Estimated incidence of influenza-virus-associated severe pneumonia in children in El Salvador, 2008-2010

• Main Authors: Wilfrido Clara (Author), Julio Armero (Author), David Rodriguez (Author), Celina de Lozano (Author), Luis Bonilla (Author), Percy Minaya (Author), Rafael Chacón (Author), Jorge Jara (Author), Natalia Blanco (Author), Marc-Alain Widdowson (Author), Joseph Bresee (Author), Xiyan Xu (Author), Alexander Klimov (Author), Eduardo Azziz-Baumgartner (Author), Nivaldo Linares-Perez (Author)
• Format: Book
• Published: The World Health Organization, 2012-10-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

OBJECTIVE: To estimate the incidence of influenza-virus-associated severe pneumonia among Salvadorian children aged < 5 years. METHODS: Data on children aged < 5 years admitted with severe pneumonia to a sentinel hospital in the western region were collected weekly. Nasal and oropharyngeal swab specimens were collected from a convenience sample of case patients for respiratory virus testing. A health-care utilization survey was conducted in the hospital catchment area to determine the proportion of residents who sought care at the hospital. The incidence of influenza-virus-associated severe pneumonia among all Salvadorian children aged < 5 years was estimated from surveillance and census data, with adjustment for health-care utilization. Influenza virus strains were characterized by the United States Centers for Disease Control and Prevention to determine their correspondence with northern and southern hemisphere influenza vaccine formulations. FINDINGS: Physicians identified 2554 cases of severe pneumonia. Samples from 608 cases were tested for respiratory viruses and 37 (6%) were positive for influenza virus. The estimated incidence of influenza-virus-associated severe pneumonia was 3.2 cases per 1000 person-years (95% confidence interval, CI: 2.8-3.7) overall, 1.5 cases per 1000 person-years (95% CI: 1.0-2.0) during 2008, 7.6 cases per 1000 person-years (95% CI: 6.5-8.9) during 2009 and 0.6 cases per 1000 person-years (95% CI: 0.3-1.0) during 2010. Northern and southern hemisphere vaccine formulations matched influenza virus strains isolated during 2008 and 2010. CONCLUSION: Influenza-virus-associated severe pneumonia occurred frequently among young Salvadorian children during 2008-2010. Antigens in northern and southern hemisphere influenza vaccine formulations corresponded to circulating strains.

Item Description

0042-9686
10.2471/BLT.11.098202