Filariasis elimination in Egypt: impact of low microfilaraemics as sources of infection for mosquitoes.
The elimination strategy for lymphatic filariasis aims at reducing blood microfilaraemia to levels at which vector transmission cannot be sustained. We aimed to determine whether patients with pre-treatment low or ultra-low microfilaria (MF) counts could be a reservoir of infection after mass drug administration (MDA) with a combined regimen. Laboratory-reared mosquitoes were fed on 30 volunteers after 2 rounds of MDA. Microfilaria uptake, infectivity rates and number of Wuchereria bancrofti L3 per mosquito were assessed. One year after MDA-1, 6 subjects transmitted MF, but up to 9 months after MDA-2 transmission failed. Six months after MDA-2 > 90% had clear MF smears and either failed to transmit MF or transmitted MF that did not develop to L3. We conclude that the transmission cycle is seriously weakened after MDA-2.
Farid
H A
HA
Research and Training Centre on Vectors of Diseases, Faculty of Science, Ain Shams University Cairo, Egypt.
Kamal
S A
SA
Weil
G J
GJ
Adham
F K
FK
Ramzy
R M R
RM
D000293:Adolescent; D000328:Adult; D015766:Albendazole / Q000627:therapeutic use*; D000818:Animals; D002353:Carrier State / Q000188:drug therapy / Q000453:epidemiology / Q000469:parasitology / Q000635:transmission; D003465:Culex / Q000469:parasitology / Q000502:physiology; D004049:Diethylcarbamazine / Q000627:therapeutic use*; D004197:Disease Reservoirs; D004534:Egypt / Q000453:epidemiology; D019353:Endemic Diseases / Q000517:prevention & control / Q000706:statistics & numerical data; D005247:Feeding Behavior; D005260:Female; D005368:Filariasis / Q000188:drug therapy* / Q000453:epidemiology / Q000469:parasitology / Q000635:transmission*; D005369:Filaricides / Q000627:therapeutic use*; D006801:Humans; D007303:Insect Vectors / Q000469:parasitology / Q000502:physiology; D008297:Male; D008842:Microfilariae / Q000187:drug effects* / Q000469:parasitology; D008875:Middle Aged; D010270:Parasite Egg Count; D013997:Time Factors; D016896:Treatment Outcome; D014958:Wuchereria bancrofti / Q000187:drug effects / Q000469:parasitology
D005369:Filaricides; D015766:Albendazole; D004049:Diethylcarbamazine