Chronic cough in primary health care attendees, Harare, Zimbabwe: diagnosis and impact of HIV infection.

Background: Cough lasting for > or = 3 weeks (i.e., chronic cough) indicates that a patient has suspected tuberculosis (TB). At the primary health care level, the spectrum of disease that causes chronic cough has not been previously investigated in a setting with a high prevalence of human immunodeficiency virus (HIV) infection.

Methods: A total of 544 adults with chronic cough were recruited systematically from 2 primary health care clinics, and they were evaluated using preset first- and second-line investigations and diagnostic case definitions.

Results: The overall prevalence of HIV infection among the study cohort was 83%. TB was the most common diagnosis, with 207 HIV-positive patients (46%) and 27 HIV-negative patients (30%) having confirmed or probable TB. Of these, 145 HIV-positive patients with TB (70%) and 20 HIV-negative patients with TB (74%) had smear-positive cases of TB. Only 17 HIV-positive and 2 HIV-negative patients had smear-negative but culture-positive cases of TB. Lower respiratory tract infections (n = 178; HIV prevalence, 79%) and pneumonia (n = 87; HIV prevalence, 89%) were the next most common diagnoses. Asthma (n = 26; HIV prevalence, 46%), posttuberculous disease and other fibrotic lung disease (n = 34; HIV prevalence, 88%), and cardiac disease (n = 15; HIV prevalence, 93%) were more common than were Pneumocystis jiroveci pneumonia and cryptococcosis (n = 8 and n = 5, respectively; HIV prevalence, 100%), and we found no cases of nocardiosis or histoplasmosis.

Conclusions: TB was diagnosed for 43% of patients who presented with chronic cough to primary health care clinics in Harare, with 71% having smear-positive disease. The findings of TB culture added relatively little to the findings of fluorescent microscopy of concentrated sputum specimens. The prevalence of HIV infection was high across a range of diagnoses, suggesting that an HIV test should be recommended in the initial investigation of chronic cough.