Clinical evaluation of an in-house human immunodeficiency virus (HIV) genotyping assay for the detection of drug resistance mutations in HIV-1 infected patients in Singapore

<p><b>INTRODUCTION</b>Human immunodeficiency virus type 1 (HIV-1) genotyping resistance test (GRT) is essential for monitoring HIV-1 drug resistance mutations (DRMs). High cost and HIV-1 genetic variability are challenges to assay availability in Singapore. An in-house Sanger sequencing-based GRT method was developed at the Communicable Disease Centre (CDC), Singapore's HIV national treatment reference centre for both subtype B and non-subtype B HIV-1.</p><p><b>MATERIALS AND METHODS</b>The in-house GRT sequenced the fi rst 99 codons of protease (PR) and 244 codons of reverse transcriptase (RT) in the pol gene. The results were compared with the Food and Drug Administration (FDA)-approved ViroSeq™ HIV-1 Genotyping System.</p><p><b>RESULTS</b>Subtype assignment for the 46 samples were as follows: 31 (67.4%) CRF01_AE, 14 (30.5%) subtype B and 1 (2.1%) subtype C. All 46 samples had viral load of ≥500 copies/mL, and were successfully amplified by the in-house primer sets. Compared to the ViroSeq™ test, our in-house assay showed drug-resistance conferring codon concordance of 99.9% at PR and 98.9% at RT, and partial concordance of 0.1% at PR and 1.1% at RT. No discordant result was observed.</p><p><b>CONCLUSION</b>The assay successfully identified DRMs in both subtype AE and B, making it suitable for the efficient treatment monitoring in genetically diverse population. At less than half of the running cost compared to the ViroSeq™ assay, the broadly sensitive in-house assay could serve as a useful addition to the currently limited HIV genotyping assay options for resource-limited settings, thereby enhancing the DRM surveillance and monitoring in the region.</p>

Severe infection with H1N1 requiring intensive care--lessons for preparedness programmes

<p><b>INTRODUCTION</b>The influenza pandemic has generated much interest in the press and the medical world. We report our experience with 15 cases of severe novel influenza A H1N1 (2009) infections requiring intensive care. The aim of this review is to improve our preparedness for epidemics and pandemics by studying the most severely affected patients.</p><p><b>CLINICAL PICTURE</b>During the epidemic, hospitals were required to provide data on all confirmed H1N1 cases admitted to an intensive care unit (ICU) to the Ministry of Health. We abstracted information from this dataset for this report. To highlight learning points, we reviewed the case notes of, and report, the fi ve most instructive cases.</p><p><b>TREATMENT</b>There were 15 cases admitted to an ICU from July 4, 2009 to August 30, 2009. Two patients died.</p><p><b>CONCLUSIONS</b>The lessons we wish to share include the following: preparedness should include having intermediate-care facilities that also provide single room isolation and skilled nursing abilities, stringent visitor screening should be implemented and influenza may trigger an acute myocardial infarction in persons with risk factors.</p>