Mumps Outbreak among Military and Police Training Camps in Bahrain: Epidemiology and Evaluation of Control Measures

摘要

BackgroundThis paper investigates an outbreak of Mumps among trainee in military and Police training camps occurs in September 2007 and the implication for vaccination policy in Bahrain. Method:A cluster of mumps cases were reported from Military Training Camp (MTC) and Police Training Camp (PTC) to Diseases control section (DCS) in public health directorate. All information were collected using a standard mumps investigation form used in diseases control section. The data entry and analysis was undertaken by EPI info program. ResultsThe total screened trainee was 317 from MTC and 797 from PTC.A total of 56 cases met the clinical criteria of having mumps. Out of the 56 , 12 were tested negative while 44 fit the WHO definition of either laboratory confirmed or epidemiologically confirmed mumps cases. The incidence rate was 3.9 % for both camps. ConclusionA total of 1114 suspected cases were reported of which 44 cases were either laboratory or epidemiologically confirmed cases with an incidence rate of 3.9%. 45.5% of the cases found to have documented one dose MMR vaccination, but none received the 2nd dose. This outbreak highlights the importance of reviewing the immunization status of all newly recruited personnel in MTC and PTC and to complete their vaccination. Introduction Mumps is an acute viral disease characterized by fever, swelling and tenderness of one or more salivary glands, usually the parotid and sometimes the sublingual or sub maxillary glands. Orchitis occurs in 20-30 % of post pubertal males and it is usually unilateral. Other complication may include sensory-neural hearing loss, encephalitis, and pancreatitis. [1,2]The disease is transmitted by droplet spread and by direct contact with the saliva of an infected person. The incubation period range between 14 to 25 days. The period of communicability of the mumps virus started 3 days before the onset of the symptoms and up to 9 days after that.[3] It can be prevented by good infection control measures and sustain high vaccination coverage. In Bahrain, an immediate notification of any suspected or confirmed cases of mumps is required from all health institutes to public health directorate in the Ministry of Health. All reported cases are investigated within 48 hours of notification by public health specialist and managed aggressively. Surveillance and control measures applied through vaccination of those below 15 years who didn’t complete two MMR doses in residency block or schools of the case.Mumps vaccination (included in MMR) is part of the routine vaccination schedule. It is given at one year of age and at school entry (5-6 years). Those who were born before 1985 did not receive any Mumps vaccination, while those who were born between 1985 to 1998 received one dose in the routine immunization schedule at age of fifteen months. Since 1998 a second MMR dose has been incorporated into the routine immunization schedule. The first is given at one year of age and the second at preschool. Moreover, catch-up immunization campaigns targeting twelve years age students at school were conducted annually between 1998 until 2006. [4]Following the introduction of routine infant measles-mumps-rubella (MMR) vaccination in Bahrain in 1985, and the addition of a second routine dose of MMR vaccine in 1998, mumps became uncommon disease. [4] The average incidence of mumps in Bahrain for the period 2001-2008 was 6.3 per 100,000 populations. [5] The total mumps cases were 80 in 2008. [6]In the absence of immunization, the annual Mumps incidence vary across the globe between 100-1000 cases per 100,000 population with epidemics peaks every 2-5 years. [7] Large scale MMR vaccination results in remarkable decrease in Mumps incidence globally. [7]It was reported that most currently licensed Mumps containing vaccines are efficacious and safe if more than one dose implemented and high immunization coverage is sustained. [7]A cluster of mumps cases were reported from a Military Training Ca