Pneumococcal disease in HIV-infected Malawian adults: acute mortality and long-term survival

Abstract

Objective: HIV-infected patients in Africa are vulnerable to severe recurrent infection with Streptococcus pneumoniae, but no effective preventive strategy has been developed. We set out to determine which factors influence in-hospital mortality and long-term survival of Malawians with invasive pneumococcal disease.

Design, setting and patients: Acute clinical features, inpatient mortality and long-term survival were described among consecutively admitted hospital patients with S. pneumoniae in the blood or cerebrospinal fluid. Factors associated with inpatient mortality were determined, and patients surviving to discharge were followed to determine their long-term outcome.

Results: A total of 217 patients with pneumococcal disease were studied over an 18-month period. Among these, 158 out of 167 consenting to testing (95%) were HIV positive. Inpatient mortality was 65% for pneumococcal meningitis (n = 64), 20% for pneumococcaemic pneumonia (n = 92), 26% for patients with pneumococcaemia without localizing signs (n = 43), and 76% in patients with probable meningitis (n = 17). Lowered consciousness level, hypotension, and age exceeding 55 years at presentation were associated with inpatient death, but not long-term outcome in survivors. Hospital survivors were followed for a median of 414 days; 39% died in the community during the study period. Outpatient death was associated with multilobar chest signs, oral candidiasis, and severe anaemia as an inpatient.

Conclusion: Most patients with pneumococcal disease in Malawi have HIV co-infection. They have severe disease with a high mortality rate. At discharge, all HIV-infected adults have a poor prognosis but patients with multilobar chest signs or anaemia are at particular risk.

Fig. 1

Patient group studied. This flow chart shows the total number of patients followed in the study and their diagnoses. The numbers of patients dying as inpatients or during follow-up are also shown.

Fig. 2

Kaplan–Meier survival estimates by clinical group. (a) Overall patient survival is plotted for the whole group divided according to the diagnosis of pneumonia, confirmed meningitis or bacteraemia. There is a significant difference in mortality rates (P < 0.0001), which is caused by inpatient mortality. (b) Outpatient survival is plotted in the same manner and shows no significant difference in mortality rates after leaving hospital by clinical group (P = 0.55). Patients dying as inpatients do not appear in (b).

Fig. 3

Outpatient risk factors. Kaplan–Meier plots showing survival among patients with multilobar chest signs (a) or oral candida (b) compared with the survival of the rest of the group. (c) All patients with a recorded haemoglobin result (n = 53) were divided according to whether or not they had anaemia (Hb < 7 g/dl at presentation, n = 16) or not (haemoglobin > 7 g/dl, n = 37). There was a significantly increased mortality rate in patients with multilobar disease compared with the rest of the group [hazard ratios (HR) 2.1, 95% confidence intervals (CI) 1.2–3.8; P = 0.01]. There was also increased mortality in the group with oral candida compared with those without oral candida (HR 1.8, CI 1.1–3.3; P = 0.03), and among patients with anaemia compared with those without anaemia (HR 3.9, CI 1.5–10.1; P = 0.005).