Albendazole, a benzimidazole derivative, was administered as a single dose of either 400 mg or 600 mg to two groups to ascertain the efficacy, tolerance and safety of the regimens. At a dose of 400 mg, a cure rate 35/36 (97%) against Ascaris was found. At 600 mg, the cure rate was 21/30 (70%), significantly lower than the 400 mg rate. Against Trichuris, albendazole at 400 mg had a cure rate of 21/48 (44%), at 600 mg there was a cure rate of 29/43 (67%). Mild side effects were noted in 7 individuals. Whether the moderate increase in efficacy against Trichuris and the loss of efficacy against Ascaris improves the cost:benefit ratio must be left to the prescriber of the drug.
Stool examination of 249 early primary schoolchildren at 2 schools in north-eastern peninsular Malaysia revealed that 73 were infected with Ascaris lumbricoides, 103 with Trichuris trichiura, and 18 with hookworms. Infected children were treated with a single dose of 400 mg of albendazole. The school attendance records during a 60 d period before treatment and 2 consecutive 60 d periods after treatment were examined. The absenteeism rate did not improve more among infected children after treatment than it did among the uninfected control children. The correlation between worm intensity and the number of lost school-days was poor. There was no evidence that intestinal helminthiasis caused school absenteeism among this group of children.
Blastocystis sp. is a gastrointestinal (GI) protozoan parasite reported to cause non-specific GI symptoms including diarrhea, flatulence, abdominal pain, and nausea. Complete eradication of Blastocystis sp. is rather challenging even with the drug of choice, i.e., metronidazole. Here, we report on two Blastocystis sp.-infected individuals, who presented increased parasite load and exacerbated symptoms upon treatment with the usual recommended dosage and regime of metronidazole. The two studies uniquely demonstrate for the first time a cyst count as high as fivefold more than the original cyst count before treatment and show an exacerbation of GI symptoms despite treatment. The study provides additional support in recognizing metronidazole resistance in Blastocystis sp. and its consequences towards the pathogenicity of the parasite.
The health impact of a Malaysian national helminth control program which provided school-based anthelmintic chemotherapy from 1974 to 1983 was re-visited after three decades post MDA and associated risk factors amongst urban poor communities identified. Stool samples collected were screened using the formalin ethyl-acetate concentration technique recovered at least one species of helminth and/or protozoan. Despite a steady decline observed between 1974-1983 however, post MDA infections continue to persist in pockets of communities moderately (18.9%; n=39/206) with higher infection recorded amongst PPR flat residents (22.5%, n=16/71). Among risk factors identified, waste management method was the primary factor for Ascaris lumbricoides infections (n=33; 16.0%), whereas age, education, employment and source of drinking water were significant risk factors for cryptosporidiosis. Despite the government's efforts to improve health through the provision of basic amenities to the general public, higher prevalence values amongst PPR flat dwellers suggests the need to implement targeted chemotherapeutic treatment of, once a year deworming as recommended by World Health Organization when the baseline prevalence of soil-transmitted helminth infections in the community is over 20%, in addition to preventive measures though improvements in health awareness programs and improved waste management methods.
Albendazole, oxfendazole, fenbendazole, levamisole, closantel, ivermectin and febantel were administered to sheep on four farms and their efficacy assessed by faecal egg count reduction test. High level of resistance of Haemonchus contortus was found to benzimidazoles (albendazole, oxfendazole, fenbendazole) on all farms and to febantel on the one farm where it was tested. No resistance to closantel and levamisole was observed. Resistance to ivermectin was absent on the three farms examined under this study, but has been reported on the fourth farm in earlier work. It is concluded that anthelmintic resistance to benzimidazoles and the probenzimidazole, febantel, is a serious and widespread problem in H. contortus in sheep in Malaysia.
The prevalence and intensity of intestinal nematode infections were assessed during 3 anthelminthic interventions in an urban community in Malaysia. The prevalence levels of Ascaris lumbricoides at Interventions 1, 2 and 3 were 30.6%, 18.9% and 15.5%, respectively and the mean intensities were 1.9, 0.75 and 0.81 worms per person. For Trichuris trichiura, the prevalence levels at Interventions 1, 2 and 3 were 46.9%, 21.6% and 15.7%, respectively. The mean intensities for T. trichiura at Interventions 1, 2 and 3 were 3.30, 0.92 and 0.07 worms per person. No gender-related prevalence and intensity were observed for the two geohelminths in this community. Prevalences and intensity had convex age profiles. Although repeated chemotherapeutic intervention reduced both prevalence and intensity levels, intensity was a more sensitive indicator than prevalence. The results indicate that age-targetting treatment at school children of 7-12 years of age would be an appropriate strategy for this community.