Comparison of four techniques of measles diagnosis: virus isolation, immunofluorescence, immunoperoxidase & ELISA.

In an attempt to develop reliable, quick, simple and less expensive methods for diagnosing measles in rural areas, a study was undertaken in December, 1989, at the main health centre in Yaoundé, during the measles outbreak, which allowed access to 80 per cent of children living in Yaoundé. During the epidemic, 120 cases of measles were detected (clinically diagnosed) among the 1580 children examined. The control group comprised 120 children without symptoms of measles. Sick and control children were between 6 and 36 months old and comprised 54 males and 64 females. Measles was diagnosed by isolation of measles virus by cell culture, direct immunoperoxidase (DIP), direct immunofluorescence (DIF) and ELISA. Using cell culture, 8 measles virus (7%), 22 herpes simplex virus type 1 (HSV1), 6 varied enterovirus and 4 adenovirus were isolated in the sick group. In the control group, 8 HSV1, 5 enteroviruses and 4 adenoviruses were isolated. By DIP and DIF, 36 positive cases were detected (30%) and 84 negative cases in the sick group. By ELISA IgM, we found 72 positive cases which confirm clinical diagnosis in 60 per cent and 48 negative cases in the sick group. None of the three methods (DIP, DIF, ELISA) yielded positive cases in the control group. Evidence of the high prevalence of HSV1 during the measles outbreak leads to the question whether there is a primo-infection by the herpes simplex virus or a reactivation by the measles virus.