Nosema is a genus of microsporidia, which have significant negative impacts on honeybees. The aim of this
study is the epidemiological evaluation and molecular characterization of Nosema spices in various counties
of East-Azerbaijan province (Northwest of Iran). 387 samples were collected from colonies maintained in
various counties of East-Azerbaijan province. Samples after preparation were examined by a light
microscope for presence of Nosema spores. PCR method (SSUrRNA gene) was used to differentiate
between Nosema apis (N. apis) and N. ceranae. Descriptive statistics were used for data analysis. Total
infection prevalence of the microscopic evaluation and PCR tests were 225 (58.1%) and 260 (67.1%)
respectively, total validity of PCR test against the microscopic test was computed equal to 1.1 in this case.
Disease distribution in various counties of study area was variable and N. ceranae was the only Nosema
species found to infect honeybees. The one species presence and different distribution of Nosema positive
samples in various counties of East-Azerbaijan province may be due to multiple reasons. Furthermore,
epidemiological information helps us to improve disease management practices in the studied area, apply
new hygiene policy and reduce extra costs of production.