Microscopic agglutination test: variables that affect the time of serologic confirmation of human cases of leptospirosis.

MORENO S; M. RIVERO; BONGIORNO F; EXEQUIEL SCIALFA; ORTIZ M

Buenos Aires

Simposio; XIX simposio Internacional Sobre Enfermedades Desatendidas; 2019

Fundación Mundo Sano

Leptospirosis is considered an endemic disease in Buenos Aires province, with human cases registered annually from rural and urban areas. The aim of the study was to describe the variables that influence the delay in the serological confirmation of leptospirosis in human cases of Buenos Aires province. Using epidemiological and serologic diagnostic data obtained of 90/150 confirmed human cases of leptospirosis (period 2006-2014) by Department of Rural Zoonoses, the following was analyzed:? Days between:?The onset of illness (clinical manifestation) and obtaining the serum sample for diagnosis (time of clinical suspicion).?The taking of the clinical sample and the arrival at the reference laboratory.?The onset of the disease and the serological confirmation of the case.? Detection of antibodies by MAT, number of serovars reactive and titers reached.In the 17% (15/90) it also demanded the serological diagnosis of other pathologies with clinical and compatible epidemiology such as the Hantavirus and the Argentine Hemorrhagic Fever disease. The confirmed human cases were distributed in 22 cities of the province. The 64% of cases could be confirmed by MAT with the first clinical sample. An average of 7.75 days (Median: 8 days) elapsed between the onset of clinical manifestations and the moment of taking the sample for the corresponding diagnosis. 68.6% of the samples delayed reaching the reference laboratory for up to 10 days, with an average of 13.5 days and a median of 13 days. Castellonis-Canicola was the most reactive serovars in MAT; the cross-reaction between serovars was evidenced from day 4 to 40 of the course of the disease. The time of confirmation of the human cases of leptospirosis was as on average at 21 days from the onset of the first clinical signs, and was affected according to the distance of the sanitary regions (P = 0.0009). The geographical distribution of confirmed human cases of leptospirosis, in addition to the high number of suspected cases and probable cases (which could not be confirmed by MAT), demonstrate that the leptospirosis is endemic and underreporting in Buenos Aires province, and distance and lack of resources could be a determinant for that.