Abstract:
National Programme to Eliminate Lymphatic Filariasis (PELF) in Sri Lanka MDA, in
2002 with 6mg/Kg diethylcarbamazine (DEC) and 400 mg albendazole. Filariasis
Research Traninig and Survice Unit (FRTSU) of University of Ruhuna evaluated them.
Changes in STH prevalence in Walgama suburb were presented elsewhere
(Yahathugoda,ef al., 2010). The August 2014 study was to evaluate its long term impact
on the same population. In three study sites selected based on pre-MDA (June 2001) and
post-MDA (Dec 2006) data from Walgama, Matara two stage cluster sampling was used
to select 59-150 age and sex matched sample in each locality for the study seven years
since MDA. Faecal examinations were performed using the modified Kato-Katz -
cellophane thick smear and direct normal saline and iodine smear methods. A total of
344 samples [Hamugewatta, n=135; Matotagama, n=59, Walgma, n=150] were
examined. They had comparable age and sex data with 2001 and 2006 samples. They
were negative for Ascaris lumbricoides, Hookworm and Trichuris trichiura only the last
detected in 2006. Albendazole used in anti-filarial MDA caused 100% disappearance of
ascariasis and hookworm infection while accumulating only trichuriasis in the
community by 2006. This may be attributed to low sensitivity of T. Trichiura to
albendazole (de Silva, et al, 2003). Current results indicated that STH could reach zero
once it was suppressed to a low level (<10%). The eliminations of STH in these
communities would have been facilitated by various reasons. According to Ministry of
Health circular all MOHs in Matara district should conduct annual Mebendazole
(500mg) MDAs, 2014 onwards. Our study indicated that a known high endemic region
reached zero prevalence even before the MDA. Therefore, all MOHs should conduct
probe surveys prior MDAs as blind MDAs are not cost-effective and may produce multi
drug resistance.
