Microbiology Today: May 2003 issue

02 May 2003

The number of sexually transmitted infections (STI) is rising rapidly. This issue of Microbiology Today focuses on various aspects of the problem. The second National Survey of Sexual Attitudes and Lifestyles (Natsal 2000), funded by the Medical Research Council, is the most recent data on sexual behaviour in Britain. This study confirmed that there have been many changes in human sexual behaviour in the past decade.

Behaviour and bacteria? (page56)
Sexually transmitted bacterial infections are in the increase, with new infections reaching more than 1 million in England and Wales in 2000. With regards to the changing patterns of behaviour in both humans and bacteria, Catherine Ison and Iona Martin, from the Department of Infectious Disease & Microbiology at Imperial College London, discuss the current treatments and prevention strategies.

When is an STD not an STD? (page 58)
Since it was linked to cervical cancer about 20 years ago, interest in human papillomavirus (HPV) has increased. This is not surprising, as cervical cancer is the second-most common form of cancer in women worldwide. Certain types of HPV are found in 99 % of cervical cancers, and Heather Cubie argues that HPV testing may be more effective than cytological screening programmes in spotting the disease.

Chlamydia trachomatis is bad for your sperm! (page 61)
There are several causes of infertility in humans, which can affect up to 15 % of couples during their lives, and micro-organisms are just one. Adrian Eley describes how the fertility of both men and women can be affected by Chlamydia.

The changing face of HIV infection (page 63)
The HIV pandemic is now a global crisis, with virtually every country having its own epidemic. The extent of morbidity and mortality caused by HIV does not compare to any other sexually transmitted infection. Philip Mortimer and Barry Evans, of the Health Protection Agency, discuss the increased incidence of HIV in the UK, as well as measures for the control and prevention of infection.

Other aspects of sex that do not relate to humans are covered:-

Bacterial sex (page 66)
Sex allows the counteraction of the build up of harmful mutations as well as helping to increase the genetic variations that permit adaptation and evolution. Bacteria have a number of methods that allow them to exchange genetic information, which offer them some of the advantages of sex. Chris Thomas explains the transfer of genetic material from one bacterium to another.

A new dimension to sex wars (page 68)
Most parasitic microbes don't care which sex they infect. However, there is a group of micro-organisms that prefer female hosts to male, as transfer of the parasite to offspring occurs through the female's eggs. To promote their continued existence, the microbes have developed a number of strategies that favour females, including feminisation, induction of asexual reproduction and assassination of males. Mike Majerus discusses the impact these parasitic microbes have on the lives of some insects.

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