An outbreak of Salmonella Typhimurium 9 at a school camp linked to contamination of rainwater tanks

In March 2007, an outbreak of gastroenteritis was identified at a school camp in rural Victoria, Australia, affecting about half of a group of 55 students. A comprehensive investigation was initiated to identify the source. Twenty-seven attendees were found to have abdominal pain, diarrhoea and nausea (attack rate 49%). Of 11 faecal specimens tested all were positive for Salmonella Typhimurium definitive phage type 9 (DT9). Of four samples taken from the untreated private water supply, two were positive for DT9. Drinking water from containers filled from rainwater tanks [relative risk (RR) 3.2, P=0.039] and participation in two recreational activities - flying fox (RR 5.3, P=0.011), and beam-balance (RR 3.9, P=0.050) - were indicative of a link with illness. Environmental and epidemiological investigations suggested rainwater collection tanks contaminated with DT9 as being the cause of the outbreak. Increased use of rainwater tanks may heighten the risk of waterborne disease outbreaks unless appropriate preventative measures are undertaken.     

Consumption of untreated tank rainwater and gastroenteritis among young children in South Australia

BACKGROUND: Tank rainwater is a source of untreated drinking water in Australia and elsewhere. The aim of this study was to determine whether the risk of gastroenteritis among children who drank tank rainwater differed from that of children who drank treated public mains water. METHODS: A cohort study of 1,016 4- to 6-year old children who drank rainwater or treated mains water in rural South Australia was undertaken in 1999. Parents kept a daily diary of their child's gastrointestinal symptoms and water consumption for a period of 6 weeks. Data on respiratory illness and other risk factors for gastroenteritis were also collected. RESULTS: The incidence of gastroenteritis among children was 3.8-5.3 episodes per child-year, but most episodes (60%) lasted just 1 day. No increase in odds of gastroenteritis was observed among children who drank rainwater compared with treated mains water. The adjusted odds ratio for gastroenteritis associated with rainwater consumption compared with mains consumption was 0.84 (95% confidence interval 0.63-1.13). CONCLUSIONS: Gastroenteritis was found to be a significant cause of morbidity among young children. Young children, who were regular consumers of tank rainwater, were at no greater odds of gastroenteritis than those who drank treated public mains water.     

A foodborne outbreak of Campylobacter jejuni (O:33) infection associated with tuna salad: a rare strain in an unusual vehicle.

We report a foodborne outbreak of Campylobacter jejuni infection in a summer camp. Outbreak-related cases occurred in 79 persons including 3 secondary cases in campers. Campylobacter jejuni was isolated from stool specimens from 16 of 21 patients who submitted a sample; 13 viable isolates were serotyped and all were serotype O:33 (somatic O scheme) or HL:18 (heat-labile scheme), and biotype III (Lior scheme). This serotype is widely distributed geographically but rarely isolated from humans. Samples of water from the wells supplying the camp were negative for faecal coliforms, and raw milk had not been served in the camp. A matched (1:1) case-control study identified tuna salad served for lunch on 19 July as the likely food item associated with illness (matched odds ratio=22; 95% confidence intervals (CI)=3.6-908). Swimming in the camp pool and other recreational water use in area lakes by the campers were not statistically associated with illness. The precise mechanism of introduction of the organism into the tuna salad remains unknown; contamination most likely occurred through cross-contamination with another food product, the hands of a food handler, or a work surface. Several deficiencies in the operation of the camp kitchen were identified. In Wisconsin, kitchens of such camps are subject to different inspection rules than restaurants. Camp staff, administrators, counselors, food managers, and infirmary staff, should fulfil important roles in their respective areas to prevent future outbreaks.     

Emerging genotype (GGIIb) of norovirus in drinking water, Sweden

From May through June 2001, an outbreak of acute gastroenteritis that affected at least 200 persons occurred in a combined activity camp and conference center in Stockholm County. The source of illness was contaminated drinking water obtained from private wells. The outbreak appears to have started with sewage pipeline problems near the kitchen, which caused overflow of the sewage system and contaminated the environment. While no pathogenic bacteria were found in water or stools specimens, norovirus was detected in 8 of 11 stool specimens and 2 of 3 water samples by polymerase chain reaction. Nucleotide sequencing of amplicons from two patients and two water samples identified an emerging genotype designated GGIIb, which was circulating throughout several European countries during 2000 and 2001. This investigation documents the first waterborne outbreak of viral gastroenteritis in Sweden, where nucleotide sequencing showed a direct link between contaminated water and illness.     

Waterborne outbreak of gastroenteritis in a religious summer camp in Norway, 2002

In July 2002 an outbreak of acute gastroenteritis occurred in a camp facility in western Norway during a 10-day seminar, with around 300 guests staying overnight and several day-time visitors. Environmental and epidemiological investigations were conducted to identify and eliminate the source of the outbreak, prevent further transmission and describe the impact of the outbreak. Of 205 respondents, 134 reported illness (attack rate, 65%). Multivariate analysis showed drinking water and taking showers at the camp-site to be significant risk factors. Secondary person-to-person spread among visitors or outside of the camp was found. Norovirus was identified in 8 out of the 10 stool samples analysed. Indicators of faecal contamination were found in samples from the private untreated water supply, but norovirus could not be identified. This outbreak investigation illustrates the importance of norovirus as a cause of waterborne illness and the additional exacerbation through person-to-person transmission in closed settings. Since aerosol transmission through showering contributed to the spread, intensified hygienic procedures such as isolation of cases and boiling of water may not be sufficient to terminate outbreaks with norovirus.     

Gastroenteritis associated with accidental contamination of drinking water with partially treated water

Due to human error, drinking water supplied to a new housing estate in The Netherlands was contaminated with grey water. The cohort of 921 accidentally exposed households (area A) had a higher attack rate for diarrhoea (54.1%) than a non-exposed cohort of 1529 households from an adjacent area (B) (24%) (RR 2.3, 95% CI 1.9-2.7). Household water score showed a dose-response with illness, in both areas A and B. For each 1000 inhabitants, 19.8 cases in area A, 7.0 cases in control area B (RRAB 2.2, 95% CI 1.3-3.8) and 3.3 cases in a more distant control area C (RRAC 4.6, 95% CI 2.7-8.0) were diagnosed with gastroenteritis by their general practitioner. A gastroenteritis outbreak associated with consumption of contaminated drinking water was observed in the exposed area. The use of grey water was banned in 2003, with the exception of rainwater use for flushing toilets. The risk of rainwater use is currently being investigated.     

Faecal contamination of a municipal drinking water distribution system in association with Campylobacter jejuni infections

After heavy rains Campylobacter jejuni together with high counts of Escherichia coli, other coliforms and intestinal enterococci were detected from drinking water of a municipal distribution system in eastern Finland in August 2004. Three patients with a positive C. jejuni finding, who had drunk the contaminated water, were identified and interviewed. The pulsed-field gel electrophoresis (PFGE) genotypes from the patient samples were identical to some of the genotypes isolated from the water of the suspected contamination source. In addition, repetitive DNA element analysis (rep-PCR) revealed identical patterns of E. coli and other coliform isolates along the distribution line. Further on-site technical investigations revealed that one of the two rainwater gutters on the roof of the water storage tower had been in an incorrect position and rainwater had flushed a large amount of faecal material from wild birds into the drinking water. The findings required close co-operation between civil authorities, and application of cultivation and genotyping techniques strongly suggested that the municipal drinking water was the source of the infections. The faecal contamination associated with failures in cleaning and technical management stress the importance of instructions for waterworks personnel to perform maintenance work properly.     

Investigation into a school enterovirus outbreak using PCR detection and serotype identification based on the 5' non-coding region

A summer camp was followed by an outbreak of illness involving around 90 children. Investigations included individual questionnaires, inspection of the camp facilities, and laboratory analysis of water and clinical samples. Contamination of drinking and swimming water was demonstrated. An enterovirus was detected by polymerase chain reaction (PCR) and/or culture in 4/4 cerebrospinal fluid samples, 9/15 (60%) stool samples from symptomatic children and 2/9 (22%) stool samples from asymptomatic children. The virus was identified as an echovirus 3 by sequencing and phylogenetic analysis of a short 5' non-coding region (NCR) PCR product. Viruses from the outbreak clustered closely and an echovirus 3 from a temporally associated non-outbreak case could be readily distinguished. Despite the lack of a standardized approach, direct molecular detection and identification of enteroviruses is an efficient epidemiological tool. Here the 5'-NCR was successfully used for both detection and 'serotyping', and the close genetic relatedness of isolates was proven.     

Epidemiologic investigation of a Yersinia camp outbreak linked to a food handler

In July 1981, an outbreak of gastroenteritis occurred at a summer diet camp. Of the 455 campers and staff, 35 per cent developed an illness characterized by abdominal pain, fever, diarrhea, and/or nausea and vomiting. A total of 53 per cent experienced abdominal pain. Seven persons were hospitalized, five of whom had appendectomies. Yersinia enterocolitica serogroup 0:8 was isolated from 37 (54 per cent) of 69 persons examined, including the camp cook and three assistants. An epidemiologic investigation demonstrated that illness was associated with consumption of reconstituted powdered milk and/or chow mein . Y. enterocolitica serogroup 0:8 was subsequently isolated from milk, the milk dispenser, and leftover chow mein . Information obtained during the investigation suggested that the Yersinia had been introduced by a food handler during food-processing procedures.     

Assessing Experiences of Children Who Attended a Camp for Children with Cancer and Their Siblings: A Preliminary Study

Summer camps are commonly implemented as a psychosocial intervention for children with chronic illnesses; however, there have been few published consumer (parent and child) satisfaction evaluations of summer camps. Such evaluations are important both for improving existing services for children and families, as well as to build an empirical understanding of camp interventions. To illustrate the use of a program evaluation methodology within the context of a chronic illness summer camp, a program evaluation was conducted of a camp for children with cancer and their siblings. Results from the evaluation indicated that parents and children were highly satisfied with the camp experience, ranging from the food, staff, facilities, to campers’ activities. Campers reported that the recreation opportunities, peer support, and respite from their lives at home were reasons they appreciated the camp experience. Parents reported that peer support for their children, respite for themselves and their children, and improvements to their child’s behaviors and level of independence were helpful features of the camp experience.     

雨水的资源化利用

中国是一个水资源缺乏的国家,雨水作为一种自然资源,污染轻、处理容易,经简单的处理即能用作生活杂用水,经有效处理也可用作生活饮用水。但雨水利用率很低,若能在排放系统的设计和地面覆盖问题上考虑雨水的资源化利用,充分合理地利用雨水资源,既有利于解决城市水资源危机、减轻城区水涝灾害,又能减轻水体污染和改善城市生态环境。     

Cryptosporidiosis outbreak at a summer camp--North Carolina, 2009

In July 2009, local, regional, state, and federal public health officials investigated a cryptosporidiosis outbreak at a youth summer camp in North Carolina. The investigation identified 46 laboratory-confirmed and probable cryptosporidiosis cases at the camp. Analyses of data from a retrospective cohort study of staff members revealed that eating ham from a sandwich bar that included camp-grown raw produce and sharing a cabin with an ill person were significantly associated with illness. Cryptosporidium isolates from stool specimens of livestock and humans at the camp were of the identical Cryptosporidium parvum subtype, IIaA17G2R1, indicating that zoonotic transmission had occurred, and suggesting a link not implicated by traditional epidemiologic methods. This investigation underscores the importance of reducing the risk for Cryptosporidium transmission in camp settings and the value of Cryptosporidium subtyping as a tool to elucidate cryptosporidiosis epidemiology.     

An outbreak of phototoxic dermatitis due to limes

During the week beginning July 29, 1984, 12 children in a day camp in a suburb of Baltimore, Maryland, were noted to have skin eruptions consistent with phototoxic dermatitis. These eruptions were confined to the hands, wrists, and forearms, and appeared as discrete and confluent polymorphous patches and linear streaks. These eruptions were also macular, hyperpigmented, and nonpruritic. Clinical examination revealed that 97 (16%) of 622 children, seven (7%) of 104 counselors, and no adult staff members had a similar rash. Onsets of the rash ranged from July 19-August 11, with peak occurrence on July 25-27. All camp members were white. Sex did not vary significantly between those affected and not affected. The mean age (5.3 years) of affected children was significantly different from the mean age (6.9 years) of unaffected children (p less than 0.001). Attack rates for the eight camp units were highest in two units (57% and 74%, respectively) and ranged between 0-6% for the other six units. Activities involving work with hands by various camp units were investigated. Only exposure to making pomander balls (sachets) in arts and crafts class (when other activities were controlled for) was significantly associated with illness (p less than 0.03). In making pomander balls, children punctured the skin of limes (the principal component) with scissors, releasing oils known to contain photoreactive furocoumarin (psoralen) compounds. These compounds evidently coated the children's skin and, upon exposure to the sun, caused a phototoxic dermatitis. An environmental and botanical survey of the camp did not reveal other phototoxic agents with which campers may have had contact. This is one of the largest reported outbreaks of phototoxic dermatitis and the first in which a citrus fruit was implicated on a large scale.     

Knowledge of measures to safeguard harvested rainwater quality in rural domestic households

Given the possibility of waterborne diseases caused by inappropriate rainwater harvesting systems, a survey was conducted in Uganda to assess existing knowledge of both physical and non-physical measures that safeguard harvested rainwater. Households who had received rainwater tanks were assessed on issues related to harvested rainwater quality. The study shows that 84% of respondents were aware of various sources of rainwater contamination, but only 5% were aware that they needed to adjust use of rainwater, depending on whether they cleaned the tank or not. Most of the respondents were not aware that gutter cleaning was necessary to improve water quality. Indeed, as the water from the collection surface is channelled through gutters, a number of measures need to be taken to control the entry of contaminations and subsequent growth of pathogens in the tank, e.g. first flush diverts, installation of filters, chemical use and mesh cleaning. The majority, however, did not take adequate care of the gutters and this impacts on health and social livelihood. Overall, the findings emphasize the need to provide more information to households when installing water harvesting tanks to ensure that the harvested rainwater is of high quality.     

Rainwater harvesting: quality assessment and utilization in The Netherlands

The use of roof-collected rainwater as a freely available and sustainable alternative to drinking water produced by drinking water companies increases worldwide. Initially, rainwater is free of microbial contamination, but it may become contaminated by animals and humans or, alternatively, human pathogens may grow in stored rainwater resulting in a significant human health risk from infectious diseases. This three-year study demonstrated that rainwater stored in different reservoirs in The Netherlands was frequently faecally contaminated and incidentally contained potential human pathogens such as Campylobacter, Cryptosporidium, Giardia, Aeromonas hydrophila and Legionella. Analysis of samples during a period with variable weather conditions showed a correlation between rainfall intensity and faecal indicator counts and increased detection of pathogens after heavy rainfall incidents. Outside temperature had a limited effect on both the temperature and the microbiological quality of the water in the reservoirs, which did not comply with Dutch drinking water legislation and should thus not be consumed without treatment. In general, a health risk may arise from exposure to pathogens when contaminated droplets are inhaled, ingested or come into contact with the skin. Health risks may be reduced by regular cleaning of the collection, storage and transport means, but to assess their efficacy field intervention studies are required.     

A salmonellosis outbreak linked to internally contaminated pork meat

In August 1995, we investigated an outbreak of salmonellosis among patrons who attended a church camp in southern Sydney. Of the 73 attendees interviewed, 22 reported a gastroenteritis illness within two days of the conclusion of the camp, with one attendee hospitalised. Two stool specimens, one from each of two attendees, were both positive for Salmonella typhimurium phage type 9. A cohort study of 68 attendees established a statistically significant association between illness and the consumption of de-boned roast pork (estimated relative risk infinite, p=0.03) and between illness and the degree of cooking of the pork meat (x² for trend 5.8, p<0.02). The outbreak was most likely caused by consumption of roast pork that had been internally contaminated during the de-boning process. Meat and meat products that may be internally contaminated, such as de-boned meats, should be thoroughly cooked. Guidelines about minimum cooking temperatures of meats liable to internal contamination should be developed for commercial food handlers in Australia.     

Multi-pathogen waterborne disease outbreak associated with a dinner cruise on Lake Michigan

We report an outbreak associated with a dinner cruise on Lake Michigan. This took place on the same day as heavy rainfall, which resulted in 42·4 billion liters of rainwater and storm runoff containing highly diluted sewage being released into the lake. Of 72 cruise participants, 41 (57%) reported gastroenteritis. Stool specimens were positive for Shigella sonnei (n=3), Giardia (n=3), and Cryptosporidium (n=2). Ice consumption was associated with illness (risk ratio 2·2, P=0·011). S. sonnei was isolated from a swab obtained from the one of the boat's ice bins. Environmental inspection revealed conditions and equipment that could have contributed to lake water contaminating the hose used to load potable water onto the boat. Knowledge of water holding and distribution systems on boats, and of potential risks associated with flooding and the release of diluted sewage into large bodies of water, is crucial for public health guidance regarding recreational cruises.     

The influence of climate variation and change on diarrheal disease in the Pacific Islands

Freshwater resources are a high-priority issue in the Pacific region. Water shortage is a serious problem in many small island states, and many depend heavily on rainwater as the source of their water. Lack of safe water supplies is an important factor in diarrheal illness. There have been no previous studies looking specifically at the relationship between climate variability and diarrhea in the Pacific region. We carried out two related studies to explore the potential relationship between climate variability and the incidence of diarrhea in the Pacific Islands. In the first study, we examined the average annual rates of diarrhea in adults, as well as temperature and water availability from 1986 to 1994 for 18 Pacific Island countries. There was a positive association between annual average temperature and the rate of diarrhea reports, and a negative association between water availability and diarrhea rates. In the second study, we examined diarrhea notifications in Fiji in relation to estimates of temperature and rainfall, using Poisson regression analysis of monthly data for 1978-1998. There were positive associations between diarrhea reports and temperature and between diarrhea reports and extremes of rainfall. These results are consistent with previous research and suggest that global climate change is likely to exacerbate diarrheal illness in many Pacific Island countries.     

赴刚果(金)维和部队初期饮用水水质检测

目的对中国赴刚果(金)维和部队驻地的水源水和饮用水进行水质检测,为维和官兵的饮用水安全提供保障。方法采用制式检水检毒箱和水质细菌检验箱,按照GJB1096-1991《军队战时饮用水标准检验方法》对驻地的饮用水源进行实地调查和紧急检测,主要包括感官性状和一般化学指标、毒理指标和微生物指标等共21个项目。结果营区内的部分自来水水样某些指标超标,不符合饮用水标准,如总硬度较高(450 mg/L)、细菌总数和大肠菌群超标(分别100 CFU/ml和3 CFU/L)等;联合国供应的部分瓶装水总硬度偏高(450 mg/L),但基本符合饮用水要求;自带净水设备制备的饮用水质量较高,根据生活饮用水水源水质标准(CJ30202-1993),达到一级水质要求。根据检测结果,对营区环境卫生进行了整治,并使用饮水消毒丸对水质进行消毒以备应急情况下使用。结论刚果(金)维和部队驻地的自来水不符合饮用水卫生标准,为保障维和官兵的用水安全,建议维和部队采用自带净水设备制备的饮用水。     

A primary school outbreak of pharyngoconjunctival fever caused by adenovirus type 3

High rates of absenteeism in a North Queensland primary school, due to eye irritation, fever, headache, and stomach pain, were reported to the Tropical Public Health Unit in October 2000. Subsequent investigation demonstrated that the symptoms were due to adenovirus infection. Symptoms were consistent with a diagnosis of pharyngoconjunctival fever. At the height of the outbreak, about 40 per cent of students were absent. There was a strong association between the development of symptoms, and having been swimming on a recent school camp. Adenovirus could not be isolated from swimming pool water from the resort where the camp had been held. However, when inspected the swimming pool was not adequately chlorinated or maintained. It is probable that adenovirus infection was transmitted via swimming pool water at the school camp, and the outbreak might have been avoided by higher standards of swimming pool maintenance.