“Only those who suffer comorbidities such as cancer remain at risk of repeated infection due to their lower immunity,” said Dr. Lalit Dar, a professor of microbiology, AIIMS.
Explaining why Chikungunya was so widespread this year after the outbreak a decade if the virus could not repeat infections, virologists said there was now a large population that had not been affected in 2006 and more patients with compromising medical conditions. Dar said many people had come to Delhi from other states since 2006. There had been affected by Chikungunya. “They are also not immune to the disease A significant number of children born since. This explains the higher incidence of Chikungunya this year,” said Dar.
According to a study published in “Journal of Virology ‘in 2014, which analyzed the immunity affected by Chikungunya in 1991 in Thailand population, infection with a strain of Chikungunya confers lasting natural immunity, even against other strains.
AIIMS tested 3,500 patients suffering from fever in the last two months. Of these, almost 2,000 were confirmed (57%) suffering from Chikungunya. It was found that the prevalence of dengue to be only 5%. Dr. K S Sharma, professor and head of department of medicine, said in 11/10 patients found co-infection of dengue and chikungunya virus.
AIIMS and the National Center for Disease Control undertook to identify the Chikungunya virus in circulation to determine whether mutations caused increased incidence and mortality of this year. However, experts strongly believed that the highest incidence was due to the great mass of non-immune population. “Fate is rare and seen only in patients with pre-existing disease. You can not blame Chikungunya death,” averred Dr M C Misra, director, AIIMS.
A committee established by the Delhi government had also refused to attribute the deaths of Chikungunya. The panel reviewed the records of 13 patients who had died after suffering from fever and found none of them caused by Chikungunya. In its report, the committee appears comorbidities such as sepsis, renal injury and pneumonia and complications that could have led to death.