Prevalance of abnormal lung function tests and associated clinical features among HIV infected children aged 7-18 years in Dar es salaam, Tanzania

Abstract

Background: HIV/AIDS is still a major health burden in Sub-Saharan Africa and the whole world at large. Recent data from African countries shows the prevalence of chronic lung disease (CLD) is high in children living with HIV/AIDS. With the initiation of antiretroviral medications early in infancy, many HIV infected children are expected to live longer, hence prone to other comorbid conditions including chronic lung disease. There is no study which has been done in Tanzania to assess the abnormal lung function tests in children living with HIV/AIDS. Hence this study will provide the baseline information about the magnitude and risks factors for chronic lung disease.

Objective To determine the prevalence of abnormal lung function tests and associated clinical features among HIV infected children aged 7-18 years in Dar es salaam, Tanzania.

Methodology This was a hospital-based cross-sectional study design, carried out in two centres, Infectious Disease Centre and Muhimbili National Hospital care and treatment clinics (CTC). Both clinics are situated within Ilala Municipality in Dar es Salaam Tanzania. Study duration was nine months. Study population included all HIV infected children aged 7-18 years who attend both centres. A structured questionnaire was used for collection of data. After the history was obtained, children underwent physical examination before assessment of lung functions by spirometry.

Data were analysed using Statistical Package for Social Science (SPSS) version 20. Continuous variables were expressed as mean, standard deviation, median and interquartile ranges. Chi-square and fisher’s exact test were used to compare categorical variables. Student’s T-test and Mann Whitney U test were used to determine if there was any significant difference between the groups with normal and abnormal functions. A P-value of <0.05 was considered statistically significant.

Results: A total of 121 children aged 7-18 years were included in this study. There was predominance of adolescents 82 (67.8%). Males were 75 (62%) and over half of the children 67 (55.4%) were orphans. The prevalence of abnormal lung function tests was found to be 17.4% (95% CI=10.7-24.8). Pulse oximetry findings showed that, none of the study participants were hypoxic at rest or post exercise. Physical findings revealed a history of chronic cough in half, lung crepitations in 19%, and peripheral cyanosis in 14% of the study participants. All these signs were associated with abnormal lung function tests (p=0.021, p<0.01, p<0.01 respectively). Most children 15 (71.4%) had advanced WHO HIV clinical disease stage (III & IV). However CD4 cell count did not affect the lung function tests (p=0.560). The median duration of HIV infection since diagnosis and the median duration on Antiretroviral Therapy (ART) use were comparatively short, 246 weeks (IQR 128 - 418) and 243 weeks (IQR 123 - 356) respectively. Assuming that most children acquire HIV infection through vertical transmission, it implies that they were diagnosed late and hence late initiation on ART which may have contributed to the abnormal lung function tests.

Conclusion and Recommendation: The prevalence of abnormal lung function tests in HIV infected children is relatively high. This implies that chronic lung disease may go undetected and can contribute to high morbidity and mortality in this population. Presence of chronic cough, peripheral cyanosis and lung crepitations have shown to be important features in HIV infected children with lung function impairment.

HIV infected children presenting with chronic cough, peripheral cyanosis and lung crepitations should undergo lung function tests for early detection of chronic lung disease. Further studies should be done to identify the actual cause of chronic lung disease among HIV infected children. This will allow timely and appropriate management which may improve their quality of life.

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