , Toxoplasmose Cerebral/diagnóstico , Síndrome da Imunodeficiência Adquirida/sangue , Síndrome da Imunodeficiência Adquirida/epidemiologia , Adulto , Análise por Conglomerados , Feminino , Guiana Francesa/epidemiologia , Genótipo , Humanos , Masculino , Repetições de Microssatélites , Pessoa de Meia-Idade , Estudos Prospectivos , Sensibilidade e Especificidade , Toxoplasma/classificação , Toxoplasmose Cerebral/sangue , Toxoplasmose Cerebral/epidemiologia
19.
Vet Parasitol ; 223: 88-90, 2016 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-27198782

RESUMO

Generally, rodents and other small mammals are considered as one of the sources of Toxoplasma gondii or Neospora caninum infection for cats and dogs as the definitive hosts of these two parasites, respectively. The aim of the study was to find out the prevalence of these two parasites in wild small mammals from the Czech Republic and to characterize T. gondii isolates by methods of molecular biology. A total of 621 wild small mammals were caught in the Czech Republic during years 2002-2014. Antibodies to T. gondii were detected by latex agglutination test in six (2.5%) of 240 small mammals (in two A. agrarius and four A. flavicollis). Antibodies to N. caninum were detected by commercially available competitive-inhibition enzyme-linked immunosorbent assay in one A. flavicolis (0.4%). Three of 427 (0.7%) liver samples were positive for T. gondii by PCR while negative for N. caninum. All embryo samples (n=102) were negative for both T. gondii and N. caninum. The three liver samples positive for T. gondii DNA (two from A. flavicollis and one from A. sylvaticus) were genotyped by 15 microsatellite markers and characterized as type II. To our knowledge, this is the first information about genetic characterization of T. gondii isolates in small mammals from Europe and the first detection of N. caninum antibodies in wild rodents from the Czech Republic.


Assuntos
Coccidiose/veterinária , Neospora/isolamento & purificação , Roedores , Musaranhos , Toxoplasma/isolamento & purificação , Toxoplasmose Animal/parasitologia , Animais , Animais Selvagens , Coccidiose/epidemiologia , Coccidiose/parasitologia , República Tcheca/epidemiologia , DNA de Protozoário/isolamento & purificação , Genótipo , Repetições de Microssatélites , Neospora/genética , Estudos Soroepidemiológicos , Toxoplasma/genética , Toxoplasmose Animal/epidemiologia
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