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.

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BackgroundIncreases in pneumococcal meningitis were reported from Ghanaian regions that lie in the meningitis belt in 2016–2017, despite introduction of 13-valent pneumococcal conjugate vaccine (PCV13) in 2012 using a 3-dose schedule (6, 10, and 14 weeks). We describe pneumococcal meningitis epidemiology in the Ghanaian Northern and Upper West regions across two meningitis seasons.MethodsSuspected meningitis cases were identified using World Health Organization standard definitions. Pneumococcal meningitis was confirmed if pneumococcus was the sole pathogen detected by polymerase chain reaction, culture, or latex agglutination in cerebrospinal fluid collected from a person with suspected meningitis during December 2015-March 2017. Pneumococcal serotyping was done using PCR. Annual age-specific pneumococcal meningitis incidence (cases per 100,000 population) was calculated, adjusting for suspected meningitis cases lacking confirmatory testing.FindingsAmong 153 pneumococcal meningitis cases, 137 (89.5%) were serotyped; 100 (73.0%) were PCV13-type, including 85 (62.0%) that were serotype 1, a PCV13-targeted serotype. Persons aged ≥5 years accounted for 96.7% (148/153) of cases. Comparing 2015–2016 and 2016–2017 seasons, the proportion of non-serotype 1 PCV13-type cases decreased from 20.0% (9/45) to 4.1% (3/74) (p = 0.008), whereas the proportion that was serotype 1 was stable (71.1% (32/45) vs. 58.1% (43/74); p = 0.16). Estimated adjusted pneumococcal meningitis incidence was 1.8 in children aged <5 years and ranged from 6.8–10.5 in older children and adults.ConclusionsHigh pneumococcal meningitis incidence with a large proportion of serotype 1 disease in older children and adults suggests infant PCV13 vaccination has not induced herd protection with this schedule in this high-transmission setting.

BackgroundGhana is affected by regular cholera epidemics and an annual average of 3,066 cases since 2000. In 2014, Ghana experienced one of its largest cholera outbreaks within a decade with more than 20,000 notified infections. In order to attribute this rise in cases to a newly emerging strain or to multiple simultaneous outbreaks involving multi-clonal strains, outbreak isolates were characterized, subtyped and compared to previous epidemics in 2011 and 2012.Methodology/Principal FindingsSerotypes, biotypes, antibiotic susceptibilities were determined for 92 Vibrio cholerae isolates collected in 2011, 2012 and 2014 from Southern Ghana. For a subgroup of 45 isolates pulsed-field gel electrophoresis, multilocus sequence typing and multilocus-variable tandem repeat analysis (MLVA) were performed. Eighty-nine isolates (97%) were identified as ctxB (classical type) positive V. cholerae O1 biotype El Tor and three (3%) isolates were cholera toxin negative non-O1/non-O139 V. cholerae. Among the selected isolates only sulfamethoxazole/trimethoprim resistance was detectable in 2011, while 95% of all 2014 isolates showed resistance towards sulfamethoxazole/trimethoprim, ampicillin and reduced susceptibility to ciprofloxacin. MLVA achieved the highest subtype discrimination, revealing 22 genotypes with one major outbreak cluster in each of the three outbreak years. Apart from those clusters genetically distant genotypes circulate during each annual epidemic.Conclusions/SignificanceThis analysis suggests different endemic reservoirs of V. cholerae in Ghana with distinct annual outbreak clusters accompanied by the occurrence of genetically distant genotypes. Preventive measures for cholera transmission should focus on aquatic reservoirs. Rapidly emerging multidrug resistance must be monitored closely.

Cholera remains a major global public health threat and continuous emergence of new Vibrio cholerae strains is of major concern. We conducted a molecular epidemiological study to detect virulence markers and antimicrobial resistance patterns of V. cholerae isolates obtained from the 2012-2015 cholera outbreaks in Ghana. Archived clinical isolates obtained from the 2012, 2014 and 2015 cholera outbreaks in Ghana were revived by culture and subjected to microscopy, biochemical identification, serotyping, antibiotic susceptibility testing, molecular detection of distinct virulence factors and Multi-Locus Variable-Number of Tandem-Repeat Analysis (MLVA). Of 277 isolates analysed, 168 (60.6%) were confirmed to be V. cholerae and 109 (39.4%) isolates constituted other bacteria (Escherichia coli, Aeromonas sobria, Pseudomonas aeruginosa, Enterobacter cloacae and Enterococci faecalis). Serotyping the V. cholerae isolates identified 151 (89.9%) as Ogawa, 3 (1.8%) as Inaba and 14 (8.3%) as non-O1/O139 serogroup. The O1 serogroup isolates (154/168, 91.7%) carried the cholera toxin ctxB gene as detected by PCR. Additional virulence genes detected include zot, tcpA, ace, rtxC, toxR, rtxA, tcpP, hlyA and tagA. The most common and rare virulence factors detected among the isolates were rtxC (165 isolates) and tcpP (50 isolates) respectively. All isolates from 2014 and 2015 were multidrug resistant against the selected antibiotics. MLVA differentiated the isolates into 2 large unique clones A and B, with each predominating in a particular year. Spatial analysis showed clustering of most isolates at Ablekuma sub-district. Identification of several virulence genes among the two different genotypes of V. cholerae isolates and resistance to first-and second-line antibiotics, calls for scaleup of preventive strategies to reduce transmission, and strengthening of public health laboratories for rapid antimicrobial susceptibility testing to guide accurate treatment.