Climate change aiding spread of deadly virus

Source: By The Indian Express

As Europe reels under a heatwave and wildfires, the rising temperatures have also raised fears of spread of viruses generally not found in colder climates. Alert has been sounded about the Crimean-Congo haemorrhagic fever (CCHF), an infection spread by ticks that has a high fatality rate, according to the World Health Organization (WHO).

The CCHF is endemic to Africa, the Balkan countries, Middle East, and parts of Asia. The first fatality from the disease in Europe was in Spain, in 2016. According to Horizon, which publishes articles about European Union-funded research, “Scientists are now warning that CCHF, which can kill between 10% and 40% of patients, is spreading northward and westward in Europe.”

Cases have so far been reported in Spain, Russia and Turkey, and the UK. In India, one person succumbed to CCHF last month in Gujarat, the state that reports the majority of the country’s cases of this disease.

What is CCHF?

According to the WHO, “Crimean-Congo haemorrhagic fever (CCHF) is a viral haemorrhagic fever usually transmitted by ticks. It can also be contracted through contact with viraemic animal tissues (animal tissue where the virus has entered the bloodstream) during and immediately post-slaughter of animals. CCHF outbreaks constitute a threat to public health services as the virus can lead to epidemics, has a high case fatality ratio (10–40%), potentially results in hospital and health facility outbreaks, and is difficult to prevent and treat.”

The virus is present in the tick family of insects. According to the US Centers for Disease Control and Prevention (CDC), animals such as cattle, goats, sheep and hares “serve as amplifying hosts for the virus. Transmission to humans occurs through contact with infected ticks or animal blood. CCHF can be transmitted from one infected human to another by contact with infectious blood or body fluids”, such as sweat and saliva. The ticks can also be hosted by migratory birds, thus carrying the virus over long distances.

While the disease was first detected among soldiers in the Crimean Peninsula (near the Black Sea) in 1944, in 1969, it was found that an ailment identified in the Congo Basin was caused by the same pathogen. Thus, the disease was named the Crimean-Congo haemorrhagic fever.

What are the symptoms, cure of CCHF?

CCHF symptoms include fever, muscle ache, dizziness, neck pain, backache, headache, sore eyes and sensitivity to light, according to the WHO.

“There may be nausea, vomiting, diarrhoea, abdominal pain and sore throat early on, followed by sharp mood swings and confusion. After 2–4 days the agitation may be replaced by sleepiness, depression and lassitude,” the WHO’s website says.

There is no vaccine for the virus in either humans or animals, and treatment generally consists of managing symptoms. According to the WHO, “the antiviral drug ribavirin has been used to treat CCHF infection with apparent benefit.”

Climate change and spread of diseases

As temperature patterns are disrupted, pathogens are thriving in geographies that traditionally had a climate hostile to them. About CCHF, Professor Ali Mirazimi, a virologist at the Karolinska Institute in Sweden, told Modern Diplomacy, “The ticks are moving up through Europe due to climate change, with longer and drier summers.”

The CDC says climate change contributes to the spread of diseases in multiple ways, including warmer temperatures expanding the habitat of ticks and other insects and giving them more time to reproduce; the habitat offered by water undergoing changes; and animals moving to newer areas and people coming into contact with them.