Category Archives: Microbial contaminants

Bacterial contamination of drinking water and health, Egypt

Ouf SA, Yehia RS, Ouf AS, Abdul-Rahim RF. Bacterial contamination and health risks of drinking water from the municipal non-government managed water treatment plants. Environmental monitoring and assessment. 2018 Oct 29;190(11):685. doi: 10.1007/s10661-018-7054-z.

Water quality and bacterial contamination from 18 drinking water municipal plants in three locations at Giza governorate were investigated. The average total count of bacteria detected after four stages of treatments in the investigated plants was 32 CFU/1 mL compared to 2330 cfu/mL for raw water, with a reduction percentage of 98.6. Although there is a relatively high removal percent of bacterial contamination from the water sources, however, several bacterial pathogens were identified in the produced water prepared for drinking including Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, and Shigella spp. After 3 days of water incubation at 30 °C, the amount of bacterial endotoxins ranged from 77 to 137 ng/mL in the water produced from the municipal plants compared to 621-1260 ng/mL for untreated water. The main diseases reported from patients attending different clinics and hospitals during summer 2014 at the surveyed locations and assuredly due to drinking water from these plants indicated that diarrheas and gastroenteritis due to E. coli and Campylobacter jejuni constituted 65.7% of the total patients followed by bacillary dysentery or shigellosis due to Shigella spp. (7.9%) and cholera due to Vibrio cholera (7.2%). There was an increase in serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) as well as urea and creatinine values of guinea pigs consuming water produced from the non-governmental plants for 6 months indicating remarkable liver and kidney damages. Histological sections of liver and kidney from the tested animal revealed liver having ballooning degeneration of hepatocytes and distortion and fragmentation of the nuclei, while the section of the kidney showed irregularly distributed wrinkled cells, degenerated Bowman’s capsule, congested blood vessels, and inflammatory cells.

Exposure routes and health effects of microcystins

Massey IY, Yang F, Ding Z, Yang S, Guo J, Tezi C, Al-Osman M, Kamegni RB, Zeng W. Exposure Routes and Health Effects of Microcystins on Animals and Humans: A Mini-review. Toxicon. 2018 Jul 9. pii: S0041-0101(18)30306-4. doi: 10.1016/j.toxicon.2018.07.010.

Microcystins (MCs) pollution has quickly risen in infamy and has become a major problem to public health worldwide. MCs are a group of monocyclic hepatotoxic peptides, which are produced by some bloom-forming cyanobacteria in water. More than 100 different MCs variants posing a great threat to animals and humans due to their potential carcinogenicity have been reported. To reduce MCs risks, the World Health Organization has set a provisional guideline of 1 µg/L MCs in human’s drinking water. This paper provides an overview of exposure routes of MCs into the human system and health effects on different organs after MCs exposure including the liver, intestine, brain, kidney, lung, heart and reproductive system. In addition, some evidences on human poisoning and deaths associated with MCs exposure are presented. Finally, in order to protect human life against the health threats posed by MCs, this paper also suggests some directions for future research that can advance MCs control and minimize human exposure to MCs.

Transmission of Helicobacter pylori

Mladenova I, Durazzo M. Transmission of Helicobacter pylori. Minerva Gastroenterol Dietol. 2018 Feb 19. doi: 10.23736/S1121-421X.18.02480-7.

The exact modes and routes of transmission of Helicobacter pylori (H. pylori) infection remain unproven. Studies showed that H. pylori bacteria can spread directly from one person to the other, or indirectly from an infected person to the environment. Presently, interpersonal pathways are more probable than environmental exposure routes. Person to person transmission can be mainly fecal-oral or oral-oral. In the last 30 years many authors have investigated the main potential sources of H. pylori infections, vectors and risk factors for both fecal-oral and oral-oral routes of transmission, eating of contaminated food, drinking of contaminated water, and exposure to animals. They have tried to isolate H. pylori from feces, saliva, dental plaque. These aspects are the basis for the effective prevention of both H. pylori acquisition and gastroduodenal pathology associated with it. These issues will be discussed in this narrative review.

Malaria Deaths Decline in Age of Global Warming

“In the visualisations below we provide estimates of the total number of deaths from the World Health Organization (WHO) from 2000 to 2015, and the Institute of Health Metrics and Evaluation (IHME), Global Burden of Disease (GBD) from 1990 to 2016. These estimates are notably different across various countries which affects the total number of reported deaths. IHME figures, as shown below, tend to be higher; they report deaths greater than 720,000 in 2015 versus only 438,000 from the WHO.” click here

Drinking water contamination with Helicobacter pylori, Peru

Boehnke KF, Brewster RK, Sánchez BN, Valdivieso M, Bussalleu A, Guevara M, Saenz CG, Alva SO, Gil E, Xi C. An assessment of drinking water contamination with Helicobacter pylori in Lima, Peru. Helicobacter. 2018 Jan 8. doi: 10.1111/hel.12462.

BACKGROUND: Helicobacter pylori is a gut bacterium that is the primary cause of gastric cancer. H. pylori infection has been consistently associated with lack of access to sanitation and clean drinking water. In this study, we conducted time-series sampling of drinking water in Lima, Peru, to examine trends of H. pylori contamination and other water characteristics.

MATERIALS AND METHODS: Drinking water samples were collected from a single faucet in Lima’s Lince district 5 days per week from June 2015 to May 2016, and pH, temperature, free available chlorine, and conductivity were measured. Quantities of H. pylori in all water samples were measured using quantitative polymerase chain reaction. Relationships between the presence/absence and quantity of H. pylori and water characteristics in the 2015-2016 period were examined using regression methods accounting for the time-series design.

RESULTS: Forty-nine of 241 (20.3%) of drinking water samples were contaminated with H. pylori. Statistical analyses identified no associations between sampling date and the likelihood of contamination with H. pylori. Statistically significant relationships were found between lower temperatures and a lower likelihood of the presence of H. pylori (P < .05), as well as between higher pH and higher quantities of H. pylori (P < .05).

CONCLUSIONS: This study has provided evidence of the presence of H. pylori DNA in the drinking water of a single drinking water faucet in the Lince district of Lima. However, no seasonal trends were observed. Further studies are needed to determine the presence of H. pylori in other drinking water sources in other districts in Lima, as well as to determine the viability of H. pylori in these water sources. Such studies would potentially allow for better understanding and estimates of the risk of infection due to exposure to H. pylori in drinking water.

Pepper mild mottle virus as a surrogate of human enteric viruses

Shirasaki N, Matsushita T, Matsui Y, Yamashita R. Evaluation of the suitability of a plant virus, pepper mild mottle virus, as a surrogate of human enteric viruses for assessment of the efficacy of coagulation-rapid sand filtration to remove those viruses. Water Research. 2017 Nov 21;129:460-469. doi: 10.1016/j.watres.2017.11.043.

Here, we evaluated the removal of three representative human enteric viruses – adenovirus (AdV) type 40, coxsackievirus (CV) B5, and hepatitis A virus (HAV) IB – and one surrogate of human caliciviruses – murine norovirus (MNV) type 1 – by coagulation-rapid sand filtration, using water samples from eight water sources for drinking water treatment plants in Japan. The removal ratios of a plant virus (pepper mild mottle virus; PMMoV) and two bacteriophages (MS2 and φX174) were compared with the removal ratios of human enteric viruses to assess the suitability of PMMoV, MS2, and φX174 as surrogates for human enteric viruses. The removal ratios of AdV, CV, HAV, and MNV, evaluated via the real-time polymerase chain reaction (PCR) method, were 0.8-2.5-log10 when commercially available polyaluminum chloride (PACl, basicity 1.5) and virgin silica sand were used as the coagulant and filter medium, respectively. The type of coagulant affected the virus removal efficiency, but the age of silica sand used in the rapid sand filtration did not. Coagulation-rapid sand filtration with non-sulfated, high-basicity PACls (basicity 2.1 or 2.5) removed viruses more efficiently than the other aluminum-based coagulants. The removal ratios of MS2 were sometimes higher than those of the three human enteric viruses and MNV, whereas the removal ratios of φX174 tended to be smaller than those of the three human enteric viruses and MNV. In contrast, the removal ratios of PMMoV were similar to and strongly correlated with those of the three human enteric viruses and MNV. Thus, PMMoV appears to be a suitable surrogate for human enteric viruses for the assessment of the efficacy of coagulation-rapid sand filtration to remove viruses.

Vibrio Pathogens a Health Concern in Sub-Saharan Africa

Osunla CA, Okoh AI. Vibrio Pathogens: A Public Health Concern in Rural Water Resources in Sub-Saharan Africa. Int J Environ Res Public Health. 2017 Oct 7;14(10). pii: E1188. doi: 10.3390/ijerph14101188.

Members of the Vibrio genus are autochthonous inhabitants of aquatic environments and play vital roles in sustaining the aquatic milieu. The genus comprises about 100 species, which are mostly of marine or freshwater origin, and their classification is frequently updated due to the continuous discovery of novel species. The main route of transmission of Vibrio pathogens to man is through drinking of contaminated water and consumption inadequately cooked aquatic food products. In sub-Saharan Africa and much of the developing world, some rural dwellers use freshwater resources such as rivers for domestic activities, bathing, and cultural and religious purposes. This review describes the impact of inadequately treated sewage effluents on the receiving freshwater resources and the associated risk to the rural dwellers that depends on the water. Vibrio infections remain a threat to public health. In the last decade, Vibrio disease outbreaks have created alertness on the personal, economic, and public health uncertainties associated with the impact of contaminated water in the aquatic environment of sub-Saharan Africa. In this review, we carried out an overview of Vibrio pathogens in rural water resources in Sub-Saharan Africa and the implication of Vibrio pathogens on public health. Continuous monitoring of Vibrio pathogens among environmental freshwater and treated effluents is expected to help reduce the risk associated with the early detection of sources of infection, and also aid our understanding of the natural ecology and evolution of Vibrio pathogens.