Nasopharyngeal Pneumococcal Density during Asymptomatic Respiratory Virus Infection and Risk for Subsequent Acute Respiratory Illness

• DOI: 10.3201/eid2511.190157
• Publication Date: 2019-09-30T12:18:10Z
• Authors: Leigh M. Howard; Yuwei Zhu; Marie R. Griffin; Kathryn M. Edwards; John V. Williams; Ana I. Gil; Jorge E. Vidal; Keith P. Klugman; Claudio F. Lanata; Carlos G. Grijalva
• Keywords: Male; Infectious and parasitic diseases; RC109-216; Risk Assessment; Pneumococcal Infections; 03 medical and health sciences; 0302 clinical medicine; Risk Factors; acute respiratory illness; Nasopharynx; Humans; viruses; Public Health Surveillance; Child; Respiratory Tract Infections; Coinfection; Research; R; 3. Good health; pneumococcal colonization density; vaccine-preventable diseases; Streptococcus pneumoniae; Child, Preschool; Asymptomatic Diseases; Medicine; Female; viral infection; pneumococcus

Increased nasopharyngeal pneumococcal (Streptococcus pneumoniae) colonization density has been associated with invasive pneumococcal disease, but factors that increase pneumococcal density are poorly understood. We evaluated pneumococcal densities in nasopharyngeal samples from asymptomatic young children from Peru and their association with subsequent acute respiratory illness (ARI). Total pneumococcal densities (encompassing all present serotypes) during asymptomatic periods were significantly higher when a respiratory virus was detected versus when no virus was detected (p<0.001). In adjusted analyses, increased pneumococcal density was significantly associated with the risk for a subsequent ARI (p<0.001), whereas asymptomatic viral detection alone was associated with lower risk for subsequent ARI. These findings suggest that interactions between viruses and pneumococci in the nasopharynx during asymptomatic periods might have a role in onset of subsequent ARI. The mechanisms for these interactions, along with other potentially associated host and environmental factors, and their role in ARI pathogenesis and pneumococcal transmission require further elucidation.