1 3 DOI 10.1007/s15010-015-0748-z Infection ORIGINAL PAPER Prevalence of Brucella antibodies on a previously acute brucellosis infected population: sensitivity, specificity and predictive values of Rose Bengal and Wright standard tube agglutination tests Panagiotis Andriopoulos · Antonia Kalogerakou · Dimitra Rebelou · Andrea Paola Rojas Gil · Sofia Zyga · Vassiliki Gennimata · Maria Tsironi Received: 27 October 2014 / Accepted: 11 February 2015 © Springer-Verlag Berlin Heidelberg 2015 presentation of brucellosis and treatment were not associ- ated with serology results. Both tests had excellent sen- sitivity (nearly 100 %), specificity 87.5 % and excellent negative predictive value (nearly 100 %); however, positive predictive value was only 11.4 %. Conclusions Rapid and low-cost tests as RBT and STA are still very useful in diagnosing acute brucellosis; how- ever, every positive test must be examined together with clinical symptoms and occupational history. The tests can be used as screening tests in endemic populations to rule out acute brucellosis. Keywords Brucella · Serology · Prevalence of brucellosis · Sensitivity and specificity of diagnostic methods · Predictive value · Acute brucellosis Introduction Human brucellosis is a zoonosis caused by intracellular, aerobic, Gram-negative bacteria of the genus Brucella, with both domesticated and wild animal reservoirs [1]. The four more common species that also cause disease in humans are B. melitensis, B. abortus, B. suis and B. canis. Humans are usually infected by contact with or by consumption of dairy products from infected animals. Aerosol transmission and laboratory exposure are also possible ways of infection [2]. The incidence of human disease is closely related to the prevalence of infection in sheep, goats and cattle. Approxi- mately half a million human brucellosis cases are annually reported though these figures may be an underestimate of the disease burden, because of inadequate surveillance, inaccurate diagnosis and inability to access health services [3]. The true incidence according to WHO is 10–25 times higher [4]. Abstract Purpose Brucellosis is a zoonosis with worldwide distri- bution. The presence of antibodies after acute infection and the prevalence of positive serology in endemic area are not well documented. Methods Patients hospitalized with acute brucellosis were relocated 3–13 years after the initial infection. Hospital records of the initial infection were retrieved, and examina- tion of Brucella antibodies using Rose Bengal test (RBT) and Wright standard tube agglutination (STA) test was performed. Results Eighty-three patients were hospitalized from 2000 to 2010; 50.6 % were farmers and 37.4 % livestock farmers. All had febrile illness and various focal compli- cations. All had positive serology, and 82.2 % had posi- tive blood cultures; 91.5 % were treated with streptomycin plus doxycycline. Seventy-two (86.7 %) were relocated on follow-up. Nine (12.5 %) had positive RBT and STA up to 1/320. Occupational history was associated with positive serology (p = 0.0172), and 8/9 of the positive individu- als were livestock farmers (38.0 % of the livestock farm- ers checked). Residence, years after the infection, clinical P. Andriopoulos (*) · A. P. R. Gil · S. Zyga · M. Tsironi Nursing Department, University of Peloponnesus, Orthias Artemidos and Plateon, 23100 Sparta, Greece e-mail: andriopa@otenet.gr A. Kalogerakou Gytheio Health Center, Tzani Tzanetaki, 23200 Gytheio, Greece D. Rebelou Sparta General Hospital, 23100 Sparta, Greece V. Gennimata Microbiology Department, Medical School, University of Athens, Mikras Asias 75, 11527 Athens, Greece