Date Published: January 20, 2017
Publisher: Public Library of Science
Author(s): Tamar Akhvlediani, Christian T. Bautista, Natalia Garuchava, Lia Sanodze, Nora Kokaia, Lile Malania, Nazibrola Chitadze, Ketevan Sidamonidze, Robert G. Rivard, Matthew J. Hepburn, Mikeljon P. Nikolich, Paata Imnadze, Nino Trapaidze, Roy Martin Roop.
Brucellosis is an endemic disease in the country of Georgia. According to the National Center for Disease Control and Public Health of Georgia (NCDC), the average annual number of brucellosis cases was 161 during 2008–2012. However, the true number of cases is thought to be higher due to underreporting. The aim of this study was to provide current epidemiological and clinical information and evaluate diagnostic methods used for brucellosis in Georgia.
Adult patients were eligible for participation if they met the suspected or probable case definition for brucellosis. After consent participants were interviewed using a standardized questionnaire to collect information on socio-demographic characteristics, epidemiology, history of present illness, and clinical manifestation. For the diagnosis of brucellosis, culture and serological tests were used.
A total of 81 participants were enrolled, of which 70 (86%) were from rural areas. Seventy-four percent of participants reported consuming unpasteurized milk products and 62% consuming undercooked meat products before symptom onset. Forty-one participants were positive by the Wright test and 33 (41%) were positive by blood culture. There was perfect agreement between the Huddelston and Wright tests (k = 1.0). Compared with blood culture (the diagnostic gold standard), ELISA IgG and total ELISA (IgG + IgM), the Wright test had fair (k = 0.12), fair (k = 0.24), and moderate (k = 0.52) agreement, respectively.
Consumption of unpasteurized milk products and undercooked meat were among the most common risk factors in brucellosis cases. We found poor agreement between ELISA tests and culture results. This report also serves as an initial indication that the suspected case definition for brucellosis surveillance purposes needs revision. Further research is needed to characterize the epidemiology and evaluate the performance of the diagnostic methods for brucellosis in Georgia.
Brucellosis, the most common bacterial zoonosis in both human and animals, has a widespread geographic distribution . Worldwide, approximately 500,000 new human cases of brucellosis are reported annually . Although brucellosis is endemic in many parts of the world, especially in Mediterranean countries, north and east Africa, the Middle East, central Asia and Latin America, this disease often goes unrecognized or unreported.
Since the first documented human case of brucellosis in Georgia was reported by Dr. Makhviladze in 1923 , the disease has been detected in several regions of the country. In the following decades, this zoonotic infection became a serious problem for livestock and a constant threat to human health. To our knowledge, few published reports have studied the epidemiology and clinical features of this endemic disease in Georgia [8–9, 15–17].
In summary, we found that brucellosis infection was more likely to occur in males, young adults aged 21–40 years, and from individuals from eastern Georgia. The high percentage of participants that reported having consumed unpasteurized milk products and undercooked meat products would suggest that the gastrointestinal route is the main mode of brucellosis transmission. In addition, B. melitensis was the most common Brucella species found in the study population, and the Wright test had a better agreement with blood culture results than did two ELISA (in house and commercial) tests. Further research is needed to characterize the epidemiology of brucellosis and to elucidate the probable routes of transmission with the aim of understanding the etiology of brucellosis and informing prevention efforts in Georgia. Our study also provides initial evidence that the suspected case definition for brucellosis surveillance purposes needs to be revised.