High occurrence of giardiasis in children living on a 'landless farm workers' settlement in Araras, São Paulo, Brazil

Epidemiology of Giardia duodenalis assemblages in Brazil: there is still a long way to go

Giardia duodenalis infection is distributed worldwide and can achieve prevalence around 60%, especially in developing countries. This protozoan is divided into eight assemblages, in which A and B have high zoonotic potential, whereas C to H are host-specific. This scenario is changing as molecular studies progress, highlighting that knowledge on host-specificity still has a long way to go. Understanding the players involved in transmission routes enables rational designs of control strategies. Considering the high prevalence of giardiasis, this review aims to gather together the data on available studies on the distribution of G. duodenalis assemblages in Brazil until September 2020.

High prevalence of enteroparasites in children from Ribeirão Preto, São Paulo, Brazil

Objective:

To determine the prevalence of intestinal parasites and possible associated factors.

Method:

Cross-sectional epidemiological study of 962 children (3-12-years) from an area within the scope of a basic health unit in Ribeirão Preto, São Paulo, Brazil. Data were collected by home interviews and three-sample stool analysis and evaluated with the chi-square and Fisher's exact tests (p<0.05).

Results:

The prevalence of intestinal parasites was significantly high (57.5%). Giardia lamblia was the most prevalent (50.8%), followed by Ascaris lumbricoides (17.8%), Entamoeba histolytica, Hymenolepis nana, Entamoeba coli and Enterobius vermiculares (5.6-7.3%) and other parasites of lower prevalence, such as Schistosoma japonicum (1%) and Schistosoma mansoni (0.5%). No statistically significant associations were detected between prevalence and the risk factors analyzed.

Conclusion:

Since the area presents good conditions of environmental sanitation, health education programs should be implemented that emphasize hygiene procedures for the hands and for food and water to be consumed by the population.

Prevalence of intestinal parasitosis and associated factors among the elderly

Abstract Objective: To identify the prevalence of intestinal parasitosis and associated factors in elderly persons resident in the community. Methods: A cross-sectional study was performed involving 236 elderly persons in Aiquara, in the state of Bahia, Brazil, in 2015. Data were collected through a coprological survey and a questionnaire for information relating to sociodemographic characteristics, health and lifestyle. The presence of parasites in stools was verified by the Hoffman method. Results: The prevalence of intestinal parasites among the elderly was 30.5%. Among infected elderly persons, 26.3% had monoparasitism, 3.8% biparasitism and 0.4% polyparasitism. There was a predominance of protozoa (80.8%) over helminths (19.2%). The most prevalent parasites were Entamoeba coli (44.6%); Endolimax nana (21.7%) and Iodamoeba bütschlii (14.5%). In the population studied, the independent variables analyzed were not associated (p>0.05) with the presence of intestinal parasites. Conclusion: the prevalence of intestinal parasitic infections in elderly people living in the urban area of the municipal region of Aiquara, Bahia, was high and there was no association between intestinal parasites and sociodemographic characteristics, lifestyle or health.

Genotyping of Giardia duodenalis isolates in asymptomatic children attending daycare centre: evidence of high risk for anthroponotic transmission

Giardia duodenalis is a common intestinal parasite infecting children attending daycare centres. This study aimed to verify Giardia occurrence and the genotypes of isolates infecting children aged 0–6 years and workers at a daycare centre in the state of São Paulo, Brazil. The families of children who tested positive for Giardia, were asked to provide stool samples from household members and their dogs. Samples (123 children, 14 centre employees, 44 household members, 19 children after treatment, and 20 dogs) were examined for intestinal parasites using concentration methods. DNA extracted from all samples was submitted for polymerase chain reaction (PCR) testing and the amplicons generated were used for multilocus sequence typing of beta-giardin (bg), triose phosphate isomerase (tpi) and glutamate dehydrogenase (gdh) genes. Giardia was detected in 15·9% and 28·6% of the 220 samples by microscopy and PCR, respectively. Analysis of sequences retrieved from 29 isolates revealed both assemblages A (31%) and B (69%). Sub-assemblages AII, BIII and BIV were identified and the alignment of the bg, gdh and tpi sequences revealed the presence of some single nucleotide polymorphisms, especially in assemblage B sequences. The higher predominance of assemblage B and the identification of the AII type support the view that anthroponotic transmission appears to be an important route of transmission in environments that concentrate children at an age when poor hygiene practices make them more vulnerable to such infection.