Mongolian Journal of Health Sciences, 2013, 1(10)

Hepatitis B virus infection among population over 40 years of age Ulaanbaatar city

( Судалгааны өгүүлэл )

Nandin-Erdene O¹, Davaalkham D¹, Okomato H²

^1*Department of Epidemiology and Biostatistics, School of Public Health, Health Sciences University of Mongolia

¹ Department of Epidemiology and Biostatistics, School of Public Health, Health Sciences University of Mongolia

² Division of Virology, Department  of  Infection and Immunity, Jichi Medical University, Japan

 

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Абстракт

In Mongolia the incidence of hepatitis was14672 in 2011 which determine 34.3 percent of total number of communicable diseases. Of total viral infections 5.1 and 1.0 percent account for hepatitis B and C respectively. Mongolia has high prevalence of viral infections which end up to severe conditions such as liver cancer, liver cirrhosis the leading causes of population morbidity and mortality. This study aimed to evaluate the prevalence of hepatitis B virus (HBV) infection and its risk factors among Ulaanbaatar city population aged over 40 years. Population-based cross-sectional study is conducted and statistical analysis performed utilizing SPSS version 17. Study results indicated prevalence of hepatitis B viral infection estimated as 9.1 %. HBVinfection occurred in 9.0% of population who had dental procedure, 10.5%and 9.5%who had injections at home and blood or blood products infusions respectively, 10.0% those who had tattoo. Study participants comprised of 37.6% male, 63.4% female. 21.8% aged 45-49 years,21.0% aged 50-54 years. Prevalence of HBV infection was 9.1%. There is no difference of HBV infection by age category but there is statistically significant difference by sex. 12.2% and 7.2% of male and female were HBV positive. (p=0.0027) 

INTRODUCTION

Worldwide, 2 billion people contacted hepatitis B virus globally there are about 400 million people became careers  that lead to chronic liver pathologies particularly raising risks for hepatocellular carcinoma.¹ It is estimated that more than 5% of those contacted hepatitis D virus are careers of HbsAg. If the number of HBsAg carriers is 300 million globally the number of persons with hepatitis D would reach 15 million.²Hepatitis C virus disseminate as endemic in most of parts of the world.  3% of  World population is infected with HCV whichdemonstrate that about  170 million people are at high risk of developing hepatocellular carcinoma.  WHO classifies the prevalence of HCV among population according to presence of antibody to HCV as high (over 10%), intermediate (2.5-10%)and low (1-2.5%). In Mongolia the incidence of hepatitis was 14672 in 2011 which determine 34.3% of total number of communicable diseases.Of total viral infections 5.1% and 1.0% account for hepatitis B and C respectively. A number of scholars have investigated prevalence of hepatitis B and C in Mongolia and ways of its decreasing.^3,4

MATERIALS AND METHODS

This is a population-based cross sectional study. Multistage random sampling method was employed to select 1289 observations above 40 years old with equivalent sex and locality from Chingeltei, Khan-Uul, Songino-Khairkhan, Bayanzurkh districts. Approval obtained from Ethical Review Board.  HBsAg was determined by ELISA (enzime-linked immunosorbent assay) method in virology laboratory of Jichi Medical University, Japan. Descriptive and advanced statistical analysis was executed using SPSS statistical package version 17.0. After ensuring normal distribution of variables Pearson’s chi-square test performed to compare proportions, t-test to compare means, univariate and multivariate regression analysis.  2-tailed p-value of less than 0.05 was considered as statistically significant.

RESULTS

Table 1.HBV infection by sex, age

	HBV (+)		HBV (-)		P value
	n	%	n	%
Male	59	12.2	426	87.8	0.0027
Female	58	7.2	746	92.8
40-44	23	10.7	191	89.3	0.13
45-49	30	10.7	251	89.3
50-54	26	9.6	245	90.4
55-59	20	10.0	181	90.0
above 60	16	5.3	285	94.7

Study participants comprised of 37.6% male, 63.4% female. 21.8% aged 45-49 years,21.0% aged 50-54 years. Prevalence of HBV infection was 9.1%. There is no difference of HBV infection by age category but there is statistically significant difference by sex. 12.2% and 7.2% of male and female were HBV positive. (p=0.0027) The percentage of HBV infection is 10.7% in age group 40-44, 9.6% in age group 50-54, 10% in 55-59 and 5.3% in age above 60 but no statistically significant differences observed. 

Table2. Some risk factors of HBV infection 

Risk factors		Total	HBV (+)		HBV (-)		P-value
		n	n	%	n	%
Dental procedure							0.908
	Yes	143	14	9.8	129	90.2
	No	1143	103	9.0	1040	91.0
Injection in hospital							0.746
	Yes	268	26	9.7	242	90.3
	No	1020	91	8.9	929	91.1
Injection at home							0.138
	Yes	586	43	7.3	543	92.7
	No	702	74	10.5	628	89.5
Surgery							0.528
	Yes	729	70	9.6	659	90.4
	No	558	47	8.4	511	91.6
Acupuncture							0.927
	Yes	813	73	9.0	740	91.0
	No	475	44	9.3	431	90.7
Infusion of blood/blood products
	Yes	1118	101	9.0	1017	91.0	0.906
	No	169	16	9.5	153	90.5
Dialysis
	Yes	1274	116	9.1	1158	90.9	0.890
	No	13	1	7.7	12	92.3
Tattoo							0.780
	Yes	1047	93	8.9	954	91.1
	No	240	24	10.0	216	90.0

 

Majority of participants (approximately 90%) who had risk factors such as dental procedure, injections, surgery, tattoo, acupuncture, dialysis, blood/ blood products infusion were HBV negative whereas only 10% had HBV positive results. Comparison of each risk factor among HBV positive and negative groups we didn’t observe any statistically significant differences. For instance HBV infection occurred in 9.0% of population who had dental procedure,  10.5% and 9.5%who had injections at home and blood or blood products infusions respectively, 10.0% those who had tattoo.

DISCUSSION

According to the study by Oyunbileg J. et al. in 1992,overall prevalence of НВsAgwas 6,8% and itincreased with age group. 7.1% in age 0-9 years., 9.3%, in 21-30 years., 15.7% in  31-40 years., 15% in age group above 50 years.⁵The latter goes in line with our study.(15% in age group above 50).Khurelbaatar N. Et al. found (2001) 29.7-31.6% НВsAg positive individuals among 167cohorts aged 19-53 years.⁶In study conducted by Oyunsuren Ts. et al. prevalence of НВsAgwas 23.1%, 15.7% among healthy population.⁷Prevalence of НВsAgamong male was 16.7% found in study by Nyamdavaa P. et al.⁸which is similar to our finding. In our study prevalence of НвsAg among male was 12.2% which has statistically significant difference comparing to female (p=0.0027). In cross sectional study by Dagvadorj Ya et al.in 2001-2003 among population aged 0-80 years prevalence of НвsAgfound to be 11.8%.⁹ Our data found the prevalence of positive НвsAg being 9.1% which display decreasing tendency of НвsAg prevalence.

CONCLUSION

 

HBVinfection has statistically significant difference in genderwhich does not apply to age groups. Although some risk factors such as tattooing, infusion of blood/ blood products, having injections at home were not statistically significant but could be potential risk factors. 

Ном зүй

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3. Davaalkham D, ‘Seroepidemiology of hepatitis B virus infection among children Mongolia: results of a nationwide survey. Pediatr Int 2007;49(3):368-74

4. Tsatsralt-Od B, Takahashi M, Endo Kazunari, Okamoto H “Prevalence of hepatitis B, C and delta virus infections among children in Mongolia”. Progress in childhood immunization. Journal of medical virology 2007;79(8):1064-1074
5. Oyunbileg J. et al. Prevalence of hepatitis B,C,D viral infection among Mongolian population. Abstracts from 8th conference “Actual problems in virology”. Ulaanbaatar;1992
6. Khurelbaatar N. Effectiveness of treating hepatitis B virus careers with plasma vaccine. Dissertation for PhD in medicine. Ulaanbaatar;. 2001.х.19-20
7. Oyunsuren Ts. et al. Prevalence of hepatitis B,C infection among Ulaanbaatar city population. Mongolian Journal of Health Science. Ulaanbaatar;4/97:17-20
8. Nyamdavaa P. et al. Prevalence of hepatitis B markers among adult Mongolian men. Abstracts from conference “Challenges in Traditional medicine” Ulaanbaatar;1998:50
9. Davgadorj Ya.et al. of hepatitis B,D infection epidemiology in Mongolia. Abstracts from 10thNational conference “ current issues in virology” Ulaanbaatar;1992:34-35

 

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