Cure and reinfection patterns of geohelminthic infections after treatment in communities inhabiting the tropical rainforest of Assam, India.

Mass de-worming targeted at socio-economically poor communities can be considered as an option for communities living in the tropical forests of Assam who do not have access to safe drinking water and proper sanitation, and consequently have a higher risk of suffering from geohelminthic infection and associated morbidity. A random sample of 265 subjects was included in this study (134 males and 131 females). The chemotherapeutic regimen followed was a single dose of albendazole 400 mg. Stools samples were collected in 10% formol-saline for detection of infection before treatment. Post-treatment stool samples were collected 10 to 14 days after treatment to determine the cure rate. Stool samples were again collected 3 to 6 months post-treatment to study the rate of reinfection. Multiple logistic regression was used to find possible associations between age, sex and treatment failure. The chi-square test was used wherever appropriate. The cure rates for Ascaris lumbricoides, Trichuris trichiura and hookworms were 70.8%, 68.7% and 93.0%, respectively. Logistic regression revealed that age was associated with treatment failure in A. lumbricoides infection. Re-infection rates after 3 months of successful treatment were 19.6% for A. lumbricoides, 30.9% for T. trichiura and 11.3% for hookworms. Six months post-treatment, the prevalence of re-infection was highest with T. trichiura (43.6%); followed by A. lumbricoides (35.3%). The rate of reinfection with hookworms was lower (11.3%) six months post-treatment. The rates of re-infection with A. lumbricoides and T. trichiura was higher in children below 15 years of age, compared with adults. Hookworm reinfection was higher in the adult age group (15 to 39 years). The rates of new infection in previously uninfected subjects were lower compared with the rates for re-infection.

El tratamiento antihelmíntico selectivo frente al tratamiento masivo: experiencia en dos comunidades hiperendémicas / Selective vs. mass treatment with antihelminthic drugs: experience in two hyperendemic communities

OBJETIVO: Evaluar la prevalencia e intensidad de las infecciones por geohelmintos en niños de dos comunidades hiperendémicas tratadas con técnicas antihelmínticas diferentes: una con tratamiento selectivo o individual, y la otra con tratamiento masivo reiterado. MÉTODOS: La población estuvo compuesta por 909 niños de uno u otro sexo, con edades entre 2 y 13 años, que vivían en dos comunidades marginales de la ciudad: Las Lomas y El Abasto, Santa Fe, Argentina. Se realizó un trabajo prospectivo longitudinal, cuasiexperimental, de comunidades. Durante los 22 meses del estudio se llevaron a cabo 5 controles parasitológicos, evaluados desde el punto de vista cualitativo y cuantitativo, y se dispensaron tratamientos antihelmínticos después de los controles 0, 2, 3 y 4. En Las Lomas se aplicó el tratamiento selectivo a los casos con diagnóstico parasitológico positivo que integraban la muestra A (n = 55) y en El Abasto, tratamiento masivo a todos los niños, incluidos los integrantes de la muestra B (n = 50). Ambas muestras fueron escogidas para realizar los controles. RESULTADOS: Se comprobó una prevalencia e intensidad de la infección por Ascaris lumbricoides significativamente mayor en El Abasto. No se detectaron diferencias para Trichuris trichiura. Al comparar las prevalencias y cargas parasitarias de A. lumbricoides entre los controles realizados dentro de una misma comunidad (inicio y final del estudio) no se observaron diferencias significativas en la muestra A, aunque sí en la muestra B. En cuanto a T. trichiura, se detectaron diferencias significativas entre ambos controles en las dos muestras. CONCLUSIONES: Solo el tratamiento masivo y reiterado logró disminuir eficaz y significativamente la prevalencia y la carga parasitaria de A. lumbricoides durante el período estudiado

A comparative trial of albendazole alone versus combination of albendazole and praziquantel for treatment of Trichuris trichiura infection.

A randomized clinical trial was conducted to compare the effectiveness of albendazole alone and albendazole combined with praziquantel in the treatment of Trichuris trichiura infection. The drug regimens consisted of single dose of albendazole 400 mg (A1, n=34), 3 days of albendazole 400 mg daily (A3, n=34), 5 days of albendazole 400 mg daily (A5, n=35), single dose of albendazole 400 mg plus praziquantel 40 mg/kg (AIP1, n=34), and 3 days of albendazole 400 mg plus praziquantel 40 mg/kg daily (A3P3, n=36). It was found that treatment with 3 or more consecutive days of albendazole with or without praziquantel resulted in a significant reduction in density of Trichuris eggs in stools while a single dose of such drug did not. Praziquantel was not shown to have synergistic or antagonistic effects with albendazole. A regimen of 400 mg of albendazole daily for 3 days was found to be the most suitable therapy for Trichuris infection.

Tratamento da estrongiloidíase humana e outras parasitoses intestinais com dose única de ivermectina / Treatment of human strongyloidiasis and other intestinal parasitosis with a single dose of ivermectin

Os autores trataram 70 pacientes portadores de estrongiloidíase, ascaríase, tricuríase e ancilostomíase com dose única de ivermectina (200 ug/kg). A cura parasitológica obtida foi de 95 porcento para estrongiloidíase, de 100 poecento para ascaríase e tricuríase e de 60 porcento para ancilostomíase. As reaçöes adversas foram observadas em 3 porcento dos pacientes - cefaléia, náuseas e vômitos.(au)

Epidemiology of human geohelminth infections (ascariasis, trichuriasis and necatoriasis) in Lushui and Puer Counties, Yunnan Province, China.

Between April and June of 1998, the prevalence and intensity of geohelminth infections caused by hookworm, Ascaris and Trichuris were investigated in two rural Yunnan villages. In Liuku, a village of Lisu indigenous people in Lushui County, there was an overall geohelminth prevalence of 72% (48%, 43% and 16% for hookworm infection, ascariasis, and trichuriasis, respectively). The prevalence of ascariasis was greatest among preschool and school aged children, whereas the prevalence of trichuriasis was greatest among teenagers and the prevalence of hookworm increased until the age of 10-15 and then remained high throughout adulthood. In Linger, a village of Han Chinese, located in Puer County, there was an overall geohelminth prevalence of 77% (30%, 60% and 36% for hookworm infection, ascariasis, and trichuriasis, respectively). The differences in prevalence for hookworm and ascariasis were statistically significant. The prevalence of hookworm in Linger increased steadily with age and did not plateau, but there were no discernible patterns of prevalence versus age for either ascariasis or trichuriasis. Heavy trichuriasis infections were noted to occur in Linger. In both villages, more than 98% of the hookworm infections were of light and moderate intensity. Both by morphologic identification of third-stage infective larvae (L3) from eggs as well as identification of adult hookworms recovered from adult residents after treatment with quantrel, Necator americanus was identified as the exclusive hookworm in each village. Geohelminth infections caused by Ascaris, Trichuris and hookworm remain highly endemic to the rural areas of Yunnan Province in southwestern China.

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).

Strongyloides stercoralis infection and chronological changes of other soil-transmitted helminthiases in an endemic area of southern Thailand.

A field survey was conducted in 4 primary schools in Nakhon Si Thammarat Province, southern Thailand. By Sasa modified Harada-Mori cultivation method, 1.8% of the schoolchildren were found to be infected with Strongyloides stercoralis, and 25.1% had hookworm infection. By Kato's thick smear method, the overall prevalence of soil-transmitted helminths was 46.8%, being Trichuris trichiura 28.5%, hookworm 18.0%, and Ascaris lumbricoides 5.7%. Fecal examination, performed by Kato's thick smear and culture method, indicated that the prevalence of hookworm infection was 26.9%. The prevalence in the present study was very much lower than many previous reports in the past decade. This may indicate the partial success of the parasite control project in Thailand by mass treatment, improving the sanitation and personal hygiene of the people in the endemic area. In light infection with Trichuris, albendazole administered at a dosage of 200 mg daily for 3 days showed a 48.7% cure rate. When mebendazole was given at 100 mg twice daily for 3 days, its effectiveness was 88.5%. A lower cure rate was obtained (70.0%) in moderate to heavy infection.

Tricocefalosis masiva en un adulto diagnosticada por colonoscopía / Massive trichuriasis in an adult diagnosed by colonoscopy

A case of massive trichuriasis in a 37 year old female from a rural locality of the Metropolitan Region of Chile, with antecedentes of alcoholism, chronic hepatic damage and portal cavernomatosis, is presented. Since 12 year ago she has had geophagia. In the las six months she has frequently presented liquid diarrhea, colic abdominal pains, tenesmus and sensation of abdminal distention. Clinical and laboratory test confirmed her hepatic affection associated with a celiac disease with anemia and hypereosinophilia. Within a week diarrhea became worse and dysentery appeared. A colonoscopy revealed and impressive and massive trichuriasis. The patient was succesfully treated with two cures of 200 mg tablets of mebendazole twice daily for three days with a week interval. After the first cure she evacuated a big amount of tricuris trichiura, fecal evacuations became normal, geophagia disappeared and recovered 4 kg of body weight

Ascariasis, trichuriasis, and growth of schoolchildren in Northeastern Peninsular Malaysia.

A study to determine the effect of antihelminthic treatment on growth and nutritional status was undertaken on 103 children in the second grade of primary school, 71 of whom were found to be infected with Ascaris lumbricoides or Trichuris trichiura. The median Ascaris and Trichuris intensities in the infected group were 19,600 (range; 0-488,000) and 2,800 (range; 0-84,600) eggs per gram of feces respectively. Forty-three children harbored both types of worm. Fourteen weeks after two 400 mg doses of albendazole were administered to infected children, the increases in weight, height, weight for age, height for age and weight for height were significantly higher among infected children than controls who were uninfected at baseline. The observed gains were independent of sex and socioeconomic status. Decrease in log transformed Trichuris intensity correlated with increases in weight (r=0.24; p=0.02) and weight for age (r=0.20; p=0.06) but decrease in Ascaris intensity did not correlate with increases in any of the anthropometric parameters. The results suggest that antihelminthic treatment has beneficial short-term effects on growth and nutritional status of a modest magnitude among early primary schoolchildren in the area.

Efficacy of single dose albendazole on the prevalence and intensity of infection of soil-transmitted helminths in Orang Asli children in Malaysia.

The efficacy of a single-dose 400 mg albendazole to treat Ascaris, Trichuris and hookworm infection was studied in Orang Asli community. Kato-Katz examination was performed on fecal samples which were collected before treatment, 1 and 4 months after treatment. A total of 123 children were involved in all three surveys. The cure rate of Ascaris infection was 97.4% and the egg reduction after treatment was 99.9%. The cure rate for hookworm infection was 93.1% with 96.6% egg reduction. Although the cure rate was low in Trichuris infection (5.5%), egg reduction was more evident (49.1%). The reinfection rate at 4 months after treatment was 54.5%, 3.6% and 10.3% for Ascaris, Trichuris and hookworm infection, respectively. Within 4 months after treatment almost one-fifth children with Ascaris and hookworm infection reached pre-treatment intensity infection. In Trichuris infection, however more than half of the children reached their pre-treatment intensity infection at 4 months after treatment. Findings suggest that 4-monthly targeted periodic treatment with 400 mg single-dose albendazole in highly endemic areas can have a significant impact on intensity infection of Ascaris and hookworm, but not on Trichuris infection.

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.

Comparative trials using albendazole and mebendazole in the treatment of soil-transmitted helminths in schoolchildren on Penang, Malaysia.

Trials using albendazole and mebendazole, as single 400 mg dose treatments, against soil-transmitted helminths, were carried out in 7-9 and 10-12 years-old schoolchildren living in urban and rural environments in Penang, Malaysia. Both drugs were equally effective in treating trichuriasis and ascariasis in both age groups and environments. However, mebendazole is not so effective in the treatment for hookworms when compared to albendazole. It is suggested that albendazole should be considered the drug of choice for mass chemotherapy for Penang.

Efficacy of common broad spectrum anthelmintics against hook worm, Ascaris and Trichiuris in Hat Yai district, Songkhla Province, Thailand.

1. The third therapeutic scheme should be used in the hospital. 2. The second and third therapeutic scheme may be used in mass treatment. 3. The 4th-6th therapeutic scheme is to be considered, reviewed, and evaluated. 4. Model and technology of permanent worms control is to be studied. 5. The treatment and control of Ascaris were simple. Cure with low reinfection rate and long reinfection period was remarkable. 6. The prevalence rate and reinfection rate of Trichiuris was high, and not so sensitive to any antelmintics. 7. The reinfection rate in the second group was not superior to the first group and the third group. This revealed no effectiveness of ovicidal and larvicidal on the helminthiasis. 8. Reinfection rate in the third therapeutic scheme was the least group. 9. Toxicity and side effect were not found in any anthelmintics. 10. Broad Spectrum Anthelmintics are necessary in mass treatment or blind treatment.

Efficacy of single-dose mebendazole, polymorphic forms A and C, in the treatment of hookworm and Trichuris infections.

A therapeutic trial of single mebendazole, 300 mg polymorph A, 300 mg polymorph C and 500 mg polymorph C, in the treatment of hookworm and Trichuris infections was carried out at primary schools in Southern Thailand. The total of 958 children were randomly allocated in seven treatment groups including the placebo control and the standard dose control (100 mg polymorph C bid for 3 days). The egg reduction rates and the cure rates of 300 mg and 500 mg polymorph C were similar, but inferior to those of the standard dose in both hookworm and Trichuris infections. The efficacy of single dose 300 mg polymorph A was not different from that of the placebo control (alpha = 0.05) in both infections.

A comparative study on the efficacy of albendazole and mebendazole in the treatment of ascariasis, hookworm infection and trichuriasis.

A comparative study of the efficacy of albendazole and mebendazole was carried out in Pattani Province in the southern part of Thailand. One hundred and ninety-six patients with single or multiple infections with Ascaris, hookworm, and Trichuris were randomized into 4 groups for different treatments. Stool examination by Kato-Katz technique were done before and on day 14 after treatment. Results of the study showed that (1) a single dose of 300 mg mebendazole (locally produced) resulted in cure rates of 50%, 0% and 0% and egg reduction rates of 87.3%, -15.3%, and 28.3%, for ascariasis, hookworm infection and Trichuris respectively; (2) a single dose of 300 mg mebendazole (original) resulted in cure rates of 100.0%, 9.1%, and 43.3%, and egg reduction rates of 100.0%, 72.0%, and 77.9%, for Ascaris, hookworm, and Trichuris respectively; (3) a single dose 500 mg mebendazole (original) resulted in cure rates of 100.0%, 30.2%, and 70.3%, and egg reduction rates of 100.0%, 70.4% and 89.9%, for Ascaris, hookworm, and Trichuris respectively and (4) a single dose of 400 mg albendazole (original) resulted in cure rates of 100.0%, 84.3%, and 67.4%, and egg reduction rates of 100.0%, 96.0% and 87.0%, for Ascaris, hookworm, and Trichuris respectively. Both mebendazole and albendazole are safe and no side effects were observed. The results of this study suggested that albendazole is the preferred benzimidazole derivative for mass treatment of multiple infections with Ascaris, hookworm, and Trichuris.

Significant changes in gastrointestinal tract parasitic infections in children of St. Kitts over the 9-year period 1982-1991

When 239 (1982) and 361 (1991) five-year and nine-year-old children in St. Kitts were assessed for the presence of parasitic infections, there were significant reductions in the prevalence of trichuriasis from 83 per cent to 58 per cent , of ascariasis from 24 per cent to 8.6 per cent and of giardiasis from 15 per cent to 9 per cent . Anthelminthic use, which appeared to be the most important responsible intervention tool, remained roughly at the same level at 59-51 per cent . However, the types of anthelminthics used changed over the period. Piperazine citrate, which was used by 66 per cent in 1982, only had 35 per cent usuage in 1991. Albendazole which was not used at all in 1982 was taken by 32 per cent of the children in 1991 and at the same time the use of laevo-tetramisole increased by 20 per cent from 14 per cent . Suggestions are made for an island-wide mass intervention programme to manage parasitic infections.

The effect of repeated chemotherapy on the prevalence and intensity of Ascaris lumbricoides and Trichuris trichiura infection.

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.

Studies on the control of hookworm and other soil-transmitted helminthiases in farmers in Zhejiang Province, China.

Different periodic selective chemotherapeutic schemes were used to control hookworm and other soil-transmitted helminthiases in eight villages in five counties in Zhejiang Province, China, 1985-1988. The results showed that the prevalence rates of hookworm, ascariasis, and trichuriasis decreased from 35.0-74.4%, 47.0-.76% and 22.9-47.5% to 3.2-15.8%, 9.9-47.8%, and 3.5-31.2%, respectively, using pyrantel pamoate (10 mg/kg for 1-2 days) or albendazole (400 mg for 1-2 days, once or twice a year for 2-3 years). The eggs per gram of feces of hookworm and Trichuris trichiura also dropped markedly after control. Moreover, the mean hemoglobin levels of sampled populations increased after several treatments. The authors recommend periodic selective chemotherapy as the main method to control soil-transmitted helminthiases, especially hookworm infections.