January 6, 2015
K-State professor encounters chikungunya epidemic while collecting canine blood samples in Grenada
A tropical paradise turned into a public health epidemic for a professor in the Kansas State University College of Veterinary Medicine.
Melinda Wilkerson was on a sabbatical in Grenada from September to November 2014, working on a project to advance knowledge about tick-borne diseases that affect dogs. While collecting canine blood samples for assay development, she contracted the chikungunya virus, which causes fever, rash and severe joint pain, among other symptoms. The vector-borne disease is spread by mosquitoes.
"I worked with a professional colleague, Dr. Diana Stone at the St. George's University School of Veterinary Medicine, to set up my research for this sabbatical in part because of the tropical environment in Grenada, which has a lot of vector-borne diseases — and chikungunya virus happens to be one of them," said Wilkerson, who is the director of the Clinical Immunology/Flow Cytometry Laboratory in the College of Veterinary Medicine's diagnostic medicine and pathobiology department. "Grenada has a lot of stray dogs referred to as 'pothounds.' Many are infected with ticks that have single and multiple zoonotic bacteria, including Ehrlichia and Anaplasma species. During my three months' time in the St. George's parish of Grenada, I was able to send back more than 400 plasma and extracted DNA samples to K-State."
The Grenadian stray dogs are caught and released by veterinary students, faculty and medical staff at St. George's University School of Veterinary Medicine who perform spay and neuter surgeries on the animals. These dogs were ideal for Wilkerson's project because they are often infected with Ehrlichia canis and Anaplasma platys. She has collaborated with Roman Ganta, a Kansas State University professor of diagnostic medicine and pathobiology who also works with other strains of Erhlichia bacteria. Wilkerson said the plasma and DNA samples are analyzed via a piece of equipment in her lab called the MagPix system, which detects antibodies to bacterial peptides or the oligionucleotides of the bacterial DNA.
"This sabbatical allowed me to learn molecular techniques and to have the time in the laboratory to practice what I learned," Wilkerson said. "I extracted and purified DNA samples from whole blood and platelet-rich plasma from 161 dogs. I also learned PCR techniques and have established collaborations with Dr. Kathryn Gibson and Dr. Diana Stone in the pathology academic department at St. George's School of Veterinary Medicine. The techniques I learned have been shared with my research assistant and postdoc in Dr. Ganta's laboratory."
Wilkerson gained some additional experiences, including a month teaching veterinary clinical pathology to the third-term veterinary students at St. George's and at a community vaccine clinic sponsored by St. George's veterinary school.
The chikungunya outbreak swept through the Caribbean in 2014 with the height of it in Grenada during the second week in September.
"I did not expect to get infected because I used a lot of deet, but was not surprised when it happened for nearly everyone at the university and the public had clinical signs," Wilkerson said. "I feel fortunate to be at K-State where there is research expertise in chikungunya. After that experience, my friends and colleagues at St. George's University are looking into future opportunities to collaborate with Kansas State University experts Roman Ganta and Stephen Higgs, director of the Biosecurity Research Institute, on global vector-born infectious disease research, including these tick-and mosquito borne diseases."
Despite having some chikungunya symptoms linger after returning to Kansas, Wilkerson said the lasting impact of her sabbatical trip will include the prospects of writing up various aspects of erhlichia and anaplasmosis research for publication. Some of these topics include the prevalence of these tick borne diseases in the St. George's parish of West Indies; correlations between PCR, ELISA and multiplex bead-based serological assays; clinical pathological data in a population of Ehrlichia/Anaplasma infected dogs; and the effects of low dose antibiotic treatment on prevention of Ehrlichia/Anaplasma infections in dogs introduced into an endemic area.