The "3 in 1" Study: Pooling Self-Taken Pharyngeal, Urethral, and Rectal Samples into a Single Sample for Analysis for Detection of Neisseria gonorrhoeae and Chlamydia trachomatis in Men Who Have Sex with Men.

Triple-site testing (using pharyngeal, rectal, and urethral/first-void urine samples) for Neisseria gonorrhoeae and Chlamydia trachomatis using nucleic acid amplification tests detects greater numbers of infections among men who have sex with men (MSM). However, triple-site testing represents a cost pressure for services. MSM over 18 years of age were eligible if they requested testing for sexually transmitted infections (STIs), reported recent sexual contact with either C. trachomatis or N. gonorrhoeae, or had symptoms of an STI. Each patient underwent standard-of-care (SOC) triple-site testing, and swabs were taken to form a pooled sample (PS) (pharyngeal, rectal, and urine specimens). The PS was created using two methods during different periods at one clinic, but we analyzed the data in combination because the sensitivity of the two methods did not differ significantly for C. trachomatis (P = 0.774) or N. gonorrhoeae (P = 0.163). The sensitivity of PS testing (92%) was slightly lower than that of SOC testing (96%) for detecting C. trachomatis (P = 0.167). For N. gonorrhoeae, the sensitivity of PS testing (90%) was significantly lower than that of SOC testing (99%) (P < 0.001). When pharynx-only infections were excluded, the sensitivity of PS testing to detect N. gonorrhoeae infections increased to 94%. Our findings show that pooling of self-taken samples could be an effective and cost-saving method, with high negative predictive values. (Interim results of this study were presented at the BASHH 2013 summer meeting.).

Staphylococcal toxins and sudden infant death syndrome.

AIMS: To investigate the hypothesis that commonly occurring bacterial toxins cause sudden infant death syndrome (SIDS) by (1), determining in which tissues bacterial toxins are concentrated after intravenous injection in rats; and (2), seeing if the same tissues contain detectable toxins in cases of SIDS. METHODS: The tissue distribution of intravenously injected staphylococcal enterotoxin A (SEA), enterotoxin B (SEB), enterotoxin C (SEC), enterotoxin D (SED), toxic shock syndrome toxin (TSST-1), and alpha-haemolysin was studied in rats using immunohistology and polyacrylamide gel electrophoresis with immunoblotting. Immunostaining was also carried out on formalin fixed kidneys from cases of SIDS and a comparison series of necropsy cases using anti-SEA, anti-SEB, anti-SEC2 and anti-SED. RESULTS: Immunohistology showed that SEB, SEC, SED and TSST-1 were all concentrated in the proximal convoluted tubular cells of the kidney. The presence of these toxins was confirmed in kidney homogenates using electrophoresis and immunoblotting. There was positive granular staining in the proximal convoluted tubular cells of the kidney in 36% of SIDS cases and 12% of the comparison series with anti SEC2 (chi 2 = 6; p < 0.025). CONCLUSION: SEC, or a bacterial toxin with epitopes in common, could have a pathogenic role in SIDS.