human cases per 100,000 people in 2002 (Pappas et al. 2006), and 77.5 per 100,000 people in 2007 (promedmail.org, Ar- chive Number 20090201.0449, published Feb 1, 2009). However, it is not known if the Kyrgyz health system coverage is exhaustive and if all patients have access to care. It is likely that the true incidence is underestimated. An earlier study by Kozukeev et al. (2006) indicated the importance of cattle for the transmission of brucellosis in Kyrgyzstan, but the role of small ruminants for the trans- mission of brucellosis in humans is not clear. Brucellosis can be diagnosed by isolation (culture) of the bacteria, direct PCR of Brucella spp. genome in contaminated specimens or indirectly by antibody detection either in serum or milk (Corbel 2006). The culturing of Brucella spp. from animal samples is complex and dangerous and requires biosafety level 3, which is not currently available in Kyrgyzstan. Hence, we rely on available and more recent serological methods for diagnosis. The objective of this study was to assess representative brucellosis seroprevalences of livestock and humans for Kyrgyzstan and the association between human and livestock brucellosis seroprevalence. Represen- tative estimates should be related to ofﬁcial reports and inform Kyrgyz public health and veterinary policy. The test characteristics of the Huddleson test in humans and Rose Bengal Test in livestock, which are currently used in Kyrgyzstan, are not known and there is no gold standard. MATERIALS AND METHODS Partnership Between Public Health and the Veterinary Sector In the Fall of 2006, an integrated assessment of human and livestock brucellosis seroprevalence was undertaken jointly by the Republican State Center for Veterinary Diagnostics, the Republican Centre for Quarantine and especially dan- gerous diseases, the State Sanitary Epidemiological Depart- ment of the Kyrgyz Republic and the Swiss Tropical and Public Health Institute. Complementary Support of Community Action for Health facilitated this partnership (Zinsstag et al. 2009). Study Design For this survey, the national census data on sheep and goat populations was used. A multistage cluster sampling pro- portional to size was determined by levels of Oblast (province), Rayon (district), and village (Bennett et al. 1991; Representative Seroprevalences of Brucellosis 133 Schelling et al. 2003). Three out of seven Oblasts were sam- pled. Naryn Oblast was selected by convenience (availability of previous serological studies), and the two others were sampled randomly in proportion to their size. In every Oblast, three Rayons, and in every Rayon, ten villages, were selected randomly in proportion to their size as shown in Fig. 1 (Bennett et al. 1991). In this way, a total of 90 villages were selected randomly and used as cluster units. We assumed an intraclass correlation roh of 0.2 between clusters and a design effect of 4.8. Sampling of 20 humans or livestock in every cluster provided a total sample size of 1,800 per species and 95% conﬁdence limits of the estimate of <3% below and above the estimated seroprevalence, which is representative for the whole country. This study was approved by the Ethical committee of the Cantons of Basel and the Kyrgyz Health Authorities. Informed written consent was provided by all persons participating in the study or of young children’s mothers, after they had received detailed patient information. Overall, the proportion of sheep to goats was estimated at 6:1. Due to the lack of more detailed information, we as- sumed that this proportion is true for all Rayons. In the year of study (2006) very few animals were vaccinated against brucellosis in Kyrgyzstan and their inﬂuence on the serological results of this study were considered negligible. Human and Livestock Sample Collection The study was conducted by three ﬁeld teams composed of one veterinarian and one physician in the spring of 2006. A total of 103 villages in the nine selected Rayons were visited. Venous blood was taken with 5 ml Vacutainer tubes and the age, sex, and names were recorded for all participants. Blood of livestock (cattle, sheep, and goats) was obtained by venipuncture with 10 ml Vacutainer tubes. Livestock and human samples were not necessarily collected from the same households as the participation was voluntary. Human blood was transported to the Rayon Health Center and animal blood was transported to the Veterinary laboratory and centrifuged. All sera were shipped to Bishkek either to the Centre for Quarantine for testing of human sera with the Huddleson agglutination test or to the Central Veterinary Laboratory in Bishkek for other tests described below. Diagnostic Tests In Kyrgyzstan, the most common test is the Huddleson agglutination test for humans (ofﬁcial test) and the Rose