Viral hepatitis is a disease characterized by inflammation of liver and in many cases permanent damage to liver tissue [1] . Common types of hepatitis virus are hepatitis A, B, C, D, E and G. Hepatitis B is the most serious type of viral hepatitis, which can lead to chronic liver disease and put people at high risk of death from cirrhosis of the liver and liver cancer. It is a DNA virus replicates in hepatocytes and damages the liver by immune response to the virus [2] .

Hepatitis B virus shares similar transmission route with human immunodeficiency virus (HIV); thus, co-in- fection with these two viruses is common and both are serious global public health problems. An estimated two billion people around the globe have been contaminated with hepatitis B virus. Persons with HIV infections are disproportionately affected by viral hepatitis. Among the estimated 40 million persons infected with HIV worldwide, an estimated 2 - 4 million (5% - 15%) have chronic HBV [3] [4] .

Viral hepatitis progresses faster among persons with HIV and persons who are infected with viruses experience greater liver related health problems than those who do not have HIV infection [1] .

Evidences indicated that HIV positive individuals are more likely to be chronic carrier and have a higher HBV replication rate than HIV negative individuals. In addition, it is evident that immuno-suppression brought by HIV infection may cause re-activation or re-infection in those previously exposed to HBV [4] . Furthermore, HIV infection exacerbates liver disease in HBV/HIV co-infected individuals and there is an even greater risk of liver disease when HIV and HBV co-infected patients are treated with HAART [5] . It has been observed that HBV/HIV co-infection leads to increased morbidity and mortality as compared to HIV or HBV mono-infections [6] .

Many of the countries with high HIV burden are also affected by high prevalence of hepatitis B infection; leading to frequent HIV/HBV co-infection. The co-infection was reported as high as 10% - 20% in countries where HBV infection is either endemic or intermediate to high HBV cases [6] .

Even though, HBV and HIV have common routes of transmission and endemic areas, HBV is about 50-100 times more infectious than HIV. Consequently, in some settings up to two thirds of all HIV-infected people have blood markers of past or present HBV infection [7] [8] .

A community based sero-epidemiological survey of Addis Ababa, Ethiopia has shown a 7% sero-prevalence for HBsAg [9] . Other hospital-based studies in the country conducted at St Paul’s General Specialized Hospital and Shashemene General Hospital documented a 3.9% to 14% of HBsAg prevalence among HIV positive individuals consecutively [10] [11] .

Hepatitis B is avoidable with a readily available and efficacious vaccine [2] . Among the groups for whom CDC recommends vaccination against hepatitis B are persons who have or are at risk for HIV infection, including men having sex with men (MSM); persons who inject drugs; susceptible sex partners of infected persons; persons with multiple sex partners; anyone with a sexually transmitted infection (STI); and health care and public safety workers exposed to blood on the job [1] .

Ethiopia is being one of the countries that most hit by HIV infection (prevalence of 2.1%) and is also found in a region classified as high endemic area for HBV; the likelihood of HBV/HIV co infection is highly anticipated [12] .

However, in Africa in general and in Ethiopia in particular, information on the magnitude of HBV positivity at different risk groups including people living with HIV/AIDS is scarce.

Because of the significant burden and clinical impact of HBV in HIV-infected individuals, understanding the epidemiologic trends, exposure proportions and associated risk factors have paramount importance to undertake effective prevention measures [13] .

From 358 HIV positive adults contacted, 348 of them were included in the analysis with a response rate of 97.2%.

Majority, 220 (63.2%) of the respondents were females, age ranged 25 - 34 years old (52.9%) with mean (±SD) age of 33.2 (9.1) years old. About 92% of them were urban residents (Table 1).

The prevalence of HBsAg was found to be 24 (6.9%); of whom 17(7.7%) were females and 7 (5.5%) were males. With respect to age, the prevalence of HBsAg was 3 (7.5%) in age category of 18-24, 15 (8.2%) in age category of 25 - 34 and 6 (4.8%) for above 34 years old. All of the participants with HBsAg positive results live in urban areas.

Concerning to their marital status, the prevalence of HBsAg was 12.3% among singles, 7.2% among married, 2.0% among divorced and 6.2% among widowed participants. Illiterate had a prevalence of 12.8%; while among those with primary and secondary schools the rate was 5.7% and 9.6% respectively (Table 2).

Bivariate logistic regression analysis was done using enter method to identify factors for the multiple logistic regression. In the analysis, average family income, WHO stage classification of HIV/AIDS, surgical history, previous history of opportunistic infection and sharing of sharp instruments were selected for the multiple logistic regression analysis based on their P-value of <0.2.

Multivariate analysis revealed that those who have previous history of surgical procedure were 4.6 times more likely to be contaminated with HBV than who did not [AOR = 4.6: 95% CI, 1.8 - 11.6] and those with previous opportunistic infection were about 5 times more likely to show HBV surface antigen marker than who did not [AOR = 5.2: 95% CI, 1.1 - 23.2] (Table 3).

In this study, the prevalence of HBsAg was 6.9%. This result is in line with HBsAg prevalence documented

NB: ^* = Significant at P-value 0.05, Hosmer and Lemeshow goodness of fit test = 0.9.

from the study conducted in India (6.3%). Other similar studies among HIV positive individuals showed that HBV/HIV co-infection prevalence of 5.6% in Malawi, 4.9% in Rwanda and 6% in Kenya which was consistent with the findings of this study [14] - [17] .

HBsAg prevalence from this study is also in agreement with previous studies conducted among HIV positive adults in Ethiopia. Studies at Debretabor Hospital and at Gondar University Teaching Hospital showed 6.1% and 5.6% HBV/HIV co-infection respectively [18] [19] .

However, the prevalence of HBsAg was found lower compared to HBV/HIV co-infection prevalence of 13.4% in Tehran, Iran, 11.4% among Nigerian HIV-infected individuals and 12.2% among similar population in Gambia [9] [20] [21] .

Similarly, it is also lower than the 14.0% reported in Shashemene, 20% among HIV positive immigrants of Israel from Ethiopia and 10.9% at Gondar [11] [22] [23] . The discrepancy might be due to the difference in the diagnostic methods followed in which these studies used ELISA technique, whereas in our study serological test was applied.

In contrast, the prevalence of HBV in this study was higher when compared to the 2.4% and 4.1% prevalence reported from Uganda and Rwanda respectively as well as 3.9% HBsAg prevalence in Addis Ababa [17] [24] .

This difference might be due to accessibility of information about mode of transmission and prevention as it can be seen from proportion of participants with poor knowledge score in this study.

In this study previous history of surgical procedure showed significant association with HBV infection. This result is in line with the results of the studies conducted in Ethiopia at Debretabor [18] .

Those with previous history of opportunistic infection were about 5 times more likely to be positive for HBV surface antigen marker than who did not. This result is also in agreement with the previous study at Debretabor Hospital [18] . The association might be due to the fact that HIV/HBV co-infected individuals have weak immunity than those with HIV mono-infected individuals which will make them more prone to opportunistic infection. In addition wounds due to opportunistic infections may increase the chance of infection [25] .

The prevalence of HBsAg was found to be intermediate in HIV positive adults at Hawassa University Referral Hospital. Previous history of opportunistic infection and history of surgical procedures have statistically significant association with hepatitis B infection.

Thus, we recommend provision of routine screening and vaccination service together with accurate information on risk factors such as opportunistic infection and surgical procedure for transmission of HBV.

In this study HBV DNA was not detected by polymerase chain reaction due to unavailability of resources, which may increase the prevalence of HBV in this study as it would allow early diagnosis of these infections before surface antigen of HBV were detectable in serum.

Fanuel Belayneh, (2015) Prevalence of Hepatitis B Virus Infection and Associated Factors among HIV Positive Adults Attending ART Clinic at Hawassa Referral Hospital, SNNPR, Ethiopia. Open Access Library Journal,02,1-7. doi: 10.4236/oalib.1101490