The immune function and measles virus infection in three different socioeconomic child populations in Karachi, Pakistan.

The immune function as well as anti-measles virus antibody level were investigated with 111 children in Karachi who were classified into high-, middle- and low-income groups. No difference in the blood cell counts or the biochemical data among three groups indicates no marked difference in the general health conditions among them. In the low-income group, levels of IgG, IgA and anti-measles virus antibody were significantly higher than those in the other two groups. Although 30% of children of the low-income group kept extremely high levels of immunoglobulin, no significant correlation was observed between IgG levels and anti-measles virus antibody levels. In the high-income group, the level of IgM was significantly lower and the incidence of anti-measles virus antibody-negative children was high (7/38; 18.4%). These antibody-negative children kept lower immunoglobulin levels although they were over four years old. These results suggest that the living environmental conditions of these different socioeconomic groups vary greatly and hygienic conditions must influence the chance of encountering infectious pathogens including measles virus. The relation between living environment and risk of subacute sclerosing panencephalitis (SSPE) in child population of Krachi is discussed.