Likely female-to-female sexual transmission of HIV--Texas, 2012.

In August 2012, the Houston Department of Health contacted CDC regarding the rare transmission of human immunodeficiency virus (HIV) likely by sexual contact between two women. The case was investigated, and laboratory testing confirmed that the woman with newly diagnosed HIV infection had a virus virtually identical to that of her female partner, who was diagnosed previously with HIV and who had stopped receiving antiretroviral treatment in 2010. This report describes this case of HIV infection, likely acquired by female-to-female sexual transmission during the 6-month monogamous relationship of the HIV-discordant couple (one negative, one positive). The woman with newly acquired infection did not report any other recognized risk factors for HIV infection, and the viruses infecting the two women had ≥ 98% sequence identity in three genes. The couple had not received any preventive counseling before acquisition of the virus by the woman who had tested negative for HIV. HIV-discordant couples should receive counseling regarding safer sex practices, and HIV-infected partners should be linked to and retained in medical care.

Late HIV diagnosis in Houston/Harris County, Texas, 2000-2007.

This cross-sectional study aimed to evaluate the prevalence and predictive factors associated with late HIV diagnoses in Houston, Texas using surveillance data. Study subjects were Houston/Harris County residents, 13 years or older, diagnosed with HIV and reported to the Houston Department of Health and Human Services. Late HIV diagnosis was defined as an AIDS diagnosis within three months of an HIV diagnosis. Logistic regression was used to investigate the association between late HIV diagnoses and predictive factors. We found 31% of the study population had late HIV diagnoses. The Hispanic population, men, older individuals, heterosexuals, and those diagnosed in private facilities were more likely to receive late HIV diagnoses. Sensitivity analysis was conducted to evaluate the effect of time from HIV to AIDS diagnosis on the prevalence of a late diagnosis, and on the predictors of late diagnosis. The sensitivity analysis showed time affects prevalence, but not the odds ratios of the risk factors for late diagnosis. This finding suggests HIV prevention programs should specifically target these populations at risk for late HIV diagnosis to encourage frequent HIV testing.

Improvement of heavy metal stress and toxicity assays by coupling a transgenic reporter in a mutant nematode strain.

Previous studies have demonstrated that wild type Caenorhabditis elegans displays high sensitivity to heavy metals in a lethality test at a level comparable to that of other bioindicator organisms. Taking advantage of the genetics of this model organism, we have tested a number of mutant strains for enhanced sensitivity in heavy metal induced lethality and stress response. These mutants are defective in genes controlling dauer formation, longevity or response to reactive oxygen species (ROS). Among the tested mutants, a double mutant daf-16 unc-75 strain was identified to have superior sensitivity. It has a 6-, 3- and 2-fold increase in sensitivity to cadmium, copper and zinc, respectively, as compared with that of wild type animals. When a fluorescent reporter transgene was coupled with this double mutant for stress detection, a 10-fold enhancement of sensitivity to cadmium over the wild type strain was observed. These transgenic animals, superior to most of the model organisms currently used in bioassays for environmental pollutants, offer a fast and economic approach to reveal the bioavailability of toxic substance in field samples. This study also demonstrates that combination of genetic mutations and transgenesis is a viable approach to identify sensitive indicator animals for environmental monitoring.