Bacterial meningitis in Malawian adults, adolescents, and children during the era of antiretroviral scale-up and Haemophilus influenzae type b vaccination, 2000-2012.
BACKGROUND
We documented bacterial meningitis trends among adults and children presenting to a large teaching hospital in Malawi during introduction of Haemophilus influenzae type b (Hib) vaccination and the rollout of antiretroviral therapy (ART).


METHODS
We analyzed data from 51 000 consecutive cerebrospinal fluid (CSF) samples obtained from adults, adolescents, and children with suspected meningitis admitted to the Queen Elizabeth Central Hospital, Blantyre, Malawi, between 2000 and 2012.


RESULTS
There was a significant decline in the total number of CSF isolates over 12 years (incident rate ratio [IRR], 0.93; 95% CI, .92-.94; P < .001). This decline was entirely in children aged <5 years (IRR, 0.87; 95% CI, .85-.88; P < .001) and coincided with the introduction of Hib vaccination. The number of adult isolates has remained unchanged (IRR, 0.99; 95% CI, .97-1.0; P = .135) despite rapid scale-up of ART provision. In children aged <5 years, Streptococcus pneumoniae, nontyphoidal salmonellae (NTS), and Hib were the most frequently isolated pathogens, and have declined over this time period. Streptococcus pneumoniae was the most frequently isolated pathogen in older children and adults. Estimated incidence of bacterial meningitis in 2012 was 20 per 100,000 cases in children aged <14 years, 6 per 100,000 adolescents, and 10 per 100,000 adults.


CONCLUSIONS
Rates of bacterial meningitis have declined in children, but not adults, coinciding with the introduction of Hib vaccination. The highly successful rollout of ART has not yet resulted in a reduction in the incidence in adults where the burden remains high. Long-term surveillance of bacterial meningitis outside of the epidemic "meningitis belt" in Africa is essential.
Malawi-Liverpool-Wellcome Trust Clinical Research Programme, University of Malawi College of Medicine, Blantyre, Malawi.
Emma C
EC
Wall
Dean B
DB
Everett
Mavuto
M
Mukaka
Naor
N
Bar-Zeev
Nicholas
N
Feasey
Andreas
A
Jahn
Mike
M
Moore
Joep J
JJ
van Oosterhout
Paul
P
Pensalo
Kenneth
K
Baguimira
Stephen B
SB
Gordon
Elizabeth M
EM
Molyneux
Enitan D
ED
Carrol
Neil
N
French
Malcolm E
ME
Molyneux
Robert S
RS
Heyderman
D000293:Adolescent; D000328:Adult; D023241:Antiretroviral Therapy, Highly Active; D016667:Bacterial Capsules; D002555:Cerebrospinal Fluid / Q000382:microbiology; D002648:Child; D002675:Child, Preschool; D004363:Drug Utilization; D015658:HIV Infections / Q000150:complications / Q000453:epidemiology; D018073:Haemophilus Vaccines; D019741:Haemophilus influenzae type b / Q000302:isolation & purification; D006801:Humans; D015994:Incidence; D007223:Infant; D008295:Malawi / Q000453:epidemiology; D016920:Meningitis, Bacterial / Q000134:cerebrospinal fluid / Q000150:complications / Q000453:epidemiology* / Q000382:microbiology; D008583:Meningitis, Haemophilus / Q000150:complications / Q000453:epidemiology / Q000382:microbiology; D008585:Meningitis, Meningococcal / Q000150:complications / Q000453:epidemiology; D008586:Meningitis, Pneumococcal / Q000150:complications / Q000453:epidemiology / Q000382:microbiology; D013296:Streptococcus pneumoniae / Q000302:isolation & purification
D018073:Haemophilus Vaccines; C044237:Haemophilus influenzae type b polysaccharide vaccine
Africa; HIV; antiretroviral therapy; meningitis; vaccination