The ongoing outbreak of mumps affecting all age groups among Gazans, occupied Palestinian territories, 2013

Abstract

Mumps is a contagious disease occurring worldwide and affecting all age groups. There is no specific treatment for mumps. Mumps can be prevented by immunization using MMR. The study aimed to describe the epidemiology of the mumps outbreak, to identify the community factors favoring a mumps outbreak and to describe the public health actions taken and the lessons learned during the outbreak. This study was a cross sectional study including all notified cases of mumps in Gaza strip (GS) during the year 2013. During the year 2013, a total of 1891 clinically diagnosed mumps cases were reported with an overall incidence of 116/100000. The majority of cases 1181 (62.5%) were male. Age varied from one year to 83 years with a mean age of 13.7 years. 1708 (90.3%) of cases occurred among children aged 6 to 15 years who received only one dose of mumps vaccine. Geographically, the disease occurred mainly in Khan-Younes governorate (53.4%) followed by Mid-Zone governorate (28%). Different complications were reported among 133 (7%) cases. These complications were orchitis (3.5%), pancreatitis (2%) and meningitis (1.5%). Number of deaths has been reported. The MMR vaccine is effective in most individuals but it does not give a complete protection. The majority of reported cases occurred in population who received one dose of mumps vaccine reflecting insufficient seroconversion rate in this group. Introducing a second dose of mumps vaccine in the year 2009 in the expanded program of immunization (EPI) clearly improved the rate of seroconversion based on the small number of reported cases among children born after that date. In conclusion, the main cause of this outbreak was the incomplete vaccine efficacy. Vaccination coverage, waning immunity and cold chain do not have a role in this outbreak. In this situation, a national immunization campaign must be implemented and a continuation of two doses of mumps vaccine policy is recommended.

Keywords: Contagious disease, immunization, epidemiology, public health, mumps virus.