Spatial Epidemiology and Temporal Trend of Brucellosis in Iran Using Geographic Information System (GIS) and Join Point Regression Analysis: An Ecological 10-Year Study.

Background: Brucellosis is one of the common diseases between humans and animals. We aimed to assess the annual incidence rate, the geographical distribution of Malta fever using GIS and its time trend.

Methods: This was an ecology study carried out in exploratory mixed design. The study population was the individuals with brucellosis in Iran during the years 2009-2018. Data analysis has been done using Joinpoint regression analysis and GIS at a significant level of α = 0.05.

Results: The average annual incidence rate of the disease rate was 19.91 per one hundred thousand people. The trend of the changes in the incidence between 2009 and 2018 has increased and the Annual Average Percent Change increased by 4.6%. However, a joinpoint was observed in 2014 and the incidence has changed significantly at this point in time, so that the annual incidence of the disease has increased more strongly between 2009 and 2014 (APC=17.1%) and then from 2014 to 2018, the incidence of the disease has decrease (APC=-9.2%). The spatial distribution showed that the western and northwestern provinces have high incidence rate, but the northern and southern provinces have low incidence rate.

Conclusion: The incidence of brucellosis in Iran is higher than in developed countries and similar to developing countries. Ten-year trend of disease incidence increased slightly, but it has decreased in recent years. It is necessary to improve the surveillance system and increase facilities for prevention and treatment in the high-risk areas including the west and northwest of Iran.