W. Nigatu et al., Measles virus strains circulating in Ethiopia in 1998-1999: Molecular characterisation using oral fluid samples and identification of a new genotype, J MED VIROL, 65(2), 2001, pp. 373-380
A measles outbreak in December 1998 in Bedelle (vaccine coverage < 40%) and
two sporadic cases in Addis Ababa, Ethiopia, were investigated. Paired ser
um and oral fluid samples were collected 2-8 days after the onset of sympto
ms. A total of 53 of 55 outbreak cases and both sporadic cases were positiv
e for serum measles virus-specific IgM. Oral fluid measles-specific IgM was
positive in 71% of cases collected up to 5 days after onset and in 90% col
lected at 6-8 days. By contrast, 100% of oral fluid samples were positive f
or measles virus RNA by RT-PCR, suggesting that early collection of samples
favoured the detection of measles virus RNA by RT-PCR. The measles virus s
train in the outbreak was identified as genotype D4. One strain from a spor
adic case was also genotype D4; the strain from the other sporadic case was
assigned to clade D but was distinct. The degree of divergence from recogn
ised clade D strains suggested that, together with three strains from the U
nited Kingdom, it represents an additional genotype of clade D (GenBank acc
ession numbers AF280800-280807). (C) 2001 Wiley-Liss, Inc.