outbreak of hepatitis a associated with treated waste water used for irrigation

Hepatitis A virus [HAV] infection is endemic in developing countries and remains a public health problem elsewhere. This study was conducted to investigate an outbreak of HAV infection, which occurred during a period of almost 5 months [January-May 1996] in the National Guard Iskan [Housing Authority] in Jeddah, Saudi Arabia. Ninety four cases were found to be positive for IgM antibody to HAV. A case control study was done to identify possible risk factors. For every case, 3 controls have been selected from the same household matched for age and sex. Information about reported cases was obtained by attending physicians through an interview questionnaire from adult cases and parents of young cases and controls [<12 y]. It included questions regarding symptoms, demographics and possible source of the infection. Results showed that the attack rate of the whole population was 1.03%, while that for children <10 years was twofold higher [2.05%] than the total population. The risk of acquiring infection among them was found to be five times that among those aged 40 years and higher [R.R=5.32]. There was a lack of association between developing hepatitis A and any of the food items or milk used in the studied area during the time of the outbreak. On the other hand exposure to irrigation water among cases was found to be significantly higher than among controls especially among children below 10 years [O.R=2.26]. Analysis of the available data suggests a strong association between illness and exposure to waste water used for irrigation of gardens through playing with it, or through occasional drinking especially among children below 10 years. The prolonged course of the outbreak [5 months] may be attributed to subsequent person to person transmission from index cases to intimate contacts especially among the same household

Raw wastewater agricultural re-use and risk of protozoal infection in beni-mellal, morocco

This study was carried out to determine the potential risk of protozoal infection associated with raw wastewater use for agricultural purposes, among children of Beni-Mellal, Morocco. In a randomly-selected sample of 1343 children 740 from 5 regions which use raw wastewater for agriculture [exposed], while 603 were from 4 control regions that do not practice wastewater irrigation [unexposed]. A questionnaire-interview with children and parents was used to collect data on demographic, hygienic, and risky water contact risk factors. One or more protozoal infection was identified among 276 [37.2%] of children living in the wastewater re-use regions, versus only among 22 [3.6%] living in control regions. The overall prevalence of 40.1% was observed among boys, and 33.3% among girls residing in exposed areas. The two identified protozoa were Entamoeba histolytica and Giardia intestinalis, which infected 34.3% and 5.1% in the exposed population compared to only 3.3% and 0.3% in the control population, respectively. We also noted that the G. intestinalis prevalence was more than 40% among the children under 9 years, but less than 17% for those who were more than 12 years. Also, a significant excess of protozoal infection was observed among children who had risky contact with agricultural lands [p<0.001]. In conclusion, raw wastewater use in Beni-Mellal can lead to a high risk of protozoal infections. Adequate treatment of wastewater prior to re-use, as well as public health education are highly recommended

Distribution of zooplankton in Abu Qir bay [Egypt]

The distribution of zooplankton in Abou-Qir Bay [Egypt] was estimated for 3 successive seasons. The community appeared more dense at the littoral stations compared with that at the off-shores. Copepods and their larval stages prevailed the other groups. The most dominant copepods comprised Paracalanus parvus, Oithona nana, Euterpina acutifrons and Centropages kroyeri. Other frequent groups included, appendicularia, Medusae, Chaetognatha, Tintinnids, Pteropods, free living nematodes, crustacean eggs and fish eggs and larvae. Meroplanktonic larvae of cirriped, polychaetes, decapods, lamellibranch and gastropods were also found. The bay can be regarded as eutrophic marine habitat. The present study showed clear signs of pollution at the western coastal stations as produced by the contaminated drain water discharged from El-Tabia pumping station and the waste products of the Urea Fertilizer Factory. The effect of pollutants was clearly seen from the reduced number of zooplankton in the area during spring and autumn