Social and behavioral factors associated with Clonorchis infection in one commune located in the Red River Delta of Vietnam.

Social behavioral factors associated with Clonorchis infection are needed for control measures. The population in Nga Tan commune were randomly sampled and questioned to determine knowledge, perception, and health behavioral factors associated with Clonorchis infection among heads of households. The cellophane thick smear method was applied to examine their stool samples. Seven hundred and seventy-one cases were examined, the positive rates were 17.2%, 66.9%, 78.7%, 15.9%, and 0.14% for Clonorchis sinensis, Ascaris lumbricoides, Trichuris trichiura, hookworm, and Dicrocoelium dendriticum respectively. There was no significant difference between the infection rate of clonorchiasis, education level, and family income groups (p > 0.05). But there was significance difference between the infection rate of clonorchiasis and people living in different family sizes (p < 0.01). Thirty-four clonorchiasis patients treated with praziquantel 25 mg/kg/day for three days showed a cure rate in 30 days of 97.1%.

Comparison of ivermectin and albendazole treatment for gnathostomiasis.

Comparative treatment of ivermectin in 21 patients (Group 1) and albendazole in 49 patients (Group 2) of gnathostomiasis gave the cure at 95.2% and 93.8% respectively. The ELISA OD and eosinophil counts were reduction after treatment. Side effects in ivermectin were hypotention, dizziness, weakness and diuresis; and side effects of albendazole were nausia, dizziness and increased alkaline phosphatase in two cases. Ivermectin should be an effective drug againts gnathostomiasis and more convenient in treatment single dose.

Efficacy of multiple dose mebendazole against trichuriasis in Thai and Karen patients.

Treatment of trichuriasis with mebendazole 500 mg for three days, and 100 mg twice daily for three days, yielded cure rates of 93.9 and 88.9% in Thai patients, while the cure rates in Karen patients were 96.2 and 95.5% respectively. The total number of Thai and Karen trichuriasis patients were 60 and 48, when tested by modified cellophane thick smear Kato-Katz technique. There were no significant differences among the two groups of patients and doses of treatment (p > 0.05).

The effects of Trichinella spiralis infection on renal function in rats.

Trichinella spiralis infection was induced in rats by oral feeding of infective larvae. Four weeks later, renal function, including renal plasma flow (RPF), glomerular filtration rate (GFR), excretion rate of protein, sodium and potassium were determined using clearance technics. There were no significant changes in these parameters. However, plasma urea nitrogen was significantly higher in the infected group, suggesting that either an impaired regulation of renal tubular urea transport or an increased skeletal muscle breakdown is likely.

Effect of albendazole and mebendazole on soil-transmitted helminth eggs.

Primary school children from Nakhon Si Thammarat Province, Thailand, on endemic area of soil-transmitted helminths, were selected for study. The infected children were divided into two groups and pair-matched according to intensity of infections: group I were given albendazole (400mg) single dose and group II were given mebendazole (100mg) twice daily for 3 days. On the day following treatment, the number of Trichuris eggs in the stool markedly increased and the egg shape was also altered. These phenomena did not occur in Ascaris infections since 100% cure rate were obtained using both drugs. Incomplete ovicidal effect of the drugs to Trichuris and Ascaris eggs were demonstrated, embryos were observed to develop within the treated eggs and they hatched after feeding them to experimental animals. In hookworm infection, albendazole stimulated the females to release more eggs after medication, but both drugs showed complete ovicidal effect upon examining the eggs from the second bowel movement.

Minimum effective doses of mebendazole in treatment of soil-transmitted helminths.

Three hundred and fifteen primary school children infected with soil-transmitted helminths were divided into 5 groups. Three groups were treated with 25, 50 and 75 mg mebendazole (MBZ) single dose. One group was given MBZ conventional dose of 100 mg twice daily for 3 days and another group was given albendazole (ABZ) standard dose of 400 mg single dose. Every trial lower MBZ dose 75 mg, 50 mg and 25 mg regimen were highly effective against Ascaris lumbricoides but only moderately effective against Trichuris trichiura and Necator americanus.

Vitamin B1, B2 and B6 deficiency in primary school children infected with hookworm.

One thousand and seven hundred thirty-six school children from two districts in Nakhon Si Thammarat Province were screened for hookworm infection using the Kato-Katz stool examination technic. Two hundred students who have at least 2,000 eggs per g of stool were recruited into the program. The students were divided into six groups: groups 1, 2 and 3 were from Tha Sala district while groups 4, 5 and 6 were from Ronpibul district. Three milliliter blood samples were obtained from the cubital vein of each subject and were evaluated for erythrocyte transketolase activity (ETK) for vitamin B1, erythrocyte glutathione oxidoreductase activity (EGR) for vitamin B2, and erythrocyte aspartate aminotransferase activity (EAST) for vitamin B6. The school children were divided into three groups: those infected only with hookworm, those with both hookworm and Trichuris trichiura, and those whose stools show no parasite eggs. The results show that 10-20% of the school children are vitamin B1 deficient, about 40% to 80% are vitamin B2 deficient, and about 14% to 23% are vitamin B6 deficient. No correlation could be made between vitamin deficiencies and parasitic infection.

Enzyme-linked immunosorbent assay for diagnosis of human strongyloidiasis.

Crude antigen (CA) was prepared from Strongyloides stercoralis filariform larvae obtained from in vitro culture of the human feces containing rhabditiform larvae. The lyophilized filariform larvae were ground and ultrasonicated in distilled water then the soluble antigenic preparation was delipidized. The protein content of the crude soluble antigen was 20% of the original dried larvae. The CA was passed through a gel filtration chromatography column and yielded three different protein fractions namely F1, F2 and F3. CA and its fractions were used in the indirect enzyme-linked immunosorbent assay (ELISA) for detecting antibodies to S. stercoralis in serum samples of 5 groups of individuals. These were patients with parasitologically confirmed strongyloidiasis (group 1), patients with mixed S. stercoralis and other parasitic infections (group 2), non-strongyloidiasis patients with other worm infestation(s) (group 3), normal parasite-free Thais (group 4) and normal parasite-free Swedes (group 5). It was found that F2 was the best antigen in the ELISA. The sensitivity, specificity and positive and negative predictive values of the test using F2 as the antigen were 95.0%, 96.4%, 95.0% and 96.4%, respectively.

Repeated doses of albendazole against strongyloidiasis in Thai children.

Fifty children aged 5 to 12 years whose fecal examination confirmed of strongyloidiasis were divided into 2 groups. One group (Group I) of 26 received 400 mg albendazole once a day for 3 consecutive days. The other group (Group II) of 24 received the same dosage but repeated a week later. Simple smear fecal examination was performed for 3 consecutive days before treatment, and stool cultures were performed on Days 13, 14, 15 21, 22 and 23 after treatment. Evaluation of successful treatment or cure was based on the absence of larvae in 6 culture specimens. The cure rates were 80.8% in Group I and 91.7% in Group II (p = 0.18). Side effect consisted of mild and transient vomiting in one patient in each group. Although the difference in cure rates between the two drug regimens was not statistically different, two courses of treatment (Group II) resulted in a higher cure rate.

Effect of single-dose albendazole and single-dose mebendazole on Necator americanus.

One hundred two children (43 males and 59 females) aged 6 to 14 years with positive stool examination by Kato-Katz and/or Harada-Mori culture techniques for N. americanus, were randomly divided into two groups. Group I with 48 children were treated with a single dose albendazole, 400 mg. Group II, 54 children, received a single dose mebendazole, 600 mg. After treatment, repeated stool examination was performed on Day 14, Day 21 and Day 28. The children were considered cured when stool examination was negative on all three occasions by both methods. The cure rate was 64% in Group I and 11% in Group II. The difference was statistically significant (p less than 0.05). The eggs reduction rate was 98% in Group I and 95% in Group II. Mild and transient side effects such as nausea, dizziness and headache were observed in both groups. Albendazole, 400 mg, as a single dose treatment was shown to be superior to mebendazole, 600 mg, single dose for the mass treatment of hookworm infection, especially that of Necator americanus, in an endemic area.

Comparative study of different doses of mebendazole in hookworm infection.

Sixty six children (40 males, 26 females) aged from 4 to 14 years with hookworm infection were treated with mebendazole. Thirty one and 35 children were treated with mebendazole 300 mg single dose and 600 mg conventional regimen respectively. Stool examination by Kato-Katz technique were done for 3 consecutive days before treatment and on day 14-16, 21-23 after treatment. The cure rate with 300 mg mebendazole was 16.1% with 90.9% egg reduction while 600 mg mebendazole gave 91.4% cure rate with 99.5% egg reduction. No side effects were observed in all children. Four hundred and six adult worms were identified, 99% were Necator Americanus, 0.5% Ancylostoma duodenale and 0.5% Ancylostoma ceylanicum.