Measles continues to be a major childhood disease in terms of global
morbidity and mortality. In the main areas of its endemicity the only
available means of diagnosis are based on clinical criteria: the presence
of a maculopapular rash and fever accompanied by cough, coryza, and/or
conjunctivitis. We have studied 38 clinically diagnosed cases of measles
in Khartoum, Sudan, by means of serology, reverse transcriptase PCR
(RT-PCR) on throat swabs and virus isolation from lymphocytes. On the
basis of serology, 28 patients were diagnosed as having an acute measles
virus (MV) infection, while in 10 cases the clinical symptoms proved to
have other causes. It was shown that in cases with low serum
immunoglobulin M (IgM) levels, an additional measurement of IgG or
virus-neutralizing antibodies was necessary to discriminate between
patients with an acute MV infection sampled during an early stage of the
disease and patients who had experienced an MV infection in the more
distant past. The serological laboratory diagnosis was validated by an
MV-specific RT-PCR: for all confirmed measles cases tested a fragment of
the correct size which hybridized with a third MV-specific primer could be
amplified, while all serologically negative cases were also RT-PCR
negative. MV could be isolated from 17 out of 23 of the serologically
confirmed cases, demonstrating that virus isolation is less reliable as a
diagnostic tool than serology or RT-PCR. This study stresses the urgent
need for a rapid diagnostic field test for measles