Patna: A mystery disease has broken out in Bihar, claiming the lives of 20 children in one week. All the deaths were reported from Muzaffarpur and the neighbouring districts of the state.

The disease, which some claim to be encephalitis, Japanese Encephalitis or Acute Encephalitis Syndrome (AES), has claimed over 1,000 lives of children in the past 15 years in Bihar, but none has been able to find out its real reason despite several studies. The disease strikes generally the northern parts of the state every year once the mercury soars but ends the moment rains starts. The symptoms of the disease include high fever, irritation and swelling of brains.

“The disease has not been diagnosed yet,” Bihar’s health secretary Deepak Kumar told the media on Friday, adding the government of India had roped in a medical team from United States to investigate the cause of infection.

“Dr Jacob John is leading the combined India-US team to diagnose the ailments. Samples of the infected children are being collected for examination in viral laboratories located in both the countries,” the heath secretary said.

What has worried experts more is that infection has spread in a virulent form this time as the survival rate of the victims looks low. Alarmed at the situation, then health authorities held an emergency meeting here on Thursday evening at which it was decided to send a high-level team of health experts to Muzaffarpur where the victims have been admitted at various hospitals for treatment.

Strangely, the health experts are still to identify the disease despite spate of studies, causing strong resentment and frustration among the victim families. The scene is quite touching at the hospitals in Muzaffarpur districts where continual wailing by victim family members moves every visitor to pity.

Every year, the government claims to having taken preventive measures to check recurrence of the disease but this ultimately turns out to be an empty promise. “The disease struck this time despite preventive measures launched by us. We had already alerted the doctors and supplies sufficient medicines to the health centres yet the disease goes unchecked,” Muzaffarpur civil surgeon Gyan Bhushan said.

The seriousness of the entire situation is underlined from the fact the mystery disease has claimed more 1,000 lives in the past one-and-a-half decade. However in the last four years, it has turned out to be quite deadlier. Last year, the disease had killed 62 children in Bihar, followed by the death of 184 children in 2012, 55 children in 2011 and 27 children in 2012.