Environmental pollution with soil-transmitted helminths in Sanliurfa, Turkey.
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Soil transmitted helminth (STH) infection are endemic in developing countries. A study was carried out of sewage farms, streams and vegetables to determine the sources and routes of STH infection in Sanliurfa, Turkey. Stool samples from farmhouse inhabitants as well as soil and vegetable samples from the gardens were collected and examined. In addition, water samples from streams and vegetable samples from the city market were collected and examined. One hundred and eighty-seven (59.5%) of a total of 314 samples, including 88.4% of the stool samples, 60.8% of the water samples, 84.4% of the soil samples and 14% of the vegetable samples, were found to be positive for STH eggs. These results indicate that the water, soil and vegetables are heavily contaminated, and suggest a vicious circle between humans and the environment. Improving environmental sanitation is imperative for the control of soil-transmitted helminthiasis in Sanliurfa. (+info)
Association of helminth infection with decreased reticulocyte counts and hemoglobin concentration in Thai falciparum malaria.
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Following a study showing an association between Ascaris and protection from cerebral malaria, we conducted a cross-sectional study comparing admission hemoglobin concentrations in relation to exposure to helminth infection in 2 separate groups of patients: 111 cerebral malaria cases and 180 mild Plasmodium falciparum malaria cases. Hookworm infections were excluded. Mean hemoglobin concentrations were significantly lower in helminth-infected patients compared to those without helminths, both in the cerebral malaria group (10.1+/-3 [n = 47] versus 11.2+/-2.4 g/dl [n = 64], P = 0.04) and the mild malaria group (11+/-2.5 [n = 89] vs 12.2+/-2.7 g/dl [n = 91], P = 0.004). Median reticulocyte counts, only available in the cerebral malaria group, were lower in helminth-infected patients compared to those without helminths (15,340/23,760 per microl, P = 0.03). Adjustments for confounders such as body mass index did not alter these associations. These data are consistent with a mechanism causing anemia linked to differences in the immune response of helminth-infected patients during malaria. (+info)
Biochemical and molecular mechanisms of drug resistance in parasites.
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Drug resistance is complicating the treatment of parasitic diseases. We review here the basic mechanisms of parasite resistance in malaria, sleeping sickness, leishmaniasis and common helminthiases. Parasites resort to multiple biochemical means to achieve resistance and we have begun to isolate and characterize the genes/proteins implicated in resistance. Understanding drug resistance is essential for the control of parasitic diseases. (+info)
Anthelmintic resistance in human helminths: a review.
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We briefly review reports on drug resistance in human helminths and compare the factors which contribute to the development of anthelmintic resistance in livestock and man, i.e. high treatment frequency, single-drug regimens, targeting and timing of mass treatments and underdosing. Conclusions are drawn from the mistakes in the treatment and control of livestock helminths. The advantages and inconveniences of current methods for the detection of drug resistance in helminths of livestock are discussed and some suggestions are put forward to standardize the tests for the detection of resistance in human helminths. Finally, based on veterinary experience, some recommendations are made to reduce the risks of development of drug resistance in human helminths. The dramatic and rapid spread of resistance to all major classes of veterinary anthelmintics should be a warning against too strong a reliance on drugs in helminth control programmes. (+info)
Drug-based helminth control in Western Pacific countries: a general perspective.
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Helminthiases still have a relevant detrimental role in the health of large groups of human population. Where poor hygiene and lack of access to education, health services and essential care characterize living conditions, parasitic infections dramatically affect essential aspects of individual life, such as nutrition, cognitive performance, susceptibility to infections and micronutrient deficiency. Severe illness is associated with schistosomiasis, lymphatic filariasis and food-borne trematode infections. Drugs are the cornerstone of control strategies for such infections, the World Health Organization (WHO) list of essential drugs contains several highly efficacious anthelmintics which are all safe, single-dose and cheap. If given regularly to infected communities, these drugs effectively control the morbidity related to the major endemic helminth infections. New strategies for mass drug administration to human populations have been tested, and several endemic Western Pacific countries have achieved excellent results in reducing morbidity in spite of continuous transmission. In this region, experience over the last decades proves the feasibility of helminth control, but also shows the need for long-term commitment and continuous support. (+info)
Association of helminth infections with increased gametocyte carriage during mild falciparum malaria in Thailand.
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The objective of this study was to determine whether pre-existing helminth infections could affect sexual forms of Plasmodium falciparum. A cross-sectional case record study compared 120 mild P. falciparum malaria cases with patent gametocyte carriage and 187 without gametocytes for helminth exposure. Relevant crude odds ratios and potential confounders were included in a logistic regression model. Helminth infections were associated with the presence of gametocytes with a crude odds ratio of 1.9 (95% confidence interval = 1.1-3.3) (P = 0.01). A positive linear trend was observed between the odds of having patent gametocytemia and the number of different helminth species (P = 0.003). However, when adjusting for hemoglobin concentration the significance of the association between helminths and gametocytes disappeared (P = 0.15). Pre-existing helminth infections may increase the severity of malarial anemia and therefore increase the likelihood of carrying gametocytes. At a population level, helminth infections may thus have a significant influence on malaria transmission. (+info)
Community perception of school-based delivery of anthelmintics in Ghana and Tanzania.
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This paper presents the results of an evaluation of community perception of two large-scale, government-run, school-based health programmes delivering anthelmintic drugs to primary school children, in Ghana (80 442 children in 577 schools) and Tanzania (110 000 children in 352 schools). Most teachers (96% in Ghana and 98% in Tanzania) were positive about their role in the programme, including administration of anthelmintic drugs, and parents and children fully accepted their taking on this role. The benefits of the programme were apparent to teachers, parents and children in terms of improved health and well-being of the children. Over 90% of parents in both Ghana and Tanzania indicated a willingness to pay for the continuation of drug treatment. The evaluation also highlighted areas that are critical to programme effectiveness, such as communication between schools and parents, the issue of collaboration between the health and education sectors, parents' perception of the importance of helminth infection as a serious and chronic health problem (compared with more acute and life threatening illnesses such as malaria), and who should pay for treatment of side-effects. (+info)
Effects of iron supplementation and anthelmintic treatment on motor and language development of preschool children in Zanzibar: double blind, placebo controlled study.
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OBJECTIVE: To measure the effects of iron supplementation and anthelmintic treatment on iron status, anaemia, growth, morbidity, and development of children aged 6-59 months. DESIGN: Double blind, placebo controlled randomised factorial trial of iron supplementation and anthelmintic treatment. SETTING: Community in Pemba Island, Zanzibar. PARTICIPANTS: 614 preschool children aged 6-59 months. MAIN OUTCOME MEASURES: Development of language and motor skills assessed by parental interview before and after treatment in age appropriate subgroups. RESULTS: Before intervention, anaemia was prevalent and severe, and geohelminth infections were prevalent and light-Plasmodium falciparum infection was nearly universal. Iron supplementation significantly improved iron status, but not haemoglobin status. Iron supplementation improved language development by 0.8 (95% confidence interval 0.2 to 1.4) points on the 20 point scale. Iron supplementation also improved motor development, but this effect was modified by baseline haemoglobin concentrations (P=0.015 for interaction term) and was apparent only in children with baseline haemoglobin concentrations <90 g/l. In children with a baseline haemoglobin concentration of 68 g/l (one standard deviation below the mean value), iron treatment increased scores by 1.1 (0.1 to 2.1) points on the 18 point motor scale. Mebendazole significantly reduced the number and severity of infections caused by Ascaris lumbricoides and Trichuris trichiura, but not by hookworms. Mebendazole increased development scores by 0.4 (-0.3 to 1.1) points on the motor scale and 0.3 (-0.3 to 0.9) points on the language scale. CONCLUSIONS: Iron supplementation improved motor and language development of preschool children in rural Africa. The effects of iron on motor development were limited to children with more severe anaemia (baseline haemoglobin concentration <90 g/l). Mebendazole had a positive effect on motor and language development, but this was not statistically significant. (+info)