Mumbai doctors blame pigeons for spike in lung disease

At his clinic in a northern suburb of Mumbai, Dr. Pralhad Prabhudesai stared at an X-ray, flipped through a chart and quickly fired a string of questions at the patient standing before him.

"Are you around pigeons often? What else are you exposed to?"

The pulmonologist is part of a group of doctors working in India's most populous city who are increasingly alarmed over what they've observed over the past seven years: a fivefold increase in cases of a severe inflammation of the lungs called hypersensitivity pneumonitis.

It's a steep spike that experts link directly to Mumbai's exploding pigeon population. The bird's droppings contain fungi that, if inhaled over a sustained period, can cause the immune system disorder.

"It's a terrible, progressive condition," said Dr. Prabhudesai in an interview with CBC News, adding that in chronic cases, hypersensitivity pneumonitis causes irreversible scarring to the lungs, which can require the patient to be on a constant supply of oxygen, or even lead to a lung transplant.

"There are more than 300 reasons to get this hypersensitivity pneumonia and [exposure to] pigeons is one of them," Prabhudesai said. "Most importantly, this is the most common cause of the disease in our country."

Other causes are allergens found in grains, feathers and air conditioning units that aren't properly maintained, but several recentstudies monitoring newly-diagnosed patients in India identified exposure to birds as the leading link to the chronic disease.

Experts are calling for further data to be collected and the Indian Council of Medical Research has now developed a registry to track cases of the lung disease, along with the identified causes.

Problem with feeding pigeons

The problem is acute in Mumbai, India's most densely-populated city that has millions of apartment buildings with flat surfaces where pigeons love to roost. The city also has a robust cultural tradition of feeding the birds for religious reasons, such as a deep-seated belief that caring for pigeons brings blessings and will help wash away a person's sins.

Mumbai is known for its kabutarkhanas, designated feeding parks often located near temples and other places of worship where thousands of pigeons gather and are fed. It's not uncommon to see people dragging large bags of grain to pour in front of the birds.

"In Mumbai, a lot of feeding is being done near your house, near temple…everywhere you go," Prabhudesai said.

He often fields questions from patients asking if there is a pigeon repellent or other technology being developed to drive the birds away from homes.

'I had no idea'

"Patient awareness [of the danger of pigeons] has started to increase over the past five years," he said, but many of them feel helpless "because they are very stubborn birds."

A hypersensitivity pneumonitis diagnosis came completely out of the blue for Namrata Trivedi, who just returned to work in the past year after more than a decade of battling the disease.

She began experiencing breathing problems and a persistent dry cough in 2011 and a string of doctors couldn't figure out what she had.

"When I saw the X-ray from my CT scan, I could see a black layer all over my lungs," she told CBC News in an interview in Gujarati.

"The doctor looked right at my husband and my mother, and told me I had only three years left to live."

Trivedi, 57, frequently used to feed pigeons and, in one of her previous homes, there were large nests of the birds tucked into a windowsill. Still, she was floored when she was diagnosed and told the cause of her lung disorder was pigeon poo.

"I had no idea, I was completely unaware," she said. "I remember thinking how can pigeons cause such a huge problem! It's not possible."

Trivedi has defied the doctors' predictions and her condition is now under control, even though she still has occasional lung pain and has to take precautions to avoid large crowds when going out.

The hairstylist wishes more people in Mumbai knew how deadly pigeon droppings can be.

"People don't understand, they keep saying feeding pigeons is 'jeev daya,'" Trivedi said, using the Hindi and Gujarati term meaning to help or show compassion to all living beings, including animals.

"But humans are also worth helping," she added, saying it breaks her heart to see children suffering from the condition because the people around them insist on feeding the birds.

Hard to avoid the pigeons

Prakash Punjabi, 68, who found out he was suffering from the chronic lung disease due to exposure to pigeon droppings last year, is trying to process the same physical and emotional pain.

He spends at least four days a week exercising at a rehabilitation centre adjacent to Prabhudesai's clinic in north Mumbai, often hooked up to an oxygen machine.

"It's very difficult," he said, panting through his oxygen supply while on the treadmill. "I find it difficult while breathing through my nose, and I feel tired all day."

Punjabi was not in the habit of feeding pigeons, but he and his doctors suspect he got the disease after spending so much time at home during the COVID-19 lockdown.

"Where I stay, there are a lot of pigeons," he explained. "We have grills and an aluminum [siding] where all the pigeons dance all day."

These days, Punjabi doesn't leave his house without wearing a mask to protect him from dust and pigeon droppings, but he said it's often hard to avoid with Mumbai's kabutarkhanas.

"People have a religious belief that if you feed them, you get the pigeon's blessings. You can't ban it, you can't do anything," he continued. "But people have to be very cautious when dealing with [pigeons]."

The city of Mumbai technically does have fines of 500 rupees ($8 Cdn) on the books for feeding pigeons in non-designated areas but residents say the bylaw is rarely enforced.

It's left to chest surgeons like Prabhudesai to sound the alarm and repeat the same advice over and over:

"We always try to tell people: "Number one, don't feed the pigeons."