Dengue, towards the worst epidemic in history in America. Italy first in Europe for cases

“There worst epidemic in the history of Dengue in America“. L'Pan American Health Organization (PAHO) has raised a new alarm about the increase in Dengue cases in the Americas. As of March 26, 2024, more have been reported in the region 3.5 million cases and more than 1,000 dead. “This is a cause for concern, because it represents three times as many cases as those reported for the same period in 2023, a record year with more than 4.5 million reports in the region,” the director of Ops Jarbas Barbosa.

Let's see what the situation is in Latin America and what we risk instead in Italy. The Ministry of Health has also published a handbook with the rules to follow when travelling.

Dengue, worst epidemic risk in history in Latin America

The Pan American Health Organization has raised a new alarm over the increase in dengue cases in the Americas. The disease is on the rise across Latin America and the Caribbean, but the countries most affected to date are Brazil (83%), Paraguay (5.3%) and Argentina (3.7%)accounting for 92% of cases and 87% of deaths.

This increase is essentially due to the higher virus transmission season in the Southern Hemisphere, when the so-called Aedes mosquito in Egyptivector of Dengue, thrives thanks to hot and rainy climate. The disease has in fact a seasonal trend: Most cases in the Southern Hemisphere occur in the first half of the year, while in the Northern Hemisphere most cases occur in the second half. The vector mosquito is distributed almost exclusively in the Americas, only Canada and mainland Chile are exempt.

PAHO director Jarbas Barbosa warned that we are also seeing an increase in cases in countries such as Barbados, Costa Rica, Guadeloupe, Guatemala, Martinique and Mexico, where transmission is usually highest in the second half of the year. And unfortunately, the presence of the mosquito vector and other cases have been detected in new geographic areas, raising concerns that some countries may not be prepared to deal with increased transmission. Of note is the case ofUruguayThat it has no cases of Dengue but it does have the mosquito in its territory.

The presence of all four dengue serotypes in the region increases the risk of epidemics and severe forms of the disease. The simultaneous circulation of two or more serotypes has been observed in 21 countries and territories in the Americas.

Barbosa stressed the importance of acting promptly to prevent and control the transmission of mosquito disease and avoid fatalities, underlining that despite the record increase in cases in 2023, Dengue case fatality rate in the region remained below 0.05%. This, she noted, “is very encouraging, considering the spikes in cases we have seen since then.”

This was possible thanks to PAHO's support to countries since 2010 through a global strategy to control Dengue and other mosquito-borne diseases. A strategy based on strengthening surveillance, early diagnosis and timely treatment of cases.

The causes of Dengue

Several environmental and social factors contribute to the spread of Dengue, includingincrease in temperaturesThe extreme weather events and the phenomenon El Niño. Also there rapid population growth and theurbanization unplanned play a crucial role. Poor housing conditions and inadequate water and sanitation services then create mosquito breeding sites through discarded objects that can collect water.

Today approximately 500 million people in the Americas are at risk of contracting Dengue. Incidence has increased in that region over the past four decades, from 1.5 million cumulative cases in the 1980s to 16.2 million in the decade 2010-2019.

In 2023, the highest number of cases was reported there, with a total of 4,565,911 cases, including 7,653 (0.17%) severe cases and 2,340 deaths, with a mortality rate of 0.051%. But it is worth noting that, after infection with one serotype, subsequent infection with a different serotype increases a person's risk of having severe to fatal dengue.

Dengue, what is mosquito disease

Dengue It is transmitted through the bite of an infected mosquito by one of the four serotypes of the virus. As the Italian Higher Institute of Health explains, therefore there is no direct contagion between human beings, even though humans are the main host of the virus. The virus circulates in the blood of the infected person for 2-7 days and in this period the mosquito can pick it up and transmit it to others.

As the Italian Ministry of Health also explains in a circular issued, it manifests itself as a febrile illness which can potentially affect everyone, newborns, children and adults, although it can even be asymptomatic in children. The infection can be symptomless even for adults, or present with symptoms ranging from a moderate fever to a disabling high fever, with severe headache, pain behind the eyes, muscle and joint pain, and skin rashes. The disease can progress to severe when shock, shortness of breath, severe bleeding and/or organ complications occur. Unfortunately, to date there is no specific drug to treat it.

There is no specific cure or drug for Dengue and in most cases people they heal completely in two weeks. However, experts recommend absolute rest, drugs to reduce fever and administration of liquids to combat dehydration. In some cases, tiredness and exhaustion can remain for a few weeks.

In Brazil, however, scientists will use millions of mosquitoes modified by the Wolbachia bacterium to fight the virus. The country led by Lula thus aims to create a containment campaign by activating a process of cytoplasmic incompatibility with the aim of putting a stop to the almost 2 million dengue infections.

The situation in Europe and Italy

In Europe there are 3 countries that have recorded cases ed native epidemics sporadic cases of Dengue, between January 1 and December 5, 2023.Unfortunately, Italy is the first, with 82 casesfollowed by France, 43 cases, and Spain, 3. Last November, a fatal case was also recorded in Florence.

As the Director General of the Ministry of Health Francesco Vaia explained, “the Aedes aegypti mosquito, a specific mosquito vector of Zika and also of the Dengue virus, is not present in our territory and, therefore, we want to prevent its arrival in Italy. Among other things, our country is one of the few if not the only one in Europe that has these measures at the border.”

In February 2023, the Aifa-Italian Medicines Agency authorized the use and marketing of Qdenga (Takeda)a Vaccine tetravalent live attenuated for the prevention of disease caused by any of the four serotypes of the virus. The vaccine also received approval from the EMA-European medicines agency in December 2022. A second vaccine, the Dengvaxia (Sanofi Pasteur), not marketed in Italyis indicated only for people residing in endemic areas and who have had a previous Dengue infection, confirmed through laboratory tests.

The advice of the Ministry of Health

The Italian Ministry of Health has developed some recommendations on who should travel, useful actions to take before, during and after the trip.

Before leaving on a trip

First of all, it is useful to find out about the presence of Dengue in the destination country, also by consulting the website of the Ministry of Foreign Affairs and International Cooperation.

It is also necessary to refer to the travel medicine center for any vaccination.

Prevent mosquito bites

When you travel, prevent mosquito bites, especially in the early morning and late afternoon, using small precautions:

  • wear long, light-colored clothing that covers most of your body
  • use mosquito and insect repellents
  • stay if possible in places equipped with mosquito nets and air conditioning.

Upon returning to Italy

Upon returning to Italy, as a precaution, the Ministry of Health suggests contacting your doctor as soon as possible, reporting your recent trip, if in the 14 days following your return you develop symptoms compatible with Dengue, such as:

  • even high fever with sudden onset
  • headache
  • eye pain
  • joint and muscle pain
  • nausea and vomit
  • enlarged lymph nodes
  • skin rashes
  • minor hemorrhages.