The prevalence and molecular characterisation of Cryptosporidium spp. in small ruminants in Zambia

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Prevalence and risk factors for Giardia duodenalis infection among children: A case study in Portugal

<p>Abstract</p> <p>Background</p> <p><it>Giardia duodenalis </it>is a widespread parasite of mammalian species, including humans. The prevalence of this parasite in children residing in Portugal is currently unknown. This study intended to estimate <it>G. duodenalis </it>infection prevalence and identify possible associated risk factors in a healthy paediatric population living in the District of the Portuguese capital, Lisbon.</p> <p>Methods</p> <p>Between February 2002 and October 2008, 844 children were randomly selected at healthcare centres while attending the national vaccination program. A stool sample and a questionnaire with socio-demographic data were collected from each child. <it>Giardia </it>infection was diagnosed by direct examination of stools and antigen detection by ELISA.</p> <p>Results</p> <p>The population studied revealed a gender distribution of 52.8% male and 47.2% female. Age distribution was 47.4% between 0-5 years and 52.6% between 6-15 years.</p> <p>The prevalence of <it>Giardia </it>infection was 1.9% (16/844) when estimated by direct examination and increased to 6.8% (57/844) when ELISA results were added. The prevalence was higher among children aged 0-5 years (7.8%), than among older children (5.8%), and was similar among genders (6.9% in boys and 6.5% in girls). The following population-variables were shown to be associated risk factors for <it>G. duodenalis </it>infection: mother's educational level (odds ratio (OR)= 4.49; confidence interval (CI): 1.20-16.84), father's educational level (OR = 12.26; CI: 4.08-36.82), presence of <it>Helicobacter pylori </it>infection (OR = 1.82; CI: 1.05-3.15), living in houses with own drainage system (OR = 0.10; CI: 0.02-0.64) and reported household pet contact, especially with dogs (OR = 0.53; CI: 0.31-0.93).</p> <p>Conclusion</p> <p>The prevalence of giardiasis in asymptomatic children residing in the region of Lisbon is high. Several risk factors were associated with <it>Giardia </it>prevalence and highlight the importance of parents' education and sanitation conditions in the children's well being. The association between <it>G. duodenalis </it>and <it>H. pylori </it>seems an important issue deserving further investigation in order to promote prevention or treatment strategies.</p

Protection against Diarrhea Associated with Giardia intestinalis Is Lost with Multi-Nutrient Supplementation: A Study in Tanzanian Children

Giardia intestinalis is a well-known cause of diarrhea in industrialized countries. In children in developing countries, asymptomatic infections are common and their role as cause of diarrhea has been questioned. In a cohort of rural Tanzanian pre-school children, we assessed the association between the presence of Giardia at baseline and subsequent diarrhea risk. The study was conducted in the context of a randomised trial assessing the effect of supplementation with zinc and other micro-nutrients on malaria, and half of the children daily received a multi-nutrient supplement. Surprisingly, we found that the presence of Giardia at baseline was associated with a substantial reduction in diarrhea risk. Multivariate statistical analysis showed that this protection could not be explained by differences in age or walking distance to the dispensary between children with and without Giardia. Because we cannot exclude that children differed in other (unmeasured) characteristics, we cannot draw firm conclusions about the causality of the observed association, but our findings support the view that the parasite is not an important cause of diarrhea in highly endemic settings. Striking was that the Giardia-associated protection was lost when children received multi-nutrients. Our data do not provide information about the mechanisms involved, but suggest that multi-nutrients may influence the compositionor pathogenicity of intestinal biota

Surveys for Mansonella perstans Filariasis in Kalabo, Kazungula, Choma and Kafue Districts of Zambia

Background: Past case reports have documented Mansonella perstans infections in Zambia. However, knowledge on the epidemiology and geographical distribution of this infection in the country is lacking.  This paper reports on surveys for M. perstans in communities in four districts (Kalabo, Kazungula, Choma and Kafue) in the Southern and Western parts of Zambia.Design: The study was cross sectional. In Kalabo District, volunteers from three villages aged one year and above were recruited and had thick blood smears prepared. In the other three districts individuals aged 15 years and above who reported to selected health centres from the surrounding communities were recruited and had thick blood smears prepared. The blood smears were stained with Giemsa and examined for M. perstans microfilariae (mf).Results: A total of 1439 individuals were recruited and examined (425, 348, 306 and 360 from Kalabo, Kazungula, Choma and Kafue, respectively). No M. perstans mf were seen in any of the blood smears.Conclusions: The failure to find M. perstans mf was surprising considering previous case reports, even from some of the surveyed areas. There is a need for more surveys to be carried in other parts of the country to ascertain the distribution of M. perstans. Health practitioners should moreover be informed  about this  infection, and trained to be able to accurately distinguish M. perstans infections from those of Wuchereria bancrofti, which are also endemic in Zambia

Surveys for Mansonella perstans Filariasis in Kalabo, Kazungula, Choma and Kafue Districts of Zambia

Background: Past case reports have documented Mansonella perstans infections in Zambia. However, knowledge on the epidemiology and geographical distribution of this infection in the country is lacking. This paper reports on surveys for M. perstans in communities in four districts(Kalabo, Kazungula, Choma and Kafue) in the Southern and Western parts of Zambia.Design: The study was cross sectional. In the Kalabo District surveys, individuals aged one year and above had thick blood smears prepared and examined for M. perstans microfilariae (mf). In the other three districts the study design was retrospective and prospective, i.e. previously examined archived malaria slides from health centres were re-examined for M. perstans mf and at the same time individuals aged 15years and above had thick blood spears prepared and examined for M. perstans mf.Results: The retrospective study could only be undertaken in Choma District due to change in malaria examination method in the other districts from conventional preparation of Giemsa stained thick blood smears to use of rapid diagnostic tests. For the prospective surveys, out of the 1439 individuals recruited and examined, no M. perstans mf were seen in any of the blood smears.Conclusions: The failure to find M. perstans mf was surprising considering previous case reports, even from some of surveyed areas. There is a need for more surveys to be carried in other parts of the country to ascertain the distribution of M. perstans. Health practitioners should moreover be informed about this infection, and trained to be able to accurately distinguish M. perstans infections from those of W. bancrofti, which are also endemic in Zambia