title: Chikungunya as a cause of acute febrile illness in southern Sri Lanka.
abstract: BACKGROUND
  Chikungunya virus (CHIKV) re-emerged in Sri Lanka in late 2006 after a 40-year hiatus. We sought to identify and characterize acute chikungunya infection (CHIK) in patients presenting with acute undifferentiated febrile illness in unstudied rural and semi-urban southern Sri Lanka in 2007.
  
  
  RESULTS
  We enrolled febrile patients ≥ 2 years of age, collected uniform epidemiologic and clinical data, and obtained serum samples for serology, virus isolation, and real-time reverse-transcriptase PCR (RT-PCR). Serology on paired acute and convalescent samples identified acute chikungunya infection in 3.5% (28/797) patients without acute dengue virus (DENV) infection, 64.3% (18/28) of which were confirmed by viral isolation and/or real-time RT-PCR. No CHIKV/DENV co-infections were detected among 54 patients with confirmed acute DENV. Sequencing of the E1 coding region of six temporally distinct CHIKV isolates (April through October 2007) showed that all isolates posessed the E1-226A residue and were most closely related to Sri Lankan and Indian isolates from the same time period. Except for more frequent and persistent musculoskeletal symptoms, acute chikungunya infections mimicked DENV and other acute febrile illnesses. Only 12/797 (1.5%) patients had serological evidence of past chikungunya infection.
  
  
  CONCLUSIONS
  Our findings suggest CHIKV is a prominent cause of non-specific acute febrile illness in southern Sri Lanka.
authors: Division of Medical Microbiology, Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America ; Hubert-Yeargan Center for Global Health, Durham, North Carolina, United States of America.
authors: Megan E
authors: ME
authors: Reller
authors: Ufuoma
authors: U
authors: Akoroda
authors: Ajith
authors: A
authors: Nagahawatte
authors: Vasantha
authors: V
authors: Devasiri
authors: Wasantha
authors: W
authors: Kodikaarachchi
authors: John J
authors: JJ
authors: Strouse
authors: Robert
authors: R
authors: Chua
authors: Yan'an
authors: Y
authors: Hou
authors: Angelia
authors: A
authors: Chow
authors: October M
authors: OM
authors: Sessions
authors: Truls
authors: T
authors: Østbye
authors: Duane J
authors: DJ
authors: Gubler
authors: Christopher W
authors: CW
authors: Woods
authors: Champica
authors: C
authors: Bodinayake
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D065632:Chikungunya Fever / Q000150:complications / Q000453:epidemiology*; D002646:Chikungunya virus / Q000472:pathogenicity*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005335:Fever of Unknown Origin / Q000453:epidemiology / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D013188:Sri Lanka / Q000453:epidemiology; D055815:Young Adult