The mystery fever

Outbreaks of viral fever occur with seasonal regularity during monsoon in India. For the past few years, dengue and chikungunya viruses have been the predominant pathogens. But this year, the country is in the grip of a strange fever. Its symptoms are similar to chikungunya and dengue but tests on patients show negative results for these mosquito-borne viral diseases.

 

      Reena, a resident of Bhogal in south Delhi, is one such patient. She ran high temperature for 10 days and suffered from severe pain in the joints, rashes, and swollen face—symptoms associated with chikungunya. But the tests showed negative results. Similar was the case of Prachi Nautiyal, a resident of Noida, Uttar Pradesh. In August, Prachi suffered from high fever, body ache, joint pain and skin rashes but tests for dengue and chikungunya showed negative results. 

The phenomenon is not limited to Delhi. Vivek Billampelly, former president of General Practitioners Association, Pune, says the city too has had a high number of viral fever cases. Samarjit Naskar, critical care expert at Belle Vue Hospital, Kolkata, also says that there is a huge number of patients with undiagnosed viral fever this year.

Difficulty in diagnosis also increases the treatment cost for patients because they have to undergo several tests. Ajay Nagar of Rajbeer Colony, Delhi, had to spend Rs 10,000 on treatment and identification of the viral strain her mother was suffering from. But the tests remained inconclusive. 

Doctors have no clue about what could be leading to this fever. Officials from hospitals in Delhi estimate that around 30 percent of all fever cases are undiagnosed. S Chatterjee, internal medicine expert at Indraprastha Apollo Hospital, Delhi, says that apart from dengue and chikungunya there are two other kinds of fever cases this year—one caused by normal respiratory infections and another which shows symptoms of chikungunya but does not get confirmed in tests. Naskar is of the opinion that the virus could have changed its genetic pattern. 

R S Taneja, head of internal medicine department at Ram Manohar Lohia Hospital, Delhi, too believes that the virus could have mutated. Billampelly says that since symptoms are similar to chikungunya, the virus could be its variant.  But there has been very little research on mutations in chikungunya and dengue, says P Jambulingam, director of Vector Control Research Centre, Puducherry. For example, a mutation in chikungunya was last identified in 2007. This mutated virus had caused a high number of cases that year, he says. However, Soumya Swaminathan, director of Indian Council of Medical Research, says that so far, the institute has not found evidence of the viruses being new or mutated versions of older dengue or chikungunya strains. 

The National Institute of Virology, Pune, the key body on viral research in the country, did not respond to phone calls and emails on the state of research on the unidentified viral strains.

Dengue and chikungunya continue to plague several states. Chatterjee says that the number of fever cases has increased at least five times since July. A pathologist from Bansal Hospital in New Friends Colony, Delhi, says that almost 150 cases come for diagnosis daily.

The hospitals are incapable of dealing with the rising number of patients. Apollo Hospital and Sir Ganga Ram Hospital have allotted more beds for fever patients. Safdarjung Hospital is using its psychiatry ward to accommodate the rising numbers. Till August 31, a total of 27,879 cases of dengue and 12,255 cases of chikungunya were reported in the country, according to data released by the Union Ministry of Health and Family Welfare. In Delhi, the figure stood at 487 for dengue and 432 for chikungunya.  Other states in the grip of chikunguya are Karnataka, Andhra Pradesh, Telangana, and Maharashtra, while states with a high number of dengue cases are Bihar, Haryana, Andhra Pradesh, West Bengal, Karnataka, and Kerala. 

Environmental factors could be behind the spurt in cases, says A C Dhariwal, Director of National Vector Borne Disease Control Programme. He warns that the numbers could rise because September and October are suitable for mosquito breeding. P K Das, former director of Vector Control Research Centre, Puducherry, points out that the problem would continue till we do not take steps to reduce the breeding points of the vector. 

Moreover, there is now evidence that vectors which earlier bred only in clean water have developed capability to breed in saline water as well. Unless the government takes steps to augment research and health infrastructure, the signs are ominous.