Hepatitis B virus, together with syphilis and human immunodeficiency virus (HIV), are important public health challenges worldwide ¹ , they are transmitted through sex (Sexual transmitted infections, STIs) ^{2– 5} and cross over affected populations ¹ . The World Health Organization (WHO) reported an estimated 36.9 million people were living with HIV in 2016 ^{6, 7} . It was also reported that 248 million had chronic Hepatitis B virus (HBV) infection (persistent HBs Ag ≥ six months) ⁸ .

It is estimated that about a million sexually transmitted infections are acquired daily throughout the world ⁵ . Moreover, STDs have impact on neonatal, sexual and reproductive health. They can also cause severe complications if not treated. Additionally, STIs pose major socioeconomic challenge on treatment costs ^{5, 9, 10} . Many studies have demonstrated a two-sided relationship between HIV and a number of STIs, including syphilis and HBV ⁴ . Syphilis and HBV has the potential to increase genital and plasma HIV 1 RNA levels. This increase can raise the likelihood of transmission of HIV 1 to others. In the same way, HIV 1 infection has the potential to impact the clinical manifestation, the therapeutic outcome and the HBV/syphilis disease progression ⁴ .

HIV is associated with a higher prevalence of both HBV and Hepatitis C Virus (HCV) in Sub-Saharan Africa ^{11– 13} in this region, many people living with HIV are HBV or HCV coinfected. About 8% of individuals infected with HIV were HBV coinfected in another study conducted in this location ¹⁴ . In a trial conducted in Sub-Saharan Africa ¹⁵ , a number of factors were associated with high rates of HIV and syphilis coinfection, including: young age, divorce, widowhood, or separation. Although it is helpful to recognize syphilis risk factors, many women without these characteristics were syphilis-seroreactive ¹⁵ . Also, a high proportion of prevalent rapid plasminogen reagin (RPR)-positive infections remain serofast despite treatment ¹⁶ .

In a number of studies conducted in Zambia and the region ^{17– 29} , it has been observed that HIV and chronic hepatitis B (CHB) coinfection was common in both children and adults. It was also observed in these patients that many risk factors such as liver complications and impaired immunologic recovery increased morbidity and mortality. In these settings, syphilis infection remains prevalent in HIV infected adults ³⁰ . As HIV, syphilis and HBV coinfections are clinically consequential, there is great need to screen for syphilis and HBV in people living with HIV/AIDS. The aim of this study was to determine the prevalence of HIV1, HBV and Treponema pallidum serological markers, and therefore their coinfection prevalence among newly diagnosed HIV individuals attending ART clinic in Mkushi rural district of Zambia. The lack of current prevalence estimates of HIV/HBV and/or syphilis co-infections in Mkushi provides the rationale for this project. Also, laboratory based diagnostic tests for the three infections are not routinely conducted together in much of Zambia.

Of the 126 participants (out of 131 enrollments in the same category), 46 were male (36.5%) and 80 were female (63.5%), 102 were between the age of 19 and 40 years excluded (81%), 100 had primary education (79.4%). While 66 patients were married (52.4%), the rest were either divorced (30/126), never married (22/126) or widowed (8/126).

A total number of 126 blood samples were collected from HIV 1 infected patients attending Mkushi district hospital/ART clinic for antiretroviral therapy initiation (see underlying data ²⁴ ). HIV 1, HBV, and Syphilis coinfections were recorded together in 2.4% of cases (3/126).

Table 1 shows the prevalence of syphilis coinfection with HIV by age group.

The overall syphilis seroprevalence was 40.5% (51/126) in the studied population. HIV infected patients in the age group 20 – 29 years recorded the highest syphilis prevalence 47% (24/51), followed by the age group 30 – 39 years at 29% (15/51), while those in the age group below 20 years recorded the lowest prevalence of 2% (1/51).

The below table shows the hepatitis B virus and syphilis coinfections results by gender among HIV infected subjects ( Table 2).

Hepatitis B surface antigen (HBsAg) was detected with a prevalence of 9.5% (12/126) among newly diagnosed HIV infected patients, while that of syphilis was as high as 40.5% (51/126) in this same population group. The above data was analyzed and the results indicate that there was no significant association between gender and syphilis (Chi square value = 0.373, p = 0.542). This study also shows that HBV presence was independent of gender (alpha significance level > 0.05).

A past medical history was taken from each individual to obtain information on past syphilis infection. The results of past and current syphilis are shown in the table below ( Table 3).

Finally, those HIV clients who had a history of syphilis infection in the past were more likely than those who had none to be HIV-syphilis coinfected (53.6% vs 34%, respectively; OR 2.236; 95% CI 1.045 – 4.782). The relative Odds of HIV-Syphilis coinfection is calculated at 1.573 (95% CI: 1.044 – 2.370).

The correlates of HIV, syphilis and hepatitis B coinfections were age (between 20 and 39 years), primary education, and of course sexual activity. This may be influenced by the rural settings where our study was conducted (especially low level of education). The HBV/HIV coinfections prevalence of 9.5% in this study is in line with the prevalence of 9.9% documented in Zambia by Kapembwa and colleagues ²⁷ , and also the 12.2 reported by Vinikoor et al. ¹⁹ . The later also demonstrated that HIV coinfected adult males were more likely to be coinfected with HBV than their female counterparts. This contrast to our findings may be due to our small sample size. In our study, Pearson Chi-square analysis showed no statistically significant difference between gender for both HIV/HBV and HIV/Syphilis coinfections. Our findings demonstrate that HIV infected clients are more likely to be infected with other STIs, especially syphilis. The coinfection prevalence of 40.5% for HIV and syphilis agrees with previous study conducted in Zambia (43%) by Odom and colleagues ¹⁶ . We found past syphilis infection to have positive association with two-fold increase risk of HIV/syphilis coinfections.

Limitations: The difference in performance observed with various hepatitis, syphilis, and HIV diagnostic test kits available in the market might influence the comparison of results with other studies. Moreover, this facility based survey may limit the generalizability of findings to all people living with HIV due to possible selection and information bias.

However, as shown earlier, the occurrence of these coinfections is clinically consequential. The information provided in this study will therefore assist policy makers re-direct resources for concomitant screenings/diagnosis of HIV, HBV, and syphilis.

CONCLUSION: The high prevalence rates for HIV, HBV, and syphilis coinfections strongly indicate the need for HBV and syphilis screening for HIV infected individuals. The 2018 Zambian consolidated guidelines for prevention and treatment of HIV infection address the management of these coinfections ³² . However, there is urgent need to monitor the implementation of HBV and syphilis testing among HIV infected subject to close the gap between policy and practice. Furthermore, in previous study conducted in Zambia, Odom and colleagues ¹⁶ demonstrated that a high proportion of RPR positive infections remain serofast despite treatment. The high number of patients previously treated for syphilis who retest positive for syphilis in this study calls for use of the Venereal Disease Research Laboratory test to identify true syphilis infection (titers ≥ 1:8 dilutions, strongly suggestive) ³³ . Both government and Non-governmental organizations need to up their efforts to support these health care service needs appropriately.