Guwahati: The tea gardens of Assam, renowned for producing over half of India’s tea, have emerged as the backdrop for a significant public health challenge. For decades, tuberculosis (TB) has plagued Assam’s tea garden workers, exacerbated by poverty, poor nutrition, and challenging living conditions.
Now, a new health burden is emerging: chronic pulmonary aspergillosis (CPA), a fungal infection that thrives in the damaged lungs of TB survivors.
A new study has, for the first time, identified chronic pulmonary aspergillosis (CPA), a life-threatening fungal infection, among workers in Assam’s tea estates—a community already grappling with high rates of tuberculosis (TB). Aspergillus fumigatus is the causative agent of CPA. Interestingly, CPA prevalence in Assam’s tea garden workers exceeds the global average.
The team, comprising Aishwarya Selvasekhar, Dr. Reema Nath, Dr. Gourangie Gogoi, and Dr. Pronami Borah from the Assam Medical College and Hospital, focused on workers and their dependents across four tea gardens in Dibrugarh district—known as the “Tea City of India.”
Chronic pulmonary aspergillosis is a chronic lung disease that occurs commonly in pre-existing lung cavities. It mostly occurs in post- or active tuberculosis patients and shares similar clinical features with tuberculosis.
The study, conducted by Assam Medical College & Hospital and published in PLOS Neglected Tropical Diseases, was a community-based, cross-sectional investigation spanning tea garden communities in the Dibrugarh district. Known as the “Tea City of India,” Dibrugarh is home to 177 tea gardens and has a high TB burden. Researchers focused on workers and their dependents who sought treatment for chronic respiratory symptoms at three tea garden hospitals and two referral hospitals within a 15 km radius of Assam Medical College.
The study examined 128 individuals with symptoms like persistent cough, haemoptysis (coughing blood), fatigue, and weight loss lasting three months or more. Using advanced serological testing (Aspergillus fumigatus-specific IgG antibodies) and radiological imaging, researchers documented a CPA prevalence of 17.2%. Among participants, 32% tested seropositive for Aspergillus fumigatus, with seropositivity reaching 48.9% in those with a history of TB, underscoring CPA as a significant post-TB complication.
The mean age of participants was 41.9 years, with a male-to-female ratio of 1.6:1. CPA was more common in middle-aged male workers, likely due to occupational exposure and higher smoking rates.
Haemoptysis and fatigue were the most significant indicators of CPA, with p-values of 0.0086 and 0.0098, respectively. Chronic cough, present in 66.4% of participants, was also prevalent.
Nearly half of the participants were employed directly in tea gardens, while others were engaged in supportive roles like masonry and plumbing. CPA prevalence did not differ significantly between these groups, suggesting broader environmental or occupational risk factors. Respiratory illnesses not only reduce productivity but also push families into cycles of debt due to medical expenses and lost wages.
The tea garden workers of Assam are particularly vulnerable to TB due to overcrowded living conditions, poor nutrition, and limited healthcare access. TB thrives in environments of poverty and malnutrition, both of which are prevalent in tea estates.
Workers recovering from TB are at risk of developing CPA, as the disease often exploits residual lung cavities left by TB bacteria. These cavities provide an ideal environment for the growth of Aspergillus fumigatus. Among TB survivors in the study, CPA seropositivity was 18.5% in active TB patients but spiked to 48.9% in those who had completed treatment (post-TB).
Chronic pulmonary aspergillosis (CPA) and tuberculosis (TB) are both respiratory diseases that can cause similar symptoms, but they differ significantly in their causes, progression, and treatment. Tuberculosis is caused by the bacterium Mycobacterium tuberculosis. It spreads through airborne droplets when an infected person coughs or sneezes, while chronic pulmonary aspergillosis is caused by Aspergillus fumigatus, a type of fungus that thrives in pre-existing lung cavities, often caused by TB or other lung diseases.
TB affects individuals with weakened immune systems, such as those with HIV, diabetes, or malnutrition. It can infect people without pre-existing lung conditions, while CPA typically develops in individuals with damaged lung tissue, such as those recovering from TB, chronic obstructive pulmonary disease (COPD), or sarcoidosis. CPA is a complication of TB in many cases.
The CPA prevalence in Assam’s tea garden workers—60 cases per 100,000 people—exceeds the global average of 42 per 100,000 and far surpasses rates in high-income countries like the U.S. (<1 per 100,000). In African nations such as Nigeria and the Democratic Republic of Congo, CPA rates range from 20 to 50 per 100,000, making Assam’s figures alarmingly high.
CPA is underdiagnosed due to limited access to advanced diagnostic tools like Aspergillus fumigatus-specific IgG testing. Only a few facilities in India, including Assam Medical College’s Advanced Mycology Lab, offer this test. Misdiagnosis as TB or other respiratory diseases delays appropriate treatment, worsening outcomes.
Tea estates are central to Assam’s economy, and respiratory illnesses like TB and CPA directly impact workforce productivity. Many workers face cycles of poverty as medical expenses and lost wages pile up. Beyond individual costs, the untreated disease burdens the healthcare system and risks destabilizing the tea industry.
The findings call for a multi-pronged approach to tackle this dual burden: integrated screening programs incorporating CPA testing for TB patients in public health initiatives, infrastructure development to equip tea garden hospitals with tools for diagnosing fungal diseases.
It also advocates for education campaigns to train healthcare providers to recognize CPA symptoms and educate workers about respiratory health, and nutrition and hygiene initiatives to address malnutrition through welfare programs and improve living and working conditions to reduce disease susceptibility.
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