IS POINT-OF-CARE TESTING A USEFUL TOOL FOR THE PREVENTION OF HIV INFECTIONS?Tomislav Rukavina, MD, PhDVanja Vasiljev Marchesi, MSE, PhDDepartment of Social Medicine and EpidemiologyUniversity of RijekaCroatia

HIV screening of all adults, adolescents and pregnant women is cost-effective as screening for breast

and colon cancer (CDC)

Point-of-care testing (POCT) is defined as medical testing near the site of patient. It gives rapid results and allows immediate medical decisions.

HIVAt the end of 2010. an estimated:34 million people globally living with HIV2.7 million new HIV infections in 20101.8 million people died of AIDS-related illnesses

Republic of Croatia in 2011. had 943 diagnosed HIV infection (2010. 862 HIV

positive patients)

STANDARD HIV DIAGNOSIS

ELISAvery sensitive test for

detection of antibodies to HIV antigens in serum or

plasma

Western blot

detects the envelope HIV proteins in patient serum or

plasmaused to confirm ELISA test

PCR detects the viral RNA/DNA from samples

ELISA

negative positive

confirm

Western blot

HIV-1 Western Blot Lane1: Positive Control Lane 2: Negative

Control Sample A: Negative Sample B:

Indeterminate Sample C: Positive

Advantages Disadvateges

false negative results during the period of seroconversion (2 weeks to 3 months) require laboratory and experienced medical stuff

the mere presence of antibody is sufficient to make a definitive diagnosis

POCT HIV DIAGNOSIS

Rapid HIV tests

Six tests were approved by FDA in USA:

1. Clearview COMPLETE2. Clearview STAT-PAK3. OraQuick Advance HIV-1/24. Multispot HIV-1/25. Reveal G36. Uni-Gold Recombigen

WHEN TO USE HIV POCT

For patients who are difficult to reach (MSM population, drug abusers)

In regions with poor laboratory access

Must include pre- and post- counselling

WHEN TO USE HIV POCT

management of transmission of HIV from mother to child during pregnancy and/or delivery for prophylaxis of exposed person to infected blood or body fluids for infected patients with specific microorganisms (Pneumocystis jirovecii pneumonia) high risk clientsPOC testing of HIV is not

designed for screening the general population!!!!

Urgent decisions to be made:

BASIC PRINCIPLE OF POCT HIV DIAGNOSIS

sample: blood, plasma, serum or oral fluid

tests contains HIV-1 and/or HIV-2 antigens and detects antibodies to HIV antigens

Immunocromatography assay

Diagram of the physical and functional components of the Efoora HIV rapid test.

Arens M Q et al. J. Clin. Microbiol. 2005;43:2399-2406

POCT HIV DISADVANTAGES

false negative results within seroconversion period (with a seroconversion panel, some tests detected HIV about 3 days later than the most sensitive HIV antibody-only EIA tests)

increasing risk of false positive results in low prevalence population

CONCLUSIONS

POCT HIV gives quick preliminary results (some within 20 minutes)

Rapid diagnosis enables a immediate treatment decisions

Rapid diagnosis reduces the possibility of spreading of virus

CONCLUSIONS

Most tests allows storing in room temperature - suitable for transport and storage in inappropriate environments

Best option for difficult to reach population

POCT HIV is good choice for areas

with poor laboratory diagnostic