Associatioin of severe anaemia with tuberculosis mycobacteraemia in HIV positive patients admitted with severe sepsis to the University Teaching Hospital, Lusaka,Zambia

Abstract

INTRODUCTION: Tuberculosis is recognised as one the leading causes of severe sepsis among HIV positive patients. Most patients with tuberculosis mycobacteraemia have advanced HIV disease with CD4 counts less than 100cells/ul and many do not present with the classical signs of tuberculosis. Unusual presentation of tuberculosis mycobacteraemia makes the diagnosis of tuberculosis in these patients a challenge. METHODOLOGY: This was a cross-sectional study which was done by analyzing data from 199 HIV positive patients enrolled in two randomized control studies; the Simplified Severe Sepsis Protocol (SSSP) and SSSP-2 and data from 2 patients enrolled independently. Participants were adults who met the inclusion criteria for severe sepsis. Baseline data was collected on demographic and laboratory characteristics including blood cultures for tuberculosis and aerobic organisms. RESULTS: The prevalence of tuberculosis mycobacteraemia in the study population was 34.8%.The study population was generally underweight but the population with tuberculosis mycobacteraemia had a significantly lower mid-upper arm circumference (MUAC) than the population without (20.2[SD: 2.4] vs 21.4 [SD: 3.8] cm; p=0.01).There was a higher proportion of patients with tuberculosis mycobacteraemia in patients who were not on anti-retroviral therapy (ART) compared to those on ART (p=0.01). The study population was generally anaemic with mean haemoglobin of 8.0(SD: 3.0) g/dl but the tuberculosis mycobacteraemia group had significantly lower haemoglobin. The population with tuberculosis mycobacteraemia had a significantly lower median CD4 count compared to the population without (44cells/dl vs 56 cells/dl; p=0.01). Aerobes were isolated in 20.4% (41) of the study population. The commonest isolate was Staphylococcus aureus 5% (10). Factors that were independently associated with tuberculosis mycobacteraemia include low MUAC, unknown ART history, low albumin and low sodium. CONCLUSION: Tuberculosis mycobacteraemia is very common in HIV infected patients with severe sepsis. Low CD4 count, albumin, sodium levels and low MUAC were independently associated with tuberculosis mycobacteraemia in patients with severe sepsis. Severe anaemia was not independently associated with tuberculosis mycobacteraemia.