title: National Trend and Characteristics of Acute Hepatitis C among HIV-Infected Individuals: A Matched Case-Control Study-Taiwan, 2001-2014.
abstract: BACKGROUND
  Hepatitis C virus (HCV) infection has been increasingly recognized among HIV-infected men who have sex with men (MSM) worldwide. We investigated the trend of and factors associated with acute hepatitis C (AHC) among HIV-infected individuals in Taiwan.
  
  
  METHODS
  The National Disease Surveillance System collects characteristics of AHC, HIV, syphilis, and gonorrhea cases through mandatory reports and patient interviews. Reported AHC patients in 2014 were interviewed additionally on sexual and parenteral exposures. Information on HCV genotypes were collected from the largest medical center serving HIV-infected Taiwanese. We defined an HIV/AHC case as a documented negative HCV antibody test result followed within 12 months by a positive test in a previously reported HIV-infected individual. Each case was matched to two HIV-infected, non-AHC controls for age, age of HIV diagnosis, sex, transmission route, HIV diagnosis date, and county/city. Conditional logistic regression was used to identify associated characteristics.
  
  
  RESULTS
  During 2001-2014, 93 of 6,624 AHC reports were HIV/AHC cases; the annual case count increased from one in 2009 to 34 in 2014. All were males (81 [87%] MSM) aged 21-49 years with AHC diagnosed 2-5,923 days after HIV diagnoses. Sixty-eight (73%) lived in the Taipei metropolitan area. Detected HCV genotypes were 2a (n = 6), 1b (n = 5), 1b + 2a (n = 1) and 2b (n = 1). Among 28 HIV/AHC patients interviewed in 2014, 13 (46%) reported engaging in unprotected sex ≤3 months before AHC diagnosis. Seventy-nine HIV/AHC cases were matched to 158 controls. HIV/AHC was associated with recent syphilis (adjusted odds ratio [aOR], 10.9; 95% confidence interval [CI], 4.2-28.6) and last syphilis >6 months (aOR, 2.9; 95% CI, 1.2-6.9).
  
  
  CONCLUSIONS
  HIV/AHC cases continued to increase particularly among sexually active HIV-infected MSM with a syphilis diagnosis in northern Taiwan. We recommend surveillance of associated behavioral and virologic characteristics and HCV counseling and testing for HIV-infected men in Taiwan.
authors.affiliation: Taiwan Centers for Disease Control, Taipei, Taiwan; Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Yi-Chun
authors.initials: YC
authors.lastname: Lo
authors.affiliation: Department of Internal Medicine, Far Eastern Memorial Hospital, New Taipei City, Taiwan.
authors.forename: Mao-Song
authors.initials: MS
authors.lastname: Tsai
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Hsin-Yun
authors.initials: HY
authors.lastname: Sun
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Chien-Ching
authors.initials: CC
authors.lastname: Hung
authors.affiliation: Taiwan Centers for Disease Control, Taipei, Taiwan.
authors.forename: Jen-Hsiang
authors.initials: JH
authors.lastname: Chuang
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D015897:Comorbidity; D015658:HIV Infections / Q000453:epidemiology*; D006526:Hepatitis C / Q000453:epidemiology*; D018451:Homosexuality, Male; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D015995:Prevalence; D012307:Risk Factors; D013624:Taiwan / Q000453:epidemiology; D047568:Unsafe Sex; D055815:Young Adult