Virulent dengue strain at work, 250 cases already reported in Mumbai Lethal Strain Affects 85% Of City Patients

Mumbai: As reasons behind dengue's increased incidence and severity continue to puzzle experts, the closest explanation seems to be the circulation of its virulent type DEN-2. It is one of the four virus types that cause dengue, and can be lethal when it combines with any of the other types to infect humans. 

    "In Mumbai, 85% of the dengue cases can be attributed to the DEN-2 type of the virus," said Dr Jayanti Shastri, incharge of the BMC's molecular diagnostic reference laboratory. Dengue has four types, commonly called DEN-1, 2, 3 and 4. "Literature suggest that if the primary infection is by DEN-2 and a secondary one by DEN-4, there is a likelihood of the patient suffering from dengue hemorrhagic fever and dengue shock syndrome, both deadly manifestations of the disease," said Shastri, also head of the microbiology department at the BYL Nair Hospital. 
    The additional director of the New Delhi-based National Vector Borne Disease Programme, Dr P K Sen, shared a similar observation. "In recent years, we have found DEN-1 to be the commonly circulating type but that seems to have shifted to 2 now. Even in Delhi, the serological studies have found type 2 to be more predominant," he said. At the national level, dengue cases had jumped to a whopping 50,222 last year, an almost 166% increase from 2011. 
    Mumbai, too, had recorded a 142% increase in dengue cases in 2012 when compared with the previous year. This year, one-third of the 727 dengue cases reported in the state were detected in the city. While, at the state level, 15 lives were lost to dengue this year, the city has not reported any fatalities. One death was reported from Mira Road on Thursday. 
    Experts say the types of dengue viruses in circulation keep shifting with one type gaining strength over the other, or at times, two or more types circulating together. Scientists from the National Institute of Virology, Pune, observed that while DEN-1 almost remained the same in 50 years, there has been a genotype shift in DEN-2, which also coincided with the disease becoming more severe. 
    Director of Haffkine Research Institute, Dr Abhay Chaudhary, said cross-infection or infections by two strains could be behind the severity of cases. Intensivist Dr Khusrav Bhajan, who consults with PD Hinduja Hospital, said, "We have treated over 10 cases, some very serious. People should not delay seeing a doctor," he said. MBMC notice to hospital on death The Mira Bhayander Municipal Corporation (MBMC) has issued a notice to the Bhaktivedanta hospital at Mira Road for failing to notify a dengue case after a patient died of the disease in the hospital on Wednesday. Vishwanath Sahu (42), a Mira Road resident who became the first victim of dengue this season, was not on the list of MBMC's list of suspected dengue patients did not have Sahu's name. The hospital authorities admitted they failed to notify the case due to miscommunication. The name of another patient being treated at Bhaktivedanta hospital for suspected dengue, Prasad Jadhav, has been notified to the municipality and his blood was sent for testing. 
Sandhya Nair | TNN