Epidemiology of the viral hepatitis B and C in female prisoners of Metropolitan Regional Prison Complex in the State of Goiás , Central Brazil

Introduction: Little information regarding hepatitis B virus (HBV) and hepatitis C virus (HCV) infections among Brazilian female prisoners exists. This study investigated the prevalence and risk factors associated with HBV and HCV infections and identified viral genotypes among female prisoners in Goiás, Central Brazil. Methods: Women incarcerated in the largest prison in the State of Goiás were invited to participate in the study. All female prisoners were interviewed and tested for the detection of hepatitis B surface antigen (HBsAg), antibodies against HBsAg (anti-HBs), against hepatitis B core antigen (anti-HBc), and antibody against HCV (anti-HCV) by ELISA. HBsAg and anti-HCV positive samples were tested for HBV DNA and HCV RNA and genotyped, respectively. Results: Participants (n=148; 98.6%) completed the study with an overall HBV prevalence of 18.9%. Age >30 years, a low education level, sex with a sexually transmitted diseases carrier, and a male sexual partner serving in the same penitentiary were associated with HBV infections. Only 24% of the women were anti-HBs positive suggesting previous HBV vaccination. Nine female prisoners (6.1%) were anti-HCV positive. Age >40 years, injecting drug use and length of incarceration were statistically associated with anti-HCV antibodies. Five samples were HCV RNA positive and classified as genotypes 1 (subtypes 1a; n=3 and 1b; n=1) and 3 (subtype 3a; n=1). The HBsAg-reactive sample was HBV DNA positive and genotype A. Conclusions: These findings highlight the necessity of public policies to control hepatitis B and C infections and emphasize the importance of hepatitis B vaccination in prison environments.


INTRODUCTION
Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are serious global public health problems.It is estimated that there are 350 and 130 million chronic carriers of these viruses, respectively, which are also at risk of developing chronic hepatitis, cirrhosis, and hepatocellular carcinoma 1,2 .
Hepatitis B virus has been classified into eight genotypes (A-H) 3 , and six HCV genotypes (1-6) and multiple subtypes have already been described 4 .The genotypic groups have variable geographic distribution and have been used to trace transmission routes.Furthermore, the genetic diversity of these viruses seems to interfere in the effectiveness of antiviral treatment 5,6 .
The prison population is at high risk for acquiring infectious diseases such as hepatitis B and C. Further some investigations have identified these viruses as important causes of deaths related to chronic liver diseases in prisoners 7,8 .Many characteristics of confined people, including low socioeconomic status, illicit drug use, and multiple sexual partners, are predictors of these infections.Therefore, most are already infected at the time of imprisonment, becoming a source of propagation and maintenance of these viruses in the prison setting [9][10][11] .
The majority of studies on HBV and HCV infections in the prison population have been carried out among male prisoners [12][13][14] .As such, the overall results of these studies generally reflect the characteristics of the dominant population.In Brazil, a continental country, the few available data on hepatitis B and C epidemiology in female prisoners are mainly from populations in the Southeast Region 10,11,15 .Thus, the purpose of this study was to investigate the prevalence and risk factors associated with HBV and HCV infections and to identify the genotypes of these viruses circulating in female prisoners of Goiás, Central Brazil.

METHODS
This was a cross-sectional study of the female population serving time in the Complexo Prisional of Aparecida de Goiânia, which represents the largest prison complex in the State of Goiás, Central Brazil 16 .From August 2007 to June 2008, all of the female inmates (n=150) were invited to participate in the study; two refused to participate.Written informed consent

RESULTS
DISCUSSION Participants were interviewed face to face on sociodemographic data and risk factors.After the interview, a blood sample was collected by venipuncture and tested by enzyme linked immunosorbent assay (ELISA) for detection of hepatitis B surface antigen (HBsAg), antibody to hepatitis B surface antigen (anti-HBs), antibody to hepatitis B core antigen (anti-HBc) (Hepanostika Uni-form Biomérieux, Netherlands), and hepatitis C virus antibody (anti-HCV) antibodies (Abbott Laboratories, Brazil).Samples weakly reactive to anti-HCV (ratio OD/cut-off <3.0) were retested by line immunoassay (INNO-LIA HCV Ab III, Innogenetics, Belgium).
Deoxyribonucleic acid (DNA) was extracted from HBsAgpositive samples, and the Pre-S/S genome region was amplified using a semi-nested PCR assay 17 .Polymerase chain reaction (PCR) products were subjected to restriction fragment length polymorphism (RFLP) genotyping analysis 18 .The detection of viral ribonucleic acid (RNA) was carried out in all anti-HCVpositive samples by reverse transcription polymerase chain reaction (RT-PCR), using primers complementary to the 5' non-coding region of the HCV genome 19 .The hepatitis C virus ribonucleic acid (HCV RNA)-positive samples were genotyped using a line probe assay (INNO-LiPA, Innogenetics, Belgium).
The HBV and HCV prevalence was estimated using a 95% confidence interval (95% CI).Initially, bivariate analysis was performed to determine the relation between the dependent variable (prevalence of HCV or HBV) and each independent variable, thus obtaining the prevalence ratios and respective confidence intervals of 95%.Variables with value p < 0.10 were included in the multivariate Poisson regression models.All analysis were performed using the Stata statistical Package v. 11.
The majority of female prisoners was ≤ 30 years of age (60.1%), had five-to-nine years of formal education (52.9%) and reported a family income of less than or equal to one Brazilian minimum wage salary per month (65.2%).Within the study population, 63% were born in Goiás and the remaining (37%) were born in other Brazilian states.Approximately half of the participants (46.6%) were married, 36.5% were single, and 16.9% were divorced/widowed.
Hepatitis B virus deoxyribonucleic acid (HBV DNA) was detected in the HBsAg positive sample, and genotype A was identified.HCV RNA was detected in five samples.Genotyping revealed the presence of genotype 1, subtypes 1a (n = 3) and 1b (n = 1), and genotype 3, subtype 3a (n = 1).
The 36 female prisoners positive for anti-HBs alone were excluded from the analysis of risk factors for HBV infection.Age over 30 years, lower education, injection drug use, sexually transmitted disease (STD) history, sex with an STD carrier and sex with a drug user were statistically associated with HBV infection (p <0.05) (Table 2).In addition to sex with a male prisoner (p=0.10),these variables were included in a multivariate Poisson regression model, and four were independently associated with HBV infection: age > 30 years, lower education, sex with an STD carrier, and sex with a male prisoner (Table 3).
With regard to HCV infection, the following variables were statistically significant: age over 40 years, injection drug use, having sex with a drug user, and the number of prisons attended (p < 0.05) (Table 2).In addition to illicit drug use (p = 0.09) and length of incarceration (p=0.07),these variables were included in a multivariate Poisson regression model.Age over 40 years, injection drug use and length of incarceration were independently associated with HCV infection (Table 3).
The present investigation confirms that female prisoners have a high risk for hepatitis B and C infections.Seropositivity for HBV markers in our study (18.9%) was three fold higher than that found in a female population aged 13 to 69 years in the Midwest Region of Brazil (6.6%) 20 .Further, the present prevalence was higher than that found in female prisoners in São Paulo (n=225; 8.4%; 95% CI: 5.3-13.0) 15but was similar to those reported by Stief et al. 21in Mato Grosso do Sul (n=242; 14%; 95% CI: 10-19.2) and in other countries such as England (n=400; 12.2%; 95% CI: 9.3-16) 22 , and the United States of America (n=555; 26%; 95% CI: 24-27) 23 .

Barros LAS et tal -Hepatitis B and C in female prisoners
Five of the nine anti-HCV-positive samples were also HCV RNA positive.These samples were genotyped as genotype 1, subtypes 1a (n = 3) and 1b (n = 1), and genotype 3, subtype 3a (n = 1).Similarly, another study conducted in male prisoners from the same penitentiary complex found genotype 1 in 80% of the samples (1a = 60%), followed by genotype 3a (13.3%) 28.In this sense, the HCV genotypes circulating in Goiás prisoners reflect the diversity of this virus in Goiás, Central Brazil 29,30 .
As observed elsewhere 21,23,24 , age was independently associated with HBV and HCV infections.In this investigation, the age association was evident among women > 30 years old for hepatitis B, while HCV infection increased after age 40.
Hepatitis B virus is efficiently transmitted by sexual contact, while HCV is spread predominantly by parental routes 1,2,31 .The present findings highlight these assumptions.There was a significant association between HBV markers and sexual variables, including sex with an STD carrier (adjusted PR: 3.0) and sex with a male serving time in the same penitentiary (adjusted PR: 2.3).By contrast, illicit injection drug use was a predictor of HCV infection (adjusted PR: 5.9), suggesting parenteral transmission of this virus.
Outbreaks of viral hepatitis are not unusual events in prisons [32][33][34] .In this investigation, one female prisoner was HBsAg and HBV-DNA positive, and five were HCV RNA positive.These individuals may serve as reservoirs of HBV and HCV and may be potential transmitters of these viruses in the prison environment and their social network.In fact, a stricter association was found between HCV positivity and length of incarceration.
Although the hepatitis B vaccine has been recommended for prisoners since it became available in the 1980s 35 , a low immunization rate is still observed in this group 36 .In Brazil, this vaccine has been recommended and free of charge for prisoners since the late 1990s.Nonetheless, only a low frequency of individuals vaccinated against hepatitis B has been observed.In Rio Claro (southern region) and Campo Grande (midwestern region), serologic evidence of previous vaccination was found in only 13.8% and 32.3% of the prisoners investigated, respectively 15,21 .Our investigation indicated a similar rate, as only 24% of the women were anti-HBs positive alone, suggesting previous vaccination against HBV.
Our results should be considered with caution.This was a crosssectional study, and behavioral findings are based on self-reports.Although this study included 98.6% (148/150) of the female inmates of the largest prison Complex in State of Goiás, Central Brazil, they may not be representative of all women confined in this state.
Prisoners should be targeted for hepatitis B and C prevention and control programs.Serological screening at the time of admission and treatment of those with chronic hepatitis may contribute to the reduction of such infections in Brazilian prison settings.A safe and effective hepatitis B vaccine is available free of charge for this population, and investigations have reported a good acceptance of this vaccine among prisoners 37 .Therefore, the low HBV vaccination rate in this population should indicate that there is a need for interventions aimed at improving hepatitis B vaccination in prison settings.

TABLE 2 -Univariate analysis of risk factors associated to hepatitis B infection and hepatitis C infection in female prisoners of the Metropolitan Regional Prison Complex of Goiás.
95% CI: 95% confidence interval; PR: prevalence ratio; HBV: hepatitis B virus; HCV: hepatitis C virus; STD: sexually transmitted diseases; IDU: Injection drug use.a denominators reflects the number of valid responses.

TABLE 3 -Variables associated with hepatitis B infection and hepatitis C infection in female prisoners of the Metropolitan Regional Prison Complex of Goiás.
Injection drug use; a adjusted Prevalence Ratio by age, schooling, IDU, STD, Sex with STD carrier, sex with IDU and sex with male prisoner; b adjusted Prevalence Ratio by age, illicit drug user, IDU, sex with IDU, length of incarceration, and number of prisons.