Meningitis is a major cause of mortality in southern Africa. We aimed to describe the aetiologies
and frequencies of laboratory-confirmed fungal and bacterial meningitis among
adults in a South African province with an 11% HIV prevalence, over 4 years.
We conducted a retrospective, observational study of secondary laboratory data, extracted
on all cerebrospinal fluid (CSF) specimens submitted to public-sector laboratories in Gauteng
province from 2009 through 2012. We calculated cause-specific incidence rates in the
general and HIV-infected populations and used Poisson regression to determine if trends
We identified 11,891 (10.7%) incident cases of meningitis from 110,885 CSF specimens.
Cryptococcal meningitis, tuberculous meningitis and pneumococcal meningitis accounted
for 62.3% (n = 7,406), 24.6% (n = 2,928) and 10.1% (n = 1,197) of cases over the four-year
period. The overall incidence (cases per 100,000 persons) of cryptococcal meningitis
declined by 23% from 24.4 in 2009 to 18.7 in 2012 (p <0.001) and decreased by 19%
among HIV-infected persons from 178.2 to 144.7 (p <0.001). Tuberculous meningitis
decreased by 40% from 11.3 in 2009 to 6.8 in 2012 (p <0.001) and decreased by 36%
among HIV-infected persons from 54.4 to 34.9 (p <0.001). Pneumococcal meningitis
decreased by 41% from 4.2 in 2009 to 2.5 in 2012 (p <0.001) and decreased by 38% among HIV-infected persons from 28.0 to 17.5 (p <0.001). Among cases of other bacterial
meningitis (248/11,891, 2.1%), Neisseria meningitidis (n = 93), Escherichia coli (n = 72)
and Haemophilus influenzae (n = 20) were the most common organisms identified.
In this high HIV-prevalence province, cryptococcal meningitis was the leading cause of laboratory-
confirmed meningitis among adults. Over a 4-year period, there was a significant
decrease in incidence of cryptococcal, tuberculous and pneumococcal meningitis. This
coincided with expansion of the national antiretroviral treatment programme, enhanced
tuberculosis control programme and routine childhood immunisation with pneumococcal