Expanded HIV Screening Should Reduce New Infections in USA

An expanded US program of Human immunodeficiency virus (HIV) screening and treatment could prevent as many as 212,000 new infections over the next 20 years and prove to be very cost-effective.

For the analysis, scientists assumed use of a third-generation ELISA test, such as the Genetic Systems HIV1/2 Plus O by Biorad Laboratories (Redmond, WA, USA). Positive tests then received follow-up testing with Western Blot.

Scientists found that screening high-risk people annually and low-risk people once in their lifetimes was a worthwhile and cost-effective approach to help curtail the HIV epidemic. The screening would need to be coupled with treatment of HIV-infected individuals, as well as programs to help change risky behavior.

The study, performed by Stanford University School of Medicine Sanford, CA, USA) investigators, is the first to use a national model of HIV transmission to gauge the impact of scaling up screening and treatment. A dynamic mathematical model of HIV transmission, disease progression, and cost-effectiveness analysis was used. The study was published in the December 2, 2010, issue of the Annals of Internal Medicine.

The investigators projected that 1.23 million people would become newly infected in the next 20 years if things remained as they are today. Some 74 % of new infections would be among high-risk individuals, particularly men who have sex with men and intravenous drug users.

The expanded screening and treatment program still would not eliminate the epidemic, as at-risk individuals would still have to change their behaviors. If men who have sex with men reduce their number of sexual partners by half and intravenous drug users cut needle sharing by the same amount, 65 % of all new infections would be prevented, the scientists found. That would reduce the incidence of HIV to approximately 20,000 new cases per year.

Treating patients is important because it avoids complications and costly hospitalizations and makes it less likely they will transmit the virus to others because the amount of virus in their systems is low. If 75 % of individuals identified as HIV-positive receive access to therapy, the health outcomes are improved and the program provides better value at US$22,000 per quality-adjusted life year (QALY) gained.

"We find that expanded screening and treatment could offer substantial health benefits, preventing 15% to 20 % of new cases," said Elisa Long, PhD, first author of the study. "And the strategy of one-time screening of low-risk individuals and annual screening of high-risk individuals is very cost-effective."

Related Links:
Biorad Laboratories
Stanford University School of Medicine