RESUMO
Recent studies have highlighted the interest in noninvasive sampling procedures coupled with real-time PCR methods for the detection of Leishmania species in South America. In French Guiana, the sampling method still relied on skin biopsies. Noninvasive protocols should be tested on a large annual cohort to improve routine laboratory diagnosis of cutaneous leishmaniasis. Therefore, we evaluated the performance of a new Leishmania detection and species identification protocol involving cotton swabs and SYBR green-based real-time PCR of the Hsp70 gene, coupled with Sanger sequencing. Between May 2017 and May 2018, 145 patients with ulcerated lesions compatible with cutaneous leishmaniasis were included in the study at the Cayenne Hospital and its remote health centers. Each patient underwent scrapings for a smear, skin biopsies for parasite culture and PCR-restriction fragment length polymorphism (RFLP) (RNA polymerase II), and sampling with a cotton swab for SYBR green-based PCR. The most accurate diagnostic test was the SYBR green-based PCR on swab samples, showing 98% sensitivity. The mean PCR cycle threshold (CT ) was 24.4 (minimum CT , 17; maximum CT , 36) and was <35 in 97.6% of samples. All samples positive by SYBR green-based real-time PCR were successfully identified at the species level by DNA sequencing. This new method should be considered for routine diagnosis of cutaneous leishmaniasis in South America and especially for remote areas, since noninvasive collection tools are easier to use and require fewer precautions for transportation.
Assuntos
Leishmaniose Cutânea , DNA de Protozoário/genética , Guiana Francesa , Humanos , Leishmaniose Cutânea/diagnóstico , Polimorfismo de Fragmento de Restrição , Reação em Cadeia da Polimerase em Tempo Real , Sensibilidade e Especificidade , América do SulRESUMO
Background:Toxoplasma gondii is a parasite of worldwide importance but its burden in indigenous communities remains unclear. In French Guiana, atypical strains of T. gondii originating from a complex rainforest cycle involving wild felids have been linked to severe infections in humans. These cases of Amazonian toxoplasmosis are sporadic and outbreaks are rarely described. We report on the investigation of an outbreak of acute toxoplasmosis in a remote Amerindian village. We discuss the causes and consequences of this emergence. Methods: In May 2017, during the rainy season and following an episode of flooding, four simultaneous cases of acute toxoplasmosis were serologically confirmed in two families living the village. Other non-diagnosed cases were then actively screened by a medical team along with epidemiological investigations. Inhabitants from nine households were tested for T. gondii antibodies and parasite DNA by PCR when appropriate. Samples of water, cat feces and cat rectal swabs, soil, and meat were tested for T. gondii DNA by PCR. Positive PCR samples with sufficient DNA amounts were genotyped using 15 microsatellite markers. Results: Between early May and early July 2017, out of 54 tested inhabitants, 20 cases were serologically confirmed. A fetus infected at gestational week 10 died but other cases were mild. Four patients tested positive for parasite DNA and two identical strains belonging to an atypical genotype could be isolated from unrelated patients. While domestic cats had recently appeared in the vicinity, most families drank water from unsafe sources. Parasite DNA was recovered from one water sample and nine soil samples. Three meat samples tested positive, including wild and industrial meat. Conclusions: The emergence of toxoplasmosis in such a community living in close contact with the Amazon rainforest is probably multifactorial. Sedentary settlements have been built in the last few decades without providing safe water sources, increasing the risk of parasite circulation in cases of dangerous new habits such as cat domestication. Public health actions should be implemented in these communities such as safe water supply, health recommendations, and epidemiological surveillance of acute toxoplasmosis. A "One Health" strategy of research involving medical anthropology, veterinary medicine, and public health needs to be pursued for a better understanding of the transmission routes and the emergence of this zoonosis.
Assuntos
Saúde Única , Toxoplasma , Toxoplasmose , Surtos de Doenças , Guiana Francesa , Humanos , Toxoplasma/genética , Toxoplasmose/diagnóstico , Toxoplasmose/epidemiologiaRESUMO
BACKGROUND: American cutaneous leishmaniasis (ACL) is endemic in French Guiana. Its epidemiology is evolving, notably because of immigration, anthropization of natural areas, and new microbiological methods. Our first objective was to update epidemiological data. Our second objective was to look for risk factors of ACL. METHODS: This multicentric study was conducted from October 2017 to June 2018 in French Guiana. Patients with suspicion of mucocutaneous leishmaniasis were included in case of positive smear, culture, or PCR-RFLP on skin biopsy. RESULTS: One hundred and twenty-three patients met the inclusion criteria. Among those patients, 59.3% were Brazilian, mostly gold miners. Most of them (58%) were between 16 and 40 years old, and 69% were male. A large proportion of patients lived in traditional wooden houses (51%). Patients living in coastal towns were usually infected during trips to the primary forest (60%) and had a shorter time to diagnosis than workers of the hinterland. Among environmental risk factors, the presence of a water spring (40%) and dogs around houses (40%) were frequently reported. Leishmania guyanensis represented 80% of cases, followed by Leishmania braziliensis (6%), Leishmania naiffi (2%), and Leishmania amazonensis (1%). CONCLUSIONS: Gold mining and trips to the primary forest represent high-risk situations for ACL in French Guiana, where the population of infected patients is dominated by Brazilian immigrants. Possible environmental risk factors such as the presence of dogs, water sources, and traditional wooden houses require further investigation.
Assuntos
Doenças Endêmicas , Leishmaniose Cutânea/epidemiologia , Pele/parasitologia , Adolescente , Adulto , Idoso , Biópsia , Exposição Ambiental/efeitos adversos , Feminino , Florestas , Guiana Francesa/epidemiologia , Ouro , Humanos , Leishmania braziliensis/isolamento & purificação , Leishmania guyanensis/isolamento & purificação , Leishmania mexicana/isolamento & purificação , Leishmaniose Cutânea/parasitologia , Masculino , Pessoa de Meia-Idade , Mineração/estatística & dados numéricos , Fatores de Risco , Adulto JovemRESUMO
Phlebotomine sand flies are insects that are highly relevant in medicine, particularly as the sole proven vectors of leishmaniasis. Accurate identification of sand fly species is an essential prerequisite for eco-epidemiological studies aiming to better understand the disease. Traditional morphological identification is painstaking and time-consuming, and molecular methods for extensive screening remain expensive. Recent studies have shown that matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a promising tool for rapid and cost-effective identification of arthropod vectors, including sand flies. The aim of this study was to validate the use of MALDI-TOF MS for the identification of Northern Amazonian sand flies. We constituted a MALDI-TOF MS reference database comprising 29 species of sand flies that were field-collected in French Guiana, which are expected to cover many of the more common species of the Northern Amazonian region, including known vectors of leishmaniasis. Carrying out a blind test, all the sand flies tested (n = 157) with a log (score) threshold greater than 1.7 were correctly identified at the species level. We confirmed that MALDI-TOF MS protein profiling is a useful tool for the study of sand flies, including neotropical species, known for their great diversity. An application that includes the spectra generated here will be available to the scientific community in the near future via an online platform.
Assuntos
Phlebotomus/genética , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Animais , Feminino , Guiana Francesa , Biblioteca Gênica , Masculino , Especificidade da EspécieRESUMO
BACKGROUND: Amazonian toxoplasmosis is a recently described form of Toxoplasma gondii infection, characterized by severe clinical and biological features and involvement of atypical genetic strains circulating through a forest-based cycle. Though mostly reported in French Guiana since 1998, this disease is probably under-diagnosed in other areas of South America. Few data are available on its specific features in children. METHODS: We retrospectively included all children seen in Cayenne between 2002 and 2017, diagnosed with acute toxoplasmosis due to an atypical strain. Clinical and biological features and risk factors of Amazonian toxoplasmosis were recorded. RESULTS: Eleven children met the inclusion criteria. The main clinical features were fever, lymphadenopathy, hepatomegaly and splenomegaly, as reported in adults. Less expected signs such as rhinorrhea, pharyngitis and maculopapular rash were also frequent. Cutaneous signs were associated with the involvement of a genetically atypical strain. Respiratory involvement was rare but associated with respiratory distress. Outcome was always favorable. Treatment by pyrimethamine/sulfadiazine or trimethoprim/sulfamethoxazole was always justified, efficient and well tolerated. Genetic analysis suggested the involvement of wild mammals in disease transmission, and strain-dependent virulence as one of the prognostic risk factors. CONCLUSIONS: As in adults, pediatric Amazonian toxoplasmosis requires a systematic treatment. Symptoms such as skin rash, rhinorrhea and pharyngitis should not be mistaken for viral infections, when associated with lymphadenopathy or fever. Pediatricians working in South America should be familiar with these clinical presentations and with the different risk factors of Amazonian toxoplasmosis.