Dengue 2018-2024 - Centro Nazionale Sangue

Dengue is a viral infection caused by the Dengue virus (DENV), transmitted to humans through the bite of infected mosquitoes. There is no direct infection between humans, even if 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 other individuals. In the Western Hemisphere the main vector is the Aedes aegypti mosquito, although cases of transmission by Aedes albopictus have been recorded. Dengue has been known for over two centuries, and is particularly present during and after the rainy season in the tropical and subtropical areas of Africa, Southeast Asia and China, India, the Middle East, Latin and Central America, Australia and several areas of the Pacific.

EpIn recent decades, the spread of dengue has grown in many tropical regions. In northern hemisphere countries, particularly in Europe, it poses a danger from a global health perspective, as it manifests itself mainly as an imported disease, the rising incidence of which is due to the increased movement of goods and people. According to the WHO, the incidence of dengue has increased 30-fold in the last 50 years. It is estimated that up to 50-100 million infections occur annually in more than 100 endemic countries, putting almost half of the world’s population at risk.

Epidemiological Surveillance (Update 15/11/2024)

The following information are based on the epidemiological updates provided by the European Center Disease and Control – ECDC, through the Multi-country (World) Monitoring global outbreaks, the following is represented.

As of January 2024, over half a million cases of DENV infection and over 100 related deaths have been reported globally. As reported in the PAHO/WHO epidemiological bulletin, the majority of cases were reported in the Americas region, with a cumulative number of 673,267 suspected cases in the first five weeks of 2024, and an increase of 156% compared to the same period in 2023 and 225% compared to the average of the last 5 years. In particular, the increase in cases has been reported in Brazil, where the circulation of all four DENV serotypes has been detected.

An increase in DENV circulation has been detected in the Department of French Guiana, with over 2,000 cases in the first four weeks of 2024. DENV circulation is still reported in the Departments of Guadeloupe and Martinique, and the Collectivities of Saint-Martin and Saint Barthèlemy ( France), with hospitalizations showing a decreasing trend after the increases in previous months.

In January 2024, circulation of DENV was also reported in the WHO South-East Asia and Western Pacific regions. The number of cases reported from Bangladesh and Sri Lanka is within expected levels, while in January 2024 Thailand reported a 7.3% increase in the number of cases compared to December 2023 (11,180 DENV cases and five deaths).

In Africa, DENV was reported in 2024 in four African Union Member States (Ethiopia, Mali, Mauritius, São Tomé and Príncipe).

With reference to the European epidemiological situation, the European Center Disease and Control – ECDC reports the presence of indigenous cases of DENV infection in the following territories:

France:
– Gard Department (Occitanie Region)

The measures are also in force for the overseas departments of Guadeloupe, French Guiana, Martinique and Réunion and for the collectivities of Saint-Martin and Saint Barthèlemy.

Spain:
– Province of Tarragona

Given the above, without prejudice to the provisions of the Ministerial Decree of 2 November 2015 relating to the exclusion criteria for travel to tropical areas, with respect to other European and non-European areas with active circulation reported by the WHO and ECDC, it is recommended to:

Strengthen surveillance measures on possible imported cases of DENV by activating anamnestic surveillance of blood donors for travel to risk areas;
For donors who have stayed in the affected areas apply a temporary suspension of 28 days starting from the return date or, alternatively, carry out the DENV NAT test on all donors;
For donors with a positive history of DENV infection (documented infection or appearance of symptoms compatible with DENV infection) apply a temporary suspension of 120 days starting from the resolution of symptoms
Raise awareness among donors to inform the competent transfusion service in the event of the appearance of symptoms compatible with DENV infection or in the event of a diagnosis of DENV infection in the 14 days following the donation (post donation information).

Italy
In Italy, following the reporting of confirmed indigenous cases of Dengue virus (DENV) infection in the municipalities of Pesaro and Fano (Pesaro-Urbino), Ortona (Chieti), Sesto Fiorentino (Florence), Castelfidardo (Ancona), the following measures remain in force for the prevention of transfusion transmission:

For the municipality of Fano (PU):
1. Temporary suspension of blood and blood component collection, alternatively, carrying out the DENV NAT test on all donors;
2. ask donors to inform the competent transfusion service in the event of the appearance of symptoms compatible with DENV infection, or in the event of a diagnosis of DENV infection, in the 14 days following the donation (post donation information).

For the municipality of Ortona (CH)
1. Temporary suspension of blood and blood component collection, alternatively, carrying out the DENV NAT test on all donors;
2. ask donors to inform the competent transfusion service in the event of the appearance of symptoms compatible with DENV infection, or in the event of a diagnosis of DENV infection, in the 14 days following the donation (post donation information).

For the municipality of Pesaro (PU)
1. Temporary suspension of blood and blood component collection, alternatively, carrying out the DENV NAT test on all donors;
2. ask donors to inform the competent transfusion service in the event of the appearance of symptoms compatible with DENV infection, or in the event of a diagnosis of DENV infection, in the 14 days following the donation (post donation information).

For the municipality of Sesto Fiorentino (FI)
1. Temporary suspension of blood and blood component collection, alternatively, carrying out the DENV NAT test on all donors;
2. ask donors to inform the competent transfusion service in the event of the appearance of symptoms compatible with DENV infection, or in the event of a diagnosis of DENV infection, in the 14 days following the donation (post donation information).

For the municipality of Castelfidardo (AN)
1. Temporary suspension of blood and blood component collection, alternatively, carrying out the DENV NAT test on all donors;
2. ask donors to inform the competent transfusion service in the event of the appearance of symptoms compatible with DENV infection, or in the event of a diagnosis of DENV infection, in the 14 days following the donation (post donation information).

At the national level:
1. Strengthening of the anamnestic selection investigation, required by current regulatory provisions, ascertaining whether the donor:

As of 12 September 2024, he/she stayed, even for a few hours, in the municipality of Fano (PU)
As of 25 September 2024, he/she stayed, even for a few hours, in the municipality of Ortona (CH).
As of 7 October 2024, he/she stayed, even for a few hours, in the municipality of Pesaro (PU).
As of 9 October 2024, he/she stayed, even for a few hours, in the municipality of Sesto Fiorentino (FI)
As of 11 October 2024, he/she stayed, even for a few hours, in the municipality of Castelfidardo (AN)

2. Temporary suspension of 28 days starting from the return date for donors who have stayed in the municipalities of Fano (PU), Ortona (CH), Pesaro (PU), Sesto Fiorentino (FI) and Castelfidardo (AN) or, alternatively, running the DENV NAT test;
3. Raising awareness among donors to inform the relevant transfusion service in the event of the appearance of symptoms compatible with DENV infection or in the event of a diagnosis of DENV infection in the 14 days following the donation (post donation information).

The National Blood Center will update these indications following the evolution of the national and international epidemiological situation. For circulars regarding prevention measures for HSCs, please refer to the dedicated CNT page

Countries/Territories/Areas reporting indigenous dengue cases (November 2022-2023). Source WHO

Decrees (Italian Text)