Kathmandu, August 3

A total of 105 persons have tested positive for scrub typhus across the country in the last two months.

According to Epidemiology and Disease Control Division, cases of scrub typhus were recorded in 27 districts of the country. Dr Bibek Kumar Lal, director at EDCD, said the number of scrub typhus patients had increased this year in comparison to last year. “In 2017, 168 people had tested positive for scrub typhus. Of them, only two had died, while this year more than a hundred persons have already been diagnosed with the disease in just two months,” he added.

Twenty cases have been recorded in Chitwan, 14 cases in Nawalparasi and 10 cases in Palpa. “Infected chiggers are, especially, found during the wet season in dense areas of scrub vegetation which is when the mites lay their eggs. Areas like forest clearings, riverbanks, and grassy regions provide favourable environment for infected mites to thrive,” said Dr Anup Bastola, chief consultant tropical medicine and spokesperson for Sukraraj Tropical Infectious Disease Hospital, Teku.

Scrub typhus was first reported in the country in 2015. That year, 101 people from 16 districts had tested positive for scrub typhus. Of them, eight succumbed to the disease. In 2016, 831 people from 14 districts had tested positive for the disease. Of them, 14 died. Teku hospital alone had tested 33 cases — 13 males and 20 females — positive for scrub typhus from June to July.

Scrub typhus, also known as tsutsugamushi disease, is an infectious illness caused by Orientia (Rickettsia) tsutsugamushi, transmitted to humans and rodents by the bite of the larva of trombiculid mites (chigger). The mites are both the vector and reservoir of the disease. The mite is very small and can only be seen through a microscope or magnifying glass. The larva is the only stage that can transmit the disease to humans and other vertebraes. The disease is transmitted from mites to ‘’rats and mice’’ and the mites in their larval stage contract the disease organism by biting these rodents.

Dr Baskota said humans are the accidental host. The disease is not directly transmitted from person to person. Human beings of all ages, including children, are influenced by it.

According to WHO, scrub typhus is probably one of the most under-diagnosed and under-reported febrile illness requiring hospitalisation in the region. The absence of definitive sign and symptoms combined with a general dependence upon serological tests make the differentiation of scrub typhus from other common febrile diseases (murine typhus, typhoid fever and leptospirosis) quite difficult.

The early manifestations are an eschar, representing localised cutaneous necrosis at the site of mite feeding (which is not always present) and regional lymphadenopathy followed by fever, headache, myalgia, generalised lymphadenopathy, cough, gastrointestinal symptoms, rash, transient hearing loss and conjunctival injection. “Two cases, has been diagnosed with Eschar recently at Teku Hospital,” said Dr Baskota.

The life threatening complications of this disease are jaundice, renal failure, pneumonitis, acute respiratory distress syndrome, septic shock, myocarditis and meningo-encephalitis.