title: Epidemiology of influenza virus types and subtypes in South Africa, 2009-2012.
abstract: To determine clinical and epidemiologic differences between influenza caused by different virus types and subtypes, we identified patients and tested specimens. Patients were children and adults hospitalized with confirmed influenza and severe acute respiratory illness (SARI) identified through active, prospective, hospital-based surveillance from 2009-2012 in South Africa. Respiratory specimens were tested, typed, and subtyped for influenza virus by PCR. Of 16,005 SARI patients tested, 1,239 (8%) were positive for influenza virus. Patient age and co-infections varied according to virus type and subtype, but disease severity did not. Case-patients with influenza B were more likely than patients with influenza A to be HIV infected. A higher proportion of case-patients infected during the first wave of the 2009 influenza pandemic were 5-24 years of age (19%) than were patients infected during the second wave (9%). Although clinical differences exist, treatment recommendations do not differ according to subtype; prevention through vaccination is recommended.
authors: Adam L
authors: AL
authors: Cohen
authors: Orienka
authors: O
authors: Hellferscee
authors: Marthi
authors: M
authors: Pretorius
authors: Florette
authors: F
authors: Treurnicht
authors: Sibongile
authors: S
authors: Walaza
authors: Shabir
authors: S
authors: Madhi
authors: Michelle
authors: M
authors: Groome
authors: Halima
authors: H
authors: Dawood
authors: Ebrahim
authors: E
authors: Variava
authors: Kathleen
authors: K
authors: Kahn
authors: Nicole
authors: N
authors: Wolter
authors: Anne
authors: A
authors: von Gottberg
authors: Stefano
authors: S
authors: Tempia
authors: Marietjie
authors: M
authors: Venter
authors: Cheryl
authors: C
authors: Cohen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D060085:Coinfection / Q000453:epidemiology; D005260:Female; D006801:Humans; D009980:Influenza A virus / Q000235:genetics; D009981:Influenza B virus / Q000235:genetics; D007251:Influenza, Human / Q000453:epidemiology* / Q000821:virology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013019:South Africa / Q000453:epidemiology; D055815:Young Adult
keywords: H1N1; H3N2; South Africa; influenza; influenza A; influenza B; pneumonia; subtypes; types; viruses