Proposed Intervention

Based on North Carolina’s experience conducting widespread PVLT, investigators believe that they can cost-effectively incorporate combined PVLT and ELISA antibody testing in developing countries with high HIV prevalence. To demonstrate the effectiveness of conducting PVLT in a developing country with high HIV prevalence, investigators propose to design, implement and evaluate a tightly coordinated AHI surveillance system and contact tracing protocol among the constellation of VCT clinics in Chennai, India (formerly Madras). We believe that a well organized PVLT will cost-effectively (1) prevent HIV transmissions and reduce HIV incidence and prevalence over time; (2) permit patients to begin antiretroviral therapy and thereby reduce secondary transmission and potentially improve long-term prognosis (Rosenberg, et al., 2000; Oxenius, et al., 2000), and when possible; (3) provide opportunities to offer post exposure prophylaxis (PEP) to recent partners of the acutely infected person.

Proposed Site

Chennai, India is an ideal place to establish such a demonstration project, as it is characterized by high rates of HIV prevalence, high population density, robust levels of sexual risk behaviors. The chart below reveals trends of HIV prevalence in Tamil Nadu, which includes Chennai, from 1998 to 2004.⁵ While prevalence rates decreased from 16.3 to 8.4 at STI clinics, 8.4 remains substantial.

Observed HIV Prevalence levels in Tamil Nadu: 1998 - 2004

Name of State/UT

Number of sites in 2004

HIV Prev. 1998 (%) (180 sites)

HIV Prev. 1999 (%) (180 sites)

HIV Prev. 2000 (%) (232 sites)

HIV Prev. 2001 (%) (320 sites)

HIV Prev. 2002 (%) (384 sites)

HIV Prev. 2003 (%) (455 sites)

HIV Prev. 2004 (%) (670 sites)

Tamil Nadu

STD 11 ANC 30 IDU 1 MSM 2

16.30 1.00

10.40 1.00

16.80 1.00 26.70 4.00

12.60 1.13 24.56 2.40

14.7 0.88 33.80 2.40

9.20 0.75 63.8 4.40

8.40 0.50 39.90 6.80

Antecedents to Proposed Project

From November 1, 2002 to October 31, 2003 investigators at the University of North Carolina, conducted a 12-month observational study comparing ELSIA HIV testing with combined ELISA HIV antibody testing and pooled viral load testing. Investigators detected 606 HIV infections out of 109,250 persons tested for HIV. Of these 23 acutely infected persons were identified only with the use of pooled viral load testing. The specificity and positive predictive value of the algorithm that included nucleic acid amplification testing was greater than .999 (95% confidence interval, .999 to >.999) and .997 (95% confidence interval, .988 to >.999, respectively. Of the 23 AHIs, 16 were detected at Voluntary Counseling and Testing clinics. The cost of adding PVLT to standard ELISA antibody testing added a 3.3% increase in the overall HIV testing budget dedicated to HIV testing and counseling services, of about 12 million USD. The total expenditure for PVLT reflected an added cost of $3.63 per processed specimen. Investigators found that antibody tests alone detected only 96% of HIV infections. According to investigators, early detection of AHI would allow the appropriate clinical management of AHI and prevent inappropriate tests and therapies often used to evaluate and treat the symptoms of AHI. Secondly, the identification of AHI can prevent further transmission of the virus especially since the probability of transmission is high during the first weeks of AHI during which time patients have a high viral burden in the blood and genital tract and are further likely to engage in risky sexual behavior.⁶

In 2006, Fiscus with Pilcher et al, conducted a similar prospective study of a busy STI clinic in Lilongwe, Malawi, combining HIV antibody testing with PVLT for patients presenting with sexual transmitted infections (STIs). From 1,450 clients, 21 (1.45%) had a negative HIV antibody test) and a positive RNA viral load indicating acute HIV infection. Based on their findings, investigators estimated that the Lilongwe STI clinic which averages about 10,000 patients per year, misses ~145 AHI annually compared to only 14 established HIV infections by using HIV antibody testing alone.⁷ Since these individuals with AHI are hyper infections they are likely to play a key role in sustaining HIV transmissions in high HIV incidence settings.

The North Carolina and Malawi study unequivocally demonstrate the cost effectiveness and feasibility of incorporating PVLT into existing HIV antibody testing algorithms in developing nations to detect AHI and interrupt chains of HIV transmission. Notably, investigators in the Malawi study have not reported outcomes associated with partner counseling and referral services for patients identified with acute infection.

While combined PVLT and HIV antibody testing has been shown to work in the U.S. and Africa the combined protocols have not been attempted in Asia. Our proposed pilot will carefully evaluate these outcomes.