Clinical and laboratory studies on the role of viruses, bacteria, Mycoplasma pneumoniae, and Bedsonia in acute respiratory illness

Seasonal Incidence of Community-acquired Pneumonia: A Retrospective Study in a Tertiary Care Hospital in Kathmandu, Nepal

Introduction

Community-acquired pneumonia (CAP) is the major cause of death in adult and elderly persons with a variety of presentations. Seasonal variation in the incidence of the disease is essential for clinicians and epidemiologists who deal with such diseases. The study was aimed at analysing the clinical profile and outcomes of community-acquired pneumonia during different seasons of the year in a tertiary care hospital, Manmohan Memorial Teaching Hospital (MMTH), of Kathmandu, Nepal.

Method

The aetiology and clinical profile of 378 patients with CAP who were admitted to MMTH over a period of one year were taken into account in this retrospective cross-sectional hospital-based study. Data were retrieved from the hospital medical records section and the Department of Pathology. All patients with a primary diagnosis of CAP admitted to the hospital were included in the study. Monthly and seasonal trends, aetiology, comorbidities, and mortality rates were analysed.

Results 

Of 378 patients with CAP, 160 patients (42.3%) had associated chronic obstructive pulmonary disease (COPD), 92 patients (24.3%) had hypertension (HTN), 59 patients (15.6%) had diabetes, 12 patients (3.1%) had active pulmonary tuberculosis, seven patients (1.85%) had kidney disease, and the remaining 48 patients (12.6%) had only CAP. Seasonal variation of CAP was noted in 131 patients (35%) in the winter, 98 (26%) in autumn, 86 (23%) in spring, and 63 patients (16%) in summer seasons. None of the patients were vaccinated against influenza and pneumococcus. The most common organism isolated in CAP was Acinetobacter calcoaceticus baumannii (ACB) complex (4.7%), which was more distinguished in the winter season. The second most isolated organism was Pseudomonas aeruginosa (2.6%). The most common clinical presentation was fever (63%), followed by cough (47%) and shortness of breath (47%). Sputum culture was found to be positive in 51 cases (13.4%). Among 378 patients, 78 patients (20.6%) received treatment in the Intensive Care Unit (ICU) and the rest of the patients received treatment in the general medical ward. The mortality rate was found to be 6.6%.

Conclusion

An incidence of sputum-positive CAP was found in 51 cases (13.4%). The most common organism was ACB complex, followed by Pseudomonas aeruginosa, which were sensitive to polymyxins. Both of them were predominant in the winter and spring.

Prevalence of Mycoplasma pneumoniae and Chlamydia pneumoniae in children with community acquired pneumonia

A prospective one year study was performed on 62 children admitted at the All India Institute of Medical Sciences with community acquired pneumonia (CAP) for the prevalence of Mycoplasma pneumoniae and Chlamydia pneumoniae. Diagnosis of infection with M. pneumoniae was based on serological tests viz microparticle agglutination test for detection of IgM antibodies and indirect immunofluorescence test for antigen detection from throat swabs (sensitivity 85.7%, specificity 93.3%). The indirect solid-phase enzyme immunoassay for detection of IgG antibodies was used to determine the prevalence of C. pneumoniae (sensitivity 88.8%, specificity 75.8%). Seventeen patients (27.4%) were found to have serological evidence of M. pneumoniae infection whereas only 4 (6.4%) patients were seropositive for C. pneumoniae. Results of this study indicate that M. Pneumoniae plays a significant role in CAP in infants and young children. Thus specialized laboratory testing for these agents should be more widely used thereby affecting empiric antibiotic regimens.