Does chikungunya kill? Yes, minister, it does. And there is evidence
Union health minister JP Nadda said on Wednesday that Chikungunya can’t be the cause of death. His remarks came on the day the death toll in chikungunya-related complications reached 10 in Delhi.
On Tuesday, Delhi health minister Satyendar Jain too said “chikungunya is not fatal”.
Both Nadda and Jain are wrong.
Chikungunya outbreaks have caused deaths across the world, shows World Health Organisation (WHO) data.
In 2005–2006, Réunion Island in the Indian Ocean reported around 2.6 lakh chikungunya cases and 254 deaths.
Till April 2015, 13.79 lakh chikungunya cases and 191 deaths attributed to the disease have been recorded in the Caribbean, Latin America and the US.
The WHO confirms that while most people recover fully, some may develop eye, neurological and heart complications.
“Serious complications are not common, but in older people, the disease can contribute to the causes of death,” states the WHO on its Chikungunya factsheet.
No deaths or missed data?
India’s worst chikungunya outbreak was in 2006, when 13.9 lakh cases were reported but there are no deaths that can attributed to the disease.
“Cases, as well as deaths may be missed if the symptoms are mild and the infection is not diagnosed or goes unrecognised. People often don’t get tested if the disease is not endemic in the area,” said Dr Sandeep Budhiraja, clinical director and director, internal medicine, Max Healthcare.
Epidemiologists say the mosquito that spreads the disease could also be affecting disease outcomes.
“The dominant vectors (mosquitoes that spread the disease) in Réunion Island are aedes albopictus, but it’s aedes aegypti in India, which could be a reason why India had no deaths. We need to investigate the disease more closely,” said a microbiologist with the National Centre for Disease Control, Delhi.
The aedes albopictus thrives on open spaces that have water-filled breeding sites. But aedes aegypti, the mosquito behind the Delhi outbreak, breeds in flower vases, water storage vessels and concrete water tanks in bathrooms.
The 2006 chikungunya outbreak in India affected 151 districts in eight states/Union Territories -- Andaman & Nicobar Islands, Andhra Pradesh, Delhi, Gujarat, Karnataka, Kerala, Madhya Pradesh, Maharashtra and Tamil Nadu -- with Karnataka, Maharashtra, Kerala and Gujarat being the worst-hit.
Ahmedabad (then with a population of 3.8 million) reported 60,777 suspected chikungunya cases between August and October.
To assess the effect of the outbreak, public health experts at the Indian Institute Management-Ahmedabad compared the death rates in 2006 with those in 2002–2005 for the same period and found an increase of 22% in August, 57% in September and 33% in October.
They found 2,944 excess deaths occurred during the chikungunya epidemic when compared with the average number of deaths in the same months during the previous four years.
“These excess deaths may be attributed to this epidemic,” the authors said in their study published in the journal Emerging Infectious Diseases.
They said since “hidden or unexplained cause of death is also possible, public health authorities should thoroughly investigate this increase in deaths associated with this epidemic”.