Foshan city in Guangdong Province is experiencing the country’s largest outbreak of chikungunya, a mosquito-borne viral disease that causes debilitating joint pain, fever, and fatigue. As of July 24, 2025, 3,645 cases have been confirmed—most of them mild, but alarming due to the rapid spread and potential for further outbreaks in surrounding regions.This surge represents the most significant chikungunya transmission on the Chinese mainland since the virus was first detected there nearly two decades ago.The epidemic began with an imported case of chikungunya in early July in Shunde District of Foshan, which is roughly 119 kilometers north of Hong Kong. Within weeks, cases ballooned to more than 3,300 in Shunde alone. Chinese officials have not officially attributed the cause, but experts cite favorable climatic conditions—hot and humid that facilitate mosquito breeding—and increased global travel as main drivers.Chikungunya is transmitted by the Aedes mosquito, most specifically Aedes aegypti and Aedes albopictus. Both insects are famous for their daytime aggression of biting and love for tropical and subtropical regions.Why Chikungunya Is No Minor Illness Even After All These Years?The World Health Organization (WHO) defines chikungunya as a disease that is marked by severe joint pain, high fever, and signs and symptoms of headache, muscle pain, rash, vomiting, and fatigue. Though the majority of Foshan cases have been reported as mild, the disabling joint pain of the disease may persist for weeks or even months and can affect daily activities and productivity.While not usually lethal, chikungunya has the potential to create large-scale public health disturbances, particularly in highly congested urban areas with inadequate mosquito control. To date, no serious or deadly cases have been reported in this outbreak, as indicated by China's Centre for Health Protection (CHP), but public health specialists caution against taking the situation lightly.How Climate and Travel Are Driving This Outbreak?Specialized tropical medicine doctors attribute the peak to favorable climatic conditions that promote quick growth of Aedes populations. These are aggressive, day-biting mosquitoes that thrive in warm, wet conditions, noting how climate change plays a major role in expanding habitats for mosquitoes.Combine this international travel—imported and first case—and lack of immunity in the general population in China, and the stage was set for an outbreak. Chikungunya is not indigenous to China, so there is no herd immunity in the general population, and it was easier for the virus to establish itself and spread rapidly.Link Between Chikungunya Cases on the Rise GloballyThis outbreak is not unique. The European Centre for Disease Prevention and Control (ECDC) has reported 220,000 cases of chikungunya and 80 deaths in 2025 thus far worldwide. The WHO has made a global call to action citing the spread of chikungunya into new regions such as France and Italy, which have each reported locally-acquired infections in 2025.Over five billion individuals in 119 countries reside in regions exposed to chikungunya infection and thus is considered a global health issue. The tropical diseases of chikungunya, dengue, and Zika are no longer limited to the equatorial belt-they are now reported from temperate regions as well.To date, Hong Kong—a highly populated international center—has not seen any chikungunya cases after 2020. The territory is not home to Aedes aegypti, the main vector mosquito, but Aedes albopictus, a secondary vector known to spread the disease, is found there. The CHP cautions that imported cases still have the potential to result in local transmission if infected persons are bitten by mosquitoes within their communicable period.Macao, just south of Guangdong, has registered its first two cases of chikungunya this year, both of them imported from Foshan and nearby Nanhai. Local authorities have stepped up mosquito control as a precaution against possible spread.How Is China Managing The Outbreak?With not much else in its bag of tricks, Guangdong Province has increased mosquito control operations, encouraging residents to clear standing water, unblock choked drains, and observe simple household sanitation. This is essential in interrupting the mosquito life cycle because still water provides a breeding ground for Aedes mosquitoes.The CHP also recommends applying insect repellents, especially containing DEET or other WHO-recommended active compounds, and wearing long-sleeved clothing, especially in the early morning and late afternoon when mosquitoes are most prevalent.The United States has only two licensed chikungunya vaccines, recommended mainly for visitors going to outbreak areas. However, China also doesn't have these vaccines available, which makes its citizens susceptible to successive waves unless mass vaccination is implemented or localized vaccines are created.This leaves health authorities with few options: mosquito control, public awareness, and early diagnosis remain the main line of defense for the time being.This epidemic is a clear message. Diseases such as chikungunya no longer remain isolated in small enclaves of tropical countries. With the climate still rising and international travel recovering after the pandemic, infectious disease is set to travel quicker and more far-reaching than ever before.Dr. Tsui, a Guangdong public health official, explained in a press statement that chikungunya has the potential to quickly blow into large-scale outbreaks, particularly in highly populated regions with low mosquito densities and little immunity. The burden on healthcare systems, particularly in fast-growing urban areas of Asia, is a legitimate and increasing concern.