Children vaccinated for MMR who present with mumps-like illnesses have other identifiable viral etiologies about 14% of the time, according to results of a Finnish study.
“When one is trying to establish the cause of mumps-like symptoms in a patient, it would be worthwhile to test at least for antibodies to EBV [Epstein-Barr virus] and the parainfluenza viruses, if not for antibodies to other viruses as well,” wrote Irja Davidkin, Ph.D., and colleagues from the National Public Health Institute in Helsinki (J. Infect. Dis. 2005;191:719-23).
The study analyzed frozen serum samples from 601 children and adolescents who had reported mumps-like illness but in whom mumps had been ruled out. Their symptoms usually included swelling of the parotid gland and low-grade fever.
A previous study of 848 patients with mumps-like symptoms, which included the 601 nonmumps patients, had confirmed mumps in 2% (17) of cases, while inadequate sample collection or storage accounted for the remaining 230 cases.
Among the 601 nonmumps cases, antibody testing revealed an acute viral infection in 84 (14%) patients; the remaining patients could not be diagnosed.
EBV was the most commonly identified viral infection, occurring in 7% of patients, which was half of the diagnosed group. Parainfluenza types 1, 2, and 3 made up another 4% of the diagnosable cases, adenovirus was seen in 3% of cases, and enterovirus was seen in 2% of cases.
Additionally, 0.5% of patients were diagnosed with parvovirus, and human herpesvirus was seen in 4% of a subgroup of children under 4 years old.
A total of 14 patients were diagnosed with 2 concomitant viral infections, and 2 patients had 3 diagnoses.
The authors noted that although adenovirus infection associated with parotitis has been previously reported only in HIV-positive patients, this study indicates it should be considered in the differential diagnosis for mumps-like symptoms in otherwise healthy children and adolescents.