What dangers do birds pose to human health?

Basically, we need to be careful with Chlamydophila psittaci, the infectious agent responsible for Chlamidiosis (Ornithosis). It is actually a parrot disease, but other birds, including pigeons, can have it. It can be transmitted to humans, taking the form of mild flu symptoms.

The bloom in bird feathers (again, all bird feathers, not just pigeons') can cause a serious allergy in sensitive people. This is called Hypersensitivity Pneumonitis (Bird Fancier's Lung). Tests for this are available from your family doctor, and if positive, you should avoid all contact with birds and areas where there are many of them, or else wear masks and other protective equipment.

Common sense must prevail when cleaning large amounts of dried bird poops/droppings. In cases where these contain moulds, they can affect breathing, just as any other form of mould found on walls, etc.

The remaining diseases carried by pigeons are bird-specific, which means the strains that affect them are different from the strains that affect humans, and so do not pose a problem.

Finally, I'm including here a humorous look at this subject:

LOOK UP BEFORE OPENING YOUR MOUTH

Posted on August 2, 2010 by Scott Weese

Recently, Kings of Leon canceled an outdoor concert after a pigeon (with very good aim, apparently) in the rafters above the stage managed to poop on band members, including one shot that hit the face of the band's bassist.

Besides, the "ick-factor," what are the concerns?

Various studies have found potentially nasty microorganisms in pigeon poop, including:

•E. coli
•Various microsporidia
•Various Cryptococcus species
•Multidrug resistant Staphylococcus spp
•Salmonella
•Chlamydophila psittaci
•Mycobacterium avium complex
The risk of disease is pretty low for most people, and we are potentially exposed to many of those bugs on a daily basis. The risks increase with higher ingested doses (so direct-deposit of poop is a much greater concern that inadvertent contamination of your hands) and in people with compromised immune systems. It's unlikely but not impossible that someone would get sick from exposure to pigeon feces, and don't eat poop is a good general philosophy for life.

Source: http://www.wormsandgermsblog.com/articles/animals/birds/

Great thread, Teresa.

With regard to Hypersentivity Pneumonitis, the symptoms can be similar to asthma and can sometimes be misdiagnosed as asthma.

Thank you for the excellent link to the info about Hypersensitivity Pneumonitis!