Lessons and Challenges for Measles Control from Unexpected Large Outbreak, Malawi

Andrea Minetti

, Matthew Kagoli, Agnes Katsulukuta, Helena Huerga, Amber Featherstone, Hazel Chiotcha, Delphine Noel, Cameron Bopp, Laurent Sury, Renzo Fricke, Marta Iscla, Northan Hurtado, Tanya Ducomble, Sarala Nicholas, Storn Kabuluzi, Rebecca F. Grais, and Francisco J. Luquero

Author affiliations: Author affiliations: Epicentre, Paris, France (A. Minetti, H. Huerga, D. Noel, S. Nicholas, R.F Grais, F.J. Luquero); Ministry of Health, Lilongwe, Malawi (M. Kagoli, A. Katsulukuta, S. Kabuluzi); Médecins Sans Frontières, Lilongwe (A. Featherstone, H. Chiotcha, C. Bopp); Médecins Sans Frontières, Paris, France (L. Sury, N. Hurtado); Médecins Sans Frontières, Brussels, Belgium (R. Fricke, T. Ducomble); Médecins Sans Frontières, Barcelona, Spain (M. Iscla)

Abstract

Despite high reported coverage for routine and supplementary immunization, in 2010 in Malawi, a large measles outbreak occurred that comprised 134,000 cases and 304 deaths. Although the highest attack rates were for young children (2.3%, 7.6%, and 4.5% for children <6 6="" 9="" and="" class="text-underline" months="" persons="" respectively="" span="">>

15 years of age were highly affected (1.0% and 0.4% for persons 15–19 and >19 years, respectively; 28% of all cases). A survey in 8 districts showed routine coverage of 95.0% for children 12–23 months; 57.9% for children 9–11 months; and 60.7% for children covered during the last supplementary immunization activities in 2008. Vaccine effectiveness was 83.9% for 1 dose and 90.5% for 2 doses. A continuous accumulation of susceptible persons during the past decade probably accounts for this outbreak. Countries en route to measles elimination, such as Malawi, should improve outbreak preparedness. Timeliness and the population chosen are crucial elements for reactive campaigns. During the prevaccine era, 130 million measles cases occurred annually worldwide, and measles was a leading cause of childhood death (1). Measles vaccines have dramatically reduced cases and deaths during recent decades. The Measles Initiative developed a joint strategic plan to reduce measles-related deaths by strengthening routine immunization, supplementary immunization activities (SIAs) in the form of mass vaccination campaigns, reinforced surveillance, and adequate case management (2,3). In 2000, the World Health Organization (WHO) Regional Office for Africa adopted a plan to reduce measles-related deaths by 50% by the end of 2005 (3,4), and measles-related deaths decreased from 535,300 in 2000 to 139,300 in 2010 (5). A recent WHO resolution called for measles elimination in the African Region by 2020 (6).
Malawi’s Expanded Program on Immunization (EPI), established in 1979, recommends 1 dose of measles-containing vaccine (MCV) for infants 9–11 months of age (7). After implementation of EPI, cases declined from >162,000 in 1980 to an annual average of 8,000 cases throughout the 1990s. Additional initiatives toward measles control (8) comprised a catch-up campaign in 1998 directed toward children 9 months–14 years of age and follow-up campaigns in 2002, 2005, and 2008 for children 9–59 months (9); administrative reported vaccine coverage was close to 100% (10). Before 2010, the last large epidemic in Malawi occurred in 1996 and 1997, when ≈10,000 cases were reported nationwide each year.