Tag Archives: waterborne disease

Waterborne Disease Associated with US Environmental Waters, 2013-2014

McClung RP, Roth DM, Vigar M, Roberts VA, Kahler AM, Cooley LA, Hilborn ED, Wade TJ, Fullerton KE, Yoder JS, Hill VR. Waterborne Disease Outbreaks Associated With Environmental and Undetermined Exposures to Water – United States, 2013-2014. MMWR Morb Mortal Wkly Rep. 2017 Nov 10;66(44):1222-1225. doi: 10.15585/mmwr.mm6644a4.

Waterborne disease outbreaks in the United States are associated with a wide variety of water exposures and are reported annually to CDC on a voluntary basis by state and territorial health departments through the National Outbreak Reporting System (NORS). A majority of outbreaks arise from exposure to drinking water (1) or recreational water (2), whereas others are caused by an environmental exposure to water or an undetermined exposure to water. During 2013-2014, 15 outbreaks associated with an environmental exposure to water and 12 outbreaks with an undetermined exposure to water were reported, resulting in at least 289 cases of illness, 108 hospitalizations, and 17 deaths. Legionella was responsible for 63% of the outbreaks, 94% of hospitalizations, and all deaths. Outbreaks were also caused by Cryptosporidium, Pseudomonas, and Giardia, including six outbreaks of giardiasis caused by ingestion of water from a river, stream, or spring. Water management programs can effectively prevent outbreaks caused by environmental exposure to water from human-made water systems, while proper point-of-use treatment of water can prevent outbreaks caused by ingestion of water from natural water systems.

Waterborne Disease Outbreaks Associated with US Drinking Water, 2013-2014

Benedict KM, Reses H, Vigar M, Roth DM, Roberts VA, Mattioli M, Cooley LA, Hilborn ED, Wade TJ, Fullerton KE, Yoder JS, Hill VR. Surveillance for Waterborne Disease Outbreaks Associated with Drinking Water – United States, 2013-2014. MMWR Morb Mortal Wkly Rep. 2017 Nov 10;66(44):1216-1221. doi: 10.15585/mmwr.mm6644a3.

Provision of safe water in the United States is vital to protecting public health (1). Public health agencies in the U.S. states and territories* report information on waterborne disease outbreaks to CDC through the National Outbreak Reporting System (NORS) (https://www.cdc.gov/healthywater/surveillance/index.html). During 2013-2014, 42 drinking water-associated† outbreaks were reported, accounting for at least 1,006 cases of illness, 124 hospitalizations, and 13 deaths. Legionella was associated with 57% of these outbreaks and all of the deaths. Sixty-nine percent of the reported illnesses occurred in four outbreaks in which the etiology was determined to be either a chemical or toxin or the parasite Cryptosporidium. Drinking water contamination events can cause disruptions in water service, large impacts on public health, and persistent community concern about drinking water quality. Effective water treatment and regulations can protect public drinking water supplies in the United States, and rapid detection, identification of the cause, and response to illness reports can reduce the transmission of infectious pathogens and harmful chemicals and toxins.

Childhood Diarrhea Prevalent in Nomadic Community, Ethiopia

Bitew BD, Woldu W, Gizaw Z. Childhood diarrheal morbidity and sanitation predictors in a nomadic community. Ital J Pediatr. 2017 Oct 6;43(1):91. doi: 10.1186/s13052-017-0412-6.

BACKGROUND: Diarrhea remains a leading killer of young children on the globe despite the availability of simple and effective solutions to prevent and control it. The disease is more prevalent among under – five children (U5C) in the developing world due to lack of sanitation. A child dies every 15 s from diarrheal disease caused largely by poor sanitation. Nearly 90% of diarrheal disease is attributed to inadequate sanitation. Even though, the health burden of diarrheal disease is widely recognized at global level, its prevalence and sanitation predictors among a nomadic population of Ethiopia are not researched. This study was therefore designed to assess the prevalence of childhood diarrheal disease and sanitation predictors among a nomadic people in Hadaleala district, Afar region, Northeast Ethiopia.

METHODS: A community based cross-sectional study design was carried out to investigate diarrheal disease among U5C. A total of 704 households who had U5C were included in this study and the study subjects were recruited by a multistage cluster sampling technique. Data were collected using a structured questionnaire and an observational checklist. All the mothers of U5C found in the selected clusters were interviewed. Furthermore, the living environment was observed. Univariable binary logistic regression analysis was used to choose variables for the multivariable binary logistic regression analysis on the basis of p- value less than 0.2. Finally, multivariable binary logistic regression analysis was used to identify variables associated with childhood diarrhea disease on the basis of adjusted odds ratio (AOR) with 95% confidence interval (CI) and p < 0.05.

RESULTS: The two weeks period prevalence of diarrheal disease among U5C in Hadaleala district was 26.1% (95% CI: 22.9 – 29.3%). Childhood diarrheal disease was statistically associated with unprotected drinking water sources [AOR = 2.449, 95% CI = (1.264, 4.744)], inadequate drinking water service level [AOR = 1.535, 95% CI = (1.004, 2.346)], drinking water sources not protected from animal contact [AOR = 4.403, 95% CI = (2.424, 7.999)], un-availability of any type of latrine [AOR = 2.278, 95% CI = (1.045, 4.965)], presence of human excreta in the compound [AOR = 11.391, 95% CI = (2.100, 61.787)], not washing hand after visiting toilet [AOR = 16.511, 95% CI = (3.304, 82.509)], and live in one living room [AOR = 5.827, 95% CI = (3.208, 10.581)].

CONCLUSION: Childhood diarrheal disease was the common public health problem in Hadaleala district. Compared with the national and regional prevalence of childhood diarrhea, higher prevalence of diarrhea among U5C was reported. Types of drinking water sources, households whose water sources are shared with livestock, volume of daily water collected, availability of latrine, presence of faeces in the compound, hand washing after visiting the toilet and number of rooms were the sanitation predictors associated with childhood diarrhea. Therefore, enabling the community with safe and continuous supply of water and proper disposal of wastes including excreta is necessary with particular emphasis to the rural nomadic communities.

Cholera Outbreak from Contaminated Lake Water, Uganda

Oguttu DW, Okullo A, Bwire G, Nsubuga P, Ario AR. Cholera outbreak caused by drinking lake water contaminated with human faeces in Kaiso Village, Hoima District, Western Uganda, October 2015. Infect Dis Poverty. 2017 Oct 10;6(1):146. doi: 10.1186/s40249-017-0359-2.

BACKGROUND: On 12 October 2015, a cholera outbreak involving 65 cases and two deaths was reported in a fishing village in Hoima District, Western Uganda. Despite initial response by the local health department, the outbreak persisted. We conducted an investigation to identify the source and mode of transmission, and recommend evidence-led interventions to control and prevent cholera outbreaks in this area.

METHODS: We defined a suspected case as the onset of acute watery diarrhoea from 1 October to 2 November 2015 in a resident of Kaiso Village. A confirmed case was a suspected case who had Vibrio cholerae isolated from stool. We found cases by record review and active community case finding. We performed descriptive epidemiologic analysis for hypothesis generation. In an unmatched case-control study, we compared exposure histories of 61 cases and 126 controls randomly selected among asymptomatic village residents. We also conducted an environmental assessment and obtained meteorological data from a weather station.

RESULTS: We identified 122 suspected cases, of which six were culture-confirmed, 47 were confirmed positive with a rapid diagnostic test and two died. The two deceased cases had onset of the disease on 2 October and 10 October, respectively. Heavy rainfall occurred on 7-11 October; a point-source outbreak occurred on 12-15 October, followed by continuous community transmission for two weeks. Village residents usually collected drinking water from three lakeshore points – A, B and C: 9.8% (6/61) of case-persons and 31% (39/126) of control-persons were found to usually use point A, 21% (13/61) of case-persons and 37% (46/126) of control-persons were found to usually use point B (OR = 1.8, 95% CI: 0.64-5.3), and 69% (42/61) of case-persons and 33% (41/126) of control-persons were found to usually use point C (OR = 6.7; 95% CI: 2.5-17) for water collection. All case-persons (61/61) and 93% (117/126) of control-persons reportedly never treated/boiled drinking water (OR = ∞, 95% CI Fisher: 1.0 – ∞). The village’s piped water system had been vandalised and open defecation was common due to a lack of latrines. The lake water was found to be contiminated due to a gully channel that washed the faeces into the lake at point C.

CONCLUSIONS: This outbreak was likely caused by drinking lake water contaminated by faeces from a gully channel. We recommend treatment of drinking water, fixing the vandalised piped-water system and constructing latrines.

Waterborne Norovirus Outbreaks in Two Undisinfected Groundwater Wells, Finland

Kauppinen A, Pitkänen T, Miettinen IT. Persistent Norovirus Contamination of Groundwater Supplies in Two Waterborne Outbreaks. Food and environmental virology. 2017 Oct 11. doi: 10.1007/s12560-017-9320-6.

Microbiological contamination of groundwater supplies causes waterborne outbreaks worldwide. In this study, two waterborne outbreaks related to microbiological contamination of groundwater supplies are described. Analyses of pathogenic human enteric viruses (noroviruses and adenoviruses), fecal bacteria (Campylobacter spp. and Salmonella spp.), and indicator microbes (E. coli, coliform bacteria, intestinal enterococci, Clostridium perfringens, heterotrophic plate count, somatic and F-specific coliphages) were conducted in order to reveal the cause of the outbreaks and to examine the effectiveness of the implemented management measures. Moreover, the long-term persistence of noro- and adenovirus genomes was investigated. Noroviruses were detected in water samples from both outbreaks after the intrusion of wastewater into the drinking water sources. In the outbreak I, the removal efficiency of norovirus genome (3.0 log10 removal) in the sand filter of onsite wastewater treatment system (OWTS) and during the transport through the soil into the groundwater well was lower than the removal efficiencies of E. coli, coliform bacteria, intestinal enterococci, and spores of C. perfringens (6.2, 6.0, > 5.9, and > 4.8 log10 removals, respectively). In the outbreak II, cleaning of massively contaminated groundwater well and drinking water distribution network proved challenging, and noro- and adenovirus genomes were detected up to 3 months (108 days). The long-term persistence study showed that noro- and adenovirus genomes can remain detectable in the contaminated water samples up to 1277 and 1343 days, respectively. This study highlights the transport and survival properties of enteric viruses in the environment explaining their potency to cause waterborne outbreaks.

V. cholerae can survive in the river systems, Bangladesh

Grant SL, Tamason CC, Hoque BA, Jensen PK. Drinking cholera: salinity levels and palatability of drinking water in coastal Bangladesh. Trop Med Int Health. 2015 Apr;20(4):455-61. doi: 10.1111/tmi.12455. 

OBJECTIVES: To measure the salinity levels of common water sources in coastal Bangladesh and explore perceptions of water palatability among the local population to investigate the plausibility of linking cholera outbreaks in Bangladesh with ingestion of saline-rich cholera-infected river water.

METHODS: Hundred participants took part in a taste-testing experiment of water with varying levels of salinity. Salinity measurements were taken of both drinking and non-drinking water sources. Informal group discussions were conducted to gain an in-depth understanding of water sources and water uses.

RESULTS: Salinity levels of non-drinking water sources suggest that the conditions for Vibrio cholerae survival exist 7-8 days within the local aquatic environment. However, 96% of participants in the taste-testing experiment reported that they would never drink water with salinity levels that would be conducive to V. cholerae survival. Furthermore, salinity levels of participant’s drinking water sources were all well below the levels required for optimal survival of V. cholerae. Respondents explained that they preferred less salty and more aesthetically pleasing drinking water.

CONCLUSION: Theoretically, V. cholerae can survive in the river systems in Bangladesh; however, water sources which have been contaminated with river water are avoided as potential drinking water sources. Furthermore, there are no physical connecting points between the river system and drinking water sources among the study population, indicating that the primary driver for cholera cases in Bangladesh is likely not through the contamination of saline-rich river water into drinking water sources.

Effectiveness of Household Water Treatment is Inconsistent

Rosa G, Clasen T. Consistency of Use and Effectiveness of Household Water Treatment among Indian Households Claiming to Treat Their Water. Am J Trop Med Hyg. 2017 Jul;97(1):259-270. doi: 10.4269/ajtmh.16-0428.

Household water treatment (HWT) can improve drinking water quality and prevent disease if used correctly and consistently by populations at risk. Current international monitoring estimates by the Joint Monitoring Programme for water and sanitation suggest that at least 1.1 billion people practice HWT. These estimates, however, are based on surveys that may overstate the level of consistent use and do not address microbial effectiveness. We sought to assess how HWT is practiced among households identified as HWT users according to these monitoring standards. After a baseline survey (urban: 189 households, rural: 210 households) to identify HWT users, 83 urban and 90 rural households were followed up for 6 weeks. Consistency of reported HWT practices was high in both urban (100%) and rural (93.3%) settings, as was availability of treated water (based on self-report) in all three sampling points (urban: 98.8%, rural: 76.0%). Nevertheless, only 13.7% of urban and 25.8% of rural households identified at baseline as users of adequate HWT had water free of thermotolerant coliforms at all three water sampling points. Our findings raise questions about the value of the data gathered through the international monitoring of HWT as predictors of water quality in the home, as well as questioning the ability of HWT, as actually practiced by vulnerable populations, to reduce exposure to waterborne diseases.