Measles outbreak in Tanzania, 2006–2007

We conducted a measles outbreak investigation in Dar es Salaam, Tanzania. Surveillance data were analyzed; a susceptibility profile developed, and case–control study conducted. The age distribution of cases peaked among those <2, 5–7, and ≥18 years, corresponding to the age distribution of susceptibles. Risk factors included being unvaccinated (aOR = 5.7, p < 0.01) or having received one dose of vaccine compared to two (aOR = 2.4, p = 0.01), being younger, and having a less-educated caretaker. Vaccine effectiveness was 88% (one dose) and 96% (two doses). Results highlight the importance of receiving one dose of measles vaccine, and the added benefit of two doses.