Escherichia coli, Species C Human Adenovirus, and Enterovirus in Water Samples Consumed in Rural Areas of Goiás, Brazil

Abstract

Rural environments lack basic sanitation services. Facilities for obtaining water and disposing sewage are often under the initiative of each resident, who may not be able to build and maintain them properly. Thus, water for human consumption is subject to fecal contamination and, consequently, the presence of waterborne pathogens, such as enteric viruses. This study evaluated fecal contamination of water samples from individual sources used for domestic water supply on small farms in the state of Goiás, Brazil. Samples were collected from 78 houses whose water sources were tubular wells, dug wells, springs, and surface waters. Escherichia coli (EC) bacteria, analyzed by the defined chromogenic substrate method, was used as a traditional indicator of fecal contamination. The enteric viruses Human mastadenovirus (HAdV) and Enterovirus (EV), analyzed by qPCR, were tested as complementary indicators of fecal contamination. At least one of these markers was found in 89.7% of the samples. Detection rates were 79.5% for EC, 52.6% for HAdV, and 5.1% for EV. The average concentration for EC was 8.82 × 10 1 most probable number (MPN) per 100 mL, while for HAdV and EV the concentrations were 7.51 × 10 5 and 1.89 × 10 6 genomic copies (GC) per liter, respectively. EC was the most frequent marker in ground and surface water samples. HAdV was detected significantly more frequently in groundwater than in surface water and was more efficient in indicating contamination in tubular wells. There was no association of frequencies or correlation of concentrations between EC and HAdV. HAdV indicated human fecal contamination and performed well as a complementary indicator. The results reveal that a large part of the analyzed population is vulnerable to waterborne diseases caused by enteric pathogens.

Comparison Between Different Seasons of the Year in Research for Rotavirus in a State of Brazil

“…The characteristics of tubular wells of having smaller opening diameter, wall coverings made of PVC plastic material and being greater in depth, ensuring greater isolation and durability, did not ensure that that the water samples collected from this source were free from RV contamination [37]. With regard to the construction aspect of the wells, Allen et al [38] obtained a positive association when relating the probability of detecting viruses in wells that do not have casing, that is, wells that are in direct contact with the aquifer (open well interval).…”

Extratos vegetais: uma perspectiva comparativa entre métodos de extração clássicos e avançados

“…Indicador viral da qualidade da água, o adenovírus, é um patógeno com resistência à luz UV que prevalece em águas residuais não tratadas durante todo o ano e causa doenças como gastroenterite, meningite e infecções respiratórias, sua presença é uma ameaça à saúde humana (Sendji et al, 2018). Suas propriedades para ser considerado indicador complementar para melhorar a avaliação da qualidade microbiológica da água são: estabilidade e resistência em variadas matrizes de água, sua maior abundância relativa a outros vírus entéricos, contínua detecção em esgotos e ter especificidade do hospedeiro humano (Lima et al, 2022;Rames et al, 2016).…”

A Contamination Predictive Model for Escherichia coli in Rural Communities Dug Shallow Wells

“…In the model diagnostic analysis, four sample points were found that are possible leverage points (5,19,28,35), characterized for demonstrating values higher than 2p/n [36], where p is the number of free parameters of the model and n is the sample size. On the other hand, no cases showed Cook's distance greater than 1 [37], indicating no evidence of influential points.…”

“…The model intercept (β0 at Equation ( 2)) can be seen in Table 6, as well as regression coefficient estimates (βm at Equation ( 2)), the standard error, statistical values for estimates significance analysis, and reasons for chance. In the model diagnostic analysis, four sample points were found that are possible leverage points (5,19,28,35), characterized for demonstrating values higher than 2p/n [36], where p is the number of free parameters of the model and n is the sample size. On the other hand, no cases showed Cook's distance greater than 1 [37], indicating no evidence of influential points.…”

“…Contaminated water consumption can cause a series of waterborne diseases, mainly infections related to pathogenic organisms' presence in humans and animals [14][15][16]. Identifying these microorganisms and the inactivate pathogens present in water is the subject of several studies [17][18][19]. However, verifying the level of contamination is usually done through physical-chemical and microbiological analyses [20,21], demanding high costs and time to obtain adequate information.…”