Figure 1: Natural history of untreated syphilis infections ... 198 Figure 2: Infectious syphilis surveillance process in SA ... 215 Figure 3: Notifications of infectious syphilis in SA by sex, January 2009 – June 2014 ... 217 Figure 4: Infectious syphilis notifications in SA by age and sex, January 2009 – June 2014 218 Figure 5: Proportion of infectious syphilis notifications in SA by sex of source, January 2009 – June 2014 ... 218 Figure 6: Notifications of infectious syphilis in people identifying as Aboriginal in SA by sex, January 2009 – June 2014 ... 220 Figure 7: Notifications of infectious syphilis in SA, 2009 – 2013 (only complete years
reported) ... 229 Figure 8: SA infectious syphilis cases between 2009 and 2013 when various case definitions are applied (only complete years reported ... 239
Abbreviations
ABS Australian Bureau of Statistics
AHCSA Aboriginal Health Council of South Australia APY Anangu Pitjantjatjara Yankunytjatjara
BBV Blood Borne Virus
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CDCB Communicable Disease Control Branch of South Australia CDNA Communicable Disease Network of Australia
ChLIA Chemiluminescent immunoassay DALYs Disability adjusted life years
GPs General Practitioners
HIV Human immunodeficiency virus
MSM Men who have sex with men NAAT Nucleic Acid Amplification Test
NIDS Notifiable Infectious Disease Surveillance NNDSS National Notifiable Diseases Surveillance System PHLN Public Health Laboratory Network
PVP Positive Value Predictive
RPR Rapid Plasma Reagin
SA South Australia
SoNG Series of National Guidelines STI Sexually Transmitted Infection
T. pallidum Treponema pallidum
TPPA Treponema pallidum particle agglutination test VIDRL Victorian Infectious Diseases Reference Laboratory NAAT Nucleic acid amplification test
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Prologue
Role
This project was identified by the STI and BBV medical consultant at the South Australian Communicable Disease Control Branch. I was then responsible for designing the evaluation with the assistance of my field and ANU supervisors, and the STI and BBV medical
consultant. I led the evaluation project and was responsible for the following activities during the evaluation:
Conducting a literature review of infectious syphilis and the public health impacts of the disease
Identifying and approaching stakeholders Developing the online stakeholder questionnaire Collating and analysing questionnaire responses Conducting stakeholder interviews
Collating interview responses
Conducting a data extraction of infectious syphilis cases Conducting a data analysis of infectious syphilis cases Writing the evaluation
Presenting the findings to stakeholders
Lessons Learned
This project taught me good communication skills. One-on-one interviewing of the external stakeholders opened my eyes to the rich information that external stakeholders can provide to the context of disease surveillance. It taught me the value of building and maintaining strong relationships with external stakeholders and how this can benefit a disease surveillance system. I was able to learn a lot about the public health impacts of infectious syphilis internationally. Prior to this I saw syphilis as a disease of the past; I had no idea that it still had such a significant impact particularly as a cause of foetal and neonatal mortality and morbidity. I am sure this knowledge will benefit me in my future public health practice. I was able to get a taste of the complex nature of disease
surveillance and develop a deeper understanding of the fact that surveillance systems are the sum of many parts which are influenced by such a broad range of factors.
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Public Health Impact
The recommendations of this evaluation have been received positively by the STI and BBV surveillance team at the CDCB. Since the evaluation, the surveillance team, IT support services and the Commonwealth Department of Health have met and resolved the problems regarding reporting of infectious syphilis case numbers at the national level. South Australian case numbers will now be accurately reflected in national reports and strategies.
The Communicable Disease Network Australia (CDNA) released a new national case definition in July 2015. The definition includes a probable category. SA Health are now well positioned to introduce this new probable definition and to understand what the impact will be for their surveillance system. The surveillance team are currently working on preparing the database to manage the new probable definition.
The surveillance team are also now developing a flow chart for clinicians to assist them to identify patients for syphilis screening and to walk them through testing, interpretation of results, treatment and public health follow up. The team plan for this tool to be printed on the back of the notification forms so they are easily accessible for doctors.
The presentation given to external stakeholders on the evaluation findings was warmly received. The stakeholders seemed particularly interested in how the case definition changes impacted on the case numbers and how they affected the sensitivity of the system. Stakeholders were also interested in discussing overseas travel as a risk factor for infectious syphilis.
Ethics Approval
The evaluation was conducted by the CDCB of the South Australian Department for Health and Ageing under powers provided in the South Australian Public Health Act 2011.
Master of Philosophy in Applied Epidemiology Requirements
This chapter addressed the evaluation of a surveillance system that is a core competency of the Master of Philosophy in Applied Epidemiology.
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Acknowledgements
I would like to thank the following people for their assistance and contributions towards this evaluation:
Dr Russell Wadell, STI and BBV medical specialist Dr Megge Miller and Dr Jane Raupach, field supervisors Dr Emily Fearnley, academic supervisor
Ingrid Tribe, Acting Manager, Disease Surveillance and Investigation Section (DSIS) STI and BBV surveillance team
STI and BBV section DSIS and CDCB staff
Information Technology Support Services of SA Health SA Pathology
Clinic 275
Aboriginal Health Council of South Australia Nganampa Health Council
O’Brien Street General Practice University Health
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Abstract
Background
Syphilis is a sexually transmitted infection of global health importance. In Australia high risk groups are men who have sex with men and Aboriginal and Torres Strait Islander people. Syphilis is a notifiable condition in South Australia and surveillance activities are conducted by the Communicable Disease Control Branch. Recently changes have been proposed to the National Notifiable Diseases Surveillance System case definition for infectious syphilis, with the objective of improving the sensitivity. An evaluation was conducted of the South Australia infectious syphilis surveillance system to measure the performance of the system against defined objectives and attributes, and assess the impact of the proposed case definition changes.
Methods
The South Australian infectious syphilis surveillance system was evaluated using the Centers for Disease Control and Prevention ‘Guidelines for Evaluating Public Health Surveillance Systems’. The ten attributes of a surveillance system defined by Centers for Disease Control and Prevention were assessed using stakeholder consultation and analysis of data from the system.
Ten external and ten internal stakeholders were contacted and asked to complete an online questionnaire regarding the system. Responses were extracted into Microsoft Excel for collation and analysis. Following this, selected stakeholders were asked to participate in a semi-structured one-on-one interview to expand and clarify responses.
Data were extracted from the surveillance system into a Microsoft Excel spreadsheet for all infectious syphilis cases notified between 1 January 2009 and 1 July 2014. These data were then analysed against the relevant system attributes.
The evaluation included a review of three new probable case definitions. The definitions were applied to the South Australian data set and their sensitivity and predictive value positive assessed.
Evaluation Findings
The evaluation found that despite lacking defined objectives, the surveillance system was performing well against a series of syphilis surveillance objectives identified by the Centers for Disease Control and Prevention. It was able to initiate timely public health management
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of cases and define high risk groups and behaviours. It is a flexible and sensitive system that appears to be accepted by most users and stakeholders. In order to achieve a high level of sensitivity the system compromises on data consistency as the case definition is not strictly applied. While data were generally complete, the quality of data produced from the system was poor and the lack of a systematically applied case definition makes it difficult to
compare with numbers reported in other jurisdictions. The system fails to capture all information required to categorise cases as infectious and the process of data extraction and analysis can be complex. The system database needs to be improved to gain stability and become more user-friendly. Methods of feedback to external stakeholders could also be improved.
The proposed probable case definition requiring a single high rapid plasma regain cut off of equal to or greater than 1:16 (not requiring a case to have risk factors) had the highest sensitivity; identifying 37 additional cases and maintaining a predictive value positive of 96% over the five year evaluation period.
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Public Health Importance
Disease and Treatment
Syphilis results from an infection with the spirochete bacteria, Treponema pallidum (T. pallidum). Inoculation occurs through direct contact with infectious lesions or mucous membranes of infected humans and transmission almost always occurs during oral, anal or vaginal sexual intercourse. However, transplacental transmission from an infected mother to foetus is also an important mode of transmission. The only known hosts for syphilis are humans (1, 2).
Syphilis is described in four stages; primary, secondary, latent and late symptomatic or tertiary (Figure 1). The primary stage is most recognisable due to a lesion or ‘chancre’ that occurs at the site of inoculation. The lesion is painless and appears between two to six weeks after exposure depending on the inoculum size (3). The fact that the lesion is painless is important as it may not trigger a visit to a health professional for diagnosis and treatment. Secondary syphilis occurs due to the rapid and wide dissemination of syphilis to various organs and tissues. Cases usually present with symptoms of secondary syphilis within three months of infection. The symptoms may include skin and mucous membrane eruptions, lymphadenopathy, nonspecific rash over trunk and extremities, mucous patches, condyloma lata (wart like lesion on the genitals) and patchy alopecia (4). Symptoms may persist for weeks or months before spontaneous resolution. In about one third of cases, successful clearance of the organism is achieved without intervention although no long term immunity is acquired. Of the remaining cases, 33% will never develop tertiary symptoms and the remaining 33% will, after a period of latency, develop tertiary syphilis (5). During the tertiary stage, cases are not infectious. The significant disease burden from syphilis infection occurs during the tertiary phase when untreated cases can develop vasculitis and chronic inflammation due to an inflammatory response. When left untreated approximately 15% of all syphilis cases will develop gummas (soft non-cancerous
granuloma) of the bone and soft tissue (including organs such as the liver), 10% will develop cardiovascular syphilis (including aortic aneurysm, stenosis and valve
insufficiencies), and 6.5% will develop neurologic disease (including meningitis, paresis, ataxic gait and personality changes). The probability of dying from untreated syphilis is approximately 13% (5, 6).
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Figure 1: Natural history of untreated syphilis infections
LaFond R, Lukehart S. Biological Basis for Syphilis, Clinical Microbiology Reviews, 2006 pg 30 (5). (Original source is Gjestland, T, 1955)
Severe consequences of syphilis occur during pregnancy, and up to 80% of congenital infections are associated with serious adverse outcomes for the pregnancy. These outcomes include spontaneous abortion, perinatal death, low birth weight, congenital malformations, organ damage and neonatal infection. Long term manifestations of congenital syphilis, including blindness, deafness, joint effusions, saddle nose and Hutchinson’s teeth, may not resolve after treatment (5).
Syphilis also plays a role in the acquisition of human immunodeficiency virus (HIV). During primary syphilis infection, a HIV negative person is more susceptible to infection with HIV, and HIV positive individuals are more likely to transmit HIV (1, 3, 4).
199 Syphilis can be prevented by:
Protective behavioural practices during sexual interactions. Early case identification, follow up and treatment of contacts. Screening and treatment of pregnant women.
Regular screening and provision of accessible treatment for high risk groups (7-9). Effective treatment for syphilis has been available for more than 60 years in the form of penicillin. A single dose of long acting intramuscular penicillin is sufficient for treatment in primary, secondary and early latent syphilis (10). For late latent syphilis, long acting penicillin is recommended weekly for three consecutive weeks and more intensive courses of intravenous penicillin are recommended for neurosyphilis, which can occur during any stage of infection (10). Treatments are equally effective for pregnant women and antenatal screening for syphilis is offered routinely in Australia (11).
Epidemiology and Impact
International Context
It is estimated 12 million cases of syphilis occur globally each year (6) and two million of all pregnancies worldwide are affected (11). The majority of maternal syphilis cases go
untreated and occur in low income countries. Infections during pregnancy are estimated to result in 500,000 still births or spontaneous abortions (11). The burden of disease from mother to child transmission is approximately 3.6 million disability adjusted life years (DALYs). This compares to tetanus at 5.1 million and HIV at 6.2 million DALYs (12). The overwhelming burden from syphilis occurs in low income countries; however disease prevalence is on the decline in these countries. In high income countries the overall burden of disease is considerably lower, but the disease prevalence has been trending upwards. This is demonstrated in the epidemiology of syphilis in Europe. In Western Europe (higher income countries) between 1998 and 2007, syphilis cases increased and male to female ratios were 5:1 or greater. In contrast in Central and Eastern European countries (lower income countries), reported declines in syphilis cases during the same period and the male to female ratio was stable at approximately 1:1 (13). This demonstrates what is found consistently in the literature (13, 14), that while cases in low income countries are occurring via heterosexual sex and are generally declining, cases in high income countries are increasing due to occurrence in the MSM population.
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Australian Context
In Australia, reducing the incidence of infectious syphilis is identified as an objective in the Third National Sexually Transmissible Infections Strategy 2014 – 2017 (15). The strategy identifies two priority populations, MSM and Aboriginal and Torres Strait Islander people. There have been two important documents that address the national response to syphilis in these populations:
National Gay Men’s Syphilis Action Plan, November 2009 (16).
Interim Guidelines for the Public Health Management of Syphilis in Remote Populations in Australia, February 2014 (17).
Syphilis notification rates within the Australian population have steadily increased over the past ten years from 3.1 per 100,000 people in 2005 to 8.6 per 100,000 people in 2014 (18). Men have higher notification rates than women. In 2014 there were 15.9 notifications per 100,000 men and 1.4 notifications per 100,000 women (18). The highest notification rates occurred in men aged 30 to 34 years (33 per 100,000 people) (19). The Gay Men’s Syphilis Action Plan was developed in response to the increasing incidence of syphilis among gay men in Australia and internationally from the late 1990’s. The goal of the strategy is to achieve a sustained reduction in the incidence of infectious syphilis in Australian gay men (16).
There is a national goal of eliminating syphilis in the Aboriginal and Torres Strait Islander population, but outbreaks are still occurring in remote populations. The rate of syphilis is four fold higher in Aboriginal and Torres Strait Islander people (27 cases per 100,000) compared to non-Aboriginal and Torres Strait Islander Australians (7 cases per 100,000) (20). Syphilis in Aboriginal and Torres Strait Islander people occurs in younger age groups and is most common in those aged 15 – 29 years. Nationally, the sex ratio of cases in this population is 60% males and 40% females, and the highest rates occur in people that reside in remote and very remote areas (21). While disproportionally high, at the time of the evaluation (2014) the incidence of infectious syphilis was declining in Aboriginal and Torres Strait Islander people (20, 21). The environment for outbreaks still exist as demonstrated by an outbreak in the Kimberly region (Western Australia) in 2000 (22) and more recently in North Queensland in 2011. The outbreak in North Queensland occurred over an 18 month period and resulted in 146 infectious syphilis cases including three cases of congenital syphilis and two foetal deaths (23). Guidelines for managing syphilis in remote populations were developed in response to the outbreak and focus on preventing widespread