Article Info
Year: 2005
Month: January
Issue: 1
Reference: Almohaimeed M., Al-Mazroa M., .Saudi Epidemiology Bulletin. 2005;12(1):.
On 1/5/1424 (1/7/2003) the General Health directorate of Hail reported to the Communicable disease department, Ministry of Health, an unusually large number of citizens from AlFarhaneih village suffering from vomiting, fever, abdominal pain, diarrhea and headache. A team from FETP traveled to Hail to investigate this outbreak. AlFarhaneih village is a rural community about 70 km west of Hail city, which is 700 km north of Riyadh. It contains several farms with a population of 600. There is no general water net and no general sewage net. There is one primary health care center that serves AlFarhaneih village and the villages close by. The investigative team visited AlFarhaneih primary health care center and reviewed the records of the cases. They also visited the main source of water supplied to AlFarhaneih in the last two months located in AlMurma village, 35 km west. The team reviewed the results of laboratory tests of some cases and the results of drinking water analysis.
It was decided to conduct a case control study to identify the source and impact of water contamination. A case was defined as any person who complained of fever, headache, vomiting, abdominal pain or diarrhea from 25/6-12/7, 2003, in AlFarhaneih village. A control was defined as any person who lived in AlFarhaneih village and was free of disease at the time of the outbreak. One control was selected for each case living in the same dwelling or neighbor. A questionnaire was designed inquiring on demographic information, symptoms, history of hospital admission, sources of water to the houses, presence of water tanks, water storage and any change in water properties color, taste or odor.
From June 25 to July 12, 2003, there were 108 cases; giving an attack rate of 18 per 100 people in AlFarhaneih village. The epidemic curve is shown in figure 1. Symptoms included fever 52 (81.3%), headache 48 (75%), vomiting 26 (40.6%), abdominal pain 20 (31.3%), and diarrhea 11 (17.2%). The age distribution of the cases ranged from 6 months to 65 years (mean 16.2, SD ±16.14). The highest age group among cases was 59 years (21.6%). A large number of cases were males (62.5%). Five cases (4.6%) were admitted into hospital, all were cured, there were no deaths nor complications. The geographical distribution of the cases was homogenous with the distribution of the citizens in the village, and the people had not been exposed to a common food or chemical poisoning or contact with infected patients or had visited an endemic area.
In the absence of any tap water, the community of AlFarhaneih relied totally on the water tank for both drinking and non-drinking purposes. Laboratory analysis of water from houses demonstrated Escherichia coli in the specimens of four houses of cases.
There were no cases in houses that did not have a ground water tank or had a tank above the ground surface exposed to the sunlight. Having a ground water tank was statistically significantly associated with development of disease (Odds Ratio (OR) 4.07, 95% Confidence Interval (CI) 1.84-9.03).
Those people who received their water supply from AlMurma well were at higher risk of developing disease than those who depended on water from other sources (OR 1.5, 95%
CI 0.09-24.9). It was found that Al Murma well did not have permission from the Ministry of water to be used as a drinking water source. A water sample from the well found it contaminated by E. coli, Salmonella and Pseudomonas.
Editorial note:
Contamination of ground water is a serious environmental problem throughout the world. According to the guidelines of the World Health Organization, a European commission directive states that drinking water should not contain pathogenic microorganisms in a quantity or at a concentration able to adversely affect human health.[1]
One child in the world dies about every eight seconds of water related diseases. In USA, contaminated water has been responsible for 35,000 cases of Salmonella infections, 150,000 cases of infection with pathogenic E. coli, and 320,000 cases of Campylobacter infections.[1]
Waterborne disease is caused by ingestion of water contaminated by bacteria, viruses, parasites or others.
However, an etiologic agent was determined in only 50% of all waterborne outbreaks. In outbreaks of ground water systems, an agent was identified in 38%, while in surface water systems, an agent was identified in 62% of outbreaks. These agents have included: Salmonella, Shigella, Campylobacter, Yersinia, Giardiasis, Cryptosporidiosis, Rotavirus, or E. coli.[2]. The major reasons behind waterborne disease outbreaks include: untreated or inadequately disinfected groundwater, untreated or inadequate disinfection of filtered surface water, distribution or storage deficiencies, untreated ground water, inadequate disinfection of ground water and cross-contamination.[2]
Escherichia coli is gram-negative rod-shaped bacteria. It causes infection of variable severity characterized by diarrhea, vomiting and abdominal cramps. It is transmitted by drinking unchlorinated or unboiled water.[3]
The major finding in this study is the association between having ground water tanks and development of disease. Also, the people of Alfurhaneih did not employ any protective measures to sterilize the water, such as chlorination or boiling.
A previous study carried out in Dareen, a semi-rural area in the Eastern province of Saudi Arabia, the gastrointestinal problem was attributed to consumption of highly saline and very hard water, and infrequent cleaning of water storage vessels.[4] Another study in Afif region revealed a similar association between ground water tanks and the development of water borne disease.[5]
The main source of drinking water of the village for the two months prior to the outbreak was AlMurma well, which was contaminated by the waste of animals that had settled nearby. We concluded that this outbreak occurred due to using contaminated water brought from an unauthorized well. The main contaminating organism was thought to be E. coli.
It was recommended that Municipalities should monitor tankers to be filled from authorized wells, health education to improve personal practices including disinfection of water by chlorination, and providing piped water supply accompanied with establishment of proper sewage system.
References
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1. Water and health in Europe. A joint report from the European Environment Agency and the WHO Regional Office for Europe. WHO Reg Publ Eur Ser 2002;(93):111-XXIII, 1-222.
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2. Blum D, Feachem R. Measuring the impact of water supply and sanitation investments on diarrhoea! diseases: problems of methodology. Int J Epidem 1983; 12: 57-365.
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3. Fang G. Intestinal Escherichia coli infections. Curr Opin Infect Dis 1993:6:48-53.
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4. Rasheed P, Saha A, Mohammed H, Al-Sibai. Perception and practice of family food and water hygiene in A semi-rural area of Saudi Arabia. SMJ 1988:9(2):157-164.
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5. Al Mudaimeegh K. Gastroenteritis in Afeef region, 2002 (unpubished).