ABSTRACT
The study was conducted from September 2003 to April 2005 to assess results of the mass deworming campaign in 5 primary schools in Quynh Luu district, central province of Nghe An. A pre-intervention survey showed a cumulative worm prevalence of 98%, of which the highest rate was Trichuris infection: 85.1% followed by Ascaris: 83.6% and hookworm 30.3%. No difference of infection between females and males was found. Mixed infection was high with 54.3% had co-infection with Ascaris and Trichuris (88%), and 24.8% had triple infection, while a low single infection rate (20.8%) of which Trichuris was predominant, was found. A low prevalence of high intensity of infections was found with Ascaris (6.5%), hookworm (1 %), Trichuris (0.5%) while a high prevalence of low intensity was found with all examined samples. The worm prevalence was found reduced after periodical mass deworming (every six months) with mebendazole 500mg, single dose. The cumulative infection reduced from 98% to 84.5% after six months and 72.2% after 18 months. Similarly, the Ascaris infection came down from 83.6% to 52.7% and 32.7%, the Trichuris from 85.1% to 70.6% and 56.1%. However, hookwonn infection remained nearly unchanged (30.3% to 31.3% and 31.1 %). The high and moderate intensity of infection was also reduced after intervention. The egg counts were reduced by 60% after 6 months, 73% after 18 months (after the third treatment) with Ascaris. Accordingly, it was reduced by 40% and 70%, respectively with Trichuris. No changes were found with hookwonn. The intestinal wonn infection control project supported by WHO has been a successful project in tenn of both technical and social aspects. The project was performed with good compliance of school children, their parents and teachers. Expertise and qualification of the provincial staffs were also enhanced with regard to public health in general, and intestinal worm infection control, in particular.