An Investigation of Ciprofloxacin-resistant Neisseria Meningitidis Serogroup B Infection Outbreak in a Provincial Prison, Nan Province, Thailand, October 2023

Abstract

Meningococcal infection is a severe illness that can result in organ damage or death. On 23 Oct 2023, a joint investigation team was notified about two inmates diagnosed with meningococcal infection in a provincial prison. The investigation aimed to confirm the outbreak, describe epidemiological characteristics, determine possible source and risks of infection, and provide recommendations and control measures. This study reviewed the situation using surveillance databases. Active case finding was conducted among inmates and prison staff. Close contacts were identified and assessed. Drug sensitivity and serogroup identification were done in the cultured-growth specimens. Surveying inmate rooms, observing inmates' behaviors, and interviewing inmates and prison staff were performed. There were 7 laboratory-confirmed cases identified (attack rate 0.5%). All cases were male inmates with a median age of 46 years (interquartile range 38.5–49.5 years). Common symptoms were fever (100%) and headache (71%). Eight cases required hospital admission and one dead case was found (CFR 14%). Among 609 close contacts, 99% were inmates. All cultured-growth specimens were Neisseria meningitidis serogroup B with ciprofloxacin resistance. Crowded inmates and sharing water cups were risk factors for intra-room spreading. Daily activities and the previous influenza outbreak promoted inmates' inter-room contact. This is the ciprofloxacin-resistant serogroup B meningococcal disease outbreak in a provincial prison revealing multiple factors, including environmental, behaviors and daily activities, that promoted the disease's spread. Rifampicin chemoprophylaxis, active surveillance, and limited inmate activities could help reduce disease spread.