23 May 2013
Hepatitis A outbreak in Bijeljina, Bosnia and Herzegovina, August 2012 - April 2013
From August 2012-April 2013, an outbreak of hepatitis A with 28 laboratory-confirmed cases occurred in Bijeljina, Bosnia and Herzegovina. The index case was in a seven year old child from the local Roma community. Cases were 7-70 years old, 7-15 year-olds (9 cases) were the most affected age group. The event highlights the susceptibility of the population due to reduced hepatitis A virus circulation with consecutive lower immunity in the population in the past years.
In January 2013, the local health authorities in Bijeljina, the fifth largest city in Bosnia and Herzegovina, informed the national authorities about an ongoing outbreak of hepatitis A. A first case had been notified in August 2012 and by mid-January the case count had raised to 20. Here we describe the outbreak investigation and control measures taken by the local health authorities.
Bijeljina is a town and municipality with about 120,000 inhabitants, located in the north-east of Bosnia and Herzegovina (Figure1). It is the fifth largest city in Bosnia and Herzegovina and second largest in the Republic of Srpska. Republic of Srpska is one of the two main - political entities of Bosnia and Herzegovina. Bijeljina municipality shares borders with Croatia and Serbia. It is a significant agricultural, trade and transit area in Bosnia and Herzegovina, with a high population density.
Figure 1. Location of Bijeljina, Bosnia and Herzegovina
In the past 21 years, the epidemiological situation of reported intestinal infectious diseases in Bijeljina municipality was stable. Only sporadic cases of salmonellosis and few family outbreaks of trichinellosis were notified (data not shown).
In the Republic of Srpska, hepatitis A is a notifiable disease in accordance with the law on protection of the population against infectious diseases . An infectious disease reporting is regulated by respective rules which do not define the criteria for reporting in detail .
Despite numerous challenges such as the Bosnian war from 1992 to 1995, migration of inhabitants elsewhere, poor socio-economic conditions and the unprecedented floods of the Drina river at the end of 2010, no hepatitis A cases were recorded before the current outbreak, in Bijeljina in the past 21 years. There is a possibility however, that cases of hepatitis A had occurred that were neither detected nor registered due to severe disruption of the surveillance of infectious diseases, especially during wartime. Before that period, from 1971 to 1991, a total of 3,399 cases of hepatitis A with an average of 154 cases per year, were registered (Figure 2).
In the last 15 years, the overall incidence of hepatitis A in Bosnia and Herzegovina decreased (Figure 3). In the same period, declining hepatitis A incidence trends were also observed in many other European countries .
Figure 2. Incidence of notified hepatitis A cases per 10,000 population in Bijeljina, Bosnia and Herzegovina, 1971-1991 (n=3,399)
Figure 3. Incidence of notified hepatitis A cases per 100,000 population, in Federation of Bosnia and Herzegovina and Republic of Srpska, Bosnia and Herzegovina, 1996-2012
On 17 January 2013, the epidemiological service of the Health Center Bijeljina notified the the Republic of Srpska Institute of Public Health about a hepatitis A outbreak in Bijeljina, due to an increased number of hepatitis A cases since August 2012.
The case definition for the investigation of the hepatitis A outbreak corresponds to the European Union case definition . Confirmed cases are only those with clinical symptoms and laboratory confirmation (IgM antibody to hepatitis A virus (anti-HAV IgM)) reported from 1 August 2012 in Bijeljina.
All available relevant clinical and epidemiological data on cases and their contacts were collected using a paper-based questionnaire by the staff of the epidemiological service of the Health Center Bijeljina.
From 15 August 2012 to 2 April 2013 a total of 28 confirmed cases were reported (Figure 4).
Figure 4. Notified cases of hepatitis A, in Bijeljina, Bosnia and Herzegovina, 15 August 2012 - 2 April 2013 (n=28)
The index case was a seven year-old child from the Roma population that resides in the area close to the canal Dasnica, to where untreated domestic sewage and wastewater of the entire city is disposed. The other cases were from the general population, mostly pupils (9 cases) and unemployed persons (13 cases).The youngest case was seven years and the oldest 70 years old (median 34 years). With nine of the 28 cases, the most affected age group was that of 7to 14 year-olds. Age and sex distribution of cases are depicted in Figure 5.
Figure 5. Age and sex distribution of notified hepatitis A cases, in Bijeljina, Bosnia and Herzegovina, 15 August 2012 - 2 April 2013 (n=28)
All 28 cases were hospitalised; 23 were treated at the general hospital in Bijeljina and five were transported to and hospitalised at the Clinic for Infectious Diseases in Banja Luka because of limited availability of hospital beds in Bijeljina. All patients had several of the following clinical findings: jaundice, fever, weakness, fatigue, abdominal pain, vomiting, diarrhoea, light colored stools and dark colored urine. The clinical course was favourable for all and there were no complications.
From all 28 patients serum samples were taken and analysed for the following hepatitis markers: hepatitis B surface antigen (HBsAg), antibodies to hepatitis E virus (anti-HEV IgM), antibodies to hepatitis C virus (anti-HCV IgM and IgG) and anti-HAV IgM.
After an initial analysis at the general hospital in Bijeljina, all samples which were not reactive for HBsAg, anti-HEV and anti-HCV, were further tested for hepatitis A at the Clinical Center of Banja Luka.
Specimens with signal to cutoff (S/CO) values ≥ 1.21 were considered reactive for IgM anti-HAV (analysed by Abbott ARCHITECT® apparatus). All reported cases were reactive. The observed values ranged from 7.08 to 19.64 (median 13.1).
Specific guidelines for case management of hepatitis A do not exist in Republic of Srpska. We inspected schools and public buildings in Bijeljina. All cases and contacts were provided with general information about the nature of the disease, ways of transmission and how to prevent hepatitis A. The local health authorities disinfected houses (with chlorine granulates dissolved in water) and the immediate environment of patients as well as premises of kindergartens and pre-schools and local boarding school facilities and other collective accommodation buildings in Bijeljina.
Monitoring of drinking water quality from the waterworks and affected households was intensified and showed that water was safe for drinking.
Vaccines and immunoglobulin against hepatitis A are not available in Republic of Srpska.
The surveillance system in Bosnia and Herzegovina dates back to the time of the former Socialist Republic of Yugoslavia and is a passive reporting system of infectious diseases. Reporting is done through paper forms and depends on cooperation of doctors who report diseases to the relevant epidemiological service in the public health authorities. Diagnosis is usually only clinical; microbiological confirmation of diseases is still quite limited.
In the current hepatitis A outbreak the first case and five more cases occurring in September, October and November 2012, were reported in the Roma population living in the southern part of Bijeljina, in an area with significant infrastructure problems e.g. unregulated water supply system and sewage. During the past 20 years this area has been exposed to a large migration of the Roma population many of whom left the town.
We assume that the infection transmission in the current outbreak which started in the Roma community, reached the general community through transmission in schools. The age distribution of cases with the most affected age group being that of children between 7 to 14 years old, compared with cases in outbreaks in Czech Republic , Latvia , Estonia  and Slovakia , is most similar to that in Estonia. These outbreaks confirm the susceptibility of the population due to a reduced HAV circulation with consecutive lower immunity in the population in the past years.
Based on epidemiological data and results of analysis of drinking water, most probable routes of transmission are (mainly) indirect faecal-oral transmission contact via common use items: door handles, sanitary devices in school and public toilets etc.
The last outbreak case was reported on 2 April 2013. The average incubation period of hepatitis A is 28–30 days (range 15–50 days) . After the double maximum incubation period from last the notified hepatitis A case, we will announce the end of this outbreak most probably at the beginning of July this year if no further cases occur.
A lesson learnt from this event is that in an increasingly susceptible population, unresolved problems in sanitary infrastructures can increase the risk of an outbreak of hepatitis A. Public hygiene was evaluated by inspection authorities, as soon as the outbreak had been declared by the local public health authorities. There is an obvious need for larger involvement of institutions responsible for public health and for the educational sector to raise the awareness of the population about the need to improve hygiene through the mass media and educational campaigns.
Also, cross-border collaboration is necessary because of the vicinity to other countries and the mobility of the local population. Hepatitis A is resurging in Europe at the moment with a number of food-related multi-country outbreak(s) and travel-related cases which show the challenge of increased susceptibility in the population .
Finally, in the present case, the surveillance system was able to pick up the outbreak and this can be considered as a positive signal for the future.
ZD and SM wrote the manuscript were responsible for its conception and design, as well as for data analysis and interpretation.
Conflict of interest
- Narodna skupština Republike Srpske. Zakon o zaštiti stanovništva od zaraznih bolesti. [National Assembly of the Republic of Srpska. Law on Protection of Population against Communicable Diseases.] 25.1.2010. Bosnian, Croatian, Serbian. Available from: http://www.narodnaskupstinars.net/images/docs/old_site/latn/zipovi/zak/Zakon_o_zastiti_stanovnistva_od_zaraznih_bolesti.zip
- Ministarstvo zdravlja i socijalne zaštite Republike Srpske. Pravilnik o načinu prijavljivanja, sadržaju evidencije i prijave o zaraznim bolestima. [Ministry of Health and Social Welfare of the Republic of Srpska. Rules on contents of notification forms and reporting of infectious diseases.] 20.10.2010. Bosnian,Croatian,Serbian. Available from: http://www.phi.rs.ba/documents/pravilnik_zarazne_bolesti.pdf
- Payne L, Coulombier D. Hepatitis A in the European Union: responding to challenges related to new epidemiological patterns. Euro Surveill. 2009;14(3):pii=19101. Available from: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=19101
- European Commission (EC). 2008/426/EC: Commission Decision of 28 April 2008 amending Decision 2002/253/EC laying down case definitions for reporting communicable diseases to the Community network under Decision No 2119/98/EC of the European Parliament and of the Council. Official Journal L 159, 18.6.2008. Brussels: EC. Available from: http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2008:159:0046:01:EN:HTML
- Cástková J, Beneš C. Increase in hepatitis A cases in the Czech Republic in 2008 – an update. Euro Surveill. 2009;14(3):pii=19091. Available from: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=19091 PMid:19161729
- Perevoscikovs J, Lucenko I, Magone S, Brila A, Curikova J. Community-wide outbreak of hepatitis A in Latvia, in 2008. Euro Surveill. 2008;13(40):pii=18995. Available from: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=18995
- Dontšenko I, Kerbo N, Pullmann J, Plank S, Võželevskaja N, Kutsar K. Preliminary report on an ongoing outbreak of hepatitis A in Estonia, 2011. Euro Surveill. 2011;16(42):pii=19996. Available from: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=19996 PMid:22027376
- Hrivniaková L, Sláčiková M, Kolcunová S. Hepatitis A outbreak in a Roma village in eastern Slovakia, August-November 2008. Euro Surveill. 2009;14(3):pii=19093. Available from: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=19093 PMid:19161727
- Heymann DL, editor. Control of Communicable Diseases Manual. 19th ed. Washington, D.C.: American Public Health Association; 2008.
- Gillesberg Lassen S, Soborg B, Midgley SE, Steens A, Vold L, Stene-Johansen K, et al. Ongoing multi-strain food-borne hepatitis A outbreak with frozen berries as suspected vehicle: four Nordic countries affected, October 2012 to April 2013. Euro Surveill. 2013;18(17):pii=20467. Available from: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=20467
- MacDonald E, Steens A, Stene-Johansen K, Gillesberg Lassen S, Midgley SE, Lawrence J, et al. Increase in hepatitis A in tourists from Denmark, England, Germany, the Netherlands, Norway and Sweden returning from Egypt, November 2012 to March 2013. Euro Surveill. 2013;18(17):pii=20468. Available from: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=20468 PMid:23647624