An outbreak of pneumococcal meningitis among older children (≥5years) and adults after the implementation of an infant vaccination programme with the 13-valent pneumococcal conjugate vaccine in Ghana.

Brenda Kwambana-Adams ,Jason M Mwenda,David Opare,Ebenezer Appiah-Denkyira,Sally-Ann Ohene,Godfred Owusu-Okyere,Franklin Asiedu-Bekoe,Ebenezer Foster-Nyarko,Osei Kuffour Afreh,Catherine Okoi,George Khumalo Kuma,Owen Kaluwa,Umberto D’Alessandro,Richard Bannerman,Charles Okot,Timothy Letsa,Madikay Senghore,Kwame Amponsa-Achiano,Chinelo Ebruke,Mark J Pallen,Badu Sarkodie,V Bampoe ,Jacob Otu ,Syed M A Zaman ,Archibald Worwui ,Gemma L Kay ,Martín Antonio

doi:10.1186/s12879-016-1914-3

Abstract

BackgroundAn outbreak of pneumococcal meningitis among non-infant children and adults occurred in the Brong-Ahafo region of Ghana between December 2015 and April 2016 despite the recent nationwide implementation of a vaccination programme for infants with the 13-valent pneumococcal conjugate vaccine (PCV13).MethodsCerebrospinal fluid (CSF) specimens were collected from patients with suspected meningitis in the Brong-Ahafo region. CSF specimens were subjected to Gram staining, culture and rapid antigen testing. Quantitative PCR was performed to identify pneumococcus, meningococcus and Haemophilus influenzae. Latex agglutination and molecular serotyping were performed on samples. Antibiogram and whole genome sequencing were performed on pneumococcal isolates.ResultsEight hundred eighty six patients were reported with suspected meningitis in the Brong-Ahafo region during the period of the outbreak. In the epicenter district, the prevalence was as high as 363 suspected cases per 100,000 people. Over 95 % of suspected cases occurred in non-infant children and adults, with a median age of 20 years. Bacterial meningitis was confirmed in just under a quarter of CSF specimens tested. Pneumococcus, meningococcus and Group B Streptococcus accounted for 77 %, 22 % and 1 % of confirmed cases respectively. The vast majority of serotyped pneumococci (80 %) belonged to serotype 1. Most of the pneumococcal isolates tested were susceptible to a broad range of antibiotics, with the exception of two pneumococcal serotype 1 strains that were resistant to both penicillin and trimethoprim-sulfamethoxazole. All sequenced pneumococcal serotype 1 strains belong to Sequence Type (ST) 303 in the hypervirulent ST217 clonal complex.ConclusionThe occurrence of a pneumococcal serotype 1 meningitis outbreak three years after the introduction of PCV13 is alarming and calls for strengthening of meningitis surveillance and a re-evaluation of the current vaccination programme in high risk countries.Electronic supplementary materialThe online version of this article (doi:10.1186/s12879-016-1914-3) contains supplementary material, which is available to authorized users.

Highlights

An outbreak of pneumococcal meningitis among non-infant children and adults occurred in the Brong-Ahafo region of Ghana between December 2015 and April 2016 despite the recent nationwide implementation of a vaccination programme for infants with the 13-valent pneumococcal conjugate vaccine (PCV13)
This study has shown that pneumococcal outbreaks caused by closely related strains can reoccur within West Africa
The results reported here are of great public health importance and summarised as follows: 1) Pneumococcus continues to be of increasing importance in meningitis outbreaks, even outside the meningitis belt; 2) In a postPCV13 era, pneumococcal serotype 1 still has the propensity to cause large outbreak; 3) Non-vaccine serotypes such as serotype 12 F can be important causes of meningitis during outbreaks

Summary

Introduction

An outbreak of pneumococcal meningitis among non-infant children and adults occurred in the Brong-Ahafo region of Ghana between December 2015 and April 2016 despite the recent nationwide implementation of a vaccination programme for infants with the 13-valent pneumococcal conjugate vaccine (PCV13). In West Africa, the highest incidence of bacterial meningitis occurs during the dry season (December to March) [1,2,3], with incidence rates in epidemics as high as 800 cases per 100,000 people [4, 5]. N. meningitidis, the meningococcus, is the leading cause of bacterial meningitis in West Africa after the first year of life, even in non-epidemic periods [1,2,3, 6, 7]. The MenAfriVacTM vaccine, which protects against meningococcal serogroup A, has been rolled out in several countries in the meningitis belt. In Ghana, MenAfriVacTM vaccination campaigns conducted in 2012 covered the three northern regions within the meningitis belt [4]

Objectives

Methods

Results

Discussion

Conclusion