challenges for the venereologist in 21 st century

Dr David Rowen, Royal South Hants

Hospital, Southampton

Challenges for the

Venereologist in the

21st Century



Challenges

Microbial drug resistance

Neisseria gonorrhoeae

Chlamydia

Mycoplasma

Implementation of HPV vaccination schemes




Standard treatments should cure 95% of

infections

Resistance rates of >5% should lead to change

in treatment protocol.

Correlation between susceptibility and outcome

of treatment is good but not absolute

Duration of carriage is site specific




Penicillin resistance is common

Penicillinase producing N.gonorrhoeae (PPNG)

Chromosomally mediated resistance (CMR)

develops incrementally; broad range of MIC

Marked increase in PPNG in early 90’s but this

is decreasing in many places

Many centres report >80% of isolates have

CMR



Quinalones

Resistance has emerged relatively recently but

first reported in 1992

>70% of isolates from SE Asia and Philippines

are resistant



Cephalosporin Resistance

3rd generation Cephalosporins unaffected by β

lactamase of PPNG

Resistance is chromosomally mediated

Shift to right in MICs resulting in increasing

doses of Ceftriaxone being used

Cefixime can no longer be recommended as

MICs beyond break point whereby there is

>95% cure rate



Treatment

Cheap treatment options have been lost

Expensive options may have limited life

Spectinomycin difficult to obtain

Combination treatments

Gentamicin+Azithromycin

Gemifloxacin+Azithromycin

Excellent cure rates but high rate of S/E

Chlamydia

Treatment failure with Azithromycin well

documented but at low level

Some failure thought to be due to absorption

issues

Resistance testing not widely available and

reliability has been questioned

However evidence of emerging resistance to

macrolides





Mycoplasma

PCR test available but rarely requested

Often NSU/cervicitis treated with single dose of

Azithromycin

This selects out resistant strains of Mycoplasma

Longer courses of Azithromycin or Doxycycline

may prevent this

Moxifloxacin is active against Azithromycin

resistant strains

HPV Vaccines

Proven efficacy in preventing genital warts and

high grade dysplasia, should prevent HPV type

16 and 18 associated malignancy

Significant cost implications in vaccination

progrmmes: Quad vaccine cost £240 in UK

Ethical issues: vaccine against STI

What strategies can be applied to resource poor

countries



HPV Vaccines: cost issues

Restrict vaccination to girls

Does prevent warts in men but ~80% coverage needed

Will not impact of homosexual men in whom AIN is

more common

Shorter courses of vaccine

Little evidence to support long term efficacy

Use bivalent vaccine which is cheaper

Prevents high grade dysplasia but not warts



HPV Vaccines: cost issues

Generic vaccines

Patents have long time to run

Is the technology available?

Charitable vaccination programmes

Government sponsored programmes

WHO programmes

Subsidized costs for resource poor

countries



HPV vaccines: logistics

How do we deliver vaccine to large populations

especially in rural communities

Mobile clinics staffed by minimally qualified workers

How can we be sure that patients receive correct

number of inoculations?

Robust but inexpensive IT support

Patient incentives ?cash



Ethical Issues

More acceptable as anti-cancer vaccine

Working with Temples, Mosques, Gudwaras and

churches may overcome some of the perceived

ethical concerns

Women more open to concept of vaccination

than men

Is it ethical to pay patients to be inoculated?



challenges for the venereologist in 21 st century

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