Molecular epidemiology of bovine anaplasmosis

Bovine anaplasmosis presents a worldwide distribution. However, specific models for studying the epidemiology of the disease are not available. Epidemiological modeling encounters some difficulties due to a lack of culturing techniques for Anaplasma marginales, the causative agent, as well as for the lack of typing techniques to characterize strains. The chronic carrier state and the population dynamics of mechanical and biological vector also create difficulties. In addition, conventional serology and blood smear diagnostic techniques fail to detect all chronica carriers. Fortunately the needs for the accurate typing of isolates and for detecting chronica carriers made it possible to encourage the development of new tools based on molecular epidemiology principles. A. marginali isolates can now be typed by using panels of monoclonal antibodies, and the genes coding for some major surface proteins can be expressed or analyzed by looking at the nucleotide arrangement level. In the same manner, the latest techniques for detecting A. marginale chronic infections use DNA and RNA probes, and PCR-based methods to detect A. marginali DNA from bovine blood samples with extremely low rickettsaemias. Currently all these new epidemiological tools are being incroporated to experimental models to analyze their applicability for epidemiological studies in the near future

Evaluation of a colorimetric Babesia bigemina-DNA probe within an epidemiological survey

An epidemiological survey was conducted in south east Mexico, in an effort to establish the serological reactivity and carrier status to Babesia bigemina of an indigenous cattle population. The prevalance was obtained through the Indirect Fluorescent Antibody Test (IFAT), using an in vitro culture-derived B. bigemina antigen. A specific, digoxigenin-coupled, ~6kb B. bigemina-DNA probe (BBDP), was used to indicate the presence of the parasite. Serum samples from 925 animals of all ages, were obtained within the three regions (I, II, III) of the state of Yucatan and tested by IFAT. In addition, whole blood samples draw from 136 of the same animals of region II were analyzed using the BBDP. Positive IFAT (IFAT+) reactions were observed in 531 sera for a 57% overall prevalence. Regional values were: I = 157 + (56%), II = 266 + (68%) and III = 108 + (42%). Only 32 (23%) of the blood samples tested with BBDP showed distinctive hybridization signal, in contrast with 100 (73%) IFAT + animals. The responses distribution for IFAT vs. BBDP was: +/+ 23, +/- 77, -/+ 9 and -/- 27 respectively. It was found that the analytical sinsitivity of BBDP appears to be low for its utilization is widespread epidemiological surveys. It was considered, however, that the colorimetric probe mifht to be useful to safely detect transmission prone carriers, since it is able to detect parasitemias as low as 0.001

Diagnostico de la zona endemica de hidroarsenicismo cronico en la Provincia del Chaco

Diagnostico del Hidroarsenicismo cronico endemico y medidas preventivas a ser tomadas por las autoridades para evitar la alta incidencia de esta patologia en el territorio del Chaco, especialmente en las zonas aridas, carentes de rios