The stakes are high. Pneumonia is responsible for the unnecessary loss of millions of lives each year. More so, it is a threat to sustainable development in developing countries.
Pneumonia is still the single leading cause of child death, killing one child every 35 seconds. Pneumonia is responsible for almost one-quarter of all deaths in children under five. There is nothing new or exotic about this disease. In fact, pneumonia is one of the oldest and most common diseases in the world; most children contract it at some point during childhood.
Pneumonia is deadly for the youngest and the poorest children. Pneumonia is a disease of poverty, concentrated within the poorest populations around the globe. Every year, more than 0.9 million children die from pneumonia, particularly in settings with limited access to health services, nutritious foods, basic sanitation, and hygiene. Low and lower-middle income countries are home to 62 percent of the world’s under-5 population, and they also account for more than 90 percent of global pneumonia deaths.
Pneumonia deaths are dropping, but not quickly enough. The burden of child deaths due to pneumonia has already halved since 2000, owing to an overall decline in child deaths and some modest improvements in coverage of preventive and treatment interventions. Despite the 51 percent decrease in pneumonia rates from 2000 to 2015, it is nowhere near the 86 percent decrease in mortality from malaria-related under-five mortality time frame.
Pneumonia was the fourth leading cause of mortality in the Philippines in 2009, occurring in about 46 for every 100,000 Filipino adults. Together with acute lower respiratory tract infections, it was the second highest cause of morbidity, with a rate of 613 per 100,000 Filipinos in the same year.
Pneumonia is an emerging health issue in the era of global population aging. Studies have shown that the risks of pneumonia and pneumonia-related death increase with age, and are highest among the elderly. It is estimated that by 2040, pneumococcal pneumonia hospitalizations will soar by 96 percent (from 401,000 in 2004 to 790,000 in 2040) as the elderly population increase by 38 percent.
The mechanism by which aging is associated with a risk for community-acquired pneumonia (CAP) is not simply related to chronological age. Instead, it is frequently associated with the following:
underlying comorbid conditions that more commonly occur in the aging population
a greater risk of being infected with antibiotic-resistant pathogens
place of residence
The burden of disease of pneumonia remains high in the Philippines. In 2016, researchers collated data on pneumonia from 18 hospitals in the Philippines. Results show these figures:
About 14,245 cases of CAP and 5,615 cases of hospital-acquired pneumonia (HAP) per 100,000 discharges
Average cost per hospital admission for pneumonia was at USD254 (P12,500)
Case fatality rates were reported at 9.1 percent for HAP and 1.4 percent for CAP
Overall average length of stay was 6.6 days (6.9 days versus 6.2 days for HAP and CAP, respectively)
Streptococcus remains the leading cause of community-acquired pneumonia (CAP) throughout the world. Yet, its decline in high-income countries resulted from the wide use of antibiotics and the introduction of pneumococcal vaccines. Meanwhile, non-pneumococcal pneumonia (e.g. respiratory viruses), particularly among elderly people, is gaining attention. Aspiration is considered a major cause of pneumonia in the elderly.
Presentation provides clues to responsible pathogens in CAP. Patients with “typical” CAP classically present with fever, a productive cough with purulent sputum, breathing difficulty, and chest pain. The following epidemiologic data may provide clues to the specific pathogen that causes CAP:
The most common overall pathogen is S. pneumoniae
Underlying chronic obstructive pulmonary disease (COPD): H.influenzae or M.catarrhalis
Recent influenza infection: S. aureus
Alcoholic patient presenting with “currant jelly” sputum: K. pneumoniae
The clinical presentation of so-called “atypical” CAP is often subacute and frequently indolent. In addition, patients with atypical CAP may present with more subtle pulmonary findings, nonlobar infiltrates on radiography, and various extrapulmonary manifestations (e.g. diarrhea, otalgia, mental confusion, prominent headache, bloody sputum). Atypical CAP pathogens include Mycoplasma pneumoniae, Chlamydia pneumoniae, etc.
Chest X-ray, sputum gram stain, and blood cultures are standard diagnostic studies for CAP. Depending on the perceived severity of illness and suspected etiology, additional workup may be warranted.
Adequate antimicrobial therapy for CAP includes coverage for S. pneumoniae and atypical bacterial pathogens. Treatment in patients with comorbidities such as chronic heart, lung, liver, or renal disease; diabetes mellitus; alcoholism; malignancy; asplenia (absence of normal spleen function); immunosuppression; prior antibiotics within 90 days; or other risk factors for drug-resistant infection may require higher antibiotic coverage.
Complications can occur following CAP infection.S. pneumoniae, K. pneumoniae (classically occurring in patients with chronic alcoholism), group A Streptococcus, and S. aureus can cause lung abscess, myocardial attack, sepsis, and death.
The use of protein-polysaccharide conjugate vaccines over the past two decades has markedly decreased the burden of disease and mortality from these organisms. The introduction of conjugate vaccines further decreased pneumonia rates by demonstrating 45.6 percent efficacy of PCV13 against the first episode of pneumonia, 45 percent against the first episode of non-bacteremic pneumococcal pneumonia, and 75 percent against the first episode of invasive pneumococcal diseases in adults older than 65 years in a recent clinical trial. Bacterial-viral co-infections are associated with increased mortality, and synergistic effects have been shown for combined vaccination.
There are two approved pneumococcal vaccines available in the Philippines. The 13-valent polysaccharide conjugate vaccine (PCV13; Prevnar 13) is indicated for children aged 6 weeks to 17 years and adults aged 50 years or older. On the other hand, the 23-valent pneumococcal polysaccharide vaccine (PPSV23; Pneumovax 23) is recommended for adults aged 65 years or older, and persons aged 2 years or older who are at increased risk for pneumococcal disease.
Last February 2016, the Advisory Committee on Immunization Practices (ACIP) published updated recommendations for pneumococcal vaccination in adults. The committee now recommends routine use of PCV13 in addition to PPSV23 for adults older than 65 years. It is recommended that an initial dose of PCV13 be given, followed by PPSV23 at least one year later. If PPSV23 has already been given, it should be followed by PCV13 a year later. A second dose of PPSV23 is not needed in immunocompetent hosts. If PPSV23 is inadvertently given prior to one year after PCV13, it need not be repeated.
Adequate nutrition is critical in improving children’s natural defenses, starting with exclusive breastfeeding for the first six months of life. In addition to being effective in preventing pneumonia, it also helps reduce the length of the illness if a child does become ill.
Addressing environmental factors such as indoor air pollution (by providing affordable clean indoor stoves, for example) and encouraging good hygiene in crowded homes also reduce the number of children who fall ill with pneumonia.