Influenza Surveillance Among Children With Pneumonia Admitted to a District Hospital in Coastal Kenya, 2007–2010

Abstract

Background. Influenza data gaps in sub-Saharan Africa include incidence, case fatality, seasonal patterns, and associations with prevalent disorders.Methods. Nasopharyngeal samples from children aged <12 years who were admitted to Kilifi District Hospital during 2007–2010 with severe or very severe pneumonia and resided in the local demographic surveillance system were screened for influenza A, B, and C viruses by molecular methods. Outpatient children provided comparative data.Results. Of 2002 admissions, influenza A virus infection was diagnosed in 3.5% (71), influenza B virus infection, in 0.9% (19); and influenza C virus infection, in 0.8% (11 of 1404 tested). Four patients with influenza died. Among outpatients, 13 of 331 (3.9%) with acute respiratory infection and 1 of 196 without acute respiratory infection were influenza positive. The annual incidence of severe or very severe pneumonia, of influenza (any type), and of influenza A, was 1321, 60, and 43 cases per 100 000 <5 years of age, respectively. Peak occurrence was in quarters 3–4 each year, and approximately 50% of cases involved infants: temporal association with bacteremia was absent. Hypoxia was more frequent among pneumonia cases involving influenza (odds ratio, 1.78; 95% confidence interval, 1.04–1.96). Influenza A virus subtypes were seasonal H3N2 (57%), seasonal H1N1 (12%), and 2009 pandemic H1N1 (7%).Conclusions. The burden of influenza was small during 2007–2010 in this pediatric hospital in Kenya. Influenza A virus subtype H3N2 predominated, and 2009 pandemic influenza A virus subtype H1N1 had little impact.

The prevalence and risk factors for acute respiratory infections in children aged 0‐59 months in rural Malawi: A cross‐sectional study

“…The cross‐sectional study design has limitations. Data were collected during the rainy season, and pneumonia cases peak from January to March, possibly inflating the point prevalence of ARI. The period prevalence should not be affected.…”

Epidemiology and Clinical Characteristics of Influenza C Virus

“…A Japanese longitudinal study of 190 ICV isolates collected over seven years found that nearly all were <6 years old, with the highest rates of infection in children 1-2 years old [60]. Rates of detection of ICV in outpatient or hospitalized children with acute respiratory illness have ranged from 0.7-10% in studies from Australia, Canada, Cuba, India, Italy, Japan, Nigeria, Peru, Scotland, and Spain [1,12,20,61,63,68,70,[91][92][93][94][95][96][97][98][99][100][101][102]. Most of these studies found higher rates of ICV infection in younger children.…”

“…Most of these studies found higher rates of ICV infection in younger children. Several studies have reported ICV as a cause of radiographic pneumonia in children, in some series as frequently as IBV [92,95,102]. These widely varied rates are likely due to varying circulation of ICV in different years; several studies have reported large outbreaks in a single year [61,94,98,99].…”

“…ICV is usually associated with mild respiratory disease. The most common symptoms associated with ICV infection are fever, rhinorrhea, and cough; however, the virus has been associated with pneumonia, bronchiolitis, and bronchitis [1,12,63,77,92,94,95,[101][102][103][104]. Symptoms of gastroenteritis in patients infected with ICV are frequently reported (Table 1).…”

Uptake and Effectiveness of a Trivalent Inactivated Influenza Vaccine in Children in Urban and Rural Kenya, 2010 to 2012

“…5 In Kenya, a country of 44 million people with a tropical climate and a per capita gross domestic product of $1800 in 2012, 6 recent studies have shown that influenza circulates year-round and the incidence of influenza is at least as high as it is in other parts of the world and particularly high in children <2 years old. 7,8 Influenza vaccine is not provided by the government, and <45,000 doses of influenza vaccine are purchased privately every year. A recent study found that Kenyans were aware of the seasonal influenza, although they were not aware of seasonal influenza vaccine.…”