Indian researchers find better therapy for life threatening bacterial infection Severe Scrub Typhus

Indian researchers have found that a combination therapy works better in the treatment of ‘Severe Scrub Typhus,’ a life-threatening infection caused by the bacteria, Orientia tsutsugamushi. This infection, which primarily affects rodents, is transmitted to humans (zoonoses) by the larvae of trombiculid mites. It is estimated that in endemic regions – in India and South Asian countries, about a billion people are at risk of contracting the infection, while a million people get infected and 1.5 lakh people die from it every year. 

The researchers found that a combination antibiotic treatment (with intravenous doxycycline and azithromycin) is more effective for treating Severe Scrub Typhus than single-drug therapies. The results of the new study, the largest ever randomised controlled trial on the treatment of Severe Scrub Typhus, was published recently in the New England Journal of Medicine.

“The implication of this study is that when using a combination of azithromycin and doxycycline to treat severe scrub typhus, more patients can be discharged from the hospital by day 7 as they would have fewer persisting complications, such as respiratory distress syndrome (ARDS), hepatitis, hypotension/shock, meningoencephalitis, and kidney failure. This trial provides evidence that combination therapy with intravenous doxycycline and azithromycin is a better therapeutic option for the treatment of severe scrub typhus than monotherapies of either drug. This new evidence will change treatment guidelines and save the lives of thousands of people with scrub typhus in the future.” Dr George M Varghese, Department of Infectious Diseases, Christian Medical College, Vellore, Tamil Nadu, said.

The institutions that collaborated in this research included the Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, Indira Gandhi Medical College & Hospital (IGMC) Shimla, Pandit Bhagwat Dayal Sharma Post Graduate Institute of Medical Sciences, Rohtak, Jawaharlal Institute of Postgraduate Medical Education & Research (JIPMER), Puducherry, Christian Medical College, Vellore, SVIMS Tirupati and KMC Manipal.

Scrub Typhus typically presents as a fever that may be associated with headaches, coughs, shortness of breath, and brain symptoms, like confusion and disorientation. Dr Varghese said that about 6% of patients infected with scrub typhus could die in spite of diagnosis and treatment. “One-third of patients develop severe disease that affects multiple organs in the body and leads to lethally low blood pressure. Death rates in severe disease can reach up to 70% without treatment and 24% with treatment”, he explained.