Kolkata: A new study by scientists from Zoological Survey of India (ZSI) has detected molecular evidence of a spotted fever group – like Rickettsial lineage in 54% of healthy personnel of the Indo-Tibetan Border Police’s (ITBP) 4th Battalion stationed at Dirang in Arunachal Pradesh. None of them reported classical symptoms of ricketssial infection, suggesting the pathogen may be present without obvious signs of illness.“54% of the healthy personnel of the battalion showed molecular evidence of an unknown lineage of spotted fever group (SFG) – like Rickettsia, though none of them reported any classical clinical symptoms associated with rickettsial infection,” said ZSI scientist Mukesh Thakur.The personnel serve in rugged Himalayan terrain, where contact with domestic animals, wildlife and potential arthropod vectors is likely. The findings raise questions about how much zoonotic transmission may go undetected when surveillance focuses only on symptomatic patients, Thakur said.The lineage showed close phylogenetic affinity to strains associated with human rickettsiosis, including Rickettsia hoogstraalii and Rickettsia asemboensis. Scientists have called for further antibody testing, repeat sampling and vector surveillance to determine whether the findings indicate active infection, recent exposure or transient bacterial presence.The study titled “Silent Circulation of Spotted Fever Group – Like Rickettsia Among Asymptomatic Border Personnel in the Eastern Himalaya” was published in the journal ‘Zoonoses and Public Health’.
