The research Christine Petersen and her colleagues are conducting on leishmaniasis is bringing much-needed insight to the problem of the disease in foxhounds and, ultimately, humans. “Because of implications of how this could help all infected creatures (not just dogs), we ran the trial all they way to the human clinical trial level,” says Petersen, CPH associate professor of epidemiology.
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In July 2017, Christy Petersen, CPH associate professor of epidemiology, traveled to Bihar, India, to conduct research on visceral leishmaniasis. She recently shared photos and details of her trip.
I traveled to India as a part of the Banaras Hindu University (BHU) Tropical Medicine Research Center faculty. The center is an NIH Specialized Center (P50) that is entering its 15th year of funding located at the Kala-Azar Medical Research Centre (KAMRC).
I worked in and around a city called Muzaffarpur in the state of Bihar, which had the honor of being the last area of the world to eradicate smallpox. Bihar is in the northeastern corner of India, next to Nepal and Bangladesh, and home to the headwaters of the Ganges River. Bihar is still one of the poorest regions of India. The power is inconsistent throughout most of the day, the water isn’t potable, and raw sewage flows down the sides of the street. As it was monsoon season while I was there, there was active malaria, Dengue, Zika, Japanese encephalitis, and other things circulating in the mosquitos, so I was sure to wear my bug spray each day.
Bihar is also endemic for visceral leishmaniasis (VL), the fatal protozoal parasite infection that is the research focus of my lab. The Muzaffarpur area had 44 new VL cases during June 2017, the month before I arrived. One of the villages I visited had 38 of 300 villagers recently seropositive for leishmaniasis; all were children under 18.
We drew crowds when we were out in the villages looking for “bimar kutta,” or sick dogs, to establish whether animals are part of the disease ecology (reservoirs). To date, this disease is believed to only circulate between humans and the vector sand flies, but in the rest of the world infection is also found in other mammals, particularly dogs and rodents as reservoirs.
I was working in the field with a team of 10 people total, myself included. This was a field team of four trained dog-catchers and three entomologists, one of whom was from the Walter Reed Army Institute of Research (the only other American present during my three weeks). Rounding out the 10 people was our driver, the PhD student from BHU whose dissertation will focus on this work, and a molecular parasitlogist who will aid us with the molecular studies stemming from these samples. She was the only other woman at KAMRC while I was there. As you might guess, as the only white woman around for miles, I was quite unusual and was the focus of many stares everywhere I went. That was probably one of the hardest things for me to adjust to as an understated Midwesterner.
Bihar was an amazing, troubling, fascinating place.
The University of Iowa is among a group of Midwestern universities taking part in a new regional center focused on improving the understanding of and public health response to diseases transmitted by mosquitoes, ticks, and fleas.
The Upper Midwestern Center of Excellence in Vector Borne Diseases, funded by a $10 million grant from the Centers for Disease Control and Prevention (CDC), will develop research and training programs to address diseases such as Zika, West Nile, and Lyme disease.
Led by personnel at the University of Wisconsin–Madison, the center includes experts from the University of Iowa College of Public Health, University of Illinois, Iowa State University, University of Michigan, and Minnesota Department of Health.
“Our role is to help train students in Iowa for a Certificate in Public Health Entomology and to increase the knowledge of vector-borne diseases in the Upper Midwest,” says Petersen. Students will be recruited from Iowa universities and the public health workforce.
“About half of the students who come into the epidemiology program at the UI identify infectious diseases as an area of interest. This new training and certificate program will be an outstanding opportunity for them to pursue that interest,” Petersen adds.
In addition to teaching and training students, Petersen and her colleagues will help identify practicum and Master of Public Health capstone experiences for students at the University of Iowa and Iowa State University with an interest in vector-borne diseases.
A recent study conducted by University of Iowa researchers indicates that Leishmaniasis – a tropical disease caused by infection with Leishmania parasites – can be transmitted from infected U.S. dogs to humans via the bite of infected sand flies.
There are several different forms of leishmaniasis in people. The most common forms are cutaneous leishmaniasis, which causes skin sores, and visceral leishmaniasis, which affects several internal organs (usually spleen, liver, and bone marrow) and is fatal.
In the United States, a species of the parasite that causes visceral leishmaniasis circulates among hounds used for hunting. Previous evidence has indicated that spread of these parasites among hounds is from mother to pups (vertical transmission) rather than by sand fly bites (vectorborne transmission).
However, experimental work reported in the December 2015 issue of Emerging Infectious Disease showed that sand flies that had fed on infected hounds were capable of supporting the parasite and spreading it to hamsters.
Christine Petersen, associate professor of epidemiology and director of the Center for Emerging and Infectious Diseases at the University of Iowa College of Public Health, served as corresponding author of the study. According to Petersen, the study shows that the U.S. strain of Leishmania doesn’t behave differently that the tropical version, and it can spread from infected U.S. dogs by an insect vector.
“Sand flies found already in this country are capable of spreading the disease that can be fatal to both people and dogs,” she says.
Peterson says the disease is fairly rare in humans, but the study indicates that given the right subject – one that is immunocompromised and working closely with infected dogs, for example – and the right conditions, the parasite can be transmitted to humans.
This vectorborne transmission from hounds (and possibly coyotes, foxes, and opossums) to another mammalian species indicates a possible risk for spread to companion dogs and people in the United States. Because no vaccines or drugs to prevent infection are available, the best way to prevent infection is to avoid insect bites.
To read the full article, visit: http://wwwnc.cdc.gov/eid/article/21/12/14-1167_article
Two CPH faculty members were interviewed recently for the Iowa Public Radio show “River to River.”
Jake Oleson, associate professor of biostatistics, spoke about a statistical model he and a colleague developed several years ago that predicted the spread of avian influenza in the Midwest. Oleson’s segment begins around the 31:50 mark at this link.
Christy Petersen, associate professor of epidemiology, discussed the use of antibiotics in animal production. Listen to the segment below.