Household transmission of Neisseria meningitidis in the African meningitis belt: a longitudinal cohort study
Authors: Oumer Ali, Abraham Aseffa, Ahmed Bedru Omer, Tsehaynesh Lema, Tesfaye Moti Demissie, Yenenesh Tekletsion, Alemayehu Worku, Haimanot Guebre Xabher, Lawrence Yamuah, Rahamatou Moustapha Boukary, Jean-Marc Collard, Ibrahim Dan Dano, Ibrahim Habiboulaye, Bassira Issaka, Jean-François Jusot, Sani Ousmane, Issoufa Rabe, Doumagoum Moto Dauglaz, Jean Pierre Gami, Kadidja Gamougam, Lodoum Mbainadji, Nathan Naibei, Maxime Narbé, Jacques Toralta, Abdoulaye Berthe, Kanny Diallo, Mahamadou Keita, Adama Coulibaly, Uma Onwuchekwa, Samba O Sow, Boubou Tamboura, Awa Traore, Aliou Toure, Tom Clark, Leonard Mayer, Mary Amodu, Omeiza Beida, Galadima Gadzama, Babatunji Omotara, Sambo Zailani, Shuaibu Yahya, Daniel Chandramohan, Brian M Greenwood, Musa Hassan-King, Olivier Manigart, Maria Nascimento, James M Stuart, Arouna Woukeu, Nicole E Basta, Xilian Bai, Ray Borrow, Helen Findlow, Serge Alavo, Hubert Bassene, Aldiouma Diallo, Marietou Dieng, Souleymane Doucouré, Jules François Gomis, Assane Ndiaye, Cheikh Sokhna, Jean François Trape, Akalifa Bugri, Abudulai Forgor, Abraham Hodgson, Isaac Osei, Stephen L Quaye, John Williams, Peter Wontuo, Thomas Irving, Caroline L Trotter, Andromachi Karachaliou, Julia Bennett, Dorothea Hill, Odile Harrison, Martin C Maiden, Lisa Rebbetts, Eleanor Watkins
Journal: The Lancet Global Health (2016)

Information on transmission of meningococcal infection in the African meningitis belt is scarce. We aimed to describe transmission patterns of Neisseria meningitidis (meningococcus) in households in the African meningitis belt.Cross-sectional carriage surveys were done in seven African meningitis belt countries (Chad, Ethiopia, Ghana, Mali, Niger, Nigeria, and Senegal) between Aug 1, 2010, and Oct 15, 2012. Meningococcal carriers identified in these surveys and all available people in their households were recruited into this longitudinal cohort study. We took pharyngeal swabs at first visit and took further swabs twice a month for 2 months and then monthly for a further 4 months. We used conventional bacteriological and molecular techniques to identify and characterise meningococci. We estimated the rates of carriage acquisition and recovery using a multi-state Markov model.Meningococci were isolated from 241 (25%) of 980 members of 133 households in which a carrier had been identified in the cross-sectional survey or at the first household visit. Carriage was detected subsequently in another household member who was not an index carrier in 75 households. Transmission within a household, suggested by detection of a further carrier with the same strain as the index carrier, was found in 52 of these 75 households. Children younger than 5 years were the group that most frequently acquired carriage from other household members. The overall individual acquisition rate was 2·4% (95% CI 1·6-4·0) per month, varying by age and household carriage status. The mean duration of carriage was 3·4 months (95% CI 2·7-4·4).In the African meningitis belt, transmission of meningococci within households is important, particularly for young children, and periods of carriage are usually of short duration.Bill & Melinda Gates Foundation, Wellcome Trust.