Autochthonous dengue outbreak in Italy 2020: clinical, virological and entomological findings.

BACKGROUND: In August 2020, in the context of COVID-19 pandemics, an autochthonous dengue outbreak was identified for the first time in Italy. METHODS: Following the reporting of the index case of autochthonous dengue, epidemiological investigation, vector control and substances of human origin safety measures were immediately activated, according to the national arbovirus surveillance plan. Dengue cases were followed-up with weekly visits and laboratory tests until recovery and clearance of viral RNA from blood. RESULTS: The primary dengue case was identified in a young woman, who developed fever after returning from Indonesia to northern Italy, on 27 July 2020. She spent the mandatory quarantine for COVID-19 at home with relatives, six of whom developed dengue within two weeks. Epidemiological investigation identified further five autochthonous dengue cases among people who lived or stayed near the residence of the primary case. The last case of the outbreak developed fever on 29 September 2020. Dengue cases had a mild febrile illness, except one with persistent asthenia and myalgia. DENV-1 RNA was detected in blood and/or urine in all autochthonous cases, up to 35 days after fever onset. All cases developed IgM and IgG antibodies which cross-reacted with West Nile virus (WNV) and other flaviviruses. Sequencing of the full viral genome from blood samples showed over 99% nucleotide identity with DENV-1 strains isolated in China in 2014-2015; phylogenetic analysis classified the virus within Genotype I. Entomological site inspection identified a high density of Aedes albopictus mosquitoes, which conceivably sustained local DENV-1 transmission. Aedes koreicus mosquitoes were also collected in the site. CONCLUSIONS: Areas in Europe with high density of Aedes mosquitoes should be considered at risk for dengue transmission. The presence of endemic flaviviruses, such as WNV, might pose problems in the laboratory diagnosis.

Emergence of Lyme borreliosis in the province of Verona, Northern Italy: Five-years of sentinel surveillance.

We investigated the epidemiology, clinical manifestations, laboratory data and antibiotic treatment of Lyme borreliosis in the province of Verona, Northern Italy, during the period 2015-2019. One hundred and 29 cases of Lyme borreliosis were diagnosed in a single hospital representing 27 % of all cases reported in the Veneto region in the same period. The mean annual incidence of Lyme borreliosis was 0.992/100,000 inhabitants. A peak incidence of 2/100,000 inhabitants was observed in 2018. Early localized Lyme borreliosis was the most common presentation (74 %), followed by early disseminated Lyme borreliosis (21 %). One possible early Lyme neuroborreliosis and two cranial neuropathies were diagnosed. IgM and/or IgG borrelia antibodies were positive in 90 % of the cases. This significant increase of Lyme borreliosis incidence in the province of Verona highlights the need to increase knowledge on its epidemiology and clinical manifestation among both the general population and clinicians to allow early diagnosis and treatment.

Epidemiology and public health response in early phase of COVID-19 pandemic, Veneto Region, Italy, 21 February to 2 April 2020.

BackgroundVeneto was one of the Italian regions hit hardest by the early phase of the coronavirus disease (COVID-19) pandemic.AimThis paper describes the public health response and epidemiology of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in the Veneto Region from 21 February to 2 April 2020.MethodsInformation on the public health response was collected from regional health authorities' official sources. Epidemiological data were extracted from a web-based regional surveillance system. The epidemic curve was represented by date of testing. Characteristics of hospitalised COVID-19 cases were described and compared to those never admitted to hospital. Age- and sex-stratified case-fatality ratios (CFRs) were calculated.ResultsKey elements of the regional public health response were thorough case-finding and contact tracing, home care for non-severe cases, creation of dedicated COVID-19 healthcare facilities and activation of sub-intensive care units for non-invasive ventilation. As at 2 April 2020, 91,345 individuals were tested for SARS-CoV-2 and 10,457 (11.4%) were positive. Testing and attack rates were 18.6 per 1,000 and 213.2 per 100,000 population, respectively. The epidemic peaked around 20 to 24 March, with case numbers declining thereafter. Hospitalised cases (n = 3,623; 34.6%) were older and more frequently male compared with never-hospitalised cases. The CFR was 5.6% overall, and was higher among males and people > 60 years of age.ConclusionIn the Veneto Region, the strict social distancing measures imposed by the Italian government were supported by thorough case finding and contact tracing, as well as well-defined roles for different levels of care.

First autochthonous dengue outbreak in Italy, August 2020.

In August 2020, during the coronavirus disease (COVID-19) pandemic, five locally acquired cases of dengue virus type 1 were detected in a family cluster in Vicenza Province, North-East Italy where Aedes albopictus mosquitoes are endemic. The primary case was an importation from West Sumatra, Indonesia. This is the first outbreak of autochthonous dengue reported in Italy. During the COVID-19 pandemic, screening of febrile travelers from endemic countries is crucial in areas where competent vectors are present.

Human and entomological surveillance of West Nile fever, dengue and chikungunya in Veneto Region, Italy, 2010-2012.

BACKGROUND: Since 2010 Veneto region (North-Eastern Italy) planned a special integrated surveillance of summer fevers to promptly identify cases of West Nile Fever (WNF), dengue (DENV) and chikungunya (CHIKV). The objectives of this study were (i) To increase the detection rate of imported CHIKV and DENV cases in travellers from endemic areas and promptly identify potential autochthonous cases.(ii) To detect autochthonous cases of WNF, besides those of West Nile Neuroinvasive Disease (WNND) that were already included in a national surveillance. METHODS: Human surveillance: a traveler who had returned within the previous 15 days from endemic countries, with fever >38°C, absence of leucocytosis (leukocyte count <10,000 µL), and absence of other obvious causes of fever, after ruling out malaria, was considered a possible case of CHIKV or DENV. A possible autochthonous case of WNF was defined as a patient with fever >38°C for <7 days, no recent travel history and absence of other obvious causes of fever. Entomologic surveillance: for West Nile (WNV) it was carried out from May through November placing CDC-CO2 traps in five provinces of Veneto Region, while for DENV and CHIKV it was also performed around residences of viremic cases. RESULTS: Human surveillance: between 2010 and 2012, 234 patients with fever after travelling were screened, of which 27 (11,5%) were found infected (24 with DENV and 3 with CHIKV). No autochthonous case of DENV or CHIKV was detected. Autochthonous patients screened for WNF were 408, and 24 (5,9%) were confirmed cases. Entomologic surveillance: the WNV was found in 10, 2 and 11 pools of Culex pipiens from 2010 to 2012 respectively, in sites of Rovigo, Verona, Venezia and Treviso provinces). No infected Aedes albopictus with DENV or CHIKV was found. CONCLUSIONS: Veneto is the only Italian region reporting WNV human cases every year since 2008. WNV is likely to cause sporadic cases and unforeseeable outbreaks for decades. Including WNF in surveillance provides additional information and possibly an early alert system. Timely detection of DENV and CHIKV should prompt vector control measures to prevent local outbreaks.

Estimating the cumulative number of human immunodeficiency virus diagnoses by cross-linking from four different sources.

BACKGROUND: We estimated the cumulative number of people diagnosed with human immunodeficiency virus (HIV) infection in a region of Italy by cross-linking data from four surveillance systems and applying capture-recapture methods. METHODS: The study was conducted using data referring to residents of the Veneto Region (population 4.4 million). We cross-linked data from the AIDS Registry (data 1983-2000), the HIV Registry (1988-2000), the Death Registry (1992-1999), and the Hospital-Discharge Registry (1997-2000), using a code based on name, birth date, and sex. A specific software for capture-recapture models (CARE-1) was used to estimate the size of the target population with two different statistical approaches (sample coverage and log-linear models). RESULTS: A total of 2801 people were reported to the AIDS Registry, 6415 to the HIV Registry, 1598 to the Death Registry as HIV/AIDS-related deaths, and 3330 to the Hospital-Discharge Registry with a diagnosis of HIV infection. Overall, 8723 people were present in at least one registry: 4896 people were present in only one registry, 2387 in two registries, 1286 in three registries, and 154 in all four registries. Using the sample coverage approach, we estimated that, since the beginning of the epidemic in Veneto, an estimated 11 281 people (95% CI: 10 981, 11 621) should have been reported to at least one registry; thus the estimated coverage of the four registries was 77.3% (i.e. 8723/11 281). Results obtained applying the log-linear approach were similar, although the fitting of this model was not adequate. CONCLUSIONS: Cross-linking data from four different sources and applying the capture-recapture method can improve the accuracy of the estimates of the dimensions of the HIV epidemic.