Colony Collapse Disorder (CCD) is a syndrome characterized by the rapid loss of adult worker bees from managed honey bee (Apis mellifera L.) colonies. A descriptive epizootiological study was conducted to better understand CCD and compare risk factors between affected and non-affected populations. The study analyzed 61 variables, including adult bee physiology, pathogen loads, and pesticide levels, but no single measure was identified as the most likely cause of CCD. Bees in CCD-affected colonies had higher pathogen loads and were co-infected with more pathogens than control populations, suggesting increased pathogen exposure or reduced resistance. Levels of the synthetic acaricide coumaphos were higher in control colonies than in CCD-affected colonies. The study found that CCD involves interactions between pathogens and other stress factors. Evidence suggests CCD may be contagious or result from exposure to a common risk factor. Potential areas for future research include the legacy effect of mite parasitism and the role of honey bee resistance to pesticides. The study mapped dead and weak colonies within CCD-affected and non-affected apiaries, finding that colonies with similar conditions were not randomly distributed, suggesting an infectious agent or common risk factor may be involved. Colony strength measurements showed that CCD-affected colonies had more dead and weak colonies than control colonies. Morphometric measurements revealed that bees from CCD colonies were more symmetrical than those from control colonies, indicating possible stress effects. Pathogen prevalence and load were compared between CCD and control colonies, with higher prevalence of certain pathogens in CCD colonies. Pesticide prevalence and residue levels were also compared, with higher levels of coumaphos in control colonies than in CCD colonies. The study found no significant differences in the mean number of pesticides detected in CCD and control colonies. The study concluded that CCD is a complex condition involving interactions between pathogens and other stress factors. While no single pathogen or parasite was found to be the sole cause, pathogens likely play a critical role. The study highlights the need for further research into the causes of CCD, including the role of pesticides and pathogen interactions.Colony Collapse Disorder (CCD) is a syndrome characterized by the rapid loss of adult worker bees from managed honey bee (Apis mellifera L.) colonies. A descriptive epizootiological study was conducted to better understand CCD and compare risk factors between affected and non-affected populations. The study analyzed 61 variables, including adult bee physiology, pathogen loads, and pesticide levels, but no single measure was identified as the most likely cause of CCD. Bees in CCD-affected colonies had higher pathogen loads and were co-infected with more pathogens than control populations, suggesting increased pathogen exposure or reduced resistance. Levels of the synthetic acaricide coumaphos were higher in control colonies than in CCD-affected colonies. The study found that CCD involves interactions between pathogens and other stress factors. Evidence suggests CCD may be contagious or result from exposure to a common risk factor. Potential areas for future research include the legacy effect of mite parasitism and the role of honey bee resistance to pesticides. The study mapped dead and weak colonies within CCD-affected and non-affected apiaries, finding that colonies with similar conditions were not randomly distributed, suggesting an infectious agent or common risk factor may be involved. Colony strength measurements showed that CCD-affected colonies had more dead and weak colonies than control colonies. Morphometric measurements revealed that bees from CCD colonies were more symmetrical than those from control colonies, indicating possible stress effects. Pathogen prevalence and load were compared between CCD and control colonies, with higher prevalence of certain pathogens in CCD colonies. Pesticide prevalence and residue levels were also compared, with higher levels of coumaphos in control colonies than in CCD colonies. The study found no significant differences in the mean number of pesticides detected in CCD and control colonies. The study concluded that CCD is a complex condition involving interactions between pathogens and other stress factors. While no single pathogen or parasite was found to be the sole cause, pathogens likely play a critical role. The study highlights the need for further research into the causes of CCD, including the role of pesticides and pathogen interactions.