The building construction activity which is going on at brisk pace in the twin industrial township of Pimpri-Chinchwad continues to pose health problems for residents. In last four months, as many as 51 citizens have been affected malaria. Another unnerving fact for citizens is that dengue cases, which are common after the rains, have also come to light. As many as 19 citizens have received treatment for dengue in different hospitals in last four months. PCMC health officials said all the malaria and dengue patients have received treatment and are doing fine. The officials said dengue continues to haunt residents even in this season because of the increased level of construction activity which have become breeding grounds for mosquoties. "Most of the dengue cases have been reported from Pimple Nilkah, Pimple Gurav, Wakad, Chinchwad and their surrounding areas. In all these suburbs, construction activity has been going on. The accumulation of fresh water is spawning dengue and dirty surrounding is spawning both malaria and dengue cases,' said a senior civic official. By December last year, Pimpri-Chinchwad reported 600-plus malaria cases and 300-plus dengue cases. Civic activists argue that when it comes to health matters, PCMC officials are generally lethargic in taking any concrete action. "They will wake up only when a big tragedies occurs,' says activist Raju Jawalkar.