Abstract

Background: Treponema pallidum, a causative agent of Syphilis is a sexually transmissible bacterium that causes infection of public health importance. Its complication can lead to inflammatory eye disease known as Ocular syphilis.

This study estimated the sero-prevalence of T. pallidum infection and its associated risk factors in people visiting two eye units in the Buea Health District. Materials and Methods: This was a cross-sectional hospital based design that involved 2 health facilities that had ophtamologic departments in the Buea Health districts (BRH and DTEC). TPHA and VDRL tests, visual acuity and slit lamp examinations were performed.

Data collected was entered into Epi Info version 7.2 software, then exported to Microsoft Excel 2016 and analyzed using SPSS. Results: A total of 315 persons took part in this study, which included 158 females and 157 males. Majority of the participants were aged 45 years and above. The participants were mostly people who had eye issues 188(59.87%).

A total of 123(39%) participants were positive for T. pallidum infection and 66(66%) out of 188 with low vision tested positive for T. pallidum infection. The number of sexual partners was statistically (, 0ne: p=0.013 and two: p=0.003, many: p=0.011) associated with the prevalence of syphilis, and can be considered a potential risk factor.

Many Participants had knowledge about the source (53.33%), cause, transmission, treatment and prevention of the disease. Conclusion: This study showed an overall sero-prevalence of T. pallidum infection of 31.85%. The potential risk factor of this infection included multiple sexual partners and majority of the participants had knowledge on the disease.

CHAPTER ONE

INTRODUCTION

1.1 Background

Syphilis is a genital ulcerative disease caused by the spirochete Treponema pallidum. It was first recognized in Europe in the late 15th century [1], having originated from the title character of a poem written in 1530 by Veronese physician and Poet Girolamo Fracastoro [2].

It can be transmitted by sexual contact with infectious lesions, from mother to fetus in utero, via blood product during transfusion, and occasionally through breaks in the skin that comes in contact with infectious lesions. When untreated, it progresses through four stages (primary, secondary, latent and tertiary) and cause multisystem disease (lymphadenopathy, nephrotic syndrome and acute hepatitis) with a variety of clinical manifestations like painless sore on the genitals, rectum or mouth, rash and damage to the brain, nerves eyes or heart [3].

Ocular syphilis typically does not manifest in the primary stage, except as chancres of eyelid and conjunctiva. The secondary stage may have ocular involvement such as keratitis, iris nodules, iridocyclitis, episcleritis, and scleritis. Latent syphilis is defined as positive serological tests with no clinical evidence of infection. However, in the first year after the initial infection, infectious mucocutaneous lesions may recur.

This is known as early latent syphilis. Late latent phase occurs after 1 year of infection, during which infectious relapses are rare. Late in the secondary stage, chorioretinitis and vitritis may develop. However, it is still more frequent in the late, latent, and tertiary stages [4, 5]. Ocular syphilis may occur as early as 6 weeks after transmission and may be the only presenting feature of systemic syphilis [6]. Ocular syphilis manifests in a spectrum of ways with the most common finding being panuveitis [7].

Globally, the prevalence of syphilis varies by region. Syphilis remains prevalent in many developing countries and in some areas of North America, Asia and Eastern Europe. The highest rates are in south and Southeast Asia, followed closely by sub Saharan Africa, and the regions of Latin America and the Caribbean’s [8]. The difficulty faced by diagnosis remains a challenge to clinicians worldwide.

The inability to readily culture T. pallidum has led to development of alternative methods of diagnosis for this infection. Serological tests such as non-treponemal tests and treponemal tests are the mainstay of diagnosis, but their sensitivity and specificity vary with the type of test, as well as the stage of syphilis [9].

1.2 Statement of the Problem

Syphilis remains a major public health problem in some parts of the world due to its asymptomatic nature. In 2008, the World Health Organization (WHO) estimated that 36.4 million people were infected with syphilis worldwide. An estimated 12 million new cases of syphilis are added every year worldwide and more than 90% are from developing countries [10]. Also, WHO reported that the annual new cases of syphilis in the African region among adults aged 15-49 was 3.4 million. However, there has been a worrying re-emergence of syphilis in recent years, particularly among homosexual males and drug users as a co-infection with HIV [3].

Between December 2014 and March 2015, 12 cases of ocular syphilis were reported from two major cities, San Francisco and Seattle. Subsequent case finding indicated more than 200 cases reported over the past 2 years from 20 states in the USA. Moreover, syphilis has a variable clinical presentation, as it can affect many organ systems of the human body including the skin, heart, blood vessels, bones, nervous system, and the eye.

Manifestations of ocular syphilis itself are also diverse. Patients may complain of eye pain, vision loss, floaters, flashing lights, and eye pressure, or photophobia. Syphilis has been documented to affect almost every structure of the eye and may affect the eye at both in the early and late stages of syphilis in both HIV-uninfected and HIV-infected patients [9, 11].

The majority of cases have been reported among HIV-uninfected homosexual men. Several of the cases have resulted in significant sequel including blindness. Also, little or no studies have been carried out on ocular syphilis, its associated risk factors and its preventive measures in the developing world in general and Cameroon in particular.

Hence ocular syphilis continues to pose a major public health problem amongst immunocompropmised individuals and those practicing homosexuality. It is with this fact that the researcher set out to study the sero-prevalence and risk factors of Treponema pallidum infection among individuals consultating in two eye units of the Buea Health District.

1.3 Rationale

Syphilis continues to cause morbidity and mortality worldwide. While syphilis infection is easily identifiable and treatable, rates of syphilis infection continue to increase among selected populations in high-income countries and remain at endemic rate in low- and middle-income countries. Continued vigilance and investment is needed to address syphilis worldwide. The epidemiology of syphilis differs in high-income and low- and middle income countries.

1.4 Research Hypothesis

The sero-prevalence of T. pallidum infection is high among the sexually active population.

1.5 Research Questions

1.5.1 General research question

What are the prevalence and associated risk factors of T. pallidum infection among the people attending two eye units in the Buea Health District?

1.5.2 Specific research questions

1. What is the sero-prevalence of T. pallidum infection, combined T. pallidum infection and visual impairment among individuals visiting the eye units in the Buea Health District?
2. What are some of the associated risk factors of syphilis among those consulting at different eye departments in the Buea Health District?
3. What is the level of awareness of syphilis in the Buea Population?

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