Surveillance of acute respiratory infections in Mumbai during 2011-12.

Purpose: Acute respiratory infections (ARIs) are a leading cause of morbidity and mortality in individuals aged less than 5 years. ARI often leads to hospitalisation, and it has been indicated that causative viral and bacterial infections go undetermined and results in the occurrence of resistant strains. The objective of the study was to assess the prevalence of various viral and bacterial infections in patients with ARIs.

Materials And Methods: Two hundred samples were collected from July 2011 to July 2012 with patients suffering from ARI. Viral and bacterial infections were determined by real time reverse transcriptase polymerase chain reaction.

Results: Influenza-like illness (ILI) consisted of 109 patients and ARI consisted of 91 patients. Pandemic influenza A H1N1 was the major viral infection with 21 (19.2%) patients in ILI as compared with 16 (17.4%) patients in ARI. Respiratory syncytial virus (RSV) was found to be 1 (0.9%) in ILI and ARI. Viral co-infections were 16 (14.4%) in ILI and 4 (4.37%) in ARI where pandemic influenza A H1N1 and influenza type B were major contributors. In bacterial infections, Streptococcus pneumoniae with 11 (10.9%) cases were predominant in both the groups. Bacterial co-infection accounted for only 1 (1.09%) case in both the groups but the most significant finding was the viral-bacterial co-infection in which Haemophilus influenzae was the major co-infecting bacteria with the influenza viruses with 4 (4.36%) cases as compared with Streptotoccus pneumoniae.

Conclusion: This data indicate the need to undertake continued surveillance that will help to better define the circulation of respiratory viruses along with the bacterial infections.