Backyard chicken-keeping is illegal in my city. I'm a member of BYC because I've really been wanting chickens. I've been looking into helping reshape the laws where I live, reading a lot about arguments in favor of urban chickens . These usually address public health concerns by talking about bird flu. But no one mentions the other diseases that cross the avian-human species barrier. I've been reading about those diseases today and there are a number of them. One of them is called histoplasmosis. Here's a bit of what I've been reading: Certain fungi prefer to grow in soils enriched with avian manures. Histoplasma capsulatum is one of these. The fungus is also associated with construction sites and caves. Birds are not susceptible to infection, but histoplasmosis can affect humans, dogs, cats, cattle, sheep, horses, and many wild mammals. The incubation period is 7-14 days. Most cases in humans are asymptomatic. Disease may be manifested in three forms: acute pulmonary (most common), chronic cavitary pulmonary, and disseminated. The acute pulmonary form is influenza-like and lasts up to several weeks. It is characterized by chills, chest pain, nonproductive cough, fever, and malaise. The chronic form occurs in people over 40 and resembles tuberculosis. It is characterized by a productive cough, pus-like sputum (material expelled from the respiratory passages), weight loss, and shortness of breath. The disseminated form occurs in the very young or the elderly. Lesions include enlarged spleen and liver, and mucosal ulceration. The disseminated form of histoplasmosis can be fatal if not treated. Amphotericin B has been used to treat histoplasmosis. Transmission occurs by inhalation of spores produced by growth of the mold. Histoplasmosis is not a communicable disease. The reservoir is the soil, especially when enriched with droppings from birds or bats. Wet the area and wear a face mask or respirator when working in suspect surroundings. Spraying the soil with a formaldehyde solution has been used to kill the fungi. Although this disease is avian-associated, it is not a zoonotic disease, because the reservoir is soil and not the birds. This is, however, of little consequence to the unfortunates who become infected. In Florida, histoplasmosis is a reportable disease. If a person is suspected of having histoplasmosis, the county public health office must be notified within 48 hours. Links to a document offering arguments in favor of backyard chicken-keeping have recently been posted in this forum and it says that urban chickens were banned because it became socially unacceptable to maintain ties to a more agrarian past. But I don't think that's what happened in my city. In 1959 chicken flocks all over the large valley that surrounds my city were hit by an epidemic of a disease that passes from chickens to humans through dried manure dust. I think reaction to that is what got backyard poultry banned. So, what kind of reassurance can those in favor of urban poultry give to those who are concerned about infectants like histoplasmosis in urban yards?