First-Ever Human Leptospirosis Detected In Meghalaya, Researchers Sound Public Health Alarm

Leptospirosis — a potentially fatal zoonotic infection long believed to spare Meghalaya’s hill ecology — has now been clinically confirmed in the Northeastern State for the first time, prompting researchers to warn of a silent and under-recognised public health threat unfolding in the region.

The researchers have cautioned that delayed recognition could allow the infection to spread unnoticed, turning sporadic cases into a larger outbreak. “The detection of human cases in a non-endemic, mountainous region like Meghalaya is a red flag that can no longer be ignored,” the researchers stressed in an article ‘Emergence of human leptospirosis in Meghalaya, India: Clinical evidence from a hilly non-endemic region’, published in the latest issue of Indian Journal of Medical Research (IJMR).

The first-ever detection of human leptospirosis in Meghalaya, coming close on the heels of similar case identification in neighbouring Assam, last year signals a worrying expansion of this life-threatening communicable disease across India’s Northeast.

Public health experts warn that the back-to-back confirmations suggest leptospirosis is quietly extending its footprint in a region where clinical suspicion has traditionally been low, raising fears of widespread underdiagnosis.

Last year, a team of scientists from the Dibrugarh-based ICMR–Regional Medical Research Centre (RMRC), while investigating an outbreak of fever and jaundice in Assam’s Goalpara district, confirmed the involvement of Leptospira wolffii — a strain never before reported in human infections from Northeast India. The findings, published last week in the Indian Journal of Medical Microbiology, underscore the evolving epidemiology of the disease in the region.

Leptospirosis is caused by Leptospira bacteria and spreads from infected animals to humans through contact with water or soil contaminated with animal urine. The illness often begins deceptively with fever, headache, vomiting, and body pain, but can rapidly progress to severe and fatal complications, including jaundice, kidney failure (Weil’s syndrome), meningitis, lung haemorrhage, heart inflammation, and internal bleeding.

Despite heavy rainfall, Meghalaya has long been considered at low risk because it lacks the large-scale flooding typically associated with leptospirosis. As a result, the disease has rarely featured in routine clinical diagnosis, contributing to missed or delayed detection.

As a result, clinical suspicion has remained low.

However, between January and December 2023, ten laboratory-confirmed cases of human leptospirosis were treated at a tertiary charitable hospital in Shillong. All diagnoses were made using IgM ELISA testing, marking the first documented clinical evidence of the disease in the state.

“This strongly suggests leptospirosis has been present but flying under the radar,” said researchers including Deepak Rajan, Benedicta Sthuti Kumar, and Sandra Albert from Department of Public Health, Indian Institute of Public Health Shillong, and Meban Aibor Kharkongor and Eman Chynnam Lyngdoh from Department of General Medicine, Dr. H Gordon Roberts Hospital, Shillong.

The patients — with a mean age of just 27 years — included daily wage workers, office employees, and a farmer, indicating that no single occupational group was exclusively at risk. While some presented with mild symptoms, others arrived critically ill.

“Alarmingly, four out of ten patients developed severe disease requiring intensive care,” the researchers reported. “All four needed blood pressure–supporting drugs, mechanical ventilation, and prolonged hospitalisation.” One of the youngest patients suffered kidney failure, liver dysfunction, severe anaemia, and dangerously low platelet counts.

Clinical symptoms such as conjunctival suffusion were largely absent, further complicating early diagnosis. However, gastrointestinal symptoms — especially abdominal pain — were seen in all severely ill patients, suggesting a potential early warning sign of disease progression, said the researchers.

All cases clustered between August and December, coinciding with the monsoon and post-monsoon period. Clear exposure to contaminated water or animals was identified in only four patients. “The absence of obvious exposure history in most cases highlights how easily transmission can occur unnoticed,” the team cautioned.

The situation is further aggravated by diagnostic gaps. Meghalaya lacks local confirmatory testing facilities, forcing clinicians to rely on clinical judgement while samples are sent to Mumbai — often after treatment has already begun, noted the researchers.

Ironically, leptospirosis is easily curable if detected early. “A full course of doxycycline costs less than Rs 50. But once diagnosis is delayed, treatment becomes complex, expensive, and life-threatening.”

Hospitalised patients incurred an average direct medical cost of nearly Rs 20,000 due to intensive care and prolonged stays, excluding travel and accommodation expenses for those referred from remote areas — indicating a far greater hidden economic burden.

Despite the absence of major floods, researchers believe Meghalaya’s high rainfall, persistent soil moisture, specific soil types, and micro-level water stagnation may support bacterial survival, the study has sounded alarm. Animal studies from the region have already shown high seropositivity, pointing to silent environmental circulation.

“The evidence clearly shows leptospirosis is present but underdiagnosed in Meghalaya,” the authors stated. “Low clinical suspicion, overlapping symptoms, and lack of diagnostics are masking its true burden.”

They urged clinicians across hill states to include leptospirosis in all cases of acute febrile illness, particularly during and after the monsoon. “Early antibiotics can prevent organ failure, save lives, and drastically reduce healthcare costs,” they emphasised.

Calling the findings a wake-up call, the researchers stressed the urgent need for increased clinical awareness, rapid diagnostic access, expanded surveillance, and identification of region-specific environmental risk factors.

“As climate change alters disease patterns, infections like leptospirosis are no longer confined to traditional geographies,” the team warned. “Hill regions are no longer immune.”