Migrant Bihari labourers coming home for the festive season comprise most of the dengue cases in Bihar, where 12 people have been afflicted with the mosquito-borne virus so far.
State health officials say this could heighten the threat of dengue in the state.
Most of the suspected dengue cases reported are of migrant labourers who arrived from dengue-hit places like Delhi, Rajasthan, Haryana and Uttar Pradesh for the upcoming Diwali and Chath festivals.
Raju Kumar, a youth of Khojpur village in Nawada district, who works in Delhi and arrived in his village a week ago, has been detected with dengue.
His father Kailash Mahto said: "When doctors in Delhi said he could be suffering from dengue, he came home to us."
Similarly, two other youth from Madhopur village in Samastipur district have been admitted to a private clinic for suspected dengue. Both had returned from Delhi a few days ago.
Mithilesh Kumar, a resident of Sabait village in Nalanda district, had returned from Faridabad a few days ago. He has also been detected with dengue.
Bhawesh Jha and Laldev Sharma, both from Delhi, are visiting their native village in Darbhanga district. They were admitted with high fever and doctors have confirmed dengue.
Sharma, who had been admitted to Delhi's Safdarjung Hospital last month, told doctors that he was among the first detected dengue cases there. He decided to get fully cured and then visit home, but is still in the grip of the virus.
Though no death from dengue has been officially confirmed, it was reported in a local daily that three people had died of the disease.
According to reports, a 15-year-old boy died in Saran district. He had returned from Kolkata last week with high fever. Another suspected dengue death was reported of Dinesh Paswan, 35, who had come from Amritsar.
The state government sounded an alert last Wednesday and asked the administration to take urgent preventive measures after four confirmed and two suspected dengue cases were reported.
The state government has directed the city municipal officials to clean garbage heaps and keep a check on stagnating water to prevent breeding of mosquitoes.
Bihar has only three centres where platelets, needed to treat critically ill dengue patients, are available. Of these, two are in Patna and one in Muzaffarpur.