Serological evidence of Rickettsia and Coxiella burnetii in humans of Buenos Aires, Argentina

• We studied the seroprevalence for Rickettsia (spotted fever and typhus groups) and Coxiella burnetii (Q fever agent) in residents of Buenos Aires city.
• IgG antibodies against Rickettsia spotted fever group, Rickettsia typhus fever group and C. burnetii were detected by IFA in 28.3%, 16.2% and 1.0% of patients, respectively.
• There is circulation of such agents (mainly the genus Rickettsia) in urban areas like the city of Buenos Aires.

In Buenos Aires city (Argentina), the circulation of these agents has been detected mainly in vectors and animals, few human cases having been described. The aim of our study was to determine the seroprevalence of Rickettsia (spotted fever – SFG – and typhus – TG – groups) and Coxiella burnetii (Q fever agent) in residents of Buenos Aires city. The study involved 99 participants. Rickettsia IgG antibodies against SFG and TG were detected by IFA in 28.3% and 16.2% of serum samples, respectively. SFG titers were mostly 1/64 (53.6%) with a maximum of 1/512 (3.5%) whereas TG titers ranged between 1/64 (62.5%) and 1/256 (6.3%). Only one sample showed a titer of 1/32 for C. burnetii (phases I and II). The circulation of these pathogens in urban areas such as the city of Buenos Aires should be considered by health services, especially at the primary care level.