Incidence and Transmission Patterns of Acute Hepatitis C in the United States, 1982-2006

[Guest guest]

http://archinte.ama-assn.org/cgi/content/abstract/171/3/242

Incidence and Transmission Patterns of Acute Hepatitis C in the United States,

1982-2006

Ian T. , PhD; Beth P. Bell, MD; Wendi Kuhnert, PhD; Miriam J. Alter, PhD

Arch Intern Med. 2011;171(3):242-248. doi:10.1001/archinternmed.2010.511

Background

Monitoring disease incidence and transmission patterns is important to

characterize groups at risk for hepatitis C virus (HCV) infection. Clinical

cases generally represent about 20% to 30% of all newly acquired infections.

Methods

We used sentinel surveillance to determine incidence and transmission patterns

for acute hepatitis C in the United States using data from 25 years of

population-based surveillance in the general community. Acute cases of hepatitis

C were identified from 1982 through 2006 by a stimulated passive surveillance

system in 4 to 6 US counties. Cases were defined by a discrete onset of

symptoms, alanine aminotransferase (ALT) levels greater than 2.5 times the upper

limit of normal (xULN), negative findings for serologic markers for acute

hepatitis A and B, and positive findings for antibody to HCV or HCV RNA.

Incidence and frequency of reported risk factors were the main outcome measures.

Results

Of 2075 patients identified, the median age was 31 years, 91.5% had ALT values

greater than 7 x ULN, 77.3% were jaundiced, 22.5% were hospitalized, and 1.2%

died. Incidence averaged 7.4 per 100 000 individuals (95% confidence interval

[CI], 6.4-8.5 per 100 000) during 1982 to 1989 then declined averaging 0.7 per

100 000 (95% CI, 0.5-1.0 per 100 000) during 1994 to 2006. Among 1748 patients

interviewed (84.2%), injection drug use (IDU) was the most commonly reported

risk factor. The average number of IDU-related cases declined paralleling the

decline in incidence, but the proportion of IDU-related cases rose from 31.8%

(402 of 1266) during 1982 to 1989 to 45.6% (103 of 226) during 1994 to 2006.

Among IDU-related cases reported during 1994 to 2006, 56 of 61 individuals

(91.8%) had been in a drug treatment program and/or incarcerated.

Conclusions

The incidence of acute HCV declined substantially over the 25 years of

population-based surveillance. Despite declines, IDU is the most common risk

factor for new HCV infection.

Author Affiliations: Division of Viral Hepatitis, Centers for Disease Control

and Prevention (CDC), Atlanta, Georgia. Dr is now with the Outbreak

Response and Prevention Branch, Division of Foodborne, Waterborne, and

Environmental Diseases, CDC, Atlanta; Dr Bell is now with the National Center

for Emerging and Zoonotic Infectious Diseases, CDC, Atlanta; Dr Kuhnert is now

with Office of the Director, National Center for Immunization and Respiratory

Diseases, CDC, Atlanta; and Dr Alter is now with the Division of Infectious

Diseases, University of Texas Medical Branch, Galveston.

[Guest guest]

http://archinte.ama-assn.org/cgi/content/abstract/171/3/242

Incidence and Transmission Patterns of Acute Hepatitis C in the United States,

1982-2006

Ian T. , PhD; Beth P. Bell, MD; Wendi Kuhnert, PhD; Miriam J. Alter, PhD

Arch Intern Med. 2011;171(3):242-248. doi:10.1001/archinternmed.2010.511

Background

Monitoring disease incidence and transmission patterns is important to

characterize groups at risk for hepatitis C virus (HCV) infection. Clinical

cases generally represent about 20% to 30% of all newly acquired infections.

Methods

We used sentinel surveillance to determine incidence and transmission patterns

for acute hepatitis C in the United States using data from 25 years of

population-based surveillance in the general community. Acute cases of hepatitis

C were identified from 1982 through 2006 by a stimulated passive surveillance

system in 4 to 6 US counties. Cases were defined by a discrete onset of

symptoms, alanine aminotransferase (ALT) levels greater than 2.5 times the upper

limit of normal (xULN), negative findings for serologic markers for acute

hepatitis A and B, and positive findings for antibody to HCV or HCV RNA.

Incidence and frequency of reported risk factors were the main outcome measures.

Results

Of 2075 patients identified, the median age was 31 years, 91.5% had ALT values

greater than 7 x ULN, 77.3% were jaundiced, 22.5% were hospitalized, and 1.2%

died. Incidence averaged 7.4 per 100 000 individuals (95% confidence interval

[CI], 6.4-8.5 per 100 000) during 1982 to 1989 then declined averaging 0.7 per

100 000 (95% CI, 0.5-1.0 per 100 000) during 1994 to 2006. Among 1748 patients

interviewed (84.2%), injection drug use (IDU) was the most commonly reported

risk factor. The average number of IDU-related cases declined paralleling the

decline in incidence, but the proportion of IDU-related cases rose from 31.8%

(402 of 1266) during 1982 to 1989 to 45.6% (103 of 226) during 1994 to 2006.

Among IDU-related cases reported during 1994 to 2006, 56 of 61 individuals

(91.8%) had been in a drug treatment program and/or incarcerated.

Conclusions

The incidence of acute HCV declined substantially over the 25 years of

population-based surveillance. Despite declines, IDU is the most common risk

factor for new HCV infection.

Author Affiliations: Division of Viral Hepatitis, Centers for Disease Control

and Prevention (CDC), Atlanta, Georgia. Dr is now with the Outbreak

Response and Prevention Branch, Division of Foodborne, Waterborne, and

Environmental Diseases, CDC, Atlanta; Dr Bell is now with the National Center

for Emerging and Zoonotic Infectious Diseases, CDC, Atlanta; Dr Kuhnert is now

with Office of the Director, National Center for Immunization and Respiratory

Diseases, CDC, Atlanta; and Dr Alter is now with the Division of Infectious

Diseases, University of Texas Medical Branch, Galveston.