Outbreak of Meningococcal Disease among Prisoners in Uttaradit Province, Thailand, March 2009

Abstract

Background: Meningococcal disease is global problem with sporadic cases in Thailand, 18% fatality between 1999 and 2008. On March 19, 2009, an outbreak of meningococcal disease occurred among prisoners in Uttaradit province. The Bureau of Epidemiology investigated the outbreak and put in place appropriate prevention and control measures.
Methods: A descriptive study was performed. We reviewed medical records and conducted face-to-face interviews. Active case finding, contact tracing and environmental surveys were performed. Blood and CSF specimens were examined from suspected cases for detecting Neisseria meningitidis DNA by PCR and bacterial culture. Nasopharyngeal swabs were collected from close contacts. A suspected case was a person who developed fever with at least one of the following symptoms: chills, stiffness of neck, convulsions, alteration of consciousness or purpura.
Results: The 4 cases, 2 confirmed and 2 suspected cases, developed symptoms on March 19 to March 24, 2009. 3 cases were hospitalized and recovered after treatment. One case died. All were 21–52 year-oldprisoners. There were 759 people imprisoned or working in the prison A. 217 people had close contact with the cases. N. meningitidis Serogroup B was identified from hemoculture of a case. Of 52 contacts, 14 (26.9%) had positive nasopharyangeal swabs PCR for N. meningitidis and 14 (26.9%) was identified Haemophilus influenzae by culture. Control measures included chemoprophylaxis for close contacts and health education for prevention and early detection. Active surveillance reported no more cases in the prison and household members.
Conclusions: A meningococcal disease outbreak that was caused by N. meningitidis serogroup B occurred in the prison A. Case fatality proportion was 25%. The outbreak might be aggravated by H. influenzae.