Prevalence and risk factors of helminths and intestinal protozoa infections among children from primary schools in western Tajikistan

Abstract

BackgroundIntestinal parasitic infections represent a public health problem in Tajikistan, but epidemiological evidence is scarce. The present study aimed at assessing the extent of helminths and intestinal protozoa infections among children of 10 schools in four districts of Tajikistan, and to make recommendations for control.MethodsA cross-sectional survey was carried out in early 2009. All children attending grades 2 and 3 (age: 7-11 years) from 10 randomly selected schools were invited to provide a stool sample and interviewed about sanitary situation and hygiene behaviour. A questionnaire pertaining to demographic and socioeconomic characteristics was addressed to the heads of households. On the spot, stool samples were subjected to duplicate Kato-Katz thick smear examination for helminth diagnosis. Additionally, 1-2 g of stool was fixed in sodium acetate-acetic acid-formalin, transferred to a specialised laboratory in Europe and examined for helminths and intestinal protozoa. The composite results from both methods served as diagnostic 'gold' standard.ResultsOut of 623 registered children, 602 participated in our survey. The overall prevalence of infection with helminths and pathogenic intestinal protozoa was 32.0% and 47.1%, respectively. There was pronounced spatial heterogeneity. The most common helminth species was Hymenolepis nana (25.8%), whereas the prevalences of Ascaris lumbricoides, hookworm and Enterobius vermicularis were below 5%. The prevalence of pathogenic intestinal protozoa, namely Giardia intestinalis and Entamoeba histolytica/E. dispar was 26.4% and 25.9%, respectively. Almost half of the households draw drinking water from unimproved sources, such as irrigation canals, rivers and unprotected wells. Sanitary facilities were pit latrines, mostly private, and a few shared with neighbours. The use of public tap/standpipe as a source of drinking water emerged as a protective factor for G. intestinalis infection. Protected spring water reduced the risk of infection with E. histolytica/E. dispar and H. nana.ConclusionsOur data obtained from the ecological 'lowland' areas in Tajikistan call for school-based deworming (recommended drugs: albendazole and metronidazole), combined with hygiene promotion and improved sanitation. Further investigations are needed to determine whether H. nana represents a public health problem.

Levels of Zinc, Copper, Magnesium Elements, and Vitamin B12, in Sera of Schoolchildren With Giardiasis and Entrobiosis in Kashan, Iran

“…Approximately 3.5 billion people are infected by intestinal parasites and more than 450 million children are ill because of this parasitic infection [1]. Current worldwide prevalence of giardiasis and enterobiasis among children under 10 years of age was to range from 15 -20% and 11.4 -61%, respectively [3,4]. Apart from causing morbidity and mortality, infection with pathogenic parasites of intestine has known to cause iron deficiency anemia, growth retardation in children and other physical and mental health problems.…”

Household and personal factors are sources of heterogenity in intestinal parasite clearance among Mexican children 6–15 months of age supplemented with vitamin A and zinc

“…Greater G. intestinalis infection risk was associated with inadequate water storage in Mexico City, while improved water sources reduced risks in Central Asia and Western Africa (Cifuentes E et al, 2004;Matthys B et al, 2011;Ouattara M et al, 2011). Our findings that children from households with animals had increased G. intestinalis infection durations may reflect the role such animals may play as parasite reservoirs (Feng Y and Xiao L, 2011;Sackey ME et al, 2003).…”

“…Heterogeneity in treatment outcomes, however, also clearly results from differences in exposure to important environmental risks that can determine parasite burden (Matthys B et al, 2011). Identifying which household and community factors determine exposure as well as treatment outcomes should be an important objective in efforts to incorporate micronutrient supplementation into parasite control programmes.…”

Water Related Health Problems in Central Asia—A Review

“…Matthys et al [79] investigated the overall prevalence of infection with helminths and pathogenic intestinal protozoa in school children for a rural area in Tajikistan. Helminthiasis and intestinal protozoa infections are of considerable public health importance in Tajikistan and elsewhere in Central Asia [80,81].…”