Bacterial Involvement in Causing Lower Respiratory Tract Infection in Adults Visiting Tribhuvan University Teaching Hospital and their Antibiotic Susceptibility Pattern

Abstract

Introduction: Respiratory conditions impose enormous burden on society. Reports indicated that the top five respiratory diseases accounted for 17.4 percent of all deaths and 13.3 percent of all Disability-Adjusted Life Years (DALYs). Also, out of total acute respiratory disease, 20-24 percent of deaths are accounted for by Lower Respiratory Tract Infection (LRTI). In developing countries like Nepal the need for timely diagnosis of the cases and the administration of appropriate therapy based on the antibiotic susceptibility test of the causative agents is critical. However, emergence of resistant strains may occur during antibiotic therapy, which is one of the contributing factors for the increase in the frequency of LRTI in recent years in the adult population of Nepal as well.

 Objectives: The study was undertaken to have a better understanding on the current trend of microbial involvement in causing LRTI in adults and to determine the efficacy of antimicrobial agents in-use in treating the infections.

Method: A hospital based cross-sectional study was carried out from March 2002 to February 2003. Total 181 adults presenting with LRTI defined by a new or increasing cough, productive sputum, chest pain, fever, anorexia, haemoptysis, headaches and throat ache were enrolled with their consent. This is a prospective study which included bacteriological culture, microscopic examination and sensitivity testing of bacterial

isolates in vitro in Health Research laboratory following Standard Operating Procedures (SOPs).

Results: Lower Respiratory Infection was established in 75 cases (41.4%). Males (61.3%) were found more at risk to LRTI than females (38.7%). LRTI was found most prevalent in 50-59 year age groups (21.3%). Altogether 15 different types of bacteria were identified majority of which were Gram-negative bacteria (72.4%). Haemophilus influenzae was the commonest isolate at 23.0 percent followed by Klebsiella pneumoniae (18.3%). Among Gram- positive isolates Streptococcs pneumoniae was predominant (12.7%) followed by

Staphylococcus aureus(9.3%).The in vitro antibiotic susceptibility test of the isolates showed that Chloramphenicol(100%) was the most effective antibiotic against Gram-negative bacteria followed by Amikacin (79.1%) and Ciprofloxaxin (66.7%), and the least effective was Co-trimoxazole (20.6%). Similarly, for the Gram-positive bacteria Ciprofloxacin (79.2%) was the most effective antibiotic and the least effective was Co-trimoxazole.

Conclusion: The study shows increasing number of respiratory pathogens resistant to antimicrobials in-use to treat the infection.

Key words: LRTI, Antibiotic susceptibility pattern.

Source: Gauchan Pa, Lekhak B b and Sherchand JBc