HIV Testing
Adding nucleic acid amplification testing to standard HIV antibody testing improves detection of acute HIV infection, according to Christopher D. Pilcher, M.D., of the University of North Carolina at Chapel Hill and his colleagues.
In a 12-month multicenter observational study, all serum samples that yielded a negative standard HIV antibody test were retested using a nucleic acid amplification pooling algorithm in an effort to identify those with acute HIV infection who were viremic but antibody negative. Pools that yielded a positive result were broken down for further testing.
Of 109,250 people tested, 606 had HIV-positive results. Of these, 23 were antibody negative and were identified as HIV-positive only with the nucleic acid amplification testing; the latter increased the HIV case identification rate by 4% over standard testing alone (N. Engl. J. Med. 2005;352:1873–83).
For a total added testing cost of $3.63 per specimen (a 3% budget increase in North Carolina, where the study was conducted), nucleic acid amplification testing led to the use of emergency HIV prevention in 21 patients whose HIV would not have been detected using standard testing methods. As a result, 48 sex partners and one fetus were protected against high-risk exposure to HIV, the investigators said.
This form of testing should be included as a standard tool for HIV prevention and surveillance, they concluded.
Xenotransplantation Standards
Recent progress in studies of animal-to-human organ transplantation is raising concerns about whether adequate controls of the practice are in place, and the World Health Organization has urged its member states to allow xenotransplantation only with appropriate oversight by national health authorities.
Several countries have rigorous guidelines and oversight procedures for xenotransplantation, but in other countries, there is a lack of quality and safety controls, according to the WHO.
The main concern is the potential for transmission of diseases and infections that originate in animals but can spread to transplant recipients and then to the larger population.
To assist member states in their efforts to implement stronger protection measures and to stop illegal performance of xenotransplantation—as well as to “harness the real potential of this promising field”—the WHO has revised an action plan by updating relevant guidelines and recommendations.
The updates describe methods for collecting and disseminating information on xenotransplantation practices, raising awareness among health authorities, and promoting high ethical standards and well-regulated practices.
The guidance and its effective regulation can be obtained from the WHO at
www.who.int/transplantation/xeno
Rapid MRSA Test
A novel, real-time polymerase chain reaction assay reliably identifies methicillin-resistant Staphylococcus aureus in nasal specimens in less than an hour, Ann Huletsky, Ph.D., of Université Laval, Sainte-Foy, Canada, and her colleagues reported.
In a study evaluating their assay, 331 nasal specimens from 162 patients at risk for colonization were tested using both the PCR assay and the standard mannitol agar culture method.
The assay detected MRSA in all 76 culture-positive samples, as well as in 9 additional culture-negative samples (5 of which proved culture positive on repeat testing), for a specificity of 98.4%, a positive predictive value of 95.3%, and a sensitivity and negative predictive value of 100% (Clin. Infect. Dis. 2005;40:976–81).
Compared with the standard surveillance culture method for detecting MRSA, which requires at least 48 hours to obtain results, the new assay could facilitate MRSA surveillance programs by enabling earlier implementation of contact precautions, thereby limiting the spread of the organism, the investigators said.
Anthrax Vaccine Contract
The U.S. Department of Health and Human Services has awarded a $123 million contract for the manufacture and delivery of 5 million doses of licensed anthrax vaccine.
The contract, awarded to BioPort Corp. (Lansing, Mich.), is the third granted under Project BioShield, a program signed into law by President Bush last year in an effort to accelerate development and acquisition of medical countermeasures for biological, chemical, radiological, and nuclear threats.
The anthrax vaccine supply will be placed in the nation's Strategic National Stockpile, along with an existing stockpile of antibiotics, for use in the event of a bioterror attack involving anthrax.