Wuchereria bancrofti infection in human and mosquito populations of a Polynesian village ten years after interruption of mass chemoprophylaxis with diethylcarbamazine

• Published in: Transactions of the Royal Society of Tropical Medicine and Hygiene Vol. 86; no. 4; pp. 414 - 416
• Main Authors: Cartel, J.-L., Nguyen, N.L., Spiegel, A., Moulia-Pelat, J.-P., Plichart, R., Martin, P.M.V., Manuellan, A.B., Lardeux, F.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.07.1992; Royal Society of Tropical Medicine and Hygiene; Elsevier
• Subjects: Adolescent; Adult; Aedes - parasitology; Aged; Animals; Antibiotics. Antiinfectious agents. Antiparasitic agents; Antiparasitic agents; Biological and medical sciences; Carrier State - epidemiology; Carrier State - parasitology; Culicidae; Diethylcarbamazine - therapeutic use; Diptera; Elephantiasis, Filarial - epidemiology; Elephantiasis, Filarial - parasitology; Elephantiasis, Filarial - prevention & control; Female; Humans; Insect Vectors; Male; Medical sciences; Middle Aged; Pharmacology. Drug treatments; Polynesia - epidemiology; Prevalence; Sex Factors; Time Factors; Tropical medicine; Wuchereria bancrofti; Wuchereria bancrofti - isolation & purification; Tahiti; Polynesia; Oceania; Human; Prevalence; Wuchereria bancrofti; Helminthiasis; Result; Infection; Mass; Sanitary control; Treatment; Nematod disease; Helmintha; Nemathelminthia; Filariosis; Invertebrata; Nematoda
• ISSN: 0035-9203; 1878-3503
• DOI: 10.1016/0035-9203(92)90245-8

In 1991, a study on Wuchereria bancrofti microfilariae (mf) and infection rates was carried out in the human and mosquito populations of a Polynesian village where, 10 years before, the mf prevalence rate was 6·4% and twice-yearly mass treatment with 3 mg/kg of diethylcarbamazine (DEC) was interrupted. Venous blood samples were collected from 575 (97%) individuals aged 15 years or more, of whom 122 (21·4%) were mf positive. The mf carrier prevalence rate was 27·4% in males, significantly higher than that of 14% in females; it increased from 7–12% in the youngest age group (15–19 years) to 40–50% in the oldest (⩾60 years) for both males and females. 387 mosquito collections were performed and 1748 female Aedes polynesiensis were dissected, of which 1176 were parous. Among the latter, 114 (9·7%) were infected with Wuchereria bancrofti larvae at L1, L2 or L3 stages. The mean number of larvae per mosquito was 2·46 (range 1–15). Of the 114 infected mosquitoes, 30 harboured L3 larvae, giving a 2·55% infective rate; the mean number of L3 larvae per mosquito was 1·15 (range 1–2). Such findings indicate that the interruption of systematic twiceyearly mass treatment with DEC (3 mg/kg) has resulted, after 10 years, in a substantial increase of microfilarial prevalence in humans, and in high infection rates in mosquitoes.