Research tests the seroconversion of dogs immunized with the Leishmune and Leish Tec vaccines in tests of the Ministry of Health

By Monique Campos, Instituto Nacional de Infectologia Evandro Chagas (INI), Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, RJ, Brazil

The study “Can vaccines against canine visceral leishmaniasis interfere with the serological diagnostics recommended by the Brazilian Ministry of Health?”, published in Ciência Rural, Vol. 47, No. 4, 2017, aimed to evaluate the seroconversion in dogs immunized with the Leishmune® and Leish tec® vaccines for one year after the vaccination protocol using the DPP® (Dual Path Platform) and the immunoenzymatic assay (EIE). For this, the researchers evaluated 28 dogs divided into two groups, each immunized with an anti-LVC vaccine and monitored for one year through clinical evaluation and laboratory tests. The results of all the dogs was negative for LVC in the three analyzed times: 30 days, 6 months and 1 year after the vaccination. In addition, the researchers proved the efficiency of the diagnostic methods used by the Ministry of Health in dogs infected with Leishmania infantum. In addition, the researchers tested the efficiency of serological diagnostic methods (DPP and EIE) used as screening by the Ministry of Health in dogs infected by Leishmania infantum, demonstrating that these tests were able to screen the true infected dogs. Also, the implementation of these tests improved the diagnosis of LVC in Brazil (SCHUBACH, et al., 2014).

For the researcher Monique Campos, the results of the study fill a scientific gap on anti-Leishmania vaccines in Brazil, whose use has been discussed about the possibility of seroconversion of immunized dogs and the generation of false-positive results in the serological tests of these animals. “The study confirms that this may not happen, since in the sample evaluated the vaccines did not provide the seroconversion of the dogs, regardless of the vaccine used,” she says. The research was done by independent researchers who are not directly involved in the development, manufacture and marketing of vaccines.

Although the Ministry of Health (2006) does not recommend the use of vaccines as a form of control, this study serves as a source of information for discussion of new forms of disease control. “Today, one of the measures of control is the recollection and euthanasia of the infected dogs, a measure that, in addition to not appearing effective, causes social annoyance and criticism on the part of the veterinary class and societies protecting animals. By showing that a vaccinated animal is not reactant in the tests, the study proves that a false positive animal would not be euthanized, “she continues.

References

Manual de vigilância e controle da leishmaniose visceral [online]. Brasília: Ministério da Saúde, 2006 [viewed 17 may 2017]. Available from: http://www.icict.fiocruz.br/sites/www.icict.fiocruz.br/ files/Manual_Vigilancia_Controle_Leishmaniose_Visceral.pdf

SCHUBACH, E. Y. P., et al. Accuracy and reproducibility of a rapid chromatographic immunoassay for the diagnosis of canine visceral leishmaniasis in Brazil. Transactions of the Royal Society of Tropical Medicine and Hygiene [online]. 2014, vol. 108, pp. 568-574 [Viewed 10 july 2016]. DOI: 10.1093/trstmh/tru109. Available from: http://www.ncbi.nlm.nih.gov/pubmed/25015665

To read the article, access it

CAMPOS, M. P., et al. Vacinas anti-leishmaniose visceral canina podem interferir no diagnóstico sorológico preconizado pelo Ministério da Saúde brasileiro?. Cienc. Rural, Santa Maria [online] 2017, vol. 47, no. 4, e20160846 [viewed 17 may 2017]. DOI: 10.1590/0103-8478cr20160846. Available from: http://ref.scielo.org/qmpxyy.

External link

Ciência Rural – CR: <http://www.scielo.br/cr>