Assessment of immunoglobulin use for hepatitis A control in New Mexico.

Community control of hepatitis A (HA) requires improvement of sanitation and timely use of immune globulin (IG) for selected contacts of ill persons. A marked increase in reported HA cases in New Mexico in late 1978 and early 1979 prompted aggressive evaluation of morbidity trends and of control efforts. This evaluation provided an opportunity to study the practices in disease reporting and IG administration in the State. In the 6-months study period January-June 1979, 596 cases of HA were reported in New Mexico (an annualized incidence rate of 95.9 cases per 100,000 population). Nearly three-fourths of the cases were reported within 14 days of onset of illness. IG was administered to the household contacts of 89 percent of the index patients; it was not indicated for the household contacts of 9 percent. Reasons for the failure to administer IG to the household contact of the other 2 percent of the index patients were not ascertained. Overall, 93 percent of the eligible household contacts received IG, and 80 percent of these contacts received it within 14 days of the onset of illness in the index patient. Differences in the relationship of physicians and health offices in the only metropolitan area in the State and in the rest of the State in respect to case reporting and IG administration were observed. The benefits from health department surveillance and control exceeded the costs by approximately fivefold. The reporting practices and the IG use of the physicians who reported HA cases were good; to improve further HA surveillance and control in the State, the focus needs to be on physicians who fail to report HA cases.