Emerging global diseases studied on campus

By Michelle Frey
Special to The Iowa State Daily
May 30, 2002

Although not currently a health issue in the United States, Leishmaniasis, an emerging global disease, is being studied here. Doug Jones, assistant professor of veterinary pathology, was the recipient of a $1.2 million grant from the National Institute of Health to continue his study on Leishmania amazonensis.

Leishmania amazonensis is one species of the global disease Leishmaniasis. The disease can have a variety of symptoms from skin ulcers and organ disease to facial disfigurations and immune systems malfunctions.

This widespread disease causes more than two million new cases a year. It is transmitted to mammals through the bite of an infected female sand fly and tends to be confined to the tropical and subtropical regions. "The key is understanding immunological response to infectious disease. Once we understand its behaviors, we will be able to overcome it," Jones said. Jones hopes to learn how this infectious organism prevents the immune response the growth of the parasite within the cell.

Better knowledge of the parasite could lead to potential treatment and prevention of Leishmaniasis and similar diseases, Jones said. "The principles of immune evasion that theses parasites employ are probably not unique to Leishmania," Jones said. "They will be applicable to other pathogens that are agents of chronic infectious diseases, such as mycobacteria." Mycobacteria are rod-like bacteria that can cause diseases such as tuberculosis.

Jones' research began with an interest in disease control and resistance. His research model involves infecting mice with two different strains of Leishmania, Leishmania major and Leishmania amazonensis. Jones and his research team discovered that Leishmania amazonensis induces a non-healing infection in the mice, while Leishmania major infections were found to be self-healing. "Understanding the mechanics behind Leishmania and why one host can heal one strain of the parasite and be susceptible to another is our main goal," said Dennis Byrne, a research associate in veterinary pathology who works with Jones.

Diseases such as Leishmania are becoming a greater concern in the United States as a result of the increase in global travel. For example, people or animals who visit other countries may bring home an insect carrying a disease, or may have contracted a contagious disease themselves.