Herd immunity to measles virus in a population of student nurses and medical students following a widespread outbreak of clinical measles in Ibadan, Nigeria.
Following an outbreak of serologically--and virologically--confirmed measles requiring large-scale hospitalisation of children in Ibadan, Nigeria, the herd immunity to measles virus among medical students and student nurses was determined. Of the 200 students tested, none lacked haemagglutination--inhibiting antibody to measles virus. The titre of HI--antibody ranged from 2(5) to 2(10). Describing a titre of 2(9) as very high, a significantly higher proportion of student nurses than medical students (P < 0.05) had very high antibody titres to measles virus. There was however no statistical difference between the sexes (P > 0.05). Using a commercial Enzyme Immuno Assay kit (EIA), anti measles IgM could not be detected from any of the students. Thus a clear evidence of recent infection with measles virus during the outbreak could not be detected among the students, a probable indication that student nurses and medical students may not participate in the maintenance of wild measles virus within the hospital environment in developing countries like Nigeria.