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

Blood lead and blood pressure in occupationally exposed workers

The association of increased blood lead concentration to elevated blood pressure was investigated in 184 male workers occupationally exposed to inorganic lead and in 51 non-exposed male workers matched for age as a control group. The study participants received complete medical examinations, including standard measurement of blood pressure and body weight. Occupational exposure to lead was detected by history taking and by measuring blood lead level, urinary delta aminolevulinic acid [delta-ALA] and hemoglobin level. Exposed workers had comparatively higher blood lead concentrations [46.08 +/- 6.54 microg/dl] than the control [26.29 +/- 5.47 microg/ dl] [P<0.001]. Similarly, urinary delta-ALA was higher than controls [P<0.001]. Both systolic and diastolic blood pressure [SBP, DBP] were higher among exposed than controls [P<0.001] for both and correlated positively with blood lead concentrations and urinary delta-ALA. The hemoglobin level was lower in the exposed group compared with the control group [P<0.01]. These data may support the existence of a causal association between higher blood lead concentrations and elevated blood pressure among occupationally exposed workers

Ocular disorders among workers exposed to mercury

Mercury vapor exposed workers may show ocular changes, as well as other systems affection. A sample of 84 workers in preparing mercury fulminate were examined for conjunctival corneal and lenticular manifestation of long duration exposure, together with mercury urinary output. Lens changes were found in 50% of the involved workers while keratopathy as recorded in 34.5% of them. No statistically significant association was found between the occurrence of eye lesions and levels of urinary elimination of mercury. These results suggest local absorption of this element is most probably the underlying cause of ocular affection

Occupational dermatoses among workers in a porcelain manufacturing factory

The objectives of the present work are to determine the prevalence and risk factors of occurrence of occupational dermatoses among workers in a porcelain manufacturing factory. The study included 235 workers [132 males and 103 females]. After history taking, dermatological examination was performed at the work place. Cases of contact dermatitis [CD] were patch tested using potassium dichromate 0.5%, Cobalt chloride 1% and Nickel sulphate 5% in petrolatum. Results showed that the prevalence of occupational dermatoses [OD] was 26.8% among exposed workers. The highest percentage of OD was found among workers in the decoration department represented 30.2% of all cases. CD was the commonest presentation among the studied group, it represented 27% of all cases of OD. Results of patch testing indicate that out of 17 cases of CD 12 cases [70%] were of the irritant variety and 5 cases [30%] were of the allergic type. The prevalence of OD was found to be affected by age, duration of work, type of exposure and daily bathing after work