Declining Incidence of Invasive Meningococcal Disease in South Africa: 2003–2016
Authors: Meiring Susan , Cohen Cheryl , de Gouveia Linda , du Plessis Mignon , Kularatne Ranmini , Hoosen Anwar , Lekalakala Ruth , Lengana Sarona , Seetharam Sharona , Naicker Preneshni , Quan Vanessa , Reubenson Gary , Tempia Stefano , von Mollendorf Claire , von Gottberg Anne ,   GERMS-SA, Black John , Pearce Vanessa , Hoosen Anwar , Kleinhans Vicky , Karstaedt Alan , Maluleka Caroline , Verwey Charl , Feldman Charles , Moore David , Reubenson Gary , Swe Swe Han Khine , Wadula Jeannette , Nel Jeremy , Lindeque Kathy , Nchabeleng Maphoshane , Samodien Nazlee , du Plessis Nicolette , Bosman Norma , Kularatne Ranmini , Seetharam Sharona , Thomas Teena , Avenant Theunis , Nana Trusha , Chibabhai Vindana , Maharj Adhil , Burra Asmeeta , Naby Fathima , Dawood Halima , Mogamberry Jade , Mlisana Koleka , Sookan Lisha , Ramjathan Praksha , Mahabeer Prasha , Naidoo Romola , Haffejee Sumayya , Coovadia Yacoob , Hamese Ken , Sibiya Ngoaka , Lekalakala Ruth , Hoyland Greta , Lebudi Jacob , Jooste Pieter , Variava Ebrahim , du Plessis Erna , Whitelaw Andrew , Reddy Kessendri , Nicol Mark , Naicker Preneshni , Brink Adrian , Prentice Elizabeth , Zietsman Inge , Botha Maria , Smith Peter , Poswa Xoliswa , Govind Chetna , Pillay Keshree , Budavari Suzy , Samuel Catherine , Senekal Marthinus , Dreyer Andries , Ahmed Khatija , Marcus Louis , Lowman Warren , Messina Angeliki , van den Bergh Dena , Swart Karin , Whitney Cynthia , Klugman Keith , Nanoo Ananta , Dreyer Andries , von Gottberg Anne , Smith Anthony , Sooka Arvinda , Miller Cecilia , Sriruttan Charlotte , Cohen Cheryl , Ihekweazu Chikwe , von Mollendorf Claire , du Plessis Desiree , Britz Erika , Radebe Frans , Ntshoe Genevie , Hunt Gillian , Mathema Hlengain , Weyer Jacqueline , Rossouw Jenny , Frean John , Keddy Karen , McCarthy Kerrigan , de Gouveia Linda , Erasmus Linda , Blumberg Lucille , Smith Marshagne , Makgoba Martha , Modise Motshabi , Ismail Nazir , Govender Nelesh , Legare Neo , Page Nicola , Ramalwa Ntsieni , Paulse Nuraan , Vazi Phumeza , Perovic Olga , Crowther-Gibson Penny , Mutevedzi Portia , Manesen Riyadh , Mpembe Ruth , Lengana Sarona , Madhi Shabir , Walaza Sibongile , Lindani Sonwabo , Njikho Sunnieboy , Meiring Susan , Motladiile Thejane , Lebaka Tiisetso , Chetty Verushka 
Published: October 2018

Abstract

Background
Invasive meningococcal disease (IMD) is endemic to South Africa, where vaccine use is negligible. We describe the epidemiology of IMD in South Africa.

Methods
IMD cases were identified through a national, laboratory-based surveillance program, GERMS-SA, from 2003–2016. Clinical data on outcomes and human immunodeficiency virus (HIV) statuses were available from 26 sentinel hospital sites. We conducted space-time analyses to detect clusters of serogroup-specific IMD cases.

Results
Over 14 years, 5249 IMD cases were identified. The incidence was 0.97 cases per 100 000 persons in 2003, peaked at 1.4 cases per 100 000 persons in 2006, and declined to 0.23 cases per 100 000 persons in 2016. Serogroups were confirmed in 3917 (75%) cases: serogroup A was present in 4.7% of cases, B in 23.3%, C in 9.4%; W in 49.5%; Y in 12.3%, X in 0.3%; Z in 0.1% and 0.4% of cases were non-groupable. We identified 8 serogroup-specific, geo-temporal clusters of disease. Isolate susceptibility was 100% to ceftriaxone, 95% to penicillin, and 99.9% to ciprofloxacin. The in-hospital case-fatality rate was 17% (247/1479). Of those tested, 36% (337/947) of IMD cases were HIV-coinfected. The IMD incidence in HIV-infected persons was higher for all age categories, with an age-adjusted relative risk ratio (aRRR) of 2.5 (95% confidence interval [CI] 2.2–2.8; P < .001) from 2012–2016. No patients reported previous meningococcal vaccine exposure. Patients with serogroup W were 3 times more likely to present with severe disease than those with serogroup B (aRRR 2.7, 95% CI 1.1–6.3); HIV coinfection was twice as common with W and Y diseases (aRRR W = 1.8, 95% CI 1.1–2.9; aRRR Y = 1.9, 95% CI 1.0–3.4).

Conclusions
In the absence of significant vaccine use, IMD in South Africa decreased by 76% from 2003–2016. HIV was associated with an increased risk of IMD, especially for serogroup W and Y diseases.