Is the eradication of donovanosis possible in Australia?

Detection and discrimination of herpes simplex viruses, Haemophilus ducreyi, Treponema pallidum, and Calymmatobacterium (Klebsiella) granulomatis from genital ulcers

BACKGROUND

Genital ulcer disease (GUD) is commonly caused by pathogens for which suitable therapies exist, but clinical and laboratory diagnoses may be problematic. This collaborative project was undertaken to address the need for a rapid, economical, and sensitive approach to the detection and diagnosis of GUD using noninvasive techniques to sample genital ulcers.

METHODS

The genital ulcer disease multiplex polymerase chain reaction (GUMP) was developed as an inhouse nucleic acid amplification technique targeting serious causes of GUD, namely, herpes simplex viruses (HSVs), H. ducreyi, Treponema pallidum, and Klebsiella species. In addition, the GUMP assay included an endogenous internal control. Amplification products from GUMP were detected by enzyme linked amplicon hybridization assay (ELAHA).

RESULTS

GUMP-ELAHA was sensitive and specific in detecting a target microbe in 34.3% of specimens, including 1 detection of HSV-1, three detections of HSV-2, and 18 detections of T. pallidum. No H. ducreyi has been detected in Australia since 1998, and none was detected here. No Calymmatobacterium (Klebsiella) granulomatis was detected in the study, but there were 3 detections during ongoing diagnostic use of GUMP-ELAHA in 2004 and 2005. The presence of C. granulomatis was confirmed by restriction enzyme digestion and nucleotide sequencing of the 16S rRNA gene for phylogenetic analysis.

CONCLUSIONS

GUMP-ELAHA permitted comprehensive detection of common and rare causes of GUD and incorporated noninvasive sampling techniques. Data obtained by using GUMP-ELAHA will aid specific treatment of GUD and better define the prevalence of each microbe among at-risk populations with a view to the eradication of chancroid and donovanosis in Australia.

Sexually transmissible infections other than HIV

Sexually transmitted infections (STIs) are notable for their fastidious requirements for transmission and growth in the laboratory and for their high physical and psychosocial morbidity. The combination of subtle or absent symptoms and stigma preventing the seeking of health care, leaves many infections undiagnosed. The development of nucleic-acid amplification tests heralded a new era in sensitive and robust diagnostic procedures for STIs. Unfortunately, many of these tests are not commercially available or are too expensive for the populations that need them most. Single-dose oral azithromycin has improved the treatment of several bacterial STIs, but quinolones are rapidly becoming ineffective for gonorrhoea. Self-treatment of genital warts with podophyllotoxin or imiquimod preparations is attractive to patients and might be cost effective for health services. The prospect of effective vaccines against genital papillomaviruses in the near future is real. Such vaccines could reduce the global incidence of some anogenital cancers. Episodic treatment of genital herpes is getting easier and cheaper, and suppressive treatment can reduce transmission to regular sexual partners. A vaccine against herpes simplex virus type 2 has shown some limited efficacy. Ultimately, better control of STIs, and reduction of their contribution to the spread of HIV, will require a broad health-sector response with adequate resourcing, and a change in social and political attitudes.

Donovanosis

Donovanosis, a chronic cause of genital ulceration, has recently been the subject of renewed interest after a long period of relative obscurity. The causative organism, Calymmatobacterium granulomatis, has been cultured for the first time in many years and a polymerase chain reaction diagnostic using a colorimetric detection system has been developed. Phylogenetic analysis confirms close similarities with the genus Klebsiella and a proposal made that C granulomatis be reclassified as Klebsiella granulomatis comb nov. Azithromycin has emerged as the drug of choice and should be used if the diagnosis is confirmed or suspected. In donovanosis endemic areas, syndromic management protocols for genital ulceration may need to be adapted locally. A significant donovanosis epidemic was reported in Durban from 1988-97 but the current status of this epidemic is unclear. The donovanosis elimination programme among Aboriginals in Australia appears successful and is a model that could be adopted in other donovanosis endemic areas. Overall, the incidence of donovanosis seems to be decreasing. Increased attention would undoubtedly be paid to donovanosis if policy makers recognised more readily the importance of genital ulcers in fuelling the HIV epidemic.