[Detection of anti-Lassa antibodies in the Western Forest area of the Ivory Coast]. / Detection des anticorps anti-virus de Lassa dans l'ouest forestier de la Côte d'Ivoire.

Lassa fever is an African viral hemorrhagic fever (VHF) known to be endemic in a number of West African countries including Nigeria, Sierra Leone, Liberia and Guinea. Despite having common borders with Liberia and Guinea, Côte d'Ivoire has never reported any cases of Lassa fever. In March 2000, as part of a research project on VHF--mainly yellow fever, Lassa fever and Ebola fever--in Guinea and Cote d'Ivoire, an exploratory survey was conducted to assess knowledge about VHF and immunological status against Lassa virus among forest workers in the Duekoue and Guiglo regions. One hundred and sixty-three male forest workers were interviewed using a questionnaire designed to assess risk factors for VHF exposure and personal medical history over the last 12 months. Detection of IgG antibodies against Lassa virus was performed by immunofluorescence assay with Lassa virus antigens from the Josiah and Las/AV strains. The overall prevalence of IgG antibodies was 26% (42/161). Among the Lassa IgG positive subjects, 38.5% were loggers including 20% that were positive at a serum dilution of 1/40 and 46.7% were national park workers or forest rangers including 69% that were positive at a dilution of 1/40 and more. Forty-one percent of subjects had heard of VHF including 14% who attributed it to animals and 2% who attributed it to plants. Contact with rodents was frequent and more than 50% of subjects had either eaten or skinned rodents. Although the prevalence of anti-Lassa IgG antibodies seemed high in the study population, no conclusion can be about level of exposure to Lassa virus.

Detection des anticorps anti-virus de Lassa dans l'ouest forestier de la Cote d'Ivoire

La fievre de Lassa est une fievre hemorragique virale (FHV) africaine endemique en Afrique de l'Ouest; notamment au Nigeria; en Sierra Leone; au Liberia et en Guinee. La Cote d'ivoire qui part age des frontieres avec le Liberia et la Guinee n'a jamais notifie de cas de fievre de Lassa. Dans le cadre d'un projet de recherche sur les fievres hemorragiques virales principalement la fievre jaune; la fievre de Lassa et la fievre Ebola en Guinee et en Cote d'Ivoire; une enquete a ete realisee en mars 2000 chez des travailleurs forestiers des prefectures de Guiglo et Duekoue; dans le but de determiner le niveau de connaissance sur les fievres hemorra-giques virales et le statut immunitaire vis a vis du virus de Lassa. Cent soixante-trois sujets de sexe masculin professionnels de la foret ont ete interroges a l'aide d'un questionnaire sur les facteurs de risque d'exposition aux FHV et leurs antecedents medicaux des 12 dern i e rs mois. Les anticorps seriques de type IgG anti-virus de Lassa ont ete detectes par technique d'immunofluorescence utilisant les antigenes Lassa des souches Josuah et LAS/AV. La prevalence globale en IgG obtenue etait de 26(42/161). Pa rmi les sujets positifs; 38;5etaient des bucherons dont 20positifs au 1/40; 46;7des agents du parc national ou gardes forestieres dont 69positifs au 1/40 et plus. De plus; 41des sujets avaient entendu parler des FHV; 14ont attribue leur origine a des animaux et 2a des plantes. Les contacts avec les rongeurs etaient frequents et plus de 50des personnes ont deja consomme ou depece des rongeurs. La proportion de sujets porteurs d'anticorps IgG anti-virus de Lassa dans cette population semblait elevee. Cependant cette prevalence ne permet pas de conclure a une exposition particuliere au virus de Lassa

In vivo sensitivity of Plasmodium falciparum to chloroquine in rural areas of Côte d'Ivoire.

In vivo testing of Plasmodium falciparum sensitivity to chloroquine was carried out in four rural sites of differing socio-geographical environment in Côte d'Ivoire. Of a total of 1282 patients of all ages with fever or previous history of fever, 649 were slide positive, with 435 patients with a pure P. falciparum infection; 191 fulfilled all the criteria for inclusion in this study, and 113 completed it. Treatment failure rates ranged from 9.7% (Djébonoua) to 38.1% (Tiéviéssou), and were most often associated with higher degrees of resistance (RII = 54.2%; RIII = 37.5%). Blood chloroquine levels measured by ELISA test suggest that many people take chloroquine routinely; furthermore 37.5% of resistance cases occurred in subjects who had high blood chloroquine concentrations on day 0. Twenty-three out of 24 cases of resistance were found in children under 7 years of age. Nearly all children with persisting parasitaemia were afebrile on day 7, even those (7/8) with RIII resistance. Children aged < 7 years represent the the best sentinel group for monitoring P. falciparum sensitivity to chloroquine in Côte d'Ivoire.