Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
: Malaria is a public health problem in French Guiana. Plasmodium vivax is the most frequent parasite. The objective of this analysis was to estimate the proportion of relapses in the burden of vivax malaria using the statistical rule stating that any case of vivax malaria occurring less than 90 days following a first episode is a relapse.A total of 622 subjects were followed for 2,9 years with 336 first single episodes of P. vivax malaria, and a total of 1,226 episodes of vivax malaria among which 559 were relapses (45.5%). For 194 patients having had falciparum malaria followed by vivax malaria it was estimated that 19% of the vivax episodes occurred less than 90 days following the falciparum episode and thus were possibly relapses due to the activation of latent hypnozoites. Despite the number of vivax cases and the number of relapses, there were only 28 recorded primaquine prescriptions (3.4% of vivax episodes, 4.5% of subjects).The present study points out that despite the fact that nearly half of the P. vivax cases, many of which in children, are caused by latent hypnozoites, only a minority of them benefit from primaquine radical cure. The obstacles to this are discussed and suggestions are made to reduce the burden of vivax malaria in Camopi and other remote health centres in French Guiana.
ISSN: 1475-2875

inserm-00903890
http://www.hal.inserm.fr/inserm-00903890
http://www.hal.inserm.fr/inserm-00903890/document
http://www.hal.inserm.fr/inserm-00903890/file/1475-2875-12-367.pdf
DOI : 10.1186/1475-2875-12-367

Éditeur(s) : HAL CCSD
Résumé : International audience
Human polycystic echinococcosis is a parasitic infection caused by the larval stage of Echinococcus vogeli which occurs in rural areas of Central and South America. Abdominal echinococcosis caused by E. vogeli is reported for the first time in a child, a 6-year-old boy in French Guiana. The diagnosis was made by histological and molecular techniques. In tropical regions, this neglected disease must be considered even in children.
ISSN: 2046-9047

hal-01484299
https://hal.univ-lorraine.fr/hal-01484299
DOI : 10.1179/2046905515Y.0000000054

Éditeur(s) : HAL CCSD
Résumé : International audience
In French Guiana, located on the northeastern coast of South America, bats of different species are very numerous. The infection of bats and their ticks with zoonotic bacteria, especially Rickettsia species, is so far unknown. In order to improve knowledge of these zoonotic pathogens in this French overseas department, the presence and diversity of tick-borne bacteria was investigated with molecular tools in bat ticks. In the beginning of 2013, 32 bats were caught in Saint-Jean-du-Maroni, an area close to the coast of French Guiana, and the ticks of these animals were collected. A total of 354 larvae of Argasidae soft ticks (Ornithodoros hasei) from 12 bats (Noctilio albiventris) were collected and 107 of them were analysed. DNA was extracted from the samples and quantitative real-time PCR was carried out to detect Rickettsia spp., Bartonella spp., Borrelia spp. and Coxiella burnetii. All tested samples were negative for Bartonella spp., Borrelia spp. and Coxiella burnetii. Rickettsia DNA was detected in 31 (28.9%) ticks. An almost entire (1118 base pairs long) sequence of the gltA gene was obtained after the amplification of some positive samples on conventional PCR and sequencing. A Bayesian tree was constructed using concatenated rrs, gltA, ompA, ompB, and gene D sequences. The study of characteristic sequences shows that this Rickettsia species is very close (98.3-99.8%) genetically to R. peacockii. Nevertheless, the comparative analysis of sequences obtained from gltA, ompA, ompB, rrs and gene D fragments demonstrated that this Rickettsia is different from the other members of the spotted fever group. The sequences of this new species were deposited in GenBank as Candidatus Rickettsia wissemanii. This is the first report showing the presence of nucleic acid of Rickettsia in Ornithodoros hasei ticks from South American bats. (C) 2016 Elsevier GmbH. All rights reserved.
TICKS AND TICK-BORNE DISEASES

hal-01459758
https://hal.archives-ouvertes.fr/hal-01459758
DOI : 10.1016/j.ttbdis.2016.09.004

Éditeur(s) : HAL CCSD
Résumé : International audience
Treatment failure and symptomatic relapse are major concerns in American tegumentary leishmaniasis (ATL). Such complications are seen frequently in L.guyanensis infections where patients respond variously to first-line anti-leishmanials and are more prone to develop chronic cutaneous leishmaniasis. The factors underlying this pathology, however, are unknown. Recently ,: we reported that a dsRNA virus (LRV1) nested within L.guyanensis parasites is able to exacerbate experimental murine leishmaniasis by inducing a hyper-inflammatory response. This report investigates the prevalence of LRV1 in human L.guyanensis infection and its effect on treatment efficacy as well as its correlation to symptomatic relapses after the first-line treatment. In our cohort of 75 patients diagnosed with primary-localised ATL, the prevalence of LRV1+ infection was elevated to 58%. All patients infected with LRV1-negative L.guyanensis were cured after one (22/31 i.e.71%) or two (31/31 i.e.100%) doses of pentamidine. Oppositely, 12 out of the 44 LRV1-positive patients presented with persistent infection and symptomatic relapse required extended therapy and the use of second-line drugs. Finally, LRV1 presence was associated with a significant increase in intra-lesional inflammatory markers. In conclusion, LRV1 status in L.guyanensis infection is significantly predictive (p=0.0009) of first-line treatment failure and symptomatic relapse, and could stand to guide therapeutic choices in ATL
Journal of Infectious Diseases

hal-01175528
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01175528
DOI : 10.1093/infdis/jiv355
PUBMED : 26123564

Éditeur(s) : HAL CCSD Mary Ann Liebert
Résumé : International audience
We screened blood from 59 bats from French Guiana for Bartonella spp. PCRs were positive for 13.6% and culture was positive in one Noctilio albiventris and one Pteronotus parnellii, as well as in Ornithodoros hasei ticks collected from bats. Two isolated strains represent possible two new species.
ISSN: 1530-3667

hal-01455597
https://hal.archives-ouvertes.fr/hal-01455597
DOI : 10.1089/vbz.2015.1918

Éditeur(s) : HAL CCSD American Society of Tropical Medicine and Hygiene
Résumé : International audience
In disease-endemic areas, histoplasmosis is the main differential diagnosis for tuberculosis among human immunodeficiency virus (HIV)-infected patients. However, no study has compared the two diseases. Thus, the objective of this study was to compare tuberculosis and histoplasmosis in HIV-infected patients. A population of 205 HIV-infected patients (99 with tuberculosis and 106 with histoplasmosis) hospitalized in Cayenne, French Guiana during January 1, 1997-December 31, 2008 were selected retrospectively from the French Hospital Database on HIV. Multivariate analysis showed that tuberculosis was associated with cough (adjusted odds ratio [AOR] = 0.20, 95% confidence interval [CI] = 0.05-0.73) and a C-reactive protein level > 70 mg/L (AOR = 0.98, 95% CI = 0.97-0.99). Variables associated with disseminated histoplasmosis were a γ-glutamyl transferase level > 72 IU/L (AOR = 4.99, 95% CI = 1.31-18.99), origin from French Guiana (AOR = 5.20, 95% CI = 1.30-20.73), disseminated localization (AOR = 6.40, 95% CI = 1.44-28.45), a concomitant opportunistic infection (AOR = 6.71, 95% CI = 1.50-29.96), a neutrophil count < 2,750 cells/mm(3) (AOR = 10.54, 95% CI = 2.83-39.24), a CD4 cell count < 60 cells/mm(3) (AOR = 11.62, 95% CI = 2.30-58.63), and a platelet count < 150,000/mm(3) (AOR = 19.20, 95% CI = 3.35-110.14). Tuberculosis and histoplasmosis have similarities, but some factors show a greater association with one of these diseases. Thus, adapted therapeutic choices can be made by using simple clinical and paraclinical criteria.
ISSN: 0002-9637

inserm-01065027
http://www.hal.inserm.fr/inserm-01065027
http://www.hal.inserm.fr/inserm-01065027/document
http://www.hal.inserm.fr/inserm-01065027/file/2014_Adenis_-_Tuberculosis_and_Histoplasmosis_among_HIV.pdf
DOI : 10.4269/ajtmh.13-0084

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
We carried out a soil sampling survey in September 2008 in central Cayenne, French Guiana, using molecular methods to assess the presence of the dimorphic fungus Histoplasma capsulatum. Four of the 31 samples collected (12.9 %) tested positive by PCR, with confirmation of the result by DNA sequencing. H. capsulatum is therefore present in urban environments in French Guiana. These results provide additional support for the primary prophylaxis of AIDS-related histoplasmosis in French Guiana
ISSN: 0301-486X

hal-01349668
https://hal.archives-ouvertes.fr/hal-01349668
https://hal.archives-ouvertes.fr/hal-01349668/file/Article%20Histo%20Cayenne%20R2.pdf
DOI : 10.1007/s11046-012-9550-y

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
: In South America, disseminated histoplasmosis due to Histoplasma capsulatum var. capsulatum (H. capsulatum), is a severe and frequent opportunistic infection in AIDS patients. In areas outside the USA where specific-Histoplasma antigen detection is not available, the diagnosis is difficult. With the galactomannan antigen (GM) detection, a test commonly used for invasive aspergillosis diagnosis, there is a cross-reactivity with H. capsulatum that can be helpful for the diagnosis of histoplasmosis. The aim of this study was to evaluate the GM detection for the diagnosis of disseminated histoplasmosis in AIDS patients. The performance of the GM detection was evaluated with serum collected in French Guiana where H. capsulatum is highly endemic. Sera from AIDS patients with disseminated histoplasmosis occurring from 2002 to 2009 and from control HIV-positive patients without histoplasmosis were tested with the GM detection and Histoplasma-specific antibody detection (IEP). In 39 AIDS patients with proven disseminated histoplasmosis, the sensitivity of the Histoplasma IEP was only 35.9% and was linked to the TCD4+ lymphocyte level. For the GM detection, the sensitivity (Se) was 76.9% and specificity (Sp) was 100% with the recommended threshold for aspergillosis diagnosis (0.5). The test was more efficient with a threshold of 0.4 (Se: 0.82 [95% CI: 0.66-0.92], Sp: 1.00 [95% CI: 0.86-1.00], LR+: >10, LR-: 0.18). This study confirms that the GM detection can be a surrogate marker for the diagnosis of disseminated histoplasmosis in AIDS patients in endemic areas where Histoplasma EIA is not available.
ISSN: 1438-4221

inserm-01065096
http://www.hal.inserm.fr/inserm-01065096
http://www.hal.inserm.fr/inserm-01065096/document
http://www.hal.inserm.fr/inserm-01065096/file/2014_Iriart_-_Complementary_tool_for_managementsur histo_infections_in_AID.pdf
DOI : 10.1016/j.ijmm.2014.07.016

Éditeur(s) : HAL CCSD
Résumé : International audience
Some of the immunologic mechanisms involved in malaria physiopathology remain unclear. In animals, the spleen seems to play a key role in protecting the host against malaria. However, little is known about the effect of spleen dysfunction on human malaria. We report two severe cases of Plasmodium falciparum infection with unusual clinical and parasitologic features in two splenectomized men living in French Guiana. The peripheral blood of these cases showed hyperparasitemia, with a high proportion of mature parasites and leukocytes with malaria pigment. Despite appropriate treatment and adequate absorption, hyperparasitemia persisted. Parasite clearance was delayed and one patient died. Only the patient who died had the merozoite surface protein 1 allele B-K1 and the varD gene genotype, which is considered to be a probable parasite virulence factor. These uncommon cases differ from most of those described in the literature, illustrating the complexity of the mechanisms underlying the protective function of the spleen in human malaria.
The American journal of tropical medicine and hygiene

pasteur-00590993
https://hal-riip.archives-ouvertes.fr/pasteur-00590993
PUBMED : 15381808