Portal de Periódicos da CAPES

Some epidemiologic features of Campylobacter jejuni/coli infections in Bosnia and Herzegovina after the war

2003; Elsevier BV; Volume: 9; Issue: 5 Linguagem: Inglês

10.1046/j.1469-0691.2003.00579.x

1469-0691

Selma Uzunović-Kamberović,

Food Safety and Hygiene

Campylobacter spp. are recognized as some of the most important enteropathogens in both industrialized and developing countries [1Tauxe RV Pegues DA Hargrett-Bean N Campylobacter infections: the emerging national pattern.Am J Public Health. 1987; 77: 1219-1221Crossref PubMed Scopus (28) Google Scholar, 2Georges-Courbot MC Baya C Beraud AM Meunier DMY Georges AJ Distribution and serotypes of Campylobacter jejuni and Campylobacter coli in enteric Campylobacter strains isolated from children in Central African Republic.J Clin Microbiol. 1986; 2: 592-594Google Scholar]. It has previously been reported that people in the Zenica region of Bosnia have high carriage rates of C. coli [3Uzunovic-Kamberovic S Changes in Campylobacter jejuni/Campylobacter coli carriage rates in the Zenica Region of Bosnia and Herzegovina in the pre- and postwar periods.J Clin Microbiol. 2001; 39: 2036Crossref PubMed Scopus (10) Google Scholar], and this prompted us to carry out a survey to determine the prevalence of Campylobacter spp. causing diarrhea in this region and the distribution among patients by demographic features. The Zenica-Doboj Canton has a total population of 432 200 in two distinct residential zones: an urban area, where most inhabitants live in apartments, and a farming and agricultural rural area. The Laboratory of Sanitary and Clinical Microbiology of the Cantonal Center for Public Health in Zenica serves all outpatients of the Zenica-Doboj Canton. From 1 July to 31 December 1998, stool specimens were received from 1703 consecutive outpatients with diarrhea. There were 1066 specimens from children under 6 years of age, 226 from elementary school students, 140 from high school students, and 273 from adults. The age, sex and zone of residence of all patients were recorded. The number of patients examined in the laboratory was compared to the number of patients reported to the Cantonal Center for Public Health in Zenica as having diarrhea during January to December 1998 (Table 1). All stool samples were cultured on modified Preston medium (Oxoid, Basingstoke, UK), and incubated in a micro-aerobic atmosphere at 42 °C for 48 h [4Karmali MA Fleming PC Application of the fortner principle to isolation of Campylobacter from stools.J Clin Microbiol. 1979; 10: 245-247PubMed Google Scholar, 5Popovic-Uroic T Sterk-Kuzmanovic N Comparison of two simple microaerobic atmospheres for cultivation of thermophilic campylobacters.J Clin Pathol. 1992; 45: 87-88Crossref PubMed Scopus (3) Google Scholar]. C. coli and C. jejuni were identified using standard microbiological methods [6Smibert RM Genus Campylobacter Sebald and Véron 1963.in: Krieg NR Holt JG Bergey's manual of systematic bacteriology. 1. Williams & Wilkins, Baltimore, MD1984: 111-118Google Scholar]. The C. jejuni control strain ATCC 33291 was used.Table 1Some epidermiologic features of Campylobacter jejuni/coli infections in Bosnia and Herzegovina after the warZone of residencePopulation servedNotified diarrhoeas in Zerica-Dobo Canton∗Notifications of “infective diarrhoes” to Cantonal Centre for Public Health Zenics for the period January to December 1998.Specimen examined†The number of specimens examined on presence of C. jejuni/coli in 6-month period. (% of notified diarrhoeas)Positive numberIsolates/100 000 populationC. jejuniC. coliTotal (%)C. jejuniC. coliTotalUrban zone194 1002234720 (32)33639 (49.4)17.03.120.1Rural zone238 1004433983 (21)251540 (50.6)10.56.316.8Total432 20066671703 (26)58217913.44.918.3∗ Notifications of “infective diarrhoes” to Cantonal Centre for Public Health Zenics for the period January to December 1998.† The number of specimens examined on presence of C. jejuni/coli in 6-month period. Open table in a new tab In the 6-month period of the study, 1703 stool samples were tested for the presence of Campylobacter spp., comprising only 25.6% of the notified cases of diarrhea in the Zenica-Doboj Canton from January to December 1998. Campylobacter strains were isolated from 79 (4.6%) specimens. About half of the isolates were from urban and half from rural dwellers, resulting in a rate of 20.1 cases per 100 000 urban population, compared with 16.8 per 100000 rural population (Table 1). In most other reports from the developed world, the rural population is more affected by campylobacters than the urban one [1Tauxe RV Pegues DA Hargrett-Bean N Campylobacter infections: the emerging national pattern.Am J Public Health. 1987; 77: 1219-1221Crossref PubMed Scopus (28) Google Scholar]. The rate of campylobacteriosis in the Zenica-Doboj Canton is similar to that reported from developing countries [7Mφlbak K Hφjlyng N High prevalence of campylobacter excretors among Liberian children related to environmental conditions.Epidemiol Infect. 1988; 100: 227-237Crossref PubMed Scopus (20) Google Scholar]. A reason for this may be the effect of the aftermath of war in Bosnia and Herzegovina. In 1998, there were many refugees in Zenica city and surrounding areas, and 18.95% of the Zenica-Doboj Canton population in 1998 were expelled [8Institute of Statistics Federation B&Ho.Statistical Yearbook of Federation B&H. Institute of Statistics Federation B&H, Sarajevo1999Google Scholar]. The crowded urban community of the Zenica-Doboj Canton lived under poor hygienic conditions, and this may have encouraged the spread of infection [9Mathan VI Rajan DP The prevalence of bacterial intestinal pathogens in a healthy rural population in southern India.J Med Microbiol. 1986; 22: 93-96Crossref PubMed Scopus (18) Google Scholar]. Although campylobacteriosis is primarily a food-borne zoonosis, person-to-person spread can occur in crowded conditions [7Mφlbak K Hφjlyng N High prevalence of campylobacter excretors among Liberian children related to environmental conditions.Epidemiol Infect. 1988; 100: 227-237Crossref PubMed Scopus (20) Google Scholar], and water-borne outbreaks may occur if water supplies are contaminated by sewage [10Engberg J Gerner-Smidt P Sheutz F et al.Waterborne Campylobacter jejuni infection in a Danish town-a 6-week continuous source outbreak.Clin Microbiol Infect. 1998; 4: 648-656Crossref PubMed Scopus (62) Google Scholar]. However, it seems more likely that secondary contamination mediated by handling of contaminated foods in kitchens is the route of transmission of infection in this situation. Although these rates are not high, they show striking differences in the age-specific distribution of infection. Most surveys in industrialized countries show a bimodal distribution of infection by age, with the highest incidence in infants and in persons aged 15-29 years [1Tauxe RV Pegues DA Hargrett-Bean N Campylobacter infections: the emerging national pattern.Am J Public Health. 1987; 77: 1219-1221Crossref PubMed Scopus (28) Google Scholar]. In the present study, 67% of Campylobacter isolates were obtained from children below 6 years of age, resulting in by far the highest rate of 120.5 cases per 100 000 population in this age group. However, in the present study, irregularities of sampling have influenced the isolation rate. This bias is inherent in all laboratory-based surveillance studies, and reflects actual clinical practice. In the present study, the age and zone of residence distribution of the population from whom specimens were received is not representative of these distributions in the Zenica-Doboj Canton population as a whole. However, by analyzing the percentage of fecal specimens positive within each age group, we can eliminate bias. When this is done, it can be shown that the highest rate in the inner city zone is again in the age group under 6 years (data not shown). This unimodal age-specific distribution resembles that of developing areas where poor sanitary conditions and inadequate personal hygiene seem to lead to greater exposure to the organism, and the prevalence of infection appears to be highest in young children [9Mathan VI Rajan DP The prevalence of bacterial intestinal pathogens in a healthy rural population in southern India.J Med Microbiol. 1986; 22: 93-96Crossref PubMed Scopus (18) Google Scholar]. C. coli is normally isolated from less than 10% of symptomatic patients [1Tauxe RV Pegues DA Hargrett-Bean N Campylobacter infections: the emerging national pattern.Am J Public Health. 1987; 77: 1219-1221Crossref PubMed Scopus (28) Google Scholar], and a high isolation rate has usually been connected with consumption of pork [11Popovic-Uroic T Campylobacter jejuni and Campylobacter coli diarrhoea in rural and urban populations in Yugoslavia.Epidemiol Infect. 1989; 102: 59-67Crossref PubMed Scopus (22) Google Scholar]. In this study, C. coli accounted for 26.5% of all isolates (71.4% rural isolates, and 28.6% urban isolates). Such a high percentage of C. coli has been reported only in the Central African Republic (39%), Croatia (54%), and Bosnia and Herzegovina (36%) [2Georges-Courbot MC Baya C Beraud AM Meunier DMY Georges AJ Distribution and serotypes of Campylobacter jejuni and Campylobacter coli in enteric Campylobacter strains isolated from children in Central African Republic.J Clin Microbiol. 1986; 2: 592-594Google Scholar, 3Uzunovic-Kamberovic S Changes in Campylobacter jejuni/Campylobacter coli carriage rates in the Zenica Region of Bosnia and Herzegovina in the pre- and postwar periods.J Clin Microbiol. 2001; 39: 2036Crossref PubMed Scopus (10) Google Scholar, 11Popovic-Uroic T Campylobacter jejuni and Campylobacter coli diarrhoea in rural and urban populations in Yugoslavia.Epidemiol Infect. 1989; 102: 59-67Crossref PubMed Scopus (22) Google Scholar]. One of the consequences of population migration during the war was the change in ethnic structure in the Zenica-Doboj Canton population. Muslims now account for 82.3% of the population (estimate of ethnicity structures by Institute of Statistics Federation B&H), so the consumption of pork, customarily associated with C. coli infection, is almost nonexistent in this region. Nevertheless, a high proportion of C. coli appears in this study, as in the prewar period [3Uzunovic-Kamberovic S Changes in Campylobacter jejuni/Campylobacter coli carriage rates in the Zenica Region of Bosnia and Herzegovina in the pre- and postwar periods.J Clin Microbiol. 2001; 39: 2036Crossref PubMed Scopus (10) Google Scholar], suggesting that the primary source of C. coli infections in this region was the same before and after the war, and might be something other than pigs. An individual well-water supply was identified as a possible source of C. coli infections in the Central African Republic [2Georges-Courbot MC Baya C Beraud AM Meunier DMY Georges AJ Distribution and serotypes of Campylobacter jejuni and Campylobacter coli in enteric Campylobacter strains isolated from children in Central African Republic.J Clin Microbiol. 1986; 2: 592-594Google Scholar]. It has been shown that C. coli was isolated more frequently than C. jejuni from poultry [12Kalenic S Gmajnicki B Milakovic-Novak LJ et al.Campylobacter coli—the prevalent campylobacter in Zagreb area.in: Pearson AD Skirrow MB Lior H Rowe B Campylobacter III. Proceedings of the Third International Workshop on Campylobacter Infections. Public Health Laboratory Service, London1985: 262-264Google Scholar] and from frozen commercial chicken livers [13Fernández H Pisón V Isolation of thermotolerant species of Campylobacter from commercial chicken livers.Int J Food Microbiol. 1996; 29: 75-80Crossref PubMed Scopus (50) Google Scholar], suggesting that C. coli may be more resistant to exposure to low temperatures or other adverse environmental conditions. Recent studies have shown that free-living birds and aquatic sources may be important parts of the transmission cycle of Campylobacter spp. [14Pearson AD Greenwood M Healing TD et al.Colonization of broiler chickens by waterborne Campylobacter jejuni.Appl Environ Microbiol. 1993; 59: 987-996PubMed Google Scholar]. Although the campylobacter isolation rate in this study was low, as in other developed countries, the high proportion of infection in children under 6 years of age in the urban zone is an epidemiologic feature also seen in developing countries. The fact that all isolates (with a single exception) in a campylobacter carriage survey in the prewar period were isolated from the rural population [3Uzunovic-Kamberovic S Changes in Campylobacter jejuni/Campylobacter coli carriage rates in the Zenica Region of Bosnia and Herzegovina in the pre- and postwar periods.J Clin Microbiol. 2001; 39: 2036Crossref PubMed Scopus (10) Google Scholar] suggests that the situation presented in this paper may be one of the effects of the war. This study shows that the environmental transmission cycle of Campylobacter spp. is not fully understood, and that sources other than animals, environmental or bacterial factors, may be involved in contamination and the transmission of Campylobacter spp. infections.