OBJECTIVE: To investigate the pattern of hepatitis B virus (HBV) infection and the prevalence of hepatitis D virus (HDV) infection among voluntary blood donors who tested reactive for HBV in Wuhan, and to provide data support for the prevention and treatment of HBV and HDV infections. METHODS: Electrochemiluminescence (ECL) method was used to detect hepatitis B serological markers in the samples with HBsAg and/or HBV DNA reactivity, and the HBV infection in different groups was statistically analyzed. The HDV IgM and IgG antibodies were screened by ELISA, and the prevalence of HDV infection in the retained samples was analyzed. RESULTS: In 351 ELISA and/or nucleic acid test (NAT) reactive samples, the serological tests for hepatitis B revealed that 4 cases (1.1%) were positive for HBsAg, HBeAg, and anti-HBc, 182 cases (51.9%) were positive for HBsAg, anti-HBe, and anti-HBc, and 55 cases (15.7%) were negative for HBsAg but positive for anti-HBc. Among them, the HBsAg ELISA dual reagent reactive group (HBsAg R&R group) and the HBsAg ELISA single reagent reactive/HBV DNA reactive group (HBsAg R&NR/HBV DNA R group) had the highest rates of HBsAg(+), anti-HBe(+), and anti-HBc(+), accounting for more than 90% and 65%, respectively, followed by low activity of HBV acute infection or chronic carriers, accounting for about 5% and 20%, respectively. In the HBsAg R&NR/HBV DNA NR group, the combined proportion of individuals with anti-HBs single positive and all hepatitis B serological markers negative accounted for 78%, and those who were HBsAg negative but anti-HBc positive accounted for approximately 20%. In the HBsAg NR&NR/HBV DNA R group, there was nearly 9% of HBsAg(+), anti-HBe(+), and anti-HBc(+), the remaining were all HBsAg negative but anti-HBc positive, with a 100% anti-HBc positivity rate in this group. No HDV IgM or IgG antibodies were detected in the retained samples. CONCLUSION Blood donors with HBV-reactive results in blood screening exhibit multiple patterns of infection indicators. The prevalence rate of HDV infection among blood donors in Wuhan is extremely low. However, the risk of asymptomatic occult hepatitis B infection (OBI) blood donors being co-infected with HDV should not be overlooked in areas with high prevalence of HBV.
Humans ; Blood Donors ; Hepatitis B/blood* ; China/epidemiology* ; Adult ; Male ; Female ; Hepatitis D/epidemiology* ; Middle Aged ; Hepatitis B virus/immunology* ; Hepatitis B Antibodies/blood* ; Young Adult ; DNA, Viral/blood* ; Hepatitis B Surface Antigens/blood* ; Prevalence ; Adolescent

OBJECTIVETo investigate the epidemic status of Hepatitis B in children aged 1-14 in 3 counties of Guangdong province in 2013, and to evaluate the effect of hepatitis control in children aged 1-14 after hepatitis B vaccine was integrated into the national immunization program in 2002 and catch-up vaccination was conducted from 2009 to 2011.

METHODSA multi-stage stratified random sampling was designed to survey 1 621 children aged 1-14 in rural area of Nanxiong county, Haifeng county and Xinxing county by questionnaires including general information, medical history and risk factors. The samples were tested with chemiluminescence method to detect hepatitis B virus (HBV) surface antigen (HBsAg), antibody to HbsAg (anti-HBs) and antibody to HBV core antigen (anti-HBc). Chi-square test was used to compare the positive rate of HBV serum markers in different age groups, vaccine histories, birth weight and HBV infection status of mother.

RESULTSAmong the children aged 1-14 in 3 counties rural regions of Guangdong province, the positive rate of HBsAg, anti-HBs, and anti-HBc was 1.11% (18/1 621), 60.69% (982/1 618) and 1.92% (31/1 617), respectively. The HBsAg positive rate of vaccinated children (0.84%, 13/1 547) was lower than that of unvaccinated children (1/13) or children with unknown vaccination status (6.56%, 4/61) (χ² = 22.64, P < 0.001). The HBsAg positive rate (0.45%, 5/1 118) of the children with birth-dose given within 24 hours was lower than those that of children given beyond 24 hours (2.63%, 61/190) (χ² = 10.21, P < 0.001). The HBsAg positive rate (5/18) of children with birth weight under 2 kilogram was higher than that of children with birth weight above 2 kilogram (0.78%, 12/1 548) (χ² = 120.8, P < 0.001). The HBsAg positive rate of children born to HBsAg-positive mothers (2.80%, 3/107) was higher than that of children born to HBsAg-negative mothers (0.21%, 1/470) (χ² = 8.50, P = 0.004). With the age increasing, the coverage and timely birth-dose coverage of Hepatitis B vaccine (HepB) decreased, and the positive rate of anti-HBs gradually decreased.

CONCLUSIONAfter the catch-up vaccination was conducted in unvaccinated children aged 1-14 years from 2009 to 2011, the HBsAg and anti-HBc positive rate decreased, while the anti-HBs positive rate increased significantly.

Adolescent ; Birth Weight ; Child ; Child, Preschool ; China ; epidemiology ; Hepatitis B ; epidemiology ; Hepatitis B Antibodies ; blood ; Hepatitis B Core Antigens ; immunology ; Hepatitis B Surface Antigens ; immunology ; Hepatitis B Vaccines ; Humans ; Immunization Programs ; Infant ; Risk Factors ; Rural Population ; Seroepidemiologic Studies ; Surveys and Questionnaires

OBJECTIVETo analyze the information of the supplementary card for hepatitis B and the laboratory confirmed result of immunoglobulin M antibody to hepatitis B virus (HBV) Core Antigen (anti-HBc IgM) for the suspected acute hepatitis B to evaluate the hepatitis B report data on pilot surveillance.

METHODS200 counties were established in China for hepatitis B pilot surveillance and 63 641 cases were reported. We added a supplementary card in National Notificable Disease Reporting System (NNDRS) and all the reported hepatitis B cases in NNDRS were required to fill the supplementary card. Venous blood 5 ml was collected and a confirmed test of anti-HBc IgM was made for suspected acute hepatitis B. We made confirmed diagnosis for the suspected acute hepatitis B according to the supplementary card information of the reporting card and the confirmed test result of anti-HBc IgM.

RESULTS63 641 hepatitis B cases were reported in 200 hepatitis B pilot surveillance counties in 2013. Among 1 723 cases which were filled with the HBsAg positive within six months in supplementary card, 735 cases were reported as chronic hepatitis B, the proportion was 42.66%. Among 4 582 cases which were filled with anti-HBc IgM positive in supplementary card, 2 436 cases were reported as acute hepatitis B, the proportion was 53.16%. 1 829 cases were reported as chronic hepatitis B, the proportion was 39.92%. The validity cases of the information for liver puncture and the HBV surface antigen (HBsAg) transform during the recovery period in supplementary cards for all the reporting cases were 579 and 4 961, and the rate were 0.91% and 7.80%, respectively. 4 302 suspected acute cases were made confirmed diagnosis, and 1 197 cases (27.82%) were confirmed acute and 2 590 cases (60.20%) were confirmed chronic.

CONCLUSIONClinical doctors failed to make full use of the information of supplementary cards to make classification diagnose for hepatitis B. Suspected acute hepatitis B with anti-HBc IgM positive should be pay attention to follow up and further distinguish acute or chronic hepatitis B according to the HBsAg transform.

China ; epidemiology ; Hepatitis B ; epidemiology ; Hepatitis B Antibodies ; blood ; Hepatitis B Core Antigens ; immunology ; Hepatitis B Surface Antigens ; immunology ; Humans ; Immunoglobulin M ; blood ; Sentinel Surveillance

OBJECTIVES: The seroprevalence of hepatitis E virus (HEV) among high-risk groups overseas is high, but studies in these groups are rare in South Korea. We conducted the present study from April to November 2012 to obtain data on the seroprevalence and associated risk factors for HEV among slaughterhouse workers in South Korea. METHODS: Slaughterhouse workers from 80 workplaces nationwide were surveyed in South Korea in 2012. The subjects comprised 1848 cases: 1434 slaughter workers and 414 residual products handlers. By visiting 80 slaughterhouses, which were mixed with 75 of which also performed residual products handling, we conducted a questionnaire survey for risk factors and obtained blood samples in order to determine the seropositivity and seroprevalence of HEV. Anti-HEV IgG and IgM were measured using HEV IgG and IgM enzyme-linked immunospecific assay kits and HEV antigen was measured by reverse transcription polymerase chain reaction (RT-PCR). RESULTS: The seropositivity of anti-HEV IgG was 33.5% (slaughter workers 32.8% and residual products handlers 36.2%), and among the seropositive individuals the seroprevalence of anti-HEV IgM was 0.5% (slaughter workers 0.5%, residual products handlers 0.7%). The response rate of HEV-antigen as measured by RT-PCR was 0.2%. Risk factors significantly related to anti-HEV IgG seropositivity were age, sex , and working duration (slaughter workers only). CONCLUSIONS: There were significant risk factors (sex, age, and working duration) for HEV identified in our study. All three positive cases for HEV-antigen by RT-PCR were related to pig slaughter but without statistical significance. To prevent HEV, an educational program and working guidelines may be needed for high risk groups.
Abattoirs ; Adult ; Aged ; Enzyme-Linked Immunosorbent Assay ; Female ; Hepatitis Antibodies/blood ; Hepatitis E/*diagnosis/epidemiology/virology ; Hepatitis E virus/genetics/*immunology/metabolism ; Humans ; Immunoglobulin G/blood ; Immunoglobulin M/blood ; Male ; Middle Aged ; Multivariate Analysis ; Prevalence ; Republic of Korea/epidemiology ; Reverse Transcriptase Polymerase Chain Reaction ; Risk Factors ; Workplace

BACKGROUND/AIMS: Thyroid dysfunction (TD) is more likely to occur in patients with chronic hepatitis C (CHC) and is particularly associated with interferon (IFN) treatment. The purpose of this study was to investigate the incidence, outcomes, and risk factors for TD during pegylated interferon (PEG-IFN) and ribavirin (RBV) combined therapy in patients with CHC. METHODS: A total of 242 euthyroid patients with CHC treated with PEG-IFN/RBV were included. Thyroid function and autoantibodies were measured at baseline, and virologic response and thyroid function were assessed every 3 months during therapy. RESULTS: TD developed in 67 patients (27.7%) during the PEG-IFN/RBV treatment. The types of TD were subclinical hypothyroidism (50.7%), hypothyroidism (14.9%), thyroiditis (11.9%), subclinical hyperthyroidism (10.4%), and hyperthyroidism (10.4%). Most of the patients with TD recovered spontaneously; however, seven patients (10.4%) needed thyroid treatment. The sustained virological response rate was higher in patients with TD than those without (65.7% vs. 49.1%, p = 0.02). Baseline thyroid stimulating hormone (TSH) concentrations (odds ratio [OR], 2.09; 95% confidence interval [CI], 1.96 to 8.77; p < 0.001), presence of the thyroid peroxidase antibody (OR, 8.81; 95% CI, 1.74 to 44.6; p = 0.009), and PEG-IFNalpha-2b (OR, 3.01; 95% CI, 1.43 to 6.39; p = 0.004) were independent risk factors for the development of TD. CONCLUSIONS: TD developed in 27.7% of patients with CHC during PEG-IFN/RBV treatment, and 10.4% of these patients needed thyroid treatment. TD is associated with a favorable virologic response to PEG-IFN/RBV. Assessment of TSH and thyroid autoantibodies at baseline and close monitoring of thyroid function during PEG-IFN/RBV therapy are necessary for early detection and management of IFN-induced TD.
Adult ; Aged ; Antiviral Agents/*adverse effects ; Autoantibodies/blood ; Biomarkers/blood ; Drug Therapy, Combination ; Female ; Hepatitis C, Chronic/diagnosis/*drug therapy ; Humans ; Incidence ; Interferon-alpha/*adverse effects ; Male ; Middle Aged ; Polyethylene Glycols/*adverse effects ; Recombinant Proteins/adverse effects ; Republic of Korea ; Retrospective Studies ; Ribavirin/*adverse effects ; Thyroid Diseases/*chemically induced/diagnosis/epidemiology/immunology/physiopathology ; Thyroid Gland/*drug effects/immunology/physiopathology ; Time Factors ; Treatment Outcome

BACKGROUNDThe prevalence of thrombocytopenia among Chinese antiretroviral therapy (ART)-naïve HIV-infected adults has not been well-described. The aim of this study was to investigate the prevalence and associated risk factors of thrombocytopenia among Chinese ART-naïve HIV-infected adults.

METHODSWe performed a cross-sectional study of Chinese adult ART-naïve HIV-infected patients from September 2005 through August 2014. Socio-demographic variables and laboratory results including platelets, CD4+ cell count, and viral load were obtained from medical records. Factors and outcomes associated with thrombocytopenia were assessed using logistic regression.

RESULTSA total of 1730 adult ART-naïve HIV-infected patients was included. The mean age was 38 years. The prevalence of thrombocytopenia was 4.5%. There were significant differences in the prevalence of thrombocytopenia between patients <30 years of age (2.8%) and 30-39 years (4.0%) compared with patients greater than 50 years (7.0%) (P = 0.006 and P = 0.044, respectively). The prevalence of thrombocytopenia was also significantly different between patients with CD4+ counts of 200-349 cells/mm 3 (3.3%) and >350 cells/mm 3 (2.8%) compared with patients with CD4+ counts of 50-199 cells/mm 3 (7.1%) (P = 0.002 and P = 0.005, respectively). The prevalence of thrombocytopenia was significantly different by hepatitis C virus antibody (HCV-Ab) seropositivity (10.2% for HCV-Ab positive vs. 3.9% for HCV-Ab negative, P = 0.001). We observed differences in prevalence of thrombocytopenia by mode of transmission of HIV infection: Blood transmission (10.7%) versus men who have sex with men (3.9%) (P = 0.002) and versus heterosexual transmission (3.9%) (P = 0.001). In binary logistic regression analyses, age ≥ 50 years, HCV-Ab positivity and having a CD4+ cell count of 50-199 cells/mm 3 were significantly associated with thrombocytopenia with adjusted odds ratio of 2.482 (95% confidence interval [CI]: 1.167, 5.281, P = 0.018), 2.091 (95% CI: 1.078, 4.055, P = 0.029) and 2.259 (95% CI: 1.028, 4.962, P = 0.042), respectively.

CONCLUSIONSThrombocytopenia is not common among adult ART-naïve HIV-infected patients in China. Older age (age over 50 years), HCV-Ab positivity and lower CD4+ cell count are associated with an increased risk of thrombocytopenia. Therefore, early diagnosis and treatment of thrombocytopenia in these patients are necessary.

Adult ; CD4 Lymphocyte Count ; Cross-Sectional Studies ; Female ; HIV Infections ; blood ; epidemiology ; immunology ; Hepatitis C Antibodies ; blood ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Thrombocytopenia ; blood ; epidemiology ; etiology

OBJECTIVETo analyze the development of liver damage and reactivation of hepatitis B virus (HBV) during the treatment of extremely severe burn injury in HBsAg positive patients, in order to provide reference for prevention and treatment of liver damage in patients with HBV infection after extremely severe burn.

METHODSMedical records of 54 HBsAg positive patients after extremely severe burn injury admitted from January 2004 to December 2014 were retrospectively analyzed. Development of liver damage and HBV reactivation of these patients during the treatment were analyzed according to the classification of their gender, results of hepatitis B e antigen (HBeAg) and HBV DNA examinations on admission, and development of sepsis in the process of treatment. Data were processed with chi-square test.

RESULTS(1) The incidence of liver damage in the process of treatment of these patients was 85.2% (46/54). Among all the patients, the proportion of liver damage was 35/38 in male, which was significantly higher than that in female (11/16, χ² = 4.867, P<0.05). Liver damage was found in all of 26 patients who were HBeAg positive on admission, 34 patients who were HBV DNA positive on admission, and 36 patients who developed sepsis in the process of treatment; the proportions were significantly higher than those in patients who were HBeAg negative on admission (20/28), patients who were HBV DNA negative on admission (12/20), and patients who did not develop sepsis in the process of treatment (10/18), with χ² values respectively 11.801, 18.384, and 20.574, P values below 0.01. (2) The incidence of HBV reactivation in these patients was 29.6% (16/54). Among all the patients, the proportion of HBV reactivation was 13/38 in male and 3/16 in female, with no statistically significant difference between them (χ² = 0.656, P>0.05). The proportions of HBV reactivation in patients who were HBeAg positive on admission, patients who were HBV DNA positive on admission, and patients who developed sepsis in the process of treatment were respectively 13/26, 16/34, and 15/36, and they were significantly higher than those in patients who were HBeAg negative on admission (3/28), patients who were HBV DNA negative on admission (0/20), and patients who did not develop sepsis in the process of treatment (1/18), with χ² values respectively 9.979, 18.615, and 5.873, P<0.05 or P<0.01.

CONCLUSIONSPatients who are HBsAg positive, HBeAg positive, HBV DNA positive on admission, and develop sepsis in the process of treatment of extremely severe burn injury are more likely to develop liver damage and HBV reactivation. It is necessary to dynamically monitor the changes in HBV DNA and liver function, in order to identity the reactivation of virus.

Alanine Transaminase ; blood ; Burns ; complications ; drug therapy ; Chemical and Drug Induced Liver Injury ; DNA, Viral ; Female ; Hepatitis Antibodies ; blood ; Hepatitis B ; drug therapy ; epidemiology ; virology ; Hepatitis B Surface Antigens ; blood ; immunology ; Hepatitis B virus ; drug effects ; immunology ; isolation & purification ; Hepatitis B, Chronic ; blood ; pathology ; virology ; Humans ; Incidence ; Liver ; pathology ; Male ; Retrospective Studies

BACKGROUND/AIMS: The Ministry of Health and Welfare and the Korea Centers for Disease Control and Prevention in South Korea have been organizing hepatitis B virus (HBV) vertical infection prevention projects since July 2002. In this single-institute study, the results of surveys conducted in target mothers who delivered babies in a tertiary hospital were investigated and analyzed. METHODS: Of the 9,281 mothers and their 9,824 neonates born between July 2002 and December 2012, 308 hepatitis B surface antigen (HBsAg)-positive mothers and their 319 neonates were selected for this study, and their records were analyzed retrospectively. RESULTS: A total of 308 mothers were HBsAg-positive, with an HBV prevalence of 3.32% (308/9,281). There were 319 neonates born to these HBsAg-positive mothers, and 252 were confirmed to as either HBsAg-positive or -negative. Four were confirmed as HBsAg-positive, with a 1.59% (4/252) HBV vertical infection rate. All the mothers of neonates who had an HBV vertical infection were hepatitis B e antigen (HBeAg)-positive. Among the HBsAg-positive neonates, three were HBeAg-positive and had an HBV DNA titer of 1.0 x 10(8) copies/mL. CONCLUSIONS: The HBV prevalence of mothers was 3.32% (308/9,281), and their vertical infection rate was 1.59% (4/252). Thus, the South Korean HBV vertical infection prevention projects are effective, and, accordingly, HBV prevalence in South Korea is expected to decrease continuously.
Adult ; Biological Markers/blood ; DNA, Viral/blood ; Female ; Health Surveys ; Hepatitis B/blood/diagnosis/epidemiology/prevention & control/*transmission/virology ; Hepatitis B Surface Antigens/blood ; Hepatitis B e Antigens/blood ; Hepatitis B virus/genetics/immunology ; Humans ; Infant, Newborn ; *Infectious Disease Transmission, Vertical/prevention & control ; *National Health Programs ; Pregnancy ; Prevalence ; Republic of Korea/epidemiology ; Retrospective Studies ; *Tertiary Care Centers ; Viral Load

OBJECTIVETo investigate the potential of hepatitis C virus (HCV) antibody measurement as a clinical approach to determine the infection status and potential for spontaneous-resolution among patients with HCV mono-infection and HCV/human immunodeficiency virus (HIV) co-infection.

METHODSA total of 340 individuals who tested positive for serum anti-HCV antibodies and/or serum anti-HW antibodies were enrolled for study in 2009 from a single village in central China. Markers of liver function (alanine aminotransferase (ALT) and aspartate aminotransferase (AST)) and infection (anti-HCV antibodies, CD4⁺ T cell counts, HCV genotype, and HCV viral load) were measured at baseline and follow-up (in July 2012). At follow-up,the subjects were grouped according to ongoing HCV mono-infection (n=129), ongoing HCV/HIV co-infection (n=98), spontaneously resolved (SR)-HCV in mono-infection (n=65), and SR-HCV in HCV/HIV co-infection (n=48) for statistical analysis.

RESULTSAlmost all of the subjects in the ongoing HCV mono-infection group showed high levels of HCV antibodies (S/CO more than or equal to 10), but the majority of the subjects in the SR-HCV in mono-infection group and in the ongoing HCV/HIV co-infection group. The SR-HCV mono-infection group showed a remarkable decrease in HCV antibodies from 2009 (HIV:7.75 ± 3.8; HIV+:7.61 ± 3.47) to 2012 (HIV:5.51 ± 3.67; HIW:4.93 ± 3.35) (HIV:t =10.67, P less than 0.01; HIV+:t =9.52, P less than 0.01). The ongoing HCV/HIV co-infection group showed a positive correlation between HCV antibodies S/CO ratio and CD4⁺ T cell count (r=028, P=0.008). In the ongoing HCV mono-infection group,the levels of HCV antibodies were significantly higher in individuals infected with HCV-1b than in those with HCV-2a (14.74 ± 1.68 vs.14.08 ± 1.44, t=2.20, P=0.03). In the ongoing HCV/HIV co-infection group, the numbers of subjects with elevated (more than 40 U/L) liver function markers were significantly different according to the HCV genotype infection:HCV-1b:ALT, 25/42 vs.16/56 (x²=9.45, P=0.002); HCV2a:AST, 28/42 vs.18/56 (x²=11.49, P=0.001). The HCV RNA positive rate was significantly higher in subjects with high HCV antibody cutoff values (S/CO more than or equal to 10) than in those with low HCV antibody (S/CO less than 10) (HIV:128/151 vs.1/43, x²=102.11, P less than 0.01; HIV+:88/98 vs.10/48, x²=69.44, P less than 0.01), regardless of HIV co-infection. Significantly more subjects in the ongoing HCV mono-infection group had elevated (more than 40 U/L) ALT or AST than the subjects in the SR-HCV mono-infection group with high levels of HCV antibody (S/CO more than or equal to 10) (ALT:57/128 vs.2/23, x²=10.52, P=0.001; AST:57/128 vs.0/23, x²=16.45, P less than 0.01).

CONCLUSIONSerum HCV antibody levels, in combination with other clinical information such as liver function and HIV infection status, may aid in the preliminarily evaluation of an individual's HCV infection status and likelihood for spontaneous resolution. Low levels of HCV antibody (S/CO less than 10) may indicate a better chance of SR-HCV, after ruling out the possibility of suffering from immunosuppressive diseases such as HIV infection.

Adult ; CD4 Lymphocyte Count ; China ; epidemiology ; Coinfection ; immunology ; virology ; Female ; Genotype ; HIV Infections ; immunology ; Hepacivirus ; genetics ; Hepatitis C ; diagnosis ; immunology ; virology ; Hepatitis C Antibodies ; blood ; Humans ; Male ; Middle Aged ; RNA, Viral ; blood ; Serologic Tests ; Viral Load

Turkey remains an intermediate area for prevalence of hepatitis B virus (HBV) surface antigenemia. The sheep-raising areas of Turkey also pose a high risk for cystic hydatid disease (CHD). Both HBV infection and CHD are major public health issues particularly in eastern parts of Turkey; however, there is no data regarding HBV infection in patients who have had CHD. The aims of this study were to evaluate the association between HBV infection and CHD and suggest ways to reduce HBV infection which is still widespread in Turkey. A retrospective study was conducted with 94 adult patients with active CHD referred to the hepatology department, Yuzuncuyil University School of Medicine from December 2010 to December 2012. All subjects came from rural areas of the region and underwent ultrasonography of abdomen which detected CHD of the liver. All the patients were serologically positive for Echinococcus granulosus. The control group consisted of 500 patients (300 men and 200 women) referred to the internal medicine clinics for other reasons. The patients with CHD and in the control group were tested for the existence of HBs antigen according to the standard procedures. The seroprevalence of HBs antigen was significantly higher in patients with active CHD than those in the control group (12.7% vs 5.2%; P=0.0017). Our data indicate that there is significant association between HBV infection and CHD. All patients with CHD should be screened for HBV infection.
Abdomen/ultrasonography ; Adolescent ; Adult ; Aged ; Aged, 80 and over ; Animals ; Echinococcosis/*complications ; Echinococcus granulosus/immunology ; Female ; Hepatitis B/*epidemiology ; Hepatitis B Surface Antigens/*blood ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Rural Population ; Seroepidemiologic Studies ; Turkey/epidemiology ; Young Adult