1. Men and STIs: Update of current epidemiological data in Victoria
Dr. David M. Lee
Nurse Practitioner (Sexual Health)
Melbourne Sexual Health Centre

2. Sexual transmission probability Anderson, RM Sex Transm Disases 1999, pg 26
Transmission probability (per partnership,
no account of type, frequency)
Mean duration of infection if untreated in years
Transmission by oral sex
Salient points
*Presence of any STI ↑ risk of acquiring and transmitting HIV
Gonorrhoea
0.5
yes
Antimicrobial resistance
chlamydia
0.2
1.0
In women, long term complications
Syphilis
0.6
HIV
8 - 12
No (very low risk)
AIDS
This table shows the median probability of transmitting the STI per partnership.
It does not take into account many variables so I would interpret these figures with caution.
Surveys of sexual behaviours reveal aggregated or nonrandom distributions of reported sex acts per unit of time. Such studies also hint at corrrelations between different measures of sexual activity such as reported sex acts and reported sex partners per unit period of time.
Both factors act to enhance the magnitude of R0
An example is with HIV – the most infectious period is the first year of seroconversion where there is a high viral load etc…

3. Epidemiology: Chlamydia trachomatis Source: DHS Victoria www. dhs. vic
Epidemiology: Chlamydia trachomatis Source: DHS Victoria
As can be seen from this graph, the number of notifications in Victoria has markedly increased. One could argue that the advances in testing through NAAT (where culture in the past had low sensitivity and specificity) may have increased this rate.
In an ecological study, chlamydia testing rates in New South Wales correlated strongly with chlamydia notification rates (r>0.9, p<0.001), suggesting that both chlamydia detection and reported rates of infection are influenced substantially by levels of testing. In New South Wales, less than 5% of people under the age of 25 were being tested for chlamydia through Medicare each year, with the bulk of infection in the population remaining undetected.
Between 1992 and 2001, hospital admission rates for pelvic inflammatory disease in New South Wales among women under 35 fell by over 50% (p<0.0001).
The incidence of ectopic pregnancy and admission rates for epididymo-orchitis were largely unchanged.
These trends were mirrored in a national representative study of Australian general practitioners.
Between 1998 and 2003, clinical encounters for pelvic inflammatory disease in women under 35 in the general practice sample fell by about 50% (p=0.02), whilst encounters for epididymitis remained steady.
These trends occurred during a period of progressively increasing chlamydia notification rates throughout Australia.
Thus, on a population level, trends in the incidence of chlamydia related diseases do not necessarily parallel those of chlamydia notification rates.
Sweden has a long and much-acclaimed history of screening women for chlamydial infection. This has reduced the prevalence of chlamydial infection and the incidences of both pelvic inflammatory disease and ectopic pregnancy.
However, these successes have begun to reverse recently, with the suggestion that Sweden’s failure to test men is a significant reason.
The demographic, behavioural, and clinical characteristics of chlamydia infected men and women attending a sexual health service in Sydney were examined.
In a clinical setting, there were key differences in the profiles of chlamydia infected men based on whether they are symptomatic or asymptomatic.
For instance, asymptomatic men were younger, more likely to be in a relationship, and more often reported contact with a chlamydia infected partner.
Infected men with a history of chlamydia were more likely to be symptomatic and to have a shorter duration of symptoms.
These findings suggest that the results of clinically based risk factor studies may vary depending on the proportion of asymptomatic and symptomatic men included in those studies.
Screening of pregnant women attending an antenatal service in Sydney revealed a chlamydia prevalence of 3.3%.
Infection was associated with younger age. Most infected women reported having only one sex partner, and no new ones, in the previous 12 months.
Almost all considered themselves and their partners to be at low risk for infection, and few reported genital symptoms.
Therefore, if chlamydia screening of antenatal women were to be based upon symptoms, history of sexual risk, or a woman’s assessment of her own risk, a large proportion of infections would be missed.
Australia needs a national chlamydia screening program. This should target younger people and other groups at risk.
With a highly accessible network of general practices and the wide availability of reliable, non-invasive testing for chlamydia, Australia is well placed to implement such a program. There are still however many unanswered questions. These include
Should testing be directed at women only; or both men and women. We know the aged group where the impact is highest are in those under 25 years – so that’s a good target.
Should we perhaps like the pap test program, set up a screening register – so that women are sent a reminder to test; or should testing remain opportunistic? If a population register is set up, what is the interval between screening? Every 6 months? 12 months? We still know very little about incidence rates and rates of re-infection or treatment failure for Chlamydia.
The Commonwealth government has implemented some targeted Chlamydia grants through the NHMRC. Three grants have been provided to the UoM and MSHC and these include a longitudinal study of chlamydia incidence and reinfection rates in young Australian women; a program to determine chlamydia infections in antenatal women and another grant looking into partner notification processes in GP land.

5. Gonorrhoea: Symptoms / Signs / Tests / Treatment /Sequelae / Follow Up

6. HIV Victorian Prevalence
Calculation of possible HIV transmission if source is unknown is based on prevalence in local population:
Homosexual men: 3-15%
Injecting Drug Users: 1%
If IDU and gay: 17%
Heterosexuals blood donors: %, STI clinic attendees 0.1%
There are many factors as to why these infections are increasing but amongst some of the hypothesis are:
The effectiveness in treatment of HIV infection – HAART (highly active antiretroviral therapy) since the mid 1990 may have increased the existence of a core group – that is the number of highly sexually active HIV positive men that might impact upon the rates of STIs;
Another hypothesis is that with treatment enthusiasm as well as message fatigue about the use of condoms may have led to men becoming complacent about the message of safer sex.
There are many more such hypothesis but I won’t explore these today.

7. Other Viral STIs ? Importance
Hepatitis A - oral to feacal transmission
Hepatitis B - blood, semen, vaginal fluids, breastmilk
HCV = BBV – > Not classified as STI
HSV (Skin-to-skin)
HPV (Skin-to-skin)

8. STI / HIV Prevention condoms for vaginal, anal and oral sex
non-penetrative contact
partner notification and treatment
raised awareness and education about STI’s
regular screening and treatment with antibiotics if detected
early detection may prevent complications and transmission of the STI to other sexual partners
regular screening encouraged amongst MSM
The critical aim of any public sexual health service is the local control of sexually transmissible infections (STI) and HIV and their consequences, through early detection of infections by screening, the treatment of these infections and contact tracing, so that the infectiousness and period of communicability can be significantly reduced. Epidemiological methods employed in such control include “efficient, effective but user-friendly” and least invasive screening methods. The most effective public health control method will selectively target ‘core groups’ most likely to impact the spread of infections, adequate partner notification systems and good surveillance systems that will closely monitor epidemiological trends in these infections. The detection of infections for the public good must be carried out in conjunction with the premise of doing no harm to the individual.

9. MSHC Resources and Supports www.mshc.org.au
Web-based Patient Information ‘Check Your Risk’
Web-based GP resources
Sexual Health Physician Advice Line:
(Toll Free) Hours available: Monday - Friday and