By Liz Highleyman

Due to overlapping routes of transmission, a significant number of HIV positive people are dually infected with the hepatitis C virus (HCV). In many countries, rates of HIV-HCV coinfection are particularly high among injection drug users; Spain has consistently had one of the highest coinfection rates in Western Europe.

As reported this week at the 48th International Conference on Antimicrobial Agents and Chemotherapy (ICAAC 2008) in Washington, DC, Spanish researchers looked at the changing epidemiology of HIV-HCV coinfection in their country.

They noted that the HIV epidemic is undergoing some changes in Spain -- mainly due to a decrease in the transmission of HIV via injection drug use -- and they hypothesized that this may have important repercussions on the epidemiology of HIV-HCV coinfection.

The invetsigators collected data from 5170 HIV positive antiretroviral-naive patients in 2 different cohorts who started care at Spanish institutions: a retrospectively assembled cohort from January 1997 through December 2003 (CoRIS-MD), and a prospective cohort from January 2004 through November 2006 (CoRIS).

Variables related to sociodemographic characteristics, HIV, and HCV infection were collected, and univariate analysis and logistic regression were performed.

Results

• The prevalence of HCV steadily decreased from 70.8% among patients who entered the study in 1997 to 16.3% among those who entered in 2006.

• During the same period, the proportion of injection drug users decreased from 67.1% to 14.5%.

• HCV infection was strongly associated with injection drug use, compared with HIV acquisition via heterosexual transmission (odds ratio 36.4; P = 0.0000).

Based on these findings, the researchers concluded, "Seroprevalence of hepatitis C coinfection in HIV positive [antiretroviral therapy]-naive patients initiating care in Spain has decreased from 1997 to 2006. This decrease is driven by a change in HIV transmission patterns."

Inst. de Salud Carlos III, Madrid, Spain; Hosp. Ramon y Cajal, Madrid, Spain;
Hosp. Gregorio Maranon, Madrid, Spain; Hosp. Donostia, San Sebastian, Spain; Hosp. La Fe, Valencia, Spain; Hosp. Elche, Elche, Spain; Hosp. Germans Trias i Pujol, Badalona, Spain; Hosp. Son Dureta, Mallorca, Spain; Hosp. Navarra, Pamplona, Spain; Hosp. Valme, Sevilla, Spain.

10/31/08

Reference
S Perez Cachafeiro, l Garcia, J Berenguer, and others. Sharp Decline in the Seroprevalence of Hepatitis C Virus among HIV-Infected Patients in Spain. 48th International Conference on Antimicrobial Agents and Chemotherapy (ICAAC 2008). Washington, DC. October 25-28, 2008. Abstract V-1629.