Caspian Journal of

Introduction
Dengue fever, caused by dengue virus (Flaviviridae: Flavivirus), is a mosquito-borne virus that poses a significant public health threat worldwide. It is classified as neglected, emerging or reemerging infectious viruses. With an estimated 390 million infections annually, it has become one of the fastest-growing mosquito-borne diseases globally. While traditionally prevalent in tropical and subtropical regions, recent years have witnessed the expansion of dengue fever into new territories, including neighboring countries in Iran [1, 2, 3, 4]. Fifteen countries have a water or land border with Iran. The countries with land borders include Afghanistan, Armenia, Pakistan and Turkey. The countries with water borders include Bahrain, Kazakhstan, Kuwait, Oman, Qatar, Russia, Saudi Arabia, and the United Arab Emirates. The countries with land and water borders include Azerbaijan, Iraq and Turkmenistan (Figure 1). This review deals with the distribution of dengue fever in Iran’s neighboring countries and the risk of transmission to Iran.



Understanding dengue fever and its global distribution
Understanding the global distribution patterns of dengue fever is crucial for effective prevention and control strategies. Several factors contribute to the spread of dengue virus, such as urbanization, population movements, climate change and inadequate mosquito control measures. By examining these factors and studying the distribution trends of dengue fever in neighboring countries of Iran, we can gain valuable insights into potential risks for Iran itself [4, 5, 6, 7].

The spread of dengue fever in neighboring countries of Iran
Dengue fever, a mosquito-borne virus, has become a growing concern in the neighboring countries of Iran (Figure 1). Regardless, dengue fever has spread to Asian countries such as Bangladesh, Indonesia, Malaysia, and the Philippines. Yemen and India, which are also involved in dengue fever, are among the countries that have relations with Iran. The disease and the infected Aedes mosquitoes with the dengue virus have reached the borders of Iran, including Afghanistan, Pakistan and Saudi Arabia. There are imported cases in more countries neighboring Iran, including Kuwait, Oman, Qatar, and Turkey. The disease is widespread in Sindh Province of Pakistan, especially in Karachi [2, 8]. Similarly, Afghanistan and Iraq have also reported an upsurge in dengue fever cases. In Afghanistan, 15 confirmed cases were reported from six provinces between May and December 2019 [9]. The first recorded case in Saudi Arabia was in October 1993. However, daily data indicated that 2023 would be a major epidemic year. The numbers of infections has reached 4099 so far during the first half of the year, which indicate a significant increase compared to previous years [10].
The increasing incidence of dengue fever cases in these regions has raised alarm bells among health authorities. Pakistan, in particular, has experienced a significant surge in dengue fever cases over the past few years. The densely populated urban areas and inadequate sanitation infrastructure contribute to the rapid spread of the virus [3, 11, 12]. The reasons behind this distribution are multifaceted. Factors such as climate change, urbanization, population movements, and insufficient vector control measures play a crucial role in facilitating the spread of dengue fever across borders [13, 14].

Factors affecting dengue fever distribution in Iran's neighboring countries
The dengue fever distribution in neighboring countries of Iran is influenced by several factors. Firstly, the geographical proximity between these countries allows for the movement of infected individuals and mosquitoes, facilitating the spread of the disease. Additionally, similar climatic conditions across neighboring regions create favorable environments for mosquito breeding and survival. Socioeconomic factors also play a significant role in dengue distribution [3, 15, 16].
Poor sanitation infrastructure, inadequate waste management, and limited access to clean water supply contribute to the proliferation of mosquito breeding sites in these areas. Moreover, population density and urbanization increase human-mosquito interactions, enhancing the transmission potential. Travel patterns and globalization further amplify the risk of dengue introduction into neighboring countries. International travel and trade facilitate the movement of infected individuals or mosquitoes carrying dengue virus strains from endemic regions to nearby areas [3, 6, 7, 17, 18].
Dengue fever poses a potential threat to the neighboring countries of Iran. While indigenous case of dengue fever has not yet been reported in Iran, its presence in nearby regions raises concerns about its potential spread due to the imported cases that have been reported. The disease is prevalent in tropical and subtropical areas, making the neighboring countries vulnerable to its transmission. Invasive Aedes mosquito species carrying the dengue virus are capable of crossing borders, especially during periods of increased travel and trade [2, 3, 17, 19, 20, 21]. Climate change further exacerbates the risk, as it creates favorable conditions for mosquito breeding and survival. With rising global temperatures, there is an increased likelihood that these disease-carrying mosquitoes may expand their range into new territories. Iran’s proximity to countries with reported dengue cases necessitates proactive measures to prevent an outbreak within its borders [3, 22].

Ethical Considerations

Compliance with ethical guidelines
There were no ethical considerations to be considered in this research

Funding
This research did not receive any grant from funding agencies in the public, commercial, or non-profit sectors. 




References