Reports say the number of deaths from an outbreak of Japanese encephalitis in India's Uttar Pradesh state has now risen to at least 175.
Health officials say they fear the death toll may be much higher as fatalities in rural areas often go unreported.
Apparently there is an acute shortage of vaccine in the northern state, but in the last few weeks more than 500 people, mostly children, have been treated for the disease.
Doctors say that children between the age of six months to 15 years are the worst-affected.
Encephalitis, which occurs regularly during India's monsoon, is a mosquito-borne disease, and it has killed 8,000 people in Uttar Pradesh since 1978.
Many believe the official figures may be under-estimates as Gorakhpur district, 250km (165 miles) east of state capital Lucknow, has itself reported 167 deaths.
Dr TN Dhole, professor of microbiology in Lucknow's Sanjay Gandhi Post Graduate Medical Institute, says that most of the victims are very poor people from rural areas.
It seems that senior officials have travelled to the area to supervise relief operations.
Dr KP Kushwaha, a paediatrician from Gorakhpur, reports that up to 50 new sufferers are arriving every day at the hospital, but there are no beds available and even the corridors are full.
Japanese encephalitis causes high fever, vomiting and can leave patients comatose.
It usually hits the state at the end of August but this time it struck in July.
The disease has recurred annually in eastern regions of the state since about 1980.
According to state health officials, Uttar Pradesh needs 50m vaccines every year, but the Kasauli-based Central Institute say they are only able to supply 200,000.