Sao Paulo Brazil Quietly Becomes Chikungunya Hot-Spot

So far this year, the mosquito-transmitted Chikungunya virus disease has caused outbreaks throughout the Region of the Americas.

Data reported on August 24, 2024, indicates that 161 Chikungunya-related deaths were reported in 2024, led by the Federative Republic of Brazil's 375,000 confirmed cases.

According to the local health department, while most of the Chikungunya cases have been reported in Brazil's mountainous regions, the country's Chikungunya hot spot could be in the state of São Paulo. 

The Municipality of São Paulo's Health Surveillance Coordination of the Health Department reported in mid-August that 29 locally acquired and 40 imported Chikungyna cases have occurred this year.

Since São Paulo is the most populous city in Brazil, with over 11 million residents, this data does not indicate a significant health risk.

However, a recent study concluded Brazil's Chikungunya infection rate is significantly under-counted.

The Lancet Infectious Diseases published results from a study in February 2024 investigating the risk of death in people infected with Chikungunya two years after the first symptoms of the disease.

This study concluded Chikungunya virus disease is associated with an increased risk of death for up to 84 days after symptom onset, including deaths from cerebrovascular diseases, ischaemic heart diseases, and diabetes.

A separate analysis of the blood samples from São José do Rio Preto, São Paulo, showed that the number of chikungunya cases in proportion to the population rose from 0.35% in 2015 to 2.3% in 2019.

These studies indicate that Chikungunya's actual health risk should be a primary concern to Sao Paulo's residents. 

In addition, regarding health risks to visitors, about 11.8 million tourists arrived in Sao Paulo in 2023, an increase of 22% over 2022.

And this trend has continued in 2024.

For example, in September, the NFL will conduct a game in Sao Paulo to attract local and international fans for the Eagles vs. Packers game on September 6, 2024, at Corinthians Arena.

From a risk-prevention option, there is now one U.S. FDA-approved Chikungyna vaccine, Valneva SE's IXCHIQ®.

The travel vaccine IXCHIQ was approved in the U.S. in 2023 and Canada and Europe in 2024. Regulatory reviews in the United Kingdom and Brazil are ongoing.

In the U.S., IXCHIQ is offered at travel vaccine clinics such as Passport Health USA and certain pharmacies.