Max Chernesky, PhD

Biography

Max Chernesky, PhD

Dr. Chernesky received his BSc from the University of Guelph; his MSc from the University of Toronto; and his PhD from the University of British Columbia. He was elected as Fellow of the Infectious Diseases Society of America in 1985, the American Academy of Microbiology in 1987, and the Canadian College of Microbiology in 1991. Dr. Chernesky is Professor Emeritus in Paediatrics, and Pathology and Molecular Medicine at McMaster University, Hamilton, ON. Pastposts have included Virologist at Hamilton Regional Virology Laboratory, St. Joseph's Healthcare, Hamilton, ON [1973-76]; Director of McMaster University Regional Virology and Chlamydiology Laboratories [1977-83]; Director of Medical Microbiology Laboratory Program, McMaster University [1990-2000]. He served as Honorary Chair at the Clinical Virology Symposium in 2006. Also in 2006, he chaired the 11th International Symposium on Human Chlamydial Infections. Dr. Chernesky received the Pan American Society for Clinical Virology Diagnostic Virology Prize in 1996 and the Canadian College of Microbiologists Distinguished Service Award for 2003. Research interests include the diagnosis and epidemiology of Sexually Transmitted Diseases [STDs], on which topic he has published 156 peer reviewed papers.

New Collection Devices for Non-invasive Screening of Sexually Transmitted Infections

Sexually transmitted infections with Chlamydia trachomatis [CT], Neisseria gonorrhoeae [GC] or Trichomonas vaginalis [TV] are often asymptomatic. Undiagnosed and untreated, lower genital tract infections can develop into upper tract complications; especially in women, who may develop pelvic pain, ectopic pregnancy or infertility. Additionally, there is risk of transmission between sexual partners. There is a need for screening programs, which are convenient and painless. The overall objective is to use existing screening programs using liquid-based Pap collection media after cytopathology is performed. Establishing new screening programs would use first catch urine [FCU] or self-collected vaginal swabs [VS] or male meatal swabs [MS] for detecting infections. The most sensitive and specific testing technology to be used will probably be the commercial nucleic acid amplification assays from Gen-Probe, Roche or Becton Dickinson. Urine samples are convenient but require the first 20 ml [FCU], which is not so easy to collect accurately, especially for women. Urine often contains amplification inhibitors and laboratories do not find FCU to be a convenient testing sample to handle.

We and others have shown that women can collect their own vaginal swabs easily and often prefer a self-collected VS to FCU. Men have traditionally avoided penis swabbing and the literature contains many conflicting reports on the success of self-collection in men. Commercial assays are usually sold with a collection tube containing some form of transport media and a wrapped swab of cotton [or similar fibres] to collect a sample. The sample is processed out of the tube at the laboratory. We have initiated two ongoing self-collection studies using flocked swabs and the eSwab (a kit containing a flocked swab and a 1 ml tube of liquid Amies medium). The female study has enrolled 100 women who are collecting one flocked swab [FS] one AC2 swab and an eSwab. The FS is put into AC2 specimen transport medium [STM] and the swab from the eSwab kit is put into the liquid Amies tube. The AC2 swab is transported in the STM. A standard volume of the Amies medium was placed in a tube of STM for testing. Seven women were found infected with CT and one with both CT and GC and all 3 swabs were positive in each. Nine of the women yielded a positive TV result using Gen-Probe Analyte Specific Reagents [ASR]. The positivity rates from samples collected in STM were almost identical to samples collected into the eSwab transport system. Specimens collected with the eSwab were compatible with the AC2 assay.

In the other study, males are self-collecting an FCU and 2 meatal swabs [Gen-Probe and flocked swabs] which are transported to the laboratory in STM to be tested by AC2. Each male is given clear instructions for self-collecting and is rating the collection process stepwise using a Likert scale from very easy to very difficult for each swab type. The study has enrolled 171 patients. Twelve [7% prevalence] are infected with CT and 1 with GC. For CT the FCU has identified 9l.6% [11/12], the STM swab 83.3% [10/12], and the FS 83.3% [10/12]. Preliminary analysis of the ease of collection questionnaire shows over 96% rating the procedure as very easy and a preference for the FS.