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Clinical cases of Chagas disease, an infection caused by the parasite Trypanosoma cruzi, have been recently described in humans and dogs in French Guiana, a French overseas department located in South America. Elsewhere in endemic countries for this disease, cases of asymptomatic infections have been described. We performed a prevalence survey of the infection in dogs in Cayenne and Kourou, the main cities of French Guiana. In 2014 and 2016, blood samples were taken from 153 dogs from Cayenne and Kourou. All dogs were apparently healthy at the time of sampling. Sex and age of the dogs were recorded as well as the location where they lived. Serum samples from dogs were screened using a rapid immunochromatographic test (Chagas Stat-Pak®Assay, Chembio, USA) detecting anti-T. cruzi antibodies. Simultaneously, a real-time PCR targeting T. cruzi kDNA was performed on the blood samples of the dog. Six dogs (3.9%) were positive only in serology and one (0.6%) only in qPCR. Two dogs were positive for both tests. The prevalence of infection (positivity for one of the two tests) was 5.8% (9/153). There was no significant difference (χ 2 test) between Cayenne (5/100) and Kourou (4/53), between males (3/60) and females (6/93), or between 2014 (2/55) and 2016 (7/98). Canine surveillance is a useful tool for the public health risk assessment of Chagas disease. Positive dogs, even when asymptomatic, should be treated as they can serve as a reservoir for T. cruzi., (Copyright © 2017. Published by Elsevier B.V.)

Dirofilaria immitis and D. repens are filarioid nematodes of animals and humans, transmitted by the bite of infected mosquitoes. Domestic and wild canids are a major natural host and reservoir for these parasites. In this study, we designed a duplex real-time PCR protocol targeting the mitochondrial cytochrome c oxidase subunit I (COI) gene, detecting both D. immitis and D. repens using two primer pairs and two Dirofilaria-specific hydrolysable probes. The sensitivity and specificity of the primers and probes were tested in both experimental and naturally infected samples. The detection limits of this assay were evaluated using plasmid DNA from D. immitis and D. repens. No cross-reaction was observed when testing this system against DNA from other filarial nematodes. The detection limit of the real-time PCR system was one copy per reaction mixture containing 5μl of template DNA. Field application of the new duplex real-time assay was conducted in Corsica. The prevalence rate of D. immitis was 21.3% (20/94) in dogs. In a locality where most dogs with Dirofilaria spp. infection were found, D. immitis and D. repens were detected in 5% (20/389) and 1.5% (6/389) of the Aedes albopictus population, respectively. These results suggest that this sensitive assay is a powerful tool for monitoring dirofilariosis in endemic or high risk areas., (Copyright © 2017 Elsevier B.V. All rights reserved.)

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., (Copyright © 2016 Elsevier GmbH. All rights reserved.)