Role of naso-gastric aspirate in HIV-positive children presenting with respiratory symptoms

Abstract

Background: Human immunodeficiency virus (HIV) infection predisposes to various opportunistic infections like tuberculosis, Pneumocystis carinii (P. carinii) pneumonia, toxoplasmosis and fungal infections. Naso-gastric aspirate (NGA) is utilized to demonstrate acid-fast-bacilli (AFB); similarly P. carinii was isolated with the help of naso-gastric aspirate in HIV positive children. Design: Prospective study. Setting: Tertiary care center. Objective: Tostudy the role of naso-gastric aspirate in HIV positive patients presenting with respiratory symptoms. Methods: HIV positive patients less than 5 years age (n = 35) presenting with respiratory symptoms of cough, breathlessness, feeding difficulties and/or tachypnoea were studied. Gastric aspirate was obtained on three consecutive mornings after overnight fasting. 1 volume of dithiotretiol (mucolytic agent) was added to 2 volumes of gastric aspirate. The mixture was incubated for 15min followed by centrifugation at 1500 r.p.m. for 5min; the supernatant was decanted. The sediment was re-suspended in phosphate buffer saline with pH of 6.8 and re-centrifuged at 1500 r.p.m. for 5min. The final sediment was again suspended in phosphate buffer saline followed by addition of 6 drops of 30% bovine serum albumin. Smears were prepared from the sample followed by Zeihl-Neelsen stain for AFB; toluidine blue, Giemsa stain and Gomori's methenamine stain for identification of trophozoite and cyst forms of P. carinii. Results: P. carinii organism was identified in 17 patients (48.57%) with 11 patients having only P. carinii while 6 patients having isolated both P. carinii and AFB. 1 patient had isolated only AFB. The total number of AFB isolated was 7 patients (20.0%). Pulmonary Koch was identified in 17 patients; however AFB was identified in 7 cases (a yield of 41.18%). No complications as a result of the procedure were identified in any of the patients. Conclusion: Naso-gastric aspirate is a simple, convenient, relatively non-invasive and economical technique for identification of AFB and/or P. carinii organisms in HIV-positive patients presenting with respiratory symptoms. © 2006 Oxford University Press.