There is a high
prevalence of central nervous system (CNS) opportunistic infections among people living with HIV in Zambia who present with CNS symptoms, investigators
report in the online edition of Clinical
Infectious Diseases. At least one pathogen was detected in 57% of patients.
The mortality rate was high, with over a third of individuals dying after their
admission to hospital.
for CNS pathogens “would save lives” write the authors.
They undertook the
study because little is known about the prevalence of CNS infections among
patients in sub-Saharan Africa.
cross-sectional study involved 331 adults living with HIV in Lusaka,
Zambia, who presented for emergency care with CNS symptoms. Cerebrospinal fluid
(CSF) samples were obtained from each patient. PCR testing was used to detect a
number of CNS pathogens, including tuberculosis (TB), Epstein-Barr virus (EBV),
JC virus (JCV), varicella zoster virus (VZV), cytomegalovirus (CMV), herpes
simplex virus-1 (HSV-1), HSV-2 and toxoplasmosis gondii (TG).
The patients had
severe immune suppression. The median CD4 count was just 89 cells/mm3.
A quarter of patients were diagnosed with HIV at the time of their
presentation. Just over a third of patients (36%) were taking antiretroviral
therapy. But the duration of this treatment was short, a median of 240 days.
antigen testing was performed for the 56% of patients who were able to pay the
$10 for this test.Overall, CNS
pathogens were detected in 189 patients (57%). Of these 189 patients, 64% had
one and 36% had multiple pathogens detected.
The most common
pathogen was EBV, detected in 28% of patients. Cryptococcus was also highly
prevalent (19%), as was TB (14%). JCV was detected in 6% of patients, a similar
proportion having VZV. Pneumococcal and meningococcal meningitis were detected
in 2% and 1% of patients, respectively. HSV-1 was rare (2%) and no cases of
toxoplasmosis or HSV-2 were detected.
A quarter of
patients who underwent cryptococcal antigen testing had a positive result.
in 24% of patients. They were most commonly seen in people with cryptococcus
(27%), JCV (25%), VZV (23%) and HSV-1 (20%). They also occurred in patients
with EBV (17%), CMV (15%) and TB (12%).
poor. A total of 117 patients (35%) died during hospitalisation. The mortality
rate was higher among patients with a CNS pathogen than among patients without
this diagnosis (41% vs 27%, p = 0.01).
The mortality rate
among patients with EBV in cerebrospinal fluid was 41%, and 39% of those with cryptococcal meningitis
died. Mortality was also high (45%) among patients with TB infection in CNS.
with HIV was associated with a significantly increased risk of mortality (p = 0.03).
“PCR uncovered the
presence of multiple pathogens that would have otherwise remained undetected,”
comment the authors. “There was a high prevalence of co-infection in the CSF,
indicative of severe immunosuppression in this population. These findings may
reflect late presentation of patients to health facilities.”
The authors believe
their study highlighted a number of factors that could improve patient care and
outcomes. These include earlier diagnosis of HIV and the more widespread use of
cryptococcal antigen testing. They also suggest use of PCR technologies to
detected EBV, TB, CMV, VZV and HSV “may improve patient survival”.