Birds may spread, not halt, fever-bearing ticks

November 30, 2012

A Turkish biologist at the University of Utah questions Turkey's use of the birds to control ticks that spread Crimean-Congo hemorrhagic fever, contending the birds instead may help spread the disease. 

Turkey raises and releases thousands of non-native guineafowl to eat ticks that carry the deadly Crimean-Congo hemorrhagic fever virus. Yet research suggests guineafowl eat few ticks, but carry the parasites on their feathers, possibly spreading the disease they were meant to stop, says a Turkish biologist working at the University of Utah.  

"They are introducing a species that is not eating many ticks, based on studies of stomach content, and is carrying the ticks, which are the best conduit for spreading Crimean-Congo hemorrhagic fever," says Çağan Şekercioğlu (pronounced Cha-awn Shay-care-gee-oh-loo), an assistant professor of biology at the University of Utah. 

"They should stop these introductions immediately because there is a risk they may be doing the opposite of what they intended," says Şekercioğlu, an ornithologist or bird expert and founder of the Turkish environmental group KuzeyDoğa Society. 

"They want to stop this disease, but they may be helping spread it." 

In a paper, set for publication soon in the journal Trends in Parasitology, Şekercioğlu reviewed existing scientific literature. He concluded that the idea guineafowl eat ticks and thus control disease is based on unconvincing evidence even though it achieved "cult status" after a 1992 study suggesting the birds could control ticks that carry Lyme disease bacteria in the U.S. Northeast, at least on lawns. Crimean-Congo hemorrhagic fever was identified as an emerging disease in Turkey in 2002. Between then and last May, the tick-borne virus infected 6,392 people in Turkey and killed 322 of them, according to statistics cited by Şekercioğlu. It was first identified in Crimea in 1944 and then in the Congo in 1969, and now it is found in Eastern and Southern Europe, the Mediterranean region, the Middle East, northwest China, central Asia and the Indian subcontinent, says the U.S. Centers for Disease Control and Prevention.

Read more at: http://phys.org/news/2012-11-birds-halt-fever-bearing.html#jCp