Risk factors associated with mycoplasmal conjunctivitis in house finches: Results from a citizen-based study.  Hartup, Barry K., Hussini O. Mohammed, George V. Kollias, and André A Dhondt. 1998. Journal of Wildlife Diseases 34(2): 281-288.

Observations from a citizen-based survey were used to identify potential risk factors associated with mycoplasmal conjunctivitis in house finches (Carpodacus mexicanus). Over two years, 778 volunteers provided 7224 monthly observations by questionnaire at residential bird feeding sites in eight states of the eastern USA. House finches were 14 to 72 times as likely to be observed with conjunctivitis than four sympactric passerines. Year, season, platform, hopper and tube type feeders were associated with conjunctivitis in house finches by Chi-square tests. Multivariate analysis suggests that increased risk was associated with the second year of the study (the third year of the outbreak; 95% confidence adjusted odds ratio (OR) = 1.4-1.7)), cooler, non-breeding periods from September through March (OR = 1.2-1.5), and the presence of tube style feeders (OR = 1.1-1.4). Platform feeders may have been protective against conjunctivitis (OR = 0.7-0.9). Prevention of disease transmission may include modifying bird feeding activities based on season and type of feeders in use.