Recent studies suggest that sand can serve as a vehicle for exposure of humans to pathogens at beach sites, resulting in increased health risks. Sampling for microorganisms in sand should therefore be considered for inclusion in regulatory programmes aimed at protecting recreational beach users from infectious disease. Here, we review the literature on pathogen levels in beach sand, and their potential for affecting human health. In an effort to provide specific recommendations for sand sampling programmes, we outline published guidelines for beach monitoring programmes, which are currently focused exclusively on measuring microbial levels in water. We also provide background on spatial distribution and temporal characteristics of microbes in sand, as these factors influence sampling programmes. First steps toward establishing a sand sampling programme include identifying appropriate beach sites and use of initial sanitary assessments to refine site selection. A tiered approach is recommended for monitoring. This approach would include the analysis of samples from many sites for faecal indicator organisms and other conventional analytes, while testing for specific pathogens and unconventional indicators is reserved for high-risk sites. Given the diversity of microbes found in sand, studies are urgently needed to identify the most significant aetiological agent of disease and to relate microbial measurements in sand to human health risk.
Beaches worldwide provide recreational opportunities to hundreds of millions of people and serve as important components of coastal economies. Beach water is often monitored for microbiological quality to detect the presence of indicators of human sewage contamination so as to prevent public health outbreaks associated with water contact. However, growing evidence suggests that beach sand can harbor microbes harmful to human health, often in concentrations greater than the beach water. Currently, there are no standards for monitoring, sampling, analyzing, or managing beach sand quality. In addition to indicator microbes, growing evidence has identified pathogenic bacteria, viruses, and fungi in a variety of beach sands worldwide. The public health threat associated with these populations through direct and indirect contact is unknown because so little research has been conducted relating to health outcomes associated with sand quality. In this manuscript, we present the consensus findings of a workshop of experts convened in Lisbon, Portugal to discuss the current state of knowledge on beach sand microbiological quality and to develop suggestions for standardizing the evaluation of sand at coastal beaches. The expert group at the "Microareias 2012" workshop recommends that 1) beach sand should be screened for a variety of pathogens harmful to human health, and sand monitoring should then be initiated alongside regular water monitoring; 2) sampling and analysis protocols should be standardized to allow proper comparisons among beach locations; and 3) further studies are needed to estimate human health risk with exposure to contaminated beach sand. Much of the manuscript is focused on research specific to Portugal, but similar results have been found elsewhere, and the findings have worldwide implications.
Seroprevalence of Toxoplasma gondii infection and associated risk factors were investigated in 401 women of childbearing age from the North of Portugal. Of the 98 (24·4%) seropositive women, 92 (93·9%) only had immunoglobulin (Ig)G, two (2·0%) only had IgM, and four (4·1%) others had both IgG and IgM. Risk factors for T. gondii infection in women were: engaging in soil-related activities without gloves [odds ratio (OR) 8·4], consumption of unwashed raw vegetables or fruit (OR 7·6), and consumption of smoked or cured (non-cooked) processed pork products (OR 2·5). Most women of childbearing age from the North Portugal are susceptible to primary infection with T. gondii and, therefore, the risk of congenital toxoplasmosis remains high.
BackgroundToxoplasma gondii is an obligate intracellular protozoan infecting up to one-third of the world's population, constituting a life threat if transmitted from mother to child during pregnancy. In Portugal, there is a lack of knowledge of the current epidemiological situation, as the unique toxoplasmosis National Serological Survey was performed in 1979/1980.MethodsWe studied the seroprevalence trends in the Portuguese general population over the past 3 decades, by assessing chronological spread cross-sectional studies, with special focus on women of childbearing age, by age group, region and gender.ResultsThe T. gondii overall seroprevalence decreased from 47% in 1979/1980 to 22% (95% CI 20% to 24%) in 2013. Generally, we observed that the prevalence of T. gondii IgG increased significantly with age and it decreased over time, both in the general population and in the childbearing women (18% prevalence in 2013).ConclusionsThe scenario observed for the latter indicates that more than 80% of childbearing women are susceptible to primary infection yielding a risk of congenital toxoplasmosis and respective sequelae. Since there is no vaccine to prevent human toxoplasmosis, the improvement of primary prevention constitutes a major tool to avoid infection in such susceptible groups.
Toxoplasma gondii is an apicomplexan parasite responsible for toxoplasmosis which infects all warm-blooded vertebrates, including mammals and birds. The majority of studies conducted in Europe have revealed that more than 80 % of strains isolated from human infections belong to genotype II, whereas genotypes I and III are responsible for a small number of cases. Atypical and recombinant strains are generally associated with more severe infections. In Portugal, there is a lack of data concerning genetic diversity as the classical typing studies in humans have never been performed. We aimed to determine the Sag2 and microsatellite-based (TUB2, TgM-A, W35, B17, B18) genotypes of T. gondii isolated from humans in Portugal, as well as to study their virulence in mice. We analyzed 48 strains from congenital and acquired toxoplasmosis collected during the last two decades. Sag2-based genotyping of T. gondii was achieved in all 48 strains where 35 (73 %) were classified as type II and 13 (27 %) were type I. The multilocus PCR of five microsatellites allowed the classification of 10 strains (21 %) as recombinant strains that had been previously identified as type II or I by Sag2 typing. Seven out of the 48 strains, including three type I, three recombinant, and one type I, were virulent in mice. This study constitutes the first evidence of recombinant strains circulating in Portugal in humans from congenital infection, highlighting the need for a better evaluation of these strains as their phenotype is still barely understood.
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