Salivary diagnosis of measles: a study of notified cases in the United Kingdom, 1991-3.
OBJECTIVE
To validate a method for salivary diagnosis of measles and to assess the diagnostic accuracy of notified cases of measles.


METHODS
Blood and saliva samples were collected within 90 days of onset of symptoms from patients clinically diagnosed as having measles and tested for specific IgM by antibody capture radioimmunoassay.


METHODS
17 districts in England and one in southern Ireland during August 1991 to February 1993.


METHODS
236 children and adults with measles notified by a general practitioner.


RESULTS
Specific IgM was detected in serum in only 85 (36%) of the 236 cases. In cases associated with outbreaks and tested within six weeks of onset, 53/57 (93%) of samples were IgM positive, thereby confirming the sensitivity of serum IgM detection as a marker of recent infection. The serological confirmation rate was lower in cases with a documented history of vaccination (13/87; 15%) than in those without (70/149; 47%) and varied with age, being lowest in patients under a year, of whom only 4/36 (11%) were confirmed. Measles specific IgM was detected in 71/77 (92%) of adequate saliva samples collected from patients with serum positive for IgM. In cases where measles was not confirmed, 6/101 had rubella specific IgM and 5/132 had human parvovirus B19 specific IgM detected in serum.


CONCLUSIONS
The existing national surveillance system for measles, which relies on clinically diagnosed cases, lacks the precision required for effective disease control. Saliva is a valid alternative to serum for IgM detection, and salivary diagnosis could play a major role in achieving measles elimination. Rubella and parvovirus B19 seem to be responsible for a minority of incorrectly diagnosed cases of measles in the United Kingdom and other infectious causes of measles-like illness need to be sought.
Brown
D W
DW
Enteric and Respiratory Virus Division, PHLS Central Public Health Laboratory, London.
Ramsay
M E
ME
Richards
A F
AF
Miller
E
E
D000293:Adolescent; D000328:Adult; D000368:Aged; D000914:Antibodies, Viral / Q000302:isolation & purification; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks; D004739:England / Q000453:epidemiology; D006801:Humans; D007075:Immunoglobulin M / Q000302:isolation & purification; D007223:Infant; D007494:Ireland / Q000453:epidemiology; D008457:Measles / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology; D008459:Measles virus / Q000276:immunology; D008875:Middle Aged; D011863:Radioimmunoassay; D012463:Saliva / Q000276:immunology*; D012680:Sensitivity and Specificity
D000914:Antibodies, Viral; D007075:Immunoglobulin M