Changing weather patterns linked to climate change are bringing new pest worries
By Andrew Mambondiyani
MUTARE, Zimbabwe, Sept 14 (Thomson Reuters Foundation) - A combination of late, heavy rains and a shortage of cattle dip have contributed to a rise in tick-borne diseases in Zimbabwe this year, a government official said.
As climate change brings more extreme and uncertain weather, as well as warmer conditions in many places, worries about such pest outbreaks are growning, experts say.
Figures released by Zimbabwe's Department of Livestock and Veterinary Services (DLVS) showed tick-borne diseases killed 3,430 cattle between last November and May - nearly twice as many as died during the same period in 2013/14.
DLVS Director Josphat Nyika said the incidence of the most lethal tick-borne killer - called theileriosis, also known as January disease - had shown a sharp increase.
About half of the tick-borne fatalities - some 1,751 cattle - succumbed to theileriosis in this period, he said. That is nearly seven times as many cattle as were lost to the disease in the previous period, according to government figures.
"The wet and warm weather contributed to rising cases of tick-borne diseases as the rainy season progressed into May this year," he said.
And, he added, a shortage of foreign currency meant Zimbabwe had imported less cattle dip - known as acaricide - leaving the country facing "a serious shortage" of the tick killer.
The solution, he said, was for farmers to dip their cattle regularly as acaricides became available, and for farmers to refrain from moving their cattle illegally from one area to another "as this will result in the spread of ticks".
In Zimbabwe's rural communities, cattle are a common source of wealth - and draught power - and about 90 percent of the country's nearly 5.5 million cattle are owned by small-scale farmers, the government said.
Washington Zhakata, climate change management director in the Ministry of Environment, Climate and Water, said not much in-country research had been done on a link between climate change and tick diseases.
But, he added, evidence from other countries showed that warming has let ticks expand into previously inhospitable areas.
Higher temperatures, he said, meant Zimbabwe's Eastern Highlands would now be suitable for cattle farming, and that would likely see the arrival of ticks.
"Ticks survive on blood and can thus follow the animal," Zhakata told the Thomson Reuters Foundation. That makes changing weather linked to climate change an "indirect cause" of their spread, he said.
Koos Coetzer, professor emeritus at the Department of Veterinary Tropical Diseases at the University of Pretoria in South Africa, told the local Farmer's Weekly magazine in January 2017 that more rain would mean a rise in diseases caused by ticks and mosquitoes in livestock.
And research published last year in SciTechnol, an online scientific journal, said global warming might allow some tick species to thrive in areas in which they previously could not survive.
"Substantial seasonal variations such as warmer, shorter winters and increased annual mean temperatures could enable greater development of tick populations," researchers said.
Climate change has moved up Zimbabwe's political agenda. With extreme weather taking a toll on farming and incomes, the government in January released a trio of climate change policies designed to make it more resistant to climate impacts and to help it meet its international carbon-cutting pledges.
Farmers in Zimbabwe's eastern province of Manicaland - one of those affected by ticks - told the Thomson Reuters Foundation that not everyone was regularly dipping their cattle, which meant tick-borne diseases were spreading.
"Out of ignorance some farmers are not taking their cattle for regular dipping. Hence we are seeing these rising cases of tick-borne diseases," said farmer Elijah Ngwarati.
Lovemore Muradzikwa, who owns cattle in the same province, said that although tick-borne diseases were affecting cattle in districts close to him, his area had not yet been affected.
"We have heard of rising cases of tick-borne diseases in some parts of the country, but we are not sure what is causing this problem. But officials from the veterinary services are encouraging us to dip our cattle regularly," Muradzikwa said.
In most parts of Zimbabwe, poor farmers depend on communal dip tanks, with the government providing subsidised chemicals for weekly treatment during the rainy season and fortnightly in the dry season.
However, some farmers said they could not afford the fee of $2 per animal per year.
A government assessment report for 2016-2017 found that tick-borne diseases were present in every province. (Reporting by Andrew Mambondiyani. Editing by Robert Carmichael and Laurie Goering. Please credit the Thomson Reuters Foundation, the charitable arm of Thomson Reuters, that covers humanitarian news, climate change, resilience, women's rights, trafficking and property rights. Visit http://news.trust.org/climate)
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