Epidemiology of non-Tubercular Chronic Pneumonic Lung Illnesses in India Pigeon Poops & Damp Kitchens Pose Public Health Challenge

Abstract

Chronic Lung infections present a distinct paradigm in infection pathogenesis which often challenge conventional notions of bacterial or viral virulence and host defenses. Two such chronic non tubercular infections are Pseudomonas Aeruginosa Pneumonia (PAP), and Chronic Hypersensitivity Pneumonia due to longtime exposure to pigeon’s poop (CHPPP). The pigeons are viewed as 'benign city friends', but they carry with them serious health risks to some individuals. Fine dust in pigeon droppings and feathers induce a condition referred to as hypersensitivity pneumonitis, which progressively destroys the lungs. Some people are facing long-term health risks, in cities with large pigeon populations, pigeon feeding habits & exposure to their poops for long durations, in cities like Delhi, Bengaluru & Mumbai. The Bombay High Court, India on Thursday the 7 August 2025, hearing a bunch of petitions filed by people who feed pigeons challenging the civic body's decision to ban such feeding and closure of Kabutarkhanas, decide that it is the State Government & Brihanmumbai Municipal Corporation to take an informed decision to ensure that the constitutional rights of every citizen are upheld.

Similarly, increasing dependence on cooks’ support and patients in hospitals, develop specific types of Pneumonias. P. aeruginosa bacteria commonly found in outdoors- soil & water, can infect cooks working in unhygienic kitchens or hospital patients to make them sick. In both these conditions most, healthy people are not affected, but some individuals develop flu-like symptoms, including cough, fever, chills, or shortness of breath, following exposure. If prolonged contact is maintained, chronic pneumonitis develops, makes breathing harder and, in extreme cases, result in lung failure. Affected individuals remain unaware of premonitory symptoms, like repeated coughing, breathlessness, chest pain, and tiredness>Even the general practitioners misconstrue symptoms such as asthma or allergies or TB. Over time individuals are plagued by these symptoms regularly or feel greater fatigue & poorer exercise tolerance.

Materials and Methods: This article is an outcome of managing one case of each CHPPP and PAP, by the author in recent times, supplemented by literature search on epidemiology, diagnostic and management approaches to guide the primary health care providers.

Keywords & Abbreviations: CLIs=Chronic Lung Infections, CAP= community-acquired pneumonia, ILD = interstitial lung disease, PAP=Pseudomonas Aeruginosa Pneumonia, CHPPP= Chronic Hypersensitivity Pneumonia due to pigeon’s poop, PFT = Pulmonary function test, DLCO = diffusing capacity of the lungs for carbon monoxide, PAP=, Pigeons’ Poop, Damp environments i.e., health care settings, Kitchens.

Introduction

The Bombay High Court, India on Thursday the 7 August 2025 refrained from staying the closure order of the Brihanmumbai Municipal Corporation (BMC). Instead, it suggested to set up an expert committee by 13 August 2025 to study whether the old Kabutarkhanas in the city should continue? as "human life is of paramount importance”. Anything that affects the larger health of senior citizens and kids, be investigated as there must be a balance, court said [1]." Further it said, it is for the Maharashtra government & BMC to take an informed decision to ensure that the constitutional rights of every citizen are upheld & not just a few interested individuals, as currently all medical reports point at irreversible damage caused by pigeons and Human life is of paramount importance. There is a wealth of medical material that needs to be investigated, and the court is not an expert to examine the same the BHC said. The expert committee can decide if the BMC's decision was right. If the committee opines that the BMC's decision was right, then a suitable alternative for the birds be suggested [1].

Bacterial pathogens are most studied for their ability to invade and injure the host, causing acute and invasive infections. In contrast, chronic infections present a distinct paradigm in infection pathogenesis which may challenge conventional notions of bacterial virulence and host defenses [9]. Two such chronic non tubercular infections are Pseudomonas Aeruginosa Pneumonia (PAP), and Chronic Hypersensitivity Pneumonia due to pigeon’s poop (CHPPP) this author and some physicians are challenged for diagnosis & management in recent times. Some people are facing long-term health risks, in cities with large pigeon populations, pigeon feeding habits & increasing dependence on cooks’ support in cities like Delhi, Bengaluru & Mumbai [2,3].

The pigeons are viewed as 'benign city friends', but they carry with them serious health risks to some individuals. Similarly, cooks and patients in hospitals are exposed to damp environments in which P. Aeruginosa thrive and pave way for specific types of Pneumonias. Fine dust in pigeon droppings and feathers induce a condition referred to as hypersensitivity pneumonitis, which progressively destroys the lungs. Pseudomonas aeruginosa (P. aeruginosa), bacteria commonly found in outdoors- soil and water, can infect cooks working in unhygienic kitchens or hospital patients to make them sick. Most healthy people are not affected, but some individuals might develop flu-like symptoms, including cough, fever, chills, or shortness of breath, following exposure. If prolonged contact is maintained, chronic pneumonitis develops, makes breathing harder and, in extreme cases, result in lung failure [3]. Most individuals remain unaware of premonitory symptoms, like repeated coughing, breathlessness, chest pain, and tiredness, which are frequently misconstrued as asthma or allergies or TB by practitioners [10]. Individuals plagued by these symptoms regularly, feel greater fatigue & poorer exercise tolerance [3,4].

Case Report

Case 1 (CHPPP): A 15-year-old girl was referred to me with persistent dry cough for 3 years, progressive dyspnea for last 2 years and significant weight loss for last 1 year. She had received anti-tubercular and anti-asthma treatment without any relief. Her past and family history were insignificant, except that they were involved in breeding around 60 pigeons at home.

Physical Examination: On examination, she was cachexic and dyspneic at rest, with tachycardia and tachypnea. Her SPO2 was 82% at room air that improved to 95% with supplemental oxygen. Respiratory system examination revealed use of accessory muscles of respiration, with pectus excavatum and fine basal crepitations. Cardiovascular system examination revealed loud P2, and normal jugular venous pressure and hepato-jugular reflux. She had no hepatomegaly. She weighed 23 kgs (< -3 SD), with a height of 144 cm (-2 to -3 SD) and body mass index of 11.11 (< -3SD). She was in tanner stage II of sexual maturity.

Investigations: i) A chest X-ray revealed bilateral ground glass haziness ii) Pulmonary function tests (PFT) revealed severe restriction (FVC 16.6 %, FEV1 17.9 %, FEV1/FVC 1.07), with reduced diffusion capacity of lung for carbon monoxide (DLCO) (19%). On further investigations, iii) Arterial blood gas revealed PO2 of 68 mmHg, with saturation of 91%. iv) Echocardiography revealed dilated pulmonary artery, dilated right ventricle and moderate tricuspid regurgitation (gradient 30 mm of Hg) suggestive of pulmonary artery hypertension (PAH). v) Work up for tuberculosis, immunodeficiency, Pseudomonas aeruginosa, sarcoidosis, connective tissue disorders, celiac disease, tropical pulmonary eosinophilia, allergic bronchopulmonary aspergillosis, cytomegalovirus and mycoplasma were negative. Fiberoptic bronchoscopy was grossly normal. Cytology of bronchoalveolar lavage and flow cytometry were inconclusive. High resolution computed tomography (HRCT) of chest revealed diffuse mosaic pattern and multiple ill-defined centrilobular nodular lesions in both upper lobes &interstitial thickening in the apical segment of left lower lobe. Histopathology of lung biopsy specimen revealed classical features of hypersensitivity Pneumonia. Test for pigeon dropping allergies in serum was positive.

She was administered i) intravenous methylprednisolone (30 mg/kg/day) for 3 days, followed by oral prednisolone and inhaled budesonide, ii Bosentan (BOSENTAS 62.5 mg twice daily) for the pulmonary hypertension. On day 45, she was discharged on home oxygen as she had dyspnea only on exertion, with SpO2 of 92% in room air and FEV1 and FVC of 32% and 25%, respectively & advised to avoid exposure to pigeons. Oral steroids and Bosentan were continued. She was followed up with monthly monitoring of respiratory rate, SpO2, pulmonary function and liver function test. Bosentan was stopped after two-dimensional echocardiography at eight weeks showed no evidence of pulmonary hypertension. She was continued on low dose prednisolone. At 10 months follow-up, she was on room air, attending school; FEV1 and FVC were 36% and 40%, respectively.

Case 2 (PAP): Purnima, a 45 yrs old lady, cook by profession in March 2022 went to a private physician in Hubballi, Karnataka for occasional cough and breathlessness on exertion. History of exposure to Tuberculosis in childhood as her father was a known TB patient and died of the disease. Her profession involves exposure to damp worksites almost daily. Sputum for AFB was negative, Xray chest was suggestive pneumonic patches in both lower lobes. While Blood examination indicated Hypothyroidism (sub-clinical). Culture of the sputum yielded Aerogenes organisms. The report read “Heavy growth of gram-positive Bacilli of P. aeruginosa, susceptible to Ciprofloxacin. She was prescribed Ciprofloxacin Hydrochloride Tablets IP 500 mg from Pradhan Mantri Bhartiya Janaushadhi Pariyojana costing about INR 20 for 10 tablets, twice daily for 4 weeks initially. It belongs to the Fluoroquinolone group, and it works by killing bacteria that cause infections. After a review in 2weeks, noting favorable improvements in symptoms and signs it was extended for another 6 weeks by the end of which Xray had shown completed resolution. Till now the lady is fine.

Discussions

Bacterial pathogens are most studied for their ability to invade and injure the host, causing acute and invasive infections. In contrast, chronic infections present a distinct paradigm in infection pathogenesis which challenge conventional notions of bacterial virulence & host defenses are sparing studied.  A systematic review on the etiology of community-acquired pneumonia (CAP) among Indian adults, revealed the pathogen distribution as:  i) Streptococcus pneumoniae was the most common organism, accounting for 33% of the cases, which was followed by ii) Klebsiella pneumoniae at 23%, iii) Staphylococcus aureus at 10%, iv) Mycoplasma pneumoniae & v) Legionella pneumophila each at 7%, vi) Chlamydia pneumoniae, vii) Haemophilus influenzae, and viii) Pseudomonas aeruginosa each at 4% [3,4,5].

An overview of multiple medical journals & research papers point out a few common chronic respiratory diseases (CRDs) in India like: i) Tuberculosis, ii) Asthma, a non-communicable disease that can affect people of any age group, iii) Chronic Obstructive Pulmonary Disease (COPD) is a group of inflammatory lung diseases that obstruct the airflow, like emphysema and chronic bronchitis, iv) Chronic Bronchitis a part of COPD, an inflammatory condition that affects the lining of our bronchial tubes, v) Lung cancer as 6.9 per 100,000 of the Indian population suffers from this. Among less common conditions clinicians need to keep in mind for respiratory conditions that do not respond to normal antibiotic therapy are :i) interstitial lung diseases, ii) obstructive sleep apnea, iii) destroyed lung/bronchiectasis/pleural thickening (fibrothorax), iv) pneumoconiosis, v) Pseudomonas Aeruginosa Pneumonia, vi) Chronic Hypersensitivity Pneumonia, vii) pulmonary hypertension, & viii) post-COVID-19 condition [3,4,5]. While P. Aeruginosa infection contributes to about 4% of pneumonia cases in hospitals, the prevalence CHPPP is not yet quantified in India, both of them are discussed in this article.

Pseudomonasis Aeruginosa Pneumonia (PAP)

Epidemiology: Pseudomonasis is a type of bacteria that's commonly found outdoors, such as in soil and water. It also thrives in moist places indoors. Pseudomonas aeruginosa (P. aeruginosa), a type of this bacteria can infect cooks working in unhygienic kitchens to make them sick. It can grow on fruits and vegetables, thrives in wet areas such as lakes, pools, hot tubs, bathrooms, kitchens, and sinks. The most severe infections easily occur in health care settings, inpatients departments of hospitals such as they easily grow in humidifiers and catheters, if they aren’t properly cleaned. If health care workers don’t wash their hands well, they can also transfer the bacteria from an infected patient to another patient.  Drains and plumbing parts, cleaning supplies, such as mops, hot tubs used for sitz’s bath, contact lenses or contaminated lens solution, body piercings or body piercing equipment, cooked food, soap bars, sanitizers toothbrushes, ice machines, disinfecting solutions & surgical instruments are other sources [7].

Signs & Symptoms: The signs of infection depend on where the Pseudomonas aeruginosa is in our body. It can infect any part, from our fingernails to our blood, lungs, stomach, urinary tract, or tendons. Pressure sores, wounds, and burns can also become infected. If bones or joints are infected with joint pain and swelling; neck or back pain that lasts weeks, if lungs are infected lead to Pneumonia with severe coughing and congestion mimicking TB.  If wounds get infected with green pus or discharge with a fruity smell, it is the hallmark! [6,7]

P. aeruginosa causes invasive and highly lethal disease in certain compromised hosts. In others, with genetic disease cystic fibrosis, etc. this pathogen causes chronic lung infections which bother for months and years. During chronic lung infections, P. aeruginosa adapts to the host environment by evolving towards a state of reduced bacterial invasiveness that favors bacterial persistence without causing overwhelming host injury [9]. Host responses to chronic P. aeruginosa infections are complex and dynamic, ranging from vigorous activation of innate immune responses that are ineffective at eradicating the infecting bacteria, to relative host tolerance and dampened activation of host immunity [9].

Treatment of P. aeruginosa infection depends upon where the infection is in our body, in the form of a cream, eye drops, ear drops, or oral antibiotic pills or injections IM or IV for 6-8 weeks. Every pseudomonas bacterium is slightly different, and strains are constantly changing, so these types of infections can be hard to treat. It is better to get culture and sensitivity done and use suitable antibiotics to get rid of Pseudomonas aeruginosa. The standard dosing regimen for adults with uncomplicated pneumonia typically involves Ciprofloxacin Hydrochloride 500 mg to 750 mg taken orally or intravenously every 12 hours, to ensure effective drug levels are maintained, promoting bacterial eradication and clinical improvement [9].

Chronic Hypersensitivity Pneumonia due to Pigeon’s Poop (CHPPP):

Pigeons have been considered the most preferred companion for human civilizations since prehistoric times. Even though pigeons offer the most palatable & nutritious food & provide pleasure to humans, they pose health risk because of carrying infectious & zoonotic organisms. Bird Breeder’s Lung or Chronic Hypersensitivity pneumonitis (CHPPP) is the commonest form of interstitial lung disease (ILD) in India. About 50% of ILD patients have HP, the typical symptoms of which are cough and breathlessness on exertion [10]. 

Epidemiology: The chronic form of hypersensitivity pneumonia results from long term low-grade exposure. It is characterized by dyspnea, chronic cough, fatigue, anorexia & weight loss. PFT (Pulmonary function test) reveals a restrictive pattern & a decrease in the diffusing capacity of the lungs for carbon monoxide (DLCO).

Pathophysiology: Chronic Hypersensitivity pneumonia due to Pigeon’s Poop (CHPPP) is an immune system disorder caused by inhaled allergens. Pigeon droppings, & dust that rises when the droppings are swept off the surface, are the most common allergen that causes CHPPP. The droppings contain fungi like aspergillus which when inhaled, can cause Histoplasmosis, which can lead to ILD. If diagnosed within six weeks, HP is reversible, but in most cases, patients approach very late, when the damage has already progressed to the irreversible stage of lung fibrosis. Other antigens implicated are animal proteins, fungi, amoeba, bacteria, medications & chemicals [11]. Avian antigens are common causes of hypersensitivity pneumonia [4,10,11,12]. Both type III & type IV hypersensitivity responses have been implicated in the disease process.

Diagnosis: High-resolution computed tomography (HRCT) scan of chest in chronic hypersensitivity pneumonia reveals fibrotic changes, irregular linear opacities, central-lobular nodules, honeycombing and traction bronchiectasis. Bronchoalveolar lavage usually reveals a significant increase in the percentage of lymphocytes with decreased CD4+/CD8+ratio. On histopathology, the interstitial and alveolar collections of foamy histiocytes are specific for hypersensitivity pneumonia due to pigeon breeder’s disease. Interstitial fibrosis and interstitial cellular infiltrates that are primarily lymphocytic with large number of plasma cells, with absence of granulomas is also observed in chronic hypersensitivity pneumonia. Common differential diagnosis to be considered are other interstitial lung diseases like immune-mediated collagen vascular diseases, sarcoidosis and malignancies. Latest diagnostic criteria for hypersensitivity pneumonia key points to consider include: i) Specific IgG antibody panel to identify antibodies against common antigens ii) Complete blood count to show leukocytosis with neutrophilia in acute phases iii) Inflammatory markers like CRP and ESR to assess disease activity iv) Pulmonary function tests and bronchoalveolar lavage to demonstrate restrictive patterns & lymphocytosis. The diagnosis of HP requires a thorough exposure history, multidisciplinary discussion of clinical and radiologic data, and assessment of bronchoalveolar lavage lymphocytosis & histopathologic findings [12].

Burden of the Disease: A meta-analysis of existing segregated literature, based on the published studies from January 2000 to October 2021, analyzing the total 18,589 samples, reported a mean prevalence estimates of pigeon pathogens worldwide were fousnd to be 17%. Serological & molecular prevalence were reported as 18% & 17%. Virus, bacteria, & protozoal pathogens were found to be 21%, 17% and 14%, respectively. The highest prevalence rate in Asia was 20%, followed by Europe 16%, Africa 16%, and America (N & S) 10%. Studies have reported prevalence rates in Iran of 20%, China 13%, Bangladesh 37%, & Poland 15%.

Treatment for chronic hypersensitivity pneumonia includes oral prednisolone over several months, depending on the response to improvement in symptoms & functional abnormalities. Early treatment leads to complete reversal in acute & sub-acute hypersensitivity pneumonia. Chronic form may proceed to irreversible lung damage despite treatment & avoidance of the offending antigen. Our case has a restrictive change at 1 year’s follow-up. The clinicians must have a high index of suspicion to make early diagnosis, minimize disease progression & irreversible lung damage [12]. Policymakers in effected countries must develop appropriate intervention strategies to prevent & control diseases in their respective locations [2].

Conclusion

Chronic Lung infections present a distinct paradigm in infection pathogenesis which often challenge conventional notions of bacterial or viral virulence and host defenses. Two such chronic non tubercular infections are Pseudomonas Aeruginosa Pneumonia (PAP), and Chronic Hypersensitivity Pneumonia due to longtime exposure to pigeon’s poop (CHPPP). The diagnosis of PAP & CHPPP requires a thorough history, clinical & biomarkers & radiologic data, and assessment of bronchoalveolar lavage lymphocytosis & histopathologic findings. PFT & bronchoalveolar lavage to demonstrate restrictive patterns & lymphocytosis. Sputum culture for growing & antibiotic sensitivity test may be needed to choose appropriate medicines [9,12].

Prevention calls for wearing a mask and gloves should always be done while cleaning pigeon congregation areas. Dry sweeping should never be used, as it disperses harmful particles; one should rather wet surfaces first before wiping them off. Keeping windows shut or fit fine-mesh screens to exclude droppings and dust from your home. Repel pigeons from nesting by excluding food and closing small openings in roofs or ledges. Basically, i) one must avoid direct contact: Do not touch pigeon droppings or nests with bare hands ii) get the droppings wet first with water and then clean so as not to stir the dust and inhale the same iii) barricade pigeon roosting areas, Patios, Balconies, attics or ledges, and use spikes or netting to exclude them iv) use gloves and mask when cleaning pigeon areas. wash the hands thoroughly after cleaning. v) Keep kitchens and hospital ward dry & clean to avoid P. aeruginosa thriving.

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