Public Health South advisory - mumps cases in Dunedin

Public Health South is issuing notice to healthcare providers and the public of a mumps outbreak after 12 confirmed cases have been reported in the Dunedin area since the last week of July. Most of the cases of suspected mumps have been notified in the last 10 days.

The mumps cases are thought to be connected to outbreaks in Auckland and the Pacific as some people have become infected with mumps after returning from travel to those areas. Not all cases are linked to each other but, in some situations, mumps has spread to others in the Dunedin community.

Public Health South has moved to a Manage It approach to dealing with cases of mumps in the community. This is because there is spread within the community, and so case-by-case investigation is no longer an effective means of controlling the outbreak. Efforts are shifting towards vaccinating at-risk populations.

At this time most of the cases appear to be connected to the university student population. Public Health South has been working closely with the tertiary institutions in Dunedin and student health centres to identify cases and prevent further spread.

The university and polytechnic have been communicating with staff and students to proactively identify people at risk and encourage those who may not be immune to get vaccinated, says Dr Naomi Gough, Medical Officer of Health, Public Health South, Southern DHB.

Primary care providers are also closely monitoring patients for new cases.

Mumps is a viral illness that is spread the same way as colds and flu – through infected saliva, and respiratory secretions. “You won’t get it walking past someone on the street with mumps, but if you are not immune and you spend time in close proximity with someone who is sick and infectious, you are at risk,” Dr. Gough says.

Symptoms of mumps include mild fever, aches and pains, and swelling around the face.

“The MMR vaccine is still the best defence against mumps and we are encouraging vaccination of at-risk groups to prevent them from getting infected prior to being exposed,” Dr Gough explains. “Many people will already be immune to the disease and for them the risk of contracting mumps remains low.

“Those most at risk are people from countries where the MMR vaccine is not available, including some Pacific Islands nations such as Tonga and Fiji, and people whose vaccination schedule is not up-to-date,” she says.

The MMR vaccine was introduced in 1990 but the current schedule of immunisations at 18-months and four years was not introduced until 2003. Many people born before 1981 are likely immune because they will have contracted it at some time and those born after 1989 with up-to-date immunisations are also likely to be protected.

The MMR vaccines are available from general practices, and through student health centres. The MMR is free for anyone who needs it.

“Primary care providers have the MMR available. There is no harm in an extra dose if a patient is unsure whether their vaccinations are up to date,” Dr Gough says.

“For people who do contract mumps, it is usually a mild but unpleasant illness. People who have had mumps before will likely recall it as painful and uncomfortable. Fortunately, complications are rare.”

The last mumps outbreak in New Zealand was in 1994. Since MMR was introduced, the disease had almost disappeared from local communities. The Otago and Southland districts have not had mumps circulating in the community for many years with only occasional cases introduced following travel.