PubMed Health⌕ Search

Biomedical subjects

H Guyatt

Publications and source records attributed to H Guyatt.

25 records · Page 2Linked to original sources
PubMed1997

Anthelmintics. A comparative review of their clinical pharmacology.

Virtually all the important helminth infections in humans can be treated with one of 5 anthelmintics currently in use: albendazole, mebendazole, diethylcarbamazine, ivermectin and praziquantel. These drugs are vital not only for the treatment of individual infections, but also useful in controlling transmission of the more common infections. This article reviews briefly the pharmacology of these 5 drugs, and then discusses current issues in the use of anthelmintics in the treatment and/or control of soil-transmitted nematode infections, filariasis, onchocerciasis, schistosomiasis (and other trematode infections), neurocysticercosis and hydatidosis. Mebendazole and albendazole are most effective against intestinal nematodes, but are contraindicated during the first trimester of pregnancy. The efficacy of prolonged therapy with these 2 drugs for treatment of larval cestode infections has not yet been established. Diethylcarbamazine is widely used to treat and control lymphatic filariasis, but adverse effects related to death of microfilariae or damage to adult worms may be marked. While ivermectin has been used in the treatment of patients with onchocerciasis, it is also undergoing investigation against lymphatic filariae. Praziquantel, used to treat schistosome infections, is also effective in other trematode infections and adult cestode infections.

Anthelmintics↗
PubMed1995

Assessing the public health importance of Schistosoma mansoni in different endemic areas: attributable fraction estimates as an approach.

Assessment of the public health importance of schistosomiasis mansoni is hampered by the nonspecificity of many of its disease symptoms. Parasitologic, clinical, and anamnestic data from two areas in Burundi were used to obtain estimates of the attributable fractions for different disease symptoms at both the population level and within different age strata. A large proportion of individuals had symptoms commonly associated with Schistosoma mansoni infection that were not attributable to this parasite. The clinical indicator with the best test efficiency was shown to be bloody diarrhea. At the population level, 35% of bloody diarrhea cases were attributable to S. mansoni, compared with only 9% of diarrhea cases without blood. The attributable fractions were age-dependent, and in the case of diarrhea (with and without blood), children had a higher proportion of cases attributable to S. mansoni infection than adults. The association between infection and disease symptoms also increased with the intensity of infection. The prevalence of morbidity attributable to S. mansoni was similar for all symptoms, and higher in children than adults. The estimation of attributable fractions provides a simple approach to quantify S. mansoni-related morbidity, which could also be extended to both S. haematobium and S. japonicum. Attributable fraction estimates for these three schistosome species in different endemic areas would greatly aid in the assessment of the health burden of this parasite and the effectiveness of control programs.

Abdominal Pain↗
PubMed1994

Controlling schistosomiasis: the cost-effectiveness of alternative delivery strategies.

Sustainable schistosomiasis control cannot be based on large-scale vertical treatment strategies in most endemic countries, yet little is known about the costs and effectiveness of more affordable options. This paper presents calculations of the cost-effectiveness of two forms of chemotherapy targeted at school-children and compares them with chemotherapy integrated into the routine activities of the primary health care system. The focus is on Schistosoma haematobium. Economic and epidemiological data are taken from the Kilombero District of Tanzania. The paper also develops a framework for possible use by programme managers to evaluate similar options in different epidemiological settings. The results suggest that all three options are more affordable and sustainable than the vertical strategies for which cost data are available in the literature. Passive testing and treatment through primary health facilities proved the most effective and cost-effective option given the screening and compliance rates observed in the Kilombero District.

Child↗
PubMedDate not supplied

Epidemiology of acute filarial episodes caused by Wuchereria bancrofti infection in two rural villages in Tamil, Nadu, south India.

This year-long study investigated the epidemiology of acute filarial episodes due to Wuchereria bancrofti in 2 rural villages in south India. The annual incidence of 96.5 episodes/1000 population was significantly higher in males (108.5) than females (84.1) an strongly age dependent. First occurrence of acute disease was observed in 0.86% of the population, and the average duration of each episode was 3.6 +/- 2.0 d. Although more than half (63.5%) of the affected individuals suffered only 1 episode, a few experienced as many as 8 over the one-year period. Individuals with chronic disease were more prone to acute attacks, with 82.9% of the total episodes occurring in this group. No seasonal pattern was observed in the frequency of episodes. Probit analysis showed that the number of episodes per affected person was dependent on sex and chronic condition. Swelling of lymph nodes in the inguinal region and fever were the most common symptoms of acute disease. The high incidence and resulting debility observed in this study suggest that acute episodes are a significant health problem associated with lymphatic filariasis. There is clearly a need for more studies on this acute form of filarial disease to aid the understanding of the aetiology and epidemiology of acute episodes, in planning appropriate control interventions, and in evaluating the resulting health burden.

Acute Disease↗
PubMedDate not supplied

Patterns of concurrent hookworm infection and schistosomiasis in schoolchildren in Tanzania.

A cross-sectional study of 6897 schoolchildren in 59 out of the 155 primary schools in Magu District on the shores of Lake Victoria, Tanzania, was undertaken in 1997 to determine the prevalence of single- and multiple-species helminth infection. Schistosoma haematobium, hookworm (primarily Necator americanus) and S. mansoni were the most common helminth species infecting schoolchildren in the district. The prevalences of Ascaris lumbricoides and Trichuris trichiura were negligible (< 1%). Anaemia and stunting were highly prevalent and widespread. Hookworm and S. mansoni occurred more frequently in multiple infections with other helminths than as single-species infections, but triple-species infection was rare. Analysis of the frequency distribution of infection amongst schools showed that prevalences of S. haematobium and hookworm tended to be normally distributed, with medians 75% and 45%, respectively, while the distribution of S. mansoni was markedly skewed such that only 17% schools had a prevalence greater than 20%. An inverse association between S. mansoni and S. haematobium was observed. Geographical information system (GIS) analysis indicated that S. mansoni infection was highly prevalent only along the shore of Lake Victoria, whilst S. haematobium was homogeneously prevalent everywhere except the lakeshore. This pattern appears to reflect the distribution of schistosome species-specific snail intermediate hosts. The results imply that joint treatment for hookworm infection and schistosomiasis would be beneficial throughout the district.

Age Distribution↗