Pediatric Infectious Diseases: Open Access

Editorial

The most frequent diseases afflicting humanity are viral
respiratory infections. Children under the age of experience the majority of the morbidity and mortality associated with these illnesses. However, these "childhood" viruses are increasingly causing sickness and even death in a large number of healthy adults, the elderly and particularly immunocompromised people. Many new diagnostic, therapeutic, and preventive measures are now or soon will be available as a result of the advancement of molecular biology tools. With these techniques, even our understanding of basic viral epidemiology is fast altering. This essay will focus on the most common viruses that infect children and cause pneumonia.

Acute Respiratory Infections (ARI) kills or contributes to the deaths of 4-5 million children in underdeveloped countries each year. Children with pneumonia account for the majority of these deaths. During their illnesses, which are commonly worsened by bacterial infections of the lower respiratory tract, around 30%- 48% of these youngsters have had respiratory viruses other than measles identified. Lower Respiratory Infections (LRI) affect more than 5 million children under the age of five in the United States each year. For the first ten years of life, boys have a larger incidence of LRI than females, with an incidence that is roughly equal into adolescence.

LRI can manifest itself in a variety of ways, including pneumonia. It is found in 23% of children with LRI who are treated as outpatients and accounts for 29%-38% of pediatric inpatient hospitalizations for LRI. The age-related incidence of pneumonia, on the other hand, does not directly correspond to the incidence of LRI. Pneumonia causes for just around 10% of LRI in children examined in an ambulatory care setting in their first year of life. The incidence rises until it peaks in the second and third years of life (about 4 to 5 cases per 100 child years), then progressively declines to 2 instances per 100 child years in the 5 to 9 age group, and then to around 1 case per 100 child years thereafter.

Guidelines for diagnosing and treating pneumonia in newborns in underdeveloped countries have been developed by the World Health Organization. Cough and/or rapid (difficult) breathing as an initial screen, combined with a respiratory rate of at least 60 per minute, severe chest wall in-drawing, and nonspecific signs (e.g, poor feeding, fever, etc), identified 83% of the cases of pneumonia confirmed by chest radiograph, according to a recent evaluation of these guidelines.

Viruses cause between 50% and 90% of LRI, depending on the child's age and the specific respiratory symptoms. Viruses have been shown to cause up to 90% of pneumonia cases, especially in the first year of life, and this ratio drops to around 50% by the time a child reaches school age.