Think HIV: Routine HIV screening programme captures undiagnosed infections

Boston, MA: It’s estimated that some 300,000 Americans are currently living with undiagnosed HIV infection. And in the US, as in the UK, around a third of those who present for HIV care for the first time, do so when their CD4 count is already below 200, the immune threshold at which the risk of opportunistic infections grows significantly.

Diagnosing HIV in this at-risk group is a priority on both sides of the Atlantic. Last year’s National Strategy on Sexual Health and HIV, from the Department of Health, aims to reduce undiagnosed infections in the UK within genitourinary medicine clinics in particular. In these settings, the primary sites for treating sexually transmitted infections, it is still not mandatory that health care workers offer an HIV test to patients.

In the US in 2001, the federal Centers for Disease Control (CDC) sought to tackle the problem through a revision to their Guidelines on HIV Counselling, Testing and Referral – hospitals with an HIV prevalence above 1% were urged to establish routine, voluntary testing programmes for all patients. It seems, however, that this rarely occurs.

Yesterday, here at the Tenth Retroviruses Meeting in snowy Boston, Rochelle Walensky of Mass General Hospital and Havard Medical School, shone a little sunshine onto this dreary picture. Dr Walensky, and colleagues from Massachusetts Department of Public Health, described Think HIV, a locally instituted programme which has established routine, voluntary HIV screening in urgent care sites in the state of Massachusetts.

Four Massachusetts hospitals with the highest rates of HIV reporting were selected for inclusion. Each were required to provide a qualified, multilingual counsellor and a private room, and to ensure that staff were committed to the programme and to providing patient referrals to an HIV clinic following an HIV-positive diagnosis. Hospital patients were encouraged to speak to a counsellor, and offered a thirty to forty-five minute counselling session. Those who took up the offer of HIV screening were then tested using the OraSure cheek swab method, and advised to return for the result within fourteen days.

The success of Think HIV in capturing undiagnosed infections was measured against the performance of a comparator group of over one hundred state-funded, self-referral HIV counselling and testing sites. Between January and September 2002, Think HIV offered over seven thousand HIV tests, of which 37% were accepted. Close to 34,000 tests were performed in the state-wide sites in the same period.

HIV was diagnosed in 48 of 2,444 tests undertaken within the Think HIV programme, and in 460 of 33,608 tests in the reference group. This equates to a yield of 2.0% in Think HIV, and 1.4% in the state-wide programme; a significant improvement. Think HIV was more likely to diagnose HIV infections in women (43% versus 38%), and in Black people (36% versus 15%), therefore reaching two groups disproportionately affected in the US.

In Think HIV, the yield in people whose only risk factor for HIV infection was heterosexual sex was double that of state-wide programmes (2% versus 1%), and the programme was also effective in diagnosing infections in people who had had a negative HIV test result in the previous year (a prevalence of 2.2%). The nine month programme costs were $232,900, which equates to just under $5,000 per HIV case identified.

Whether routine screening programmes will be this successful elsewhere depends on several factors, not least the cost and availability of skilled health care staff, as well as local HIV prevalence. But in a somewhat stagnant area of the HIV field, Think HIV no doubt offers food for thought.