Water-borne hepatitis E virus epidemic in Islamabad, Pakistan: a common source outbreak traced to the malfunction of a modern water treatment plant.

During December 1993 and in the first three months of 1994, an explosive water-borne epidemic of hepatitis E virus (HEV) occurred in two sectors of Islamabad, Pakistan. In a survey of a population of 36,705 individuals, a total of 3,827 cases of acute icteric hepatitis were recorded with an overall attack rate (AR) of 10.4%. The etiologic role of HEV in the epidemic was proven by demonstrating anti-HEV IgG and HEV IgM in the tested serum samples. The water-borne nature of the epidemic was suggested by a study of the case distribution according to water supply. Prior to the epidemic, there had been an operational breakdown in a water treatment plant that distributed water to the affected areas while transforming its purification system from slow sand to rapid sand filtration. The primary source of water for the plant was derived from a heavily contaminated stream. The highest AR (16.3%) was observed in the areas where the source of drinking water was exclusively from the purification plant, followed by ARs of 12.4% and 5.3% for those receiving 50% and 30% or less of their water supply from the treatment plant, respectively, while the lowest AR (1.8%) was observed in the neighboring areas that did not receive water from this source. The AR was significantly higher in the group 11-30 years of age (15.3%) as compared with children less than 11 years of age (1.4%) and also relative to the group greater than 30 years of age (10.5%). The AR among the 162 recorded pregnant females was 21.6%, which was higher than that found among nonpregnant females of child-bearing age (10.9%). All four reported adult deaths occurred among females in their third trimester of pregnancy with a case fatality rate of 11.4%, while the other four fatal cases were newborn infants of mothers with acute icteric hepatitis. Although the aggregation of cases within households was significantly related to family size, the temporal relationship between cases in households with two or more cases revealed that 83.7% of 1,463 presumed secondary cases occurred within one month of the first case in the same household, which is not suggestive of person-to-person transmission of disease. The termination of providing water from the source was effected, which was followed by an apparent decrease in cases.

Female health workers boost primary care.

Women residing in villages in three districts of Pakistan were recruited, trained to deliver primary care and mobilize their communities for health, assigned to limited catchment areas, provided with supervisory and managerial support, and remunerated. Their comprehensive activities substantially reduced infant, child and maternal mortality within a year and generated positive perceptions of family planning in the communities. The programme was cost-effective and appeared suitable as a model for reforming the organization and provision of health care services.

PIP: In 1993, women residing in three rural districts of Pakistan were recruited, hired, trained to deliver primary health care and to promote health-seeking behavior within their limited catchment areas (1000-1500 people), and provided with supervisory and managerial support. Each village nominated candidates for the positions who had a minimum of 8 years of formal education, lived in the villages they would serve, were aged 18-45, and were, preferably, married. Each woman underwent 3 months of initial training in the delivery of primary health care and ongoing training interposed with period of service delivery for the next year. Data collected on the village population included information about births and deaths in the previous year. The health workers kept records about births, deaths, morbidity, and service delivery. Men's and women's community groups organized to identify health priorities and strategies, and the health workers made regular home visits for health promotion, case management, and family planning services. A year after implementation, infant and maternal mortality rates dropped from 130 to 64 and from 596 to 246, respectively. There was also a highly significant drop in the mortality of children aged 1-4 years from acute diarrhea and from measles. Immunization coverage increased, contraceptive use increased, and the provision of sanitation and safe water improved. The cost of the program was US$386 per health worker. Capital and yearly recurrent costs per person of $0.39 and $1.13, respectively, were lower than public sector allocations for the same period. It is clear that trained, locally resident female health workers can improve the delivery of primary health care in Pakistan.

Evaluation of oral poliovirus vaccine delivery during the 1994 national immunization days in Pakistan.

Pakistan conducted national immunization days (NIDs) for the first time in 1994. To estimate coverage, to evaluate risk factors for failure to be immunized, and to determine the effectiveness of mass media, parents of 1288 children in 714 households in four districts were surveyed after the first NID round. In each district, a high proportion of children (93%-96%) received oral poliovirus vaccine (OPV) during the NID. In three districts, unimmunized or partially immunized children were less likely to receive NID OPV than were fully immunized children (Kohistan, P < .001; Quetta, P < .001; and Sibi, P = .05). Although a high proportion of children in each age cohort received NID OPV, in three districts children 0-11 months of age were less likely to receive NID OPV than were older children. Television and radio reached a high proportion of survey households, but other mass media were less effectively utilized. Risk factor and media effectiveness surveys provide important information that is useful for planning future NIDs.