Kathmandu, November 9 The number of patients suffering from scrub typhus, a disease caused by parasites found in rats, has drastically increased in Kathmandu valley along with other districts across the country this year. According to the Epidemiology and Disease Control Division of the Department of Health Services the valley had reported 15 cases of scrub typhus in 2018, but the number of patients increased to 121 this year. Rupandehi reported 129 scrub typhus cases followed by Dhading (104), Dadeldhura (91), Palpa (84) Kailali (69) and Chitwan (67) this year. A total of 1,271 people have tested positive for scrub typhus in 63 districts of the country between July 17 and November 3. In 2018, the number of people infected by the disease was 1,098. Scrub typhus is an infectious disease caused by a parasite called chigger, which is found in rats and mice. The mites contract the disease in their larval stage. Thus, the mites are both vector and reservoir of the disease. “Many cases were unidentified earlier. After reporting and recording system of such diseases were prioritised and orientation on scrub typhus was given to health practitioners, more cases were reported this year,” said Ghanashyam Pokharel, senior public health administrator at Epidemiology and Disease Control Division. “As bushes grow in abundance here rats and mice get proper environment to grow. The rodents enter homes and come into contact with human beings. This is why a large number of cases are seen during the months of September, October and November,” said Dr Anup Bastola, consultant, tropical medicine, at Sukraraj Tropical and Infectious Disease Hospital, Teku. Infected chiggers are mostly found during the wet season in forest clearings, river banks and grassy fields. “Nepal provides a favourable environment for parasites, which in turn has resulted in increased cases of scrub typhus. Change in temperature provides favourable environment for the parasites to grow, and lack of environmental sanitation is also one of the factors for a large number of cases in cold areas,” added Pokharel. This year, the disease was also reported in Taplejung and Solukhumbu. The chigger enables the spread of the disease in temperatures between 20 to 30 degree Celsius. As temperature has gone up in high altitude areas, a number of cases of scrub typhus have been reported in such areas, said Pokharel. “Rainfall, rise in temperature and humidity provide a favourable environment for bacterial growth,” said Dr Bastola. The most common symptoms of scrub typhus, also referred to as bush typhus, are fever, headache, body ache and rashes, similar to dengue.