Comparative study of Chest X-Ray features in Pulmonary Tuberculosis With and Without HIV Co-Infection

INTRODUCTION: Tuberculosis is a specific infectious disease caused by mycobacterium tuberculosis. The disease primarily affects lungs and causes pulmonary tuberculosis. Tuberculosis remains a world wide public health problem despite the fact that the causative organism was discovered more than 100 years ago. It is estimated that about 1/3 rd of current global population is infected asymptomatically with tuberculosis of whom 5-10 percent will develop clinical disease during their life time. Most new cases and deaths occur in developing countries where infection is often acquired in childhood. Comparing different parts of the world the African region (24%). South east Asia region (35%) and Western Pacific region (24%) together accounted for 83% of all notified new and relapse cases.3 India is the highest TB burden country in the world and accounts for nearly one fifth (20%) of global burden of tuberculosis. Every year approximately 1.8 million persons develop tuberculosis of which about 0.8 million are new smear positive highly infectious cases. World wide the number of people infected with both HIV and tuberculosis is rising. The HIV virus damages the body natural defenses – the immune system – and accelerates the speed at which TB progresses from a harmless infection to a life threatening condition. TB has already become the most frequent opportunistic infection that kills HIV positive people. The diagnosis of tuberculosis in individual patients using the standard diagnostic tools can be more difficult if they have advanced HIV infection. AIM OF THE STUDY: 1. To compare the chest X ray features of HIV positive pulmonary tuberculosis patients with HIV negative pulmonary tuberculosis patients. 2. To determine the percentage of patients with atypical chest x ray in HIV positive and negative groups 3. To determine the relationship between atypical chest x rays and CD4 count. MATERIALS AND METHODS: The cases analysed in this study were patients who have registered under RNTCP programme in thoracic medicine department of Govt. Rajaji Hospital, Madurai after referral from various other departments. After recording the presenting complaints, specific history of Diabetes mellitus, chronic kidney disease, immuno suppression therapy, and haematological malignancy is obtained. Patients with h/o any of the above conditions are excluded. As these condition can cause chest x ray pictures similar to HIV infection in pulmonary tuberculosis patients. A complete physical examination is done. Patients with positive sputum AFB results whose HIV status is already checked or who are willing to check are included in the study. After obtaining the HIV status all the patients under went chest x ray evaluation except those patients who had a recent chest x ray after diagnosis of tuberculosis. Inclusion Criteria : 1. Pulmonary tuberculosis proved by atleast one positive sputum AFB result. 2. Presence of chest x ray taken immediately after diagnosis of tuberculosis. 3. Known HIV status. 4. Known CD4 count if HIV positive. 5. Consent. Exclusion Criteria : Any condition which can cause immuno suppression 1. Diabetes mellitus. 2. Chronic kidney disease. 3. Immuno suppression therapy. 4. Hematological malignancy. Patients who satisfied both criteria were selected for this study. SUMMARY: • The aims of study were stated • Literature on Tuberculous, HIV and tuberculosis coinfection, chest x ray of TB and chest x ray of HIV and TB co-infection was reviewed. • Materials and methods of the study were stated. • Analysis of data was done. Total number of patients were 60, HIV positive patients were 26, HIV negative patients were 34. • HIV positive patients had significantly higher incidence of lower zone infiltration. • HIV positive patients had significantly lower incidence of cavities and upper zone infiltrates. • Normal chest x rays are found in higher proportion of HIV positive individual but was found to be not significant. • HIV positive patients had significantly higher incidence of atypical features on chest x ray than HIV negative patients. • Atypical features on chest x ray correlates with CD4 count as lower CD4 count patients had higher incidence of atypical features on chest x ray. From the discussion it was inferred that HIV co-infection is associated with higher incidence of atypical features. Atypical features found in this study included higher incidence of lower zone infiltrates and lower incidence of upper zone infiltrates and cavity. Atypical features occurred more frequently with lower CD4 count. The diagnosis of pulmonary tuberculosis in HIV infected patients are difficult as the clinical and investigational evidences are altered especially chest radiography. CONCLUSION: There is a significant relationship between HIV co-infection and chest radiography in pulmonary tuberculosis. Atypical chest radiography is significantly higher in HIV co-infected patients with pulmonary tuberculosis. Atypical chest radiographic findings are more common in patients with lower CD4 counts. These findings emphasize the use of various investigations together with clinical features for the accurate diagnosis of pulmonary tuberculosis in patients with HIV co-infection