infectious diseases
Dr. Patrick Bryant, Wadsworth Center Virology Laboratory
Wadsworth Center Virology Laboratory Identifies
Large Mumps Outbreak in Nassau County, NY
by Patrick Bryant, PhD, research scientist, New York State Department of Health and Kirsten St. George, PhD, chief of viral
diseases, New York State Department of Health
Mumps is a vaccine preventable, viral
illness caused by a member of the family
Paramyxoviridae, genus Rubulavirus. Mumps
usually involves pain, tenderness and swelling in
one or both parotid salivary glands. Despite the
ready availability of a vaccine, mumps activity
in the United States has begun to surge over the
past decade, with one of the largest outbreaks in
20 years occurring in 2006. Since then, numerous
outbreaks have occurred in the United States,
particularly in young adults in their 20s and 30s.
I
n its role as one of four APHL-funded viral Vaccine Preventable Diseases
(VPD) Reference Centers, the Virology Laboratory at the Wadsworth Center
identified a large mumps outbreak this year in Nassau County, NY. During
the outbreak, the laboratory received buccal swab samples from the middle
of May into September that were collected from individuals with parotitis.
Samples from 116 suspected mumps cases in Nassau County were tested and
34 were confirmed positive by mumps rRT-PCR. Of particular note, several
symptomatic cases occurred in patients who had previously received two
doses of the MMR vaccine in accordance with recommended dosing and
20
LAB MATTERS Fall 2016
scheduling. Ongoing research suggests evidence of waning immunity as well
as possible antigenic differences between the currently circulating strain and
the vaccine.
As with all viruses detected by the reference laboratory, the positive samples
were genotyped by Sanger sequencing of the SH gene. All were found to
be genotype G including the index case—a student who attended Harvard
University during a campus mumps outbreak and returned to Nassau County
following graduation. Mumps genotype G has also been the cause of the other
recent outbreaks in the US. As of September 10, 44 states were reporting some
level of mumps activity.
Testing of new cases is ongoing to determine if the mump