America’s Chikungunya Spread Amid Rising Cases- Report
Infected female Aedes mosquitoes spread chikungunya. The most common symptom is sudden fever and joint pain that lasts two weeks.
While disease mortality is low, some patients experience debilitating pain for up to 6 months, affecting their ability to work, move, and care for others. Chikungunya means “bent over in pain” in Makonde.
Nearly 115 countries have reported seasonal or sporadic outbreaks of the disease. However, five Americas countries saw increased chikungunya circulation in 2023.
Chikungunya arrived in the Americas in 2013 on St. Martin and spread to most countries a year later. The continent’s first year saw over a million cases.
Chikungunya cases increased by 214,000 in the first four months of 2023.
This year we see magnitude and timing changes. Thais dos Santos, PAHO/WHO Advisor on Surveillance and Control of Arboviral Diseases, said during the WHO EPI-WIN webinar: Chikungunya—Americas outbreak response experiences.
“Paraguay had its worst epidemic in history with 138,730 cases,” dos Santos said.
In 2023, Argentina and Uruguay reported local transmission for the first time, and Bolivia reported high levels of chikungunya (1,150 cases) and dengue (116,224 cases), another mosquito-borne disease.
Climate change, and unplanned urbanization drive gearbox
Climate change spreads chikungunya. Aedes mosquitoes have invaded areas where they couldn’t survive due to high temperatures, anticipated or increased rains, and humidity.
“Longer stretches of warmer periods in the south of the Americas have enabled the mosquito to do well in places where it didn’t before,” dos Santos said.
Aedes prefer urban and warm environments, breeding in household water sources like plant holders or vases. Unplanned urbanization may also be spreading it.
Movement restrictions during the COVID-19 pandemic may have limited vector control methods like house control to remove breeding sites and insecticide resistance.
There is no approved chikungunya vaccine or treatment, but seven are in development, and three are in Phase-3 clinical trials.
Avoid mosquitoes for now. Insecticides, nets, and mosquito breeding sites are recommended.
“We must engage communities, identify local mosquito ecology and hotspots, and develop a control plan and strategy,” said panelist Dr. Thomas Scott, Professor Emeritus of Entomology and Nematology at the University of California Davis.
Following the COVID-19 pandemic, disease surveillance is essential. “PCR testing capacity has expanded enormously and can be used for other pathogens,” said WHO Emerging Diseases and Zoonoses Unit Head Dr. Maria Van Kerkhove. She also suggested expanding genomic surveillance to other pathogens.
In January, the Pan American Health Organisation (PAHO) warned of rising chikungunya cases, especially in Paraguay, and on February 13, it issued an alert urging countries to improve diagnosis and treatment.
Since the outbreak began, the organization has sent seven technical missions to Paraguay and Bolivia to support clinical management, surveillance, laboratory, and integrated vector control.
“We trained thousands of clinicians, filling an important gap in disease management,” dos Santos said. The organization quickly arranged for experts from countries with more virus experience, like Brazil, to help others with genotyping or pediatric case management.
PAHO also implemented innovative strategies for collaborative surveillance among countries using shared virtual spaces to support automated analysis and visualization for case data and is working on an integrated vector management tool to help countries map vector circulation risk areas to inform quick interventions.