Publication: Prevalence of Moraxella catarrhalis infections of the lower respiratory tract in elderly patients
Date
2005
Journal Title
Journal ISSN
Volume Title
Publisher
Kathmandu University
Abstract
Objectives: To determine:
• rate of isolation of Moraxella catarrhalis in elderly patients having lower respiratory tract infection
• The antibiotic susceptibility pattern of Moraxella catarrhalis isolates.
• The predisposing factors responsible for Moraxella catarrhalis infections of lower respiratory tract.
Material and Method: This is a prospective study carried out at Manipal Teaching Hospital, Pokhara during May
2002 to April 2003. A total of 716 sputum samples collected from patients with suspected lower respiratory tract
infection were investigated. The samples were subjected to Gram stain, culture and sensitivity. Sputum samples
were inoculated on blood and chocolate agar and incubated at 370C for 18 to 24 hours in candle jar containing 3-5%
Co2. For the identification of bacterial isolates, the cultural and colonial characteristics were recorded and identified
with the use of biochemical test. The susceptibility of bacterial isolates to antimicrobial agent was performed
following Kirby-Bauer method. Result: Out of the 716 samples, 355 (49.58%) grew normal commensals of the
upper respiratory tract. Respiratory pathogens were recovered from 361 (50.41%) samples. The most common
respiratory pathogen was H. influenzae (26. 86%), followed by S. pneumoniae (21.16%). Moraxella catarrhalis
accounted for 6.90%. Rate of isolation of Moraxella catarrhalis was higher in males than in females. Out of 25
isolates 16 were from males and 9 were from females. Frequency of isolation of Moraxella catarrhalis was more
frequently seen in age group 61-70 years. It was most commonly recovered in winter. The most effective antibiotics
were amoxicillin-clavulanate and ceftriaxone and least was ampicillin. Conclusion: Moraxella catarrhalis isolation
from sputum especially in persons above 60 years of age and in the absence of other well established pathogens
should not be disregarded as they can cause lower respiratory tract infection in these individuals.
Key words: Moraxella catarrhalis, lower respiratory tract infection, Nepal, Gram negative diplococci