Watch out for mite bites this season

PANAJI: It was a baffling case-young man with a fever that just did not seem to abate.
His blood test results were even more puzzling-negative for dengue, malaria and the dreaded leptospirosis.
None of the drugs administered by his worried physicians at the Goa Medical College (GMC) and hospital, Bambolim, seemed to work, and the young patient started developing liver problems.
Well into his second week of fever and jaundice, by a stroke of luck, his doctor discovered a tiny black scab on his armpit.
The scab, a tell-tale sign of a mite bite helped doctors cinch the diagnosis later confirmed by an advanced blood test-the youth was suffering from scrub typhus.
Considered an uncommon zoonotic disease until now, scrub typhus is showing an increased incidence in Goa, report doctors here.
If picked up in time, the disease is easy to treat with antibiotics; but without treatment, the infection can lead to multi-organ failure and death.
Experts from the Christian Medical College, Vellore, Tamil Nadu, estimate the average fatality rate of scrub typhus to be between 8% and 12%.
The infectious disease spreads when chiggers, essentially 'forest mites', bite a person and inject the pathogen Orientia tsutsugamushi into the bloodstream.
Of course, only mites carrying the bacteria-like germ can transmit the Rickettsial disease, say doctors.
"This patient was lucky-not everyone may still have the black scab on his body when they get to hospital," says Dr Kedareshwar Narvekar, senior physician at GMC's department of medicine.
He adds that as scrub typhus is "now being reported all over India, and even from metros, we now suspect the infection in any patient with a persistent fever, once all the usual suspects are ruled out."
Additional signs like fall in blood platelet count, jaundice and renal failure can also help to diagnose the infection, he says.
"The disease was earlier restricted to people who visited forests or rural areas with thick shrubbery, but we now know that the mites can grow in any vegetation," says Narvekar, adding, "Also, there's a very thin line between urban and rural areas, especially in Goa."
Dr Edwin Gomes, head of the department, says, "While there is a specific blood test to confirm diagnosis of scrub typhus, the test kits are expensive and are not accessible to all patients."
"Even if we are unable to do the confirmation test on every case of suspected scrub typhus, we can begin treatment quickly. The antibiotic of choice, doxycycline, is cheap and easily available, and usually works like a charm," he adds.
In a bid to document the infection trend in Goa, the GMC team even published in December 2013 a study titled 'Scrub typhus in patients reporting with acute febrile illness at a tertiary healthcare institution in Goa' in the Indian Journal of Medical Research.
"As the prevalence of scrub typhus has been reported in neighbouring states and the existence of trombiculid mites is reported from the Western Ghats, the present study was undertaken to assess the aetiological agent in these fever cases in Goa," states the study.
It reports "a post-monsoon surge of cases" between July and November. "This is because, during the months of August to October, farmers are involved in harvesting activity in fields where they are exposed to bites of larval mites. Further, in the immediate post-monsoon period there is growth of secondary scrub vegetation which is the habitat for the mites," the paper states.
Of the 44 patients with undiagnosed fevers included in the study, 15 were diagnosed with scrub typhus using the Elisa test for specific antibodies. Five patients, who were admitted to the hospital too late and could not be dosed with the right antibiotics in time, died of multiple-organ failure.