Spécificités épidémiologiques de la fièvre Q en Guyane

Abstract

Les études scientifiques menées sur la fièvre Q en Guyane au cours des quinze dernières années ont permis de répondre à de nombreuses interrogations sur l’épidémiologie humaine et animale de cette maladie. Les résultats observés démontrent une réelle spécificité locale de la fièvre Q, avec une souche de Coxiella burnetii unique et hypervirulente, une transmission suburbaine et en bordure de forêt, principalement sur la ville de Cayenne et ses alentours, des formes pulmonaires prédominantes, un réservoir sauvage de la bactérie et la possibilité d’une transmission vectorielle par les tiques. La prévalence réelle de la maladie dans la population guyanaise reste inconnue et conditionne la mise en oeuvre d’une stratégie de santé publique dédiée. Cette communication se propose de faire une synthèse sur l’ensemble des connaissances acquises et sur les questions qui demeurent, dans une approche One Health.

Ecology, evolution, and epidemiology of zoonotic and vector-borne infectious diseases in French Guiana: Transdisciplinarity does matter to tackle new emerging threats

“…A longitudinal survey conducted in vampire colonies showed substantial temporal fluctuations in prevalence, with waves of seroconversions and waning immunity. These results suggest (i) frequent exposure of animals, (ii) the ability of the infected host to control and eliminate the virus, and (iii) more relaxed modes of exposure between bats than the commonly assumed infection via direct contact with saliva of infected animals (de Thoisy et al, 2016). RABV circulation is hypothesized to be principally maintained in the pristine forest habitats that may provide sufficient food resources to allow vampire bats, the main prevalent host species, to maintain and propagate RABV, at larger scales by vampire males and within bat colonies chiefly by females, as suggested by dispersal patterns (Huguin et al, 2018).…”

“…In French Guiana, an extensive literature is available on the putative or confirmed roles of animal species as carriers of a large set of microbes, including bacteria (Christen et al, 2020;Davoust et al, 2014;Gay et al, 2014;Schaub et al, 2020), parasites (de Thoisy et al, 2003;Fandeur et al, 2000;Volney et al, 2002), and viruses (de Thoisy et al, 2009Thoisy et al, , 2016Lavergne et al, 2015Lavergne et al, , 2016). An open list of infected species, from either molecular or serological evidence, is important to direct further research, but provides little information on the functional role of host or vector species and of species communities in the disease cycle and expected responses to habitat changes.…”

“…Based on molecular and serological surveys on almost 1,500 bats from 30 species, RABV was molecularly detected in a common vampire and in a frugivorous bat in French Guiana. Species seroprevalence ranged from 0 to 20%, and the risk of seropositivity was higher in bats with a hematophagous diet, living in monospecific colonies and in dense forests (de Thoisy et al, 2016). Together with those bioecological drivers, immunity gene characterization in several species suggested differential abilities to control viral infection (Sarkis et al, 2018).…”

“…One of the ecological consequences is the disappearance of resources for secondary or tertiary consumers, and populations of vampires may then shift to alternative resources such as cattle, domestic animals, and humans. Therefore, intact forest allows both a dilution effect in highly rich bat communities and the maintenance of large bat-prey populations of medium-sized and large mammals, which should prevent their migration to anthropized areas (de Thoisy et al, 2016).…”

Human Q Fever on the Guiana Shield and Brazil: Recent Findings and Remaining Questions

“…More recently, the PCR analysis of capybara droppings ( Hydrochoerus hydrochaeris ) was positive for Cb , this analysis was performed in the investigation of the cluster that occurred among the sailors of the French Navy at the Comté river [ 23 ]. Other species have also been found anecdotally positive for Cb : the collared peccary ( Tayassu pecari ) and the white-lipped peccary ( Pecari tajacu ) (Amazonian wild boar species) [ 27 ]. On the other hand, while part of the Guianese population is convinced that Q fever is transmitted by bats, no study has shown it.…”