Jamshedpur: East Singhbhum health authorities have intensified surveillance and preventive measures after two dengue cases were confirmed in the city during the peak transmission season.District surveillance officer Dr Asad said the patients — an 11-year-old boy from Sitaramdera and a 28-year-old nurse residing at Tata Main Hospital’s nursing hostel in Bistupur — tested positive for dengue. “Both patients have been undergoing treatment at Tata Main Hospital since Monday and are being closely monitored,” he said.The department is also investigating two suspected cases. Their blood samples have been sent to the microbiology department of Mahatma Gandhi Memorial Medical College and Hospital for confirmation.The district administration has deployed multipurpose workers to conduct door-to-door inspections, identify mosquito breeding sites and destroy larvae.“Areas where dengue cases have been reported are being accorded priority. Routine surveillance is also under way in vulnerable localities,” Dr Asad said.Residents have been advised to prevent water from accumulating in coolers, flower pots, discarded tyres and other containers that can become breeding grounds for the dengue-causing Aedes mosquito. Officials have also recommended maintaining cleanliness and using mosquito repellents.Dr Asad said the period from July to Oct is considered the peak dengue season and urged residents to follow preventive measures.According to health department data, more than 4,000 dengue tests were conducted in East Singhbhum between Jan and July, with only two positive cases detected. Officials said close vigil was being maintained to prevent an outbreak.