In June, the US Centers for Disease Control and Prevention (CDC) shared the unwelcome news that countries listed in the Americas are currently reporting higher-than-usual numbers of dengue cases. Case numbers in Argentina, for instance, are fast-approaching the 80,000 reported throughout 2016 – itself a record year. What’s behind these numbers?

The Americas may still be feeling the impact of last year’s dengue outbreaks, which reached an all-time high. During 2019, case numbers across the region exceeded 3.1 million, with 1,500 fatalities, according to the most recent data from the Pan American Health Organization (PAHO). Dengue hit Brazil the hardest. The country reported more than 2.2 million cases and almost 800 fatalities.

Paraguay and Bolivia are seeing unprecedented case numbers. According to PAHO data, Paraguay reported almost 220,000 infections up until early June, which is 50 times the number reported during the same period in 2019 and 18 times the 2019 total. Bolivia reported almost 83,000 up until epidemiological week 22, which is nearly ten times the same period in 2019 and five times the 2019 total.

Argentina borders both Paraguay and Bolivia to its north. Here total dengue numbers had been continuing a gradual year-on-year rise: 3,220 in 2019, 1,829 in 2018, and 557 in 2017. The early months of 2020 were a different story; like Paraguay and Bolivia, numbers exploded: 72,701 dengue infections, including 24 fatalities – 29 times the number reported during the same period in 2019 and 24 times the 2019 total.

Numbers are also on the rise in Belize, Colombia, Costa Rica, Dominican Republic, El Salvador, Guadeloupe, Guatemala, Honduras, Mexico, Nicaragua, Peru and Saint Martin. Brazil, on the other hand, is seeing fewer cases in 2020. Until early June, the country had only reported two-thirds of the number reported during the same period in 2019: just under 1.1 million in 2020 versus just shy of 1.7 million in 2019.

Dengue has also reached North America. Miami-Dade in South Florida reported the state’s first locally-acquired dengue fever case of 2020 late in May, reports CBS Miami.

Is COVID-19 to blame?

The Americas are a major hotspot for COVID-19 outbreaks, reports Euractiv. While the larger US epidemics – in New York and New Jersey – are in decline, thousands of cases are reported daily in Brazil, Peru, Mexico and Chile. Although testing capacity in some countries is limited, Latin America appears to be the world’s worst-affected region, now that European outbreaks have abated. And many country’s health services are not sufficiently financed for this kind of emergency.

Could numbers, therefore, be down to dengue patients not receiving the treatment they need? Are they staying at home because they’re worried about COVID-19? Are overwhelmed hospitals having to turn them away?

Paraguayan lawyer Sonia Fernandez told Reuters that she had avoided seeking care when she and her two daughters got sick with dengue at the beginning of April. “All three of us had dengue, we had all the symptoms, the pain, the rash, but we didn’t go to a clinic or a health centre so as not to expose ourselves [to COVID-19],” Fernandez said. All three have since recovered, the report reveals.

People not seeking treatment may also lead to under-reporting, as Esteban Ortiz, a global health researcher at Quito’s University of the Americas in Ecuador, explained to Reuters: “Very clearly dengue is being under-reported. Cases haven’t decreased; the diagnosis of cases has decreased.” Ecuador has thus far reported 9,300 dengue cases in 2020, 1,100 more than 2019 totals.

COVID-19 may also be slowing the spread of dengue. Shut borders and flight restrictions are halting its march around the globe.

Are you currently in the Americas? Tell us how COVID-19 is impacting dengue infections and what could be done to limit that in your community.