In the last post, “Enjoying the Interactive Wildlife” we looked at some of the benefits of sharing our cities with feral pigeons. This post is about the drawbacks: pigeon-related zoonoses, or the diseases common between us. From the standpoint of the pigeons, the benefits outweigh the risks, they love living around us because humans = ample food sources and good architecture for roosting. Humans however, do worry about catching diseases from animals like pigeons. The animal we catch the most diseases from are other humans, but we do need to be aware of the diseases associated with pigeons since they live with us in our cities too.
What we have learned so far is that the disease concerns around pigeons are focused on their droppings. New York City’s department of Health and Mental Hygiene puts out this informative fact sheet about the 3 health risks associated with pigeon droppings – in particular the cleaning of them – which they characterize as a small health risk.
1) Histoplasmosis – this is a disease caused by a fungus that grows in the soil and in concentrations of bird and bat droppings, which are high in nitrogen. It is a common disease – people living in places where the fungus grows naturally, such as the Ohio River Valley, are likely to have already had it, but not developed any symptoms. It is transmitted through airborne spores, not between people or animals. If symptoms develop, they are flu-like and include cough, headache, muscle aches, chills, shortness of breath. Mild cases go away without treatment, but severe cases need to be treated with anti-fungal medications. This disease can be very serious, even deadly, for people with compromised immune systems. More info.
2) Cryptococcosis – also a soil-dwelling, bird and bat dropping-loving fungus that can infect humans when they breathe in the spores. It is unlikely to get this infection, even by breathing in many spores. However, it is a concern because it can be very serious for people with weakened immune systems. It can even spread from the lungs into the brain and become deadly. 85% of Cryptococcosis patients are HIV-positive, according to the US Center for Disease Control (CDC). The CDC recommends that we avoid disturbing any accumulations of bird or bat manure so spores do not get released. Another interesting recommendation with regards to this disease comes from PubMedHealth “Practice safe sex to reduce the risk of getting HIV and the infections associated with a weakened immune system.”
3) Psittacosis – a bacteria found in the droppings and nasal discharges in infected birds and spread through the air. It causes pneumonia-like symptoms and is sometimes called Parrot Fever because it infects mostly parrot-like birds. It is considered rare among humans and most of the reported cases are people who contracted it from pet birds. Pigeons can also get this disease and potentially spread it to humans through exposure to infected, dried droppings or respiratory secretions. I’m looking through the literature to see how often this happens. More on Psittacosis.
All three of these diseases are common to chickens and chicken manure.
And what about bird flu? Fortunately, that is one we don’t have to worry about with pigeons, as they have been found to be resistant to avian influenza.
Other things to be worried about? Maybe salmonella? Anything else? I’ll be continuing this pursuit of pigeon-related zoonoses and report back in a future post.
Filed under Biology, Health