The end of postoperative antimicrobial prophylaxis?

See Articles page 381 In The Lancet Infectious Diseases, Hiroshi Imamura and colleagues report data from a randomised controlled trial of antimicrobial prophylaxis in patients having distal gastrectomy for cancer. Patients were randomly assigned to receive 1 g of cefazolin before the incision only or an additional dose once after closure and twice daily for 2 days after surgery. The rates of surgicalsite infection were much the same between groups: 9% in the extended treatment group and 5% in the intraoperative alone group. The investigators conclude that postoperative antimicrobial prophylaxis is not recommended for patients undergoing surgery to treat gastric cancer. This study adds to the data showing the lack of effi cacy for postoperative prophylactic antibiotics after closure of the surgical incision, at least in patients with an intact immune system. A large meta-analysis including patients having various surgical procedures showed no diff erence in rates of surgical-site infections between single and multiple doses of prophylactic antibiotics. A Japanese randomised controlled trial of single-dose versus multiple-dose antimicrobial prophylaxis in 501 patients undergoing gastric cancer surgery also showed no benefi t to multiple doses. Furthermore, prolonged prophylactic administration leads to increased risks of Clostridium diffi cile disease and antimicrobial resistance. thus less accurate) would be expected from its marginally lower sensitivity estimate. In clinical practice, we know now that eff ective antiretroviral treatment reduces HIV-related morbidity and mortality, and through the reduction of the population viral load, such therapy can potentially contribute also to the prevention of transmission. A crucial link between this scientifi c evidence and the desirable clinical and public health outcomes is the promotion of access to an accurate point-of-care rapid HIV test (fi gure). Oral fl uid-based Oraquick off ers the attraction of being more convenient and noninvasive. However, although its better acceptability might promote access to HIV screening, this seems to be at the cost of a substantial false-positive rate, even though the estimated specifi city of 99·74% might have dwarfed that of most other diagnostic tests in use. This factor must be considered for test interpretation, especially when the availability of such a rapid test allows penetration of screening programme into lowerrisk groups. Being dependent on host immunological responses, substantial biological variations would be expected for Oraquick both for oral and blood specimens in the presence and timing of a positive result. Repeat testing after the window period or use of an alternative test is indicated if clinical suspicion remains high despite an initial negative test. Similarly, confi rmatory testing is generally thought necessary for a diagnosis with such major implications, even in view of a relatively low chance of false-positive results. *Chi Chiu Leung, Shui Shan Lee Tuberculosis and Chest Service, Department of Health, Hong Kong, China (CCL); and School of Public Health, Chinese University of Hong Kong, Hong Kong, China (SSL) [email protected]