An unusual increase of Hepatitis A cases from Mashash Awadh village, Majmaah district, Riyadh region, was identified through surveillance from Apr. 25 May. 10, 1999. An epidemiological investigation was identified to estimate the extent and size of the outbreak, and to identify its source and mode of transmission.
A case of hepatitis A was defined as an onset of jaundice in a resident or a visitor of Mashash Awadh village between Mar. 25 and May. 10, 1999.
Affected families were interviewed about common exposure to other cases and common foods. A case-control study was conducted of 26 case-persons. Two control-persons for each case-person were selected from the nearest neighboring household and matched for age allowing a difference of 2 years.
Twenty-seven outbreak-associated cases of hepatitis A were detected through both passive and active case-findings. Of these, 26 were Mashash Awadh residents (attack rate [AR] =6.4%). Only one case (index case); was a six year old Saudi girl who came from another village to visit her aunt in Mashash Awadh while in the infective stage of hepatitis A (she became jaundice 3 days after her arrival). Of the 26 Mashash Awadh cases, only 1 (the co-index case) was a relative of the index case.
The outbreak begun during the eleventh international week; cases increased to a peak number by the seventeenth international week (Figure 1). The index and co-index cases knew each other (cousins). The other cases lived near to each other. The outbreak was preceded by the index and co-index cases. Twenty-five cases appeared from the seventeenth to the nineteenth international week.
A gathering banquet, where the cases shared food from the same plate and drank water from the same bowel with the co-index case, was performed at the end of the fourteenth international week. The 1-5-year-old age group had the highest AR (3.9%). All cases were in pre-school age children. Interviews revealed common exposure of affected families to other hepatitis A cases, common meals and eating-places.
The risk of having Hepatitis A virus among cases who did not wash their hands after meals was ten-fold more than that of the control-persons. All cases and controls used the same sources of drinking water.
Three samples were taken from three different case-patient households; the testing of these samples found no organisms.
Both overall socioeconomic and sanitation status were poor for Mashash Awadh village residents. A common-source outbreak of hepatitis A, through sharing food with the co-index case in a gathering banquet, was probably responsible for this outbreak.
Editorial note:
Although hepatitis A is normally transmitted person-to-person and appears as propagated pattern. Point or common-source outbreaks have been associated with food, water and milk [1,2). This out-break of hepatitis A occurred suddenly with a rise to a peak. Interviews indicated that A common-source outbreak of hepatitis A, through sharing food with the co-index case in a gathering banquet, was probably responsible for this outbreak. Sanitary and hygiene practices have to be improved to eliminate fecal contamination of food and water for Mashash Awadh village. An additional field epidemiology survey is recommended to investigate the village of the index case for the possibility of similar illnesses. .
Many outbreaks of hepatitis A occurred in North America and Europe [3]. These outbreaks were spread through person-to-person transmission. Other outbreaks were associated with a contaminated food and water.
In Saudi Arabia, outbreaks of hepatitis A were reported from rural water systems and food contamination. This is the first outbreak that has been investigated in this village.
Many microorganisms (cholera, Cryptosporalium, Compylobacter spp, Cynabacteria, Escherichia coli, Enteroinvasive E.coli, Shigella, Salmonella, Giardia lambia, protozoa parasites, hepatitis E and hepatitis A) that cause diseases are transmitted through a fecal-oral route.
Sanitary and hygiene practices have to be improved to eliminate fecal contamination of food and water for Mashash Awadh village. An additional field epidemiology survey is recommended to investigate the village of the index case for the possibility of similar illnesses.
References
- Verma BL,Sirvastava RN. Measurment of personal cost of illness due to some major water-related diseases in an Indian rural population. Int J Epidemiol 1990;19(1):169-176.
- Eesrey SA, Collett J, Miliotis MD, Koornhoof HJ, Makhale P. the risk of infection from Giardia larnbia due to drinking water supply, use of water, and latrines among preschool children in rural Lesotho. Int J Epidemiol 1989;18 (1):284-52.
- Feachem Rg, Bradley DJ, Garelick H, Mara DD. Sanitation and disease: Health aspects of excreta and waste water management(world bank studies in water supply and sanitation. New York: John wiley & sons, 1983;173-78.
