Texas suffers mumps outbreak

Despite widespread use of the measles, mumps, and rubella (MMR) vaccine in the United States since 1967, mumps may be enjoying a renewed resurgence, as evidenced by a recent outbreak in Texas, where cases of mumps are currently at a 10-year high.

The initial mumps outbreak in Johnson County, TX, has grown to include over 50 cases in the Dallas area, spreading to Dallas, Collin, Denton, and Tarrant counties. Fifty cases may not seem like a lot, until one compares them to the no more than 20 cases of mumps recorded per year throughout the entire state of Texas since 2011.

Cristie Columbus, MD, vice dean, Texas A&M College of Medicine, Dallas campus, and infectious disease specialist, reviewed some of the more important characteristics of mumps infection.

In 1967, the mumps vaccine was widely introduced in this country. Before this, almost every child was infected by mumps, caused by the Rubulavirus, of the Paramyxovirus family. Despite a decline of 99% in the number of infections since then, outbreaks have occurred, similar to the current one in Texas.

Symptoms usually appear 12 to 25 days after initial infection, but in some individuals, they can be evident within 16 to 18 days. Classic mumps symptoms include swollen salivary glands, which in turn cause swollen cheeks and jaws that may make it difficult to eat. Fever, fatigue, head and muscle aches can also occur and last 7 to 10 days. 

Up to 40% of people infected with mumps exhibit only mild symptoms or none at all, and thus may not realize they are infected. Risk of transmission still exists—regardless of the presence or absence of symptoms—and occurs via saliva or mucus. Contagion lasts from 2 to 5 days before symptoms appear, until approximately 5 days after.

Most people will recover completely from the mumps in a few weeks, but in some, serious complications may occur, especially those infected as adults. For example, men and adolescent boys can develop a mumps infection of the testicles, and this will cause pain, swelling, and possibly sterility. Meningitis and encephalitis may also occur, with the potential of permanent hearing loss, disability, and even death.

For children, immunization with two doses of MMR vaccine is recommended by the CDC between the ages of 12 months and 15 months, and then again between 4 and 6 years of age. In older children and those born after 1956 who did not receive two doses as children, vaccination is also recommended, except during pregnancy or in those who may be immunocompromised in some way. In addition, two doses of the vaccine are recommended for those at increased risk, including international travelers, heath care workers, and college students.