WHO sends dengue warning signal - Global surveillance begins

High risk globally and due to summer

Screenshot 9 10 dengue, WHO

The World Health Organization (WHO) classifies dengue fever as a global public health threat and raises the risk level to high, as more than 7,6 million cases of dengue fever have been reported so far this year, with 3,4 million cases have also been laboratory confirmed. Serious cases exceeded 16.000 and deaths were over 3.000.

In the last five years, there has been a significant increase in Dengue Fever cases internationally, mainly in the Americas, where cases exceeded 7 million by the end of April, surpassing 4,6 million cases in 2023.

With this data, the WHO is creating an application with a real-time monitoring table of cases and highlights the risks of spreading the disease due to travel.

Europe is likely to expect limited, localized transmission during the coming summer months and early autumn

Dengue, Chikungunya and Zika and their spread around the world. In blue all three diseases, in green the two except Zika

At the same time, the global surveillance system also operates, where monthly reports are drawn up from all regions to monitor the trends and frequency of the disease.

The WHO notes that dengue outbreaks are spreading, the risk of international transmission exists, and given the complexity of factors influencing transmission, "the overall global risk is still assessed as high and therefore dengue remains a global threat to public health".

Spreading problem

From the data recorded so far, 90 countries have active dengue transmission this year, but not all cases have been officially reported. In addition, many countries where the virus is endemic lack robust detection and reporting mechanisms, resulting in the true burden of the disease not being fully captured.

In order to control transmission more effectively, robust real-time dengue surveillance is needed to address the risks of: potential undetected cases, co-circulation of other arboviruses and misdiagnosis, and spread of the virus through travel.

These factors could contribute to the spread of the disease without recognition and create a potential risk for local transmission in countries where the virus is not endemic.

The dengue virus is transmitted to humans by the bite of an infected mosquito.

Cases are usually asymptomatic or the disease is mild with fever. However, in some cases the illness is severe and may include shock, severe bleeding or severe organ damage.

The overall capacity of countries to respond to multiple, simultaneous outbreaks continues to be strained due to global resource shortages, leading to shortages of good quality diagnostic tests for early detection, lack of trained personnel to control the disease in humans, and to observe course of mosquitoes that carry the virus, as well as to raise awareness among citizens.

Emergency response mechanisms are in place and WHO is supporting high-risk countries in affected areas.

Aedes albopictus and Aedes aegypti mosquitoes can transmit in addition to dengue and the chikungunya and zika viruses

The aedes aegypti mosquito has established itself in Cyprus and Portugal

aedes aegypti cdc9256 f3a802 dengue, WHO

In Europe

Dengue is not endemic in Europe, where reported cases are mostly travel-related. Nevertheless, since 2010 indigenous cases of dengue have been recorded in Croatia, France, Italy, Portugal (Madeira) and Spain.

In 2023, indigenous cases were reported in three countries: Italy 82, France 45 and Spain three.

No indigenous cases of dengue fever have been reported in Europe this year, although summer, when mosquito activity begins, has not yet begun.

Dengue testing is limited in many countries of the WHO European Region, especially outside the European Union. At the same time, most cases are estimated to be first-time infections, so they will be mild and will not require treatment. Thus, it is expected that the incidence of the disease will be underestimated.

The WHO notes that Europe is likely to expect limited, localized transmission during the coming summer months and early fall.

He emphasizes that the mosquitoes that carry the disease are Aedes albopictus and Aedes aegypti. Aedes albopictus has become established in northern and western Europe in the last ten years. Aedes aegypti has already established itself in Cyprus and Madeira, Portugal.

The aedes albopictus mosquito has been established in Europe for 10 years

Aedes albopictus dengue, WHO

Double infections

As these mosquitoes can be infected with both the chikungunya and Zika viruses, they can transmit all three dangerous viruses. Thus, in some areas, parallel infections are found, such as in the Minas Gerais region of Brazil, where of the approximately 830.000 cases of possible arboviruses, 65,9% were chikungunya infections and 34,1% dengue.

The WHO points out that since it is the same carrier of all the above viruses, then common policies to limit these viruses aimed at prevention through mosquito control and public awareness can prove effective for all mosquito-borne diseases. The exception is Zika, which poses a threat to pregnant women, but is extremely limited in Latin America, with 7.000 cases reported this year alone, when more than 2024 cases of chikungunya are expected by 250.000.

Source: in.gr