Pneumococcal Pneumonia Health Article

Prevention

The pneumococcal vaccine is the only way to prevent persons from contracting pneumococcal pneumonia. Vaccines are available for children and adults.

The CDC National Immunization Program recommends immunization against pneumococcal pneumonia for the following groups:

• persons aged 65 years old or older;
• persons with serious long-term health problems, such as heart disease, sickle cell disease, alcoholism, leaks of cerebrospinal fluid, lung disease (not including asthma), diabetes, or liver cirrhosis;
• persons whose systems are immunocompromised because of concurrent diseases or treatments;
• persons of Alaskan Native or of certain Native American heritage; and.
• all infants and children younger than 23 months.

To access the 2005 US Childhood and Adolescent Immunization Schedule (PDF), visit http://www.cdc.gov/nip/recs/child-schedule.PDF.

To access the October 2004 to September 2005 US Recommended Adult Immunization Schedule (PDF), visit http://www.cdc.gov/nip/recs/adult-schedule.pdf.

Updated - September 26, 2005.

The continued use of 7-valent pneumococcal conjugate vaccine (PCV7) in children younger than 5 years old has resulted in great strides in the prevention and incidence of invasive pneumococcal disease (IPD), according to a report compiled by the Centers for Disease Control and Prevention (CDC). This report was made on the basis of an analysis of US surveillance data and was recounted in the September 16, 2005, issue of Morbidity and Mortality Weekly Report. .

This report updates a previous assessment of the impact of PCV7 on IPD and extends analysis through 2003 by using population-based data from the Active Bacterial Core surveillance of the Emerging Infections Program Network, a cooperative surveillance program conducted by several state health departments and the CDC. According to background information provided in the article, PCV7 was licensed for routine use in young children in the United States in 2000. The vaccine is used for the prevention of infection caused by Streptococcus pneumoniae (pneumococcus), a leading cause of pneumonia and meningitis in the United States that disproportionately affects young children and older adults.

According to the article, the results of this analysis indicated that routine vaccination of young children with PCV7 continued to result in statistically significant declines in the incidence of IPD through 2003 in the age group targeted for vaccination and among older children and adults. In addition, the use of the vaccine prevented more than twice as many IPD cases in 2003 through indirect effects on pneumococcal transmission (ie, herd immunity) than through its direct effect of protecting vaccinated children. Finally, the increases in disease caused by pneumococcal serotypes not included in the vaccine (ie, replacement disease) occurred in certain populations but were small compared with overall declines in vaccine-serotype disease.

The CDC concluded that ongoing surveillance is needed to assess whether reductions in vaccine-serotype IPD are sustained and whether replacement disease will erode the substantial benefits of routine vaccination.

In related news, it was reported that no significant differences existed in the clinical efficacy of two different therapeutic approaches to the treatment of inpatients with community acquired pneumonia (CAP). The two approaches compared in the study were a pathogen-directed antibiotic approach and an empiric strategy using broad-spectrum antibiotics. Findings of this study were published in the August 2005 issue of Thorax. .

Dutch researchers conducted a prospective, randomized study of 303 hospitalized patients between 1998 and 2000. The patients were randomly assigned to receive either an empirical broad-spectrum antibiotic treatment (EAT) or a pathogen-directed treatment (PDT) in accordance with guidelines established in 1993 by the American Thoracic Society. The primary determinant of clinical efficacy was defined by length of hospital stay (LOS). Other parameters for clinical efficacy included quality of life, adverse effects, resolution of fever, duration of antibiotic treatment, 30-day mortality, and assessment of therapeutic failure on antibiotics.

Data for analysis was obtained from 262 patients; the remaining 41 patients were excluded from the study. Between the two treatment groups, no significant differences were found in resolution of fever, clinical failure, 30-day mortality, or LOS. Adverse effects were more frequently assessed in patients in the EAT group than in the PDT group (60% vs 17%; 95% confidence interval, –0.5 to –0.3; P <.001), though this did not significantly influence the outcome parameters.

The researchers concluded that a PDT approach to the management of hospitalized patients with CAP has comparable clinical efficacy to an EAT strategy with broad-spectrum antibiotics.

Finally, it was reported that use of a rapid quantitative real-time polymerase chain reaction (PCR) assay could provide a means to quickly and accurately diagnose pneumococcal pneumonia in adult patients with CAP. This study was conducted by researchers at Johns Hopkins University, and its findings were published in the July 2005 issue of Journal of Clinical Microbiology. .

The trial was designed as a prospective clinical observational study, and it was implemented to test the utility of a PCR assay that performs analysis of sputum samples for the identification of S pneumoniae. Consecutive patients who presented to the emergency department with CAP were enrolled in the study. The patients were included for evaluation only if they were able to produce excess good-quality sputum samples.

The quantitative PCR method used in the study targeted the pneumolysin gene. The researchers compared the findings of PCR testing with those obtained through the Gram stain of sputum samples and sputum/blood cultures, which are the standard means used to identify S pneumoniae. The log-transformed threshold and the area under the curve (AUC) were calculated.

Only 129 of the enrolled 487 subjects could be evaluated. Receiver operating characteristic curve analysis established an AUC of 0.87. Sensitivity and specificity were 90% and 80%, respectively, and positive and negative predictive values were 58.7% and 96.2%, respectively.

In conclusion, the researchers found that a quantitative rapid pneumolysin PCR assay has favorable accuracy for the diagnosis of pneumococcal pneumonia in adult patients with CAP. In addition, it is speculated that this test might enable acute-care clinicians to rapidly identify pathogens and therefore provide guidance for selecting appropriate antibiotic therapy.