Low-cost assays for monitoring HIV infected individuals in resource-limited settings.

Use of a combination of CD4 counts and HIV viral load testing in the management of antiretroviral therapy (ART) provides higher prognostic estimation of the risk of disease progression than does the use of either test alone. The standard methods to monitor HIV infection are flow cytometry based for CD4+ T cell count and molecular assays to quantify plasma viral load of HIV. Commercial assays have been routinely used in developed countries to monitor ART. However, these assays require expensive equipment and reagents, well trained operators, and established laboratory infrastructure. These requirements restrict their use in resource-limited settings where people are most afflicted with the HIV-1 epidemic. With the advent of low-cost and/or low-tech alternatives, the possibility of implementing CD4 count and viral load testing in the management of ART in resource-limited settings is increasing. However, an appropriate validation should have been done before putting them to use for patient testing.

HIV-1 Drug Resistance Among Newly HIV-1 Infected Individuals Attending Tertiary Referral Center in Chennai, India.

Context: In the era of free HAART, accessibility and availability of ARV has been dramatically increased in India. However, rates of treatment literacy and adherence appear to be sub-optimal. Therefore, it is essential to monitor the extent of primary drug resistance in such settings. Materials and Methods: Between July and October 2006, 18 anti-retroviral-naοve individuals were identified as recent infected by the BED-Capture enzyme immunoassay in a VCTC clinic in Chennai. Specimens from these individuals were subjected to genotypic drug resistance testing. Phylogenetic trees were generated using MEGA for Windows version 4.0 using neighbor-joining method. The significant differences in polymorphic mutation frequencies between the study specimens and established subtype C-specific polymorphisms were examined using the Chi-square test. Results: Amino acid substitution (K103N and V106MV) at drug resistance positions occurred in two (11%) isolates, conferring high-level resistance to the non-nucleoside reverse-transcriptase inhibitors nevirapine (NVP), efavirenz (EFV), delavirdine (DLV) and notably extensive genetic variations were observed. K122E (94.4%) and K49R/KR (11.1%) polymorphisms identified in this study have not been previously described in established subtype-C specific polymorphisms. The rate of polymorphisms showed marked difference at the locations V60, D121, V35, and D123 (P < 0.0001). All the sequences showed maximum homology with Indian HIV-1 subtype C reference strain C.IN.95IN21068. Conclusions: The finding of resistance to NNRTIs is of public health importance. There is an urgent need to establish surveillance for primary drug resistance in large scale. Further studies are required to determine the phenotype impact of newer polymorphic mutations in relation to drug resistance and viral fitness.

Low-cost monitoring of HIV infected individuals on highly active antiretroviral therapy (HAART) in developing countries.

The standard methods to monitor HIV infection are flow cytometry-based for CD4+ T lymphocyte count and molecular assays to quantify plasma viral load of HIV. Few laboratories in resource-limited countries can run these tests as a majority of the HIV infected individuals are poor. A number of currently available low-cost assays which require less expensive equipment and reagents, may be well-suited to such countries. These include manual and ELISA based CD4 cell assays, and ultrasensitive reverse transcriptase quantitation (Cavidi) and p24 (ELAST) assays to monitor virus load. But better internal quality assurance and quality control (QA/QC) programmes are essential. This review discusses the low-cost assays and their role in clinical monitoring of HIV infected individuals in resource-limited countries like as India.