Study of Invasive Pneumococcal Infection in Adults with Reference to Penicillin Resistance

Invasive pneumococcal infections often prove rapidly fatal, even where good medical treatment is readily available. In developed countries, up to 20% of people who contract pneumococcal meningitis die; however, in developing world, mortality is closer to 50%, even among hospitalized patients. The World Health Organization estimated 600,000-800,000 adult deaths each year from pneumococcal pneumonia, meningitis, and sepsis.

This study aims to estimate isolation rate of invasive pneumococcal infection in adults, to determine the antimicrobial susceptibility profile of Streptococcus pneumoniae isolates and to study the associated risk factors.

A total of 120 patients with suspected invasive infection such as meningitis, septicemia, and pleural effusion, were included in the study. Various clinical specimens such as pus, cerebrospinal fluid, and other sterile body fluids were processed for isolation and identification of S. pneumoniae. Kirby-Bauer disc diffusion method was performed to determine the antimicrobial susceptibility profile. Minimum inhibitory concentration test was performed to determine the penicillin resistance.

Of 120 patients, 40 (33.33%) cases were proven by culture to have an invasive pneumococcal infection. The most common clinical condition observed was meningitis followed by pneumonia with pleural effusion and sepsis. Pneumococcal isolates exhibited 40% resistance to cotrimoxazole and 12.73% to chloramphenicol. Two meningeal isolates exhibited penicillin resistance. Comorbidities observed in 21 (52.5%) cases were mainly Diabetes mellitus, smoking, and alcoholism.

Invasive pneumococcal infection has poor prognosis and penicillin-resistant strains have become increasingly common. This study emphasizes the importance of judicious use of antibiotics, especially to refrain their use in mild self-limiting upper respiratory infections.