Spread of Blood-Borne Viruses Among Conscripts of the Bulgarian Army

Introduction

Contact with blood of battlefield casualties, blood transfusion, use of injection or none-injection drugs, tattoo, piercing and sharing of personal hygiene items are the main route of transmission for blood-borne viral infections among military personnel. Transmission is mainly parenteral by the sharing of contaminated injection equipment. 

The purpose of this study was to determine the prevalence of the main four blood-borne infections (HBV, HCV, HDV and HIV) and to examine the risk factors among conscripts of the Bulgarian army.

Materials and Methods

A cross-sectional study was conducted among 504 young military recruits joining the Bulgarian Army from May 2009 to December 2010. 

Epidemiological data regarding age, geographic area of residence, marital status, ethnicity, educational level and prior occupation were collected by means of personal interviews (table 1). We collected data concerning their risk factors such as history of surgery, history of dentalprocedures, transfusion of blood and blood products, tattoo, piercing, circumcision, needle stick, history of hospitalization. The questionnaire addressed non-specific drug use, use of injectable drugs, history of selfinjection, and use of marijuana, heroin, amphetamines, cocaine, barbiturates and alcohol. In addition, information was solicited about history of STD, promiscuity, homosexual behaviour, and history of disciplinary problems while in the military. 

Table 1

Sociodemographic and risky behavioral characteristics

Variables	Number of recruits	n=504
	n	%
Ages (years)	18-28 (20.1±6.8) (mean±SD)
Ethnic group
Bulgarians	451	89.5%
Gipsy	12	2.4%
Turkish	41	8.1%
Drug use
i.v. drug users	26	5%
none i.v. drug users	59	12%
alcohol users	109	22%
Homosexuals	5	1%

Blood samples were checked using enzyme-linked immunosorbent assay (ЕLISA) tests commercially available from DiaSorin S.R.I. Italy, according to the manufacturer's instructions. For anti-HCV screening, we used Ortho HCV 3.0 ELISA, and positive results were confirmed by Immunoassay Blot. Unlinked anonymous testing was performed in all specimens.

Statistical analyses were performed by SPSS for Windows version 17.0 (SPSS Inc, Chicago,  IL, USA). A backward multivariable logistic regression model was used in order to estimate relationships between recruits epidemiological factors and HBV, HCV, HDV and HIV serological markers.

Results

All 504 conscripts were male, and their mean age (± SD) was 20.1±6.8, ranged from 18 to 28.

Prevalence of viral hepatitis antibodies

81 army recruits (16%) had positive results to one or more of the viral hepatitis (table 2). 

 

Table 2 

Prevalence of viral hepatitis and HIV

 

Serological markers for viral hepatitis	Number of recruits	n=504
	n	%	95% CI
anti-HBc total	71	14,1%	8.6-18.8
HBsAg	21	4.2%	2.8-6.4
anti-HBc IgM	0	0%	-
HBeAg	8	1.6%	0.9-2.3
anti-HBe	48	9.5%	7.2-11.7
anti-HCV	12	2.4%	1.8-2.6
anti-HDV	9	1.8%	0.9-2.8
anti-HIV	0	0%	-

Hepatitis B

The overall prevalence of anti-HBc was 14.1% (95% confidence interval 8.6% to 18.8%), HBsAg positive prevalence was 4.2% (95% CI 2.8% to 6.4%), representing current or past HBV infection. HBV prevalence rates by selected sociodemographic and risky behavioral factors are shown on table 3.

Table 3

Association between socio-demographic and risky behavioral factors and HBV seropositivity

Variables	Total		anti-HBc (+)			HBsAg (+)
	(n=504)		(n=71)			(n=21)
	n %	n %	OR	95% CI	n %	OR	95% CI
Ethnic Group
Bulgarians	451(90%)	61(14%)	1.00		19(4%)	1.00
Gipsy	12(2%)	5(42%)	2.98***	1.44-4.11	1(8%)	2.02***	1.14-4.04
Turkish	41(8%)	5(12%)	0.88	0.11-1.27	1(2%)	0.56	0.08-1.12
Parenteral interventions
deny	284(56%)	25(9%)	1.00		9(3%)	1.00
surgical	37(7%)	6(16%)	1.76**	0.45-3.21	1(3%)	1.03	0.31-2.10
dental	114(23%)	18(16%)	1.78**	0.49-3.22	7(6%)	1.96**	1.63-3.97
tattoo	172(34%)	34(20%)	2.24***	1.28-4.11	15(9%)	2.96***	1.56-4.86
earrings/piercing	74(15%)	12(16%)	1.77**	0.47-3.23	8(10%)	3.02***	1.64-5.35
circumcision	46(9%)	4(9%)	1.02	0.31-2.10	2(4%)	1.34	0.86-2.58
Use of drugs
deny	414(82%)	46(11%)	1.00		14(3%)	1.00
i.v. drug users	26(5%)	10(38%)	3.44***	2.10-5.88	5(19%)	5.88***	3.81-8.18
non i.v. drug users	59(12%)	11(19%)	1.74**	0.91-3.14	7(12%)	3.89***	2.23-6.06
use of alcohol	109(22%)	20(18%)	1.65	0.91-3.11	9(8%)	1.79**	0.91-3.22
Sexual activity
heterosexuals	488(97%)	68(14%)	1.00		25(5%)	1.00
homosexuals	6(1%)	3(50%)	3.21***	1.86-5.82	2(33%)	4.44***	2.84-7.84
STD	31(8%)	7(22%)	1.56**	0.88-3.14	3(10%)	1.88**	1.04-3.21
≥ 5 sexual partners	51(10%)	12(23%)	1.61**	0.91-3.15	8(16%)	2.74***	2.16-5.86

*p<0.20
**p<0.10
***p<0.05

Logistic regression models were constructed to clarify the associations between sociodemographic and risky behavioral factors and the likelihood to be positive to antibodies to hepatitis B cor antigen and HBsAg. Anti-HBc and HBsAg were significantly associated with gipsy ethnicity, tattoo, earrings/piercing (only for HBsAg), history of injecting drugs, use of non i.v. drugs (only for HBsAg), homosexuality, STDs and promiscuity (only for HBsAg). No other variables were significantly associated with HBV infection.

Hepatitis C

Table 4 shows multivariate analysis assessing the relationship between sociodemographic and risky behavioral factors and HCV seropositive status.

Table 4

Variables	Total		anti-HCV (+)		OR	95% CI
	(n=504)		(n=12)
	n	%	n	%
Ethnic group
Bulgarians	451	90%	9/451	2%	1.00
Gipsy	12	2%	2/12	17%	7.88***	4.11-12.8
Turkish	41	8%	1/41	2%	1.02	0.26-2.11
Parenteral interventions
deny	284	56%	5/284	2%	1.00
surgical	37	7%	1/37	3%	1.48	0.83-2.82
dental	114	23%	3/114	3%	1.50	0.86-2.91
tattoo	172	34%	8/172	5%	2.48***	1.32-4.14
earrings/piercing	74	15%	3/74	4%	1.79**	1.01-2.87
circumcision	46	9%	1/46	2%	1.04	0.23-2.01
Use of drugs
deny	419	83%	1/419	0.2%	1.00
i.v. drug users	26	5%	9/26	35%	18.2***	10.4-28.2
non i.v. drug users	59	12%	2/59	3%	2.88***	1.52-4.76
use of alcohol	109	22%	2/109	2%	1.86**	0.96-3.42
Sexual activity
heterosexuals	488	97%	11/488	2%	1.00
homosexuals	6	1%	1/6	17%	1.44**	0.76-4.06
STD	31	6%	3/31	10%	1.66**	0.88-6.48
≥ 5 sexual partners	51	10%	4/51	9%	1.46**	0.62-4.21

*p<0.20
**p<0.10
***p<0.05

According to the multivariate logistic regression analysis, being gipsy, performing non commercial tattoo, i.v. drug use and non i.v. drug use were identified as significantly associated with a positive anti-HCV serologic test.

Hepatitis D

Table 5 shows multivariate analysis assessing the relationship between sociodemographic and risky behavioral factors and HDV seropositive status.

Table 5

Variables	Total		anti-HDV (+)		OR	95%CI
	(n=504)		(n=9)
	n	%	n	%
Ethnic group
Bulgarians	451	90%	4/451	1%	1.00
Gipsy	12	2%	3/12	25%	12.85***	7.68-22.8
Turkish	41	8%	2/41	5%	4.86***	2.99-8.67
Parenteral interventions
deny	284	56%	2/284	1%	1.00
surgical	37	7%	0/37	0%	-	-
dental	114	23%	2/114	2%	1.66*	1.01-2.78
tattoo	172	34%	8/172	5%	3.86***	1.88-7.92
earrings/piercing	74	15%	1/74	1%	0.98	0.52-1.91
circumcision	46	9%	1/46	2%	1.76**	1.04-2.06
Use of drugs
deny	419	83%	4/414	1%	1.00
i.v. drug users	26	5%	4/26	15%	12.21***	7.14-20.11
non i.v. drug users	59	12%	1/59	2%	1.74**	0.98-2.96
use of alcohol	109	22%	3/109	3%	1.68**	1.02-3.12
Sexual activity
heterosexuals	488	97%	7/488	1%	1.00
homosexuals	6	1%	2/6	33%	18.98***	10.11-29.5
STD	31	6%	1/31	3%	1.68**	0.91-3.65
≥ 5 sexual partners	51	10%	2/51	4%	3.81***	2.09-5.38

*p<0.20
**p<0.10
***p<0.05

According to the multivariate logistic regression analysis, being with gipsy or Turkish origin, performing non commercial tattoo, i.v. drug use, homosexual activity and promiscuity were identified as significantly associated with a positive anti-HDV serologic test.

Only two cases of HCV/HBV co-infection were observed among 504 samples tested for both markers.

In our study we did not find any conscript with positive serological markers to HIV.

Discussion

Several risk behaviors for transmission of HBV, HCV, HDV and HIV occur in the military, including the contact with blood ofbattlefield casualties, injection of illicit drugs, tattooing with inadequately disinfected equipment, sharing of personal hygiene items as well as unprotected sexual intercourse including male to male anal intercourse. Together these factors potentially increase the risk of transmission of these infections in this population [1,8,10,11]. In this cross-sectional survey among conscript of the Bulgarian Army we found that the prevalence of HCV infection is much higher than that of the general Bulgarian population (2.4% vs.1.1%) [2]. Using multivariate logistic regression analysis 4 variables were identified to be significantly associated with HCV infection: 1) gipsy origin; 2) tattoo; 3) i.v. drug use; 4) non i.v. drug use. Considering the age range and the prevalence rates of HCV in our study, the most probable mode of transmission of this infection is through percutaneous exposure represented by intravenous drug use, tattooing and occupational exposure to blood.

Prevalence of HBV serological markers among recruits including in our study is nearly 2 times less than of the general Bulgarian population, but higher than young people at the same age [13]. The other point is about HBsAg positive soldiers with prevalence of 4.2%, that is higher than that of the general population in Bulgaria at the same age [13]. Using multivariate logistic regression analysis 4 variables were identified to be significantly associated with HBV infection: 1) gipsy origin; 2) tattoo; 3) i.v. drug use; 4) homosexual activity. Another interesting finding of our study is that earrings/piercing, promiscuity and non i.v. drug use were independently associated with HBsAg seropositivity.

Special attention should be paid on the risky behaviors that can transmit such infections among soldiers. The relation between hepatitis B, C, D and HIV infection to drug abuse and sexual behaviour has been well established in both civilian and military population. Our results collaborate with the findings of other studies which have shown that infected soldiers compared to non-infected ones are significantly more likely to have shared their syringe/needles. Furthermore, tattooing which can transmit these viruses was obviously common way among recruits in this study [1,6,9,11,15,16].

Only two cases of HBV/HCV co-infection were observed among 504 samples tested for serological markers for viral hepatitis. This may indicate different prevalences in the general population and different modes of transmission for each virus. 

Most of the recruits did not know about their disease (86%), and only 2.4% soldiers had clinical complications. As a matter of fact, HBV, HCV and HDV is a threatening factor among the military personnel. By early detection and treatment, we can prevent those infections in the military forces and reduce expenses because the new treatment protocols are very expensive, and the damages caused by the diseases is nearly irreversible. Detecting these patients at early stage, and using the antiviral treatment for them can control the disease and prevent the severity of hepatitis. Furthermore, by detecting and controling these cases, we can prevent new cases in their families.

We did not find any recruits with HIV because of low rate of the infection in the country and negative impact that admitting to drug abuse or homosexual contact would have on an individual’s military career. By now Bulgaria is still a country with a low HIV/AIDS prevalence located in one of the regions with most rapidly growing rates of the epidemics. In spite of this there are some groups of people with high risk such as injecting drug users, homosexuals and gipsy population that may provide an increasing risk for HIV spread within the national population. 

Because of the convenience sampling, the result of this study can not be generalized to all military personnel in Bulgaria, they show the presence of these infections among them in such high rates and give us a sketch of their general epidemiological characteristics.

Conclusion 

Although this population theoretically had a low risk of HBV, HCV and HDV infection, these results are higher than expected for this age range. There were no recruits found with HIV. Based on the prevalence of serological markers we recommend vaccination against HBV infection after prevaccination screening. 

Date: 01/25/2011

Source: MCIF 1/11