Current status of laboratory testing for HIV in the Philippines

Prevalence of HIV infection in the Philippines remains low. This may be partly due to reliance on passive reporting for surveillance. The algorithm for laboratory testing for HIV infection has become more stringent in the sense that the screening assays are repeated in the confirmatory centers, before Western Blot is performed. This has been due to the high rate of false positives before 2005. Nucleic Acid Amplification testing (NAAT) has been performed routinely for blood banking purposes in other countries. In a few pilot studies, it has proven useful in identifying those cases in the early stage of the infection, which are missed on testing by antibody-based assays. The assay may prove useful in knowing whether false negatives happen with the current testing algorithm in the Philippines. Coupled with the detuned assay, identification of new cases may be critical for prevention of transmission, surveillance of cases, and early medical management if needed.

Comparison of three Dade-Behring Dimension AR machines in a clinical chemistry laboratory.

Three Dade-Behring Dimension AR Analyzers are presently in use in the Philippine General Hospital Department of Laboratories. One machine was acquired 2 years ago and two new ones were added recently. In order to determine whether the three machines would produce equivalent results 16 samples were selected for patients with hepatic and/or renal disorder. All 16 samples were tested for 16 different analytes. The results were subjected to tests for coefficient correlation, simple linear regression using slope and intercept and t-test for comparison. We concluded that for two assays (globulin and phosphorus), the values were sufficiently similar. For seven other assays (for total protein, albumin, sodium, potassium, chloride, calcium, and magnesium), the results were statistically significantly different, and for the remaining eight assays (total hiliruhin, direct bilirubin, AST, ALT, ALP, glucose, BUN, and creatinine), the values obtained were not ideal for drawing up conclusions about comparability. For the latter group of assays we plan to pool patient specimens of appropriate numbers and levels and repeat testing at some specified later date.