Sequential or Combination Treatments as Rescue Therapies in Immunocompromised Patients with Persistent SARS-CoV-2 Infection in the Omicron Era: A Case Series.

Prolonged SARS-CoV-2 infections are widely described in immunosuppressed patients, but safe and effective treatment strategies are lacking. We aimed to outline our approach to treating persistent COVID-19 in patients with immunosuppression from different causes. In this case series, we retrospectively enrolled all immunosuppressed patients with persistent SARS-CoV-2 infections treated at our centers between March 2022 and February 2023. Patients received different sequential or combination regimens, including antivirals (remdesivir, nirmatrelvir/ritonavir, or molnupiravir) and/or monoclonal antibodies (mAbs) (tixagevimab/cilgavimab or sotrovimab). The main outcome was a complete virological response (negative SARS-CoV-2 RT-PCR on nasopharyngeal swabs) at the end of treatment. Fifteen patients were included as follows: eleven (11/15; 73%) with hematological disease and four (4/15; 27%) with recently diagnosed HIV/AIDS infection. Six patients (6/15; 40%) received a single antiviral course, four patients (4/15; 27%) received an antiviral and mAbs sequentially, and two patients (13%) received three lines of treatment (a sequence of three antivirals or two antivirals and mAbs). A combination of two antivirals or one antiviral plus mAbs was administered in three cases (3/15, 20%). One patient died while still positive for SARS-CoV-2, while fourteen (14/15; 93%) tested negative within 16 days after the end of treatment. The median time to negativization since the last treatment was 2.5 days. Both sequential and combination regimens used in this study demonstrated high efficacy and safety in the high-risk group of immunosuppressed patients.

The Influence of Sex, Gender, and Age on COVID-19 Data in the Piedmont Region (Northwest Italy): The Virus Prefers Men.

Several important sex and gender differences in the clinical manifestation of diseases have been known for a long time but are still underestimated. The infectious Coronavirus 2019 disease pandemic has provided evidence of the importance of a sex and gender-based approach; it mainly affected men with worse symptomatology due to a different immune system, which is stronger in women, and to the Angiotensin-converting enzyme 2 and Transmembrane protease serine 2 roles which are differently expressed among the sexes. Additionally, women are more inclined to maintain social distance and smoke less. Analysis of data on the infectious Coronavirus 2019 disease testing from people admitted to the Amedeo di Savoia Hospital, a regional referral center for infectious diseases, has been applied to the whole of 2020 data (254,640 records). A high percentage of data in the dataset was not suitable due to a lack of information or entering errors. Among the suitable samples, records have been analyzed for positive/negative outcomes, matching records for unique subjects (N = 123,542), to evaluate individual recurrence of testing. Data are presented in age and sex-disaggregated ways. Analyses of the suitable sample also concerned the relation between testing and hospital admission motivation and symptoms. Our analysis indicated that a sex and gender-based approach is mandatory for patients and the National Health System's sustainability.

Fast and reliable real life data on COVID-19 triaging with ID NOW.

In the context of SARS-CoV-2 pandemic, rapid and easy-to-perform diagnostic methods are essential to limit the spread of the virus and for the clinical management of COVID-19 patients. Although real-time polymerase chain reaction remains the "gold standard" to diagnose acute infections, this technique is expensive, requires trained personnel, well-equipped laboratory and is time-consuming. A prospective evaluation of the Abbott ID NOW COVID-19 point-of-care testing that uses isothermal nucleic acid amplification for the qualitative detection of SARS-CoV-2 RdRp gene was run in the Emergency Department during the third wave of COVID-19 pandemic. ID-NOW significantly simplified SARS-CoV-2 identification and COVID-19 patient triaging, being highly valuable in rapidly locating febrile patients in or out of COVID-19 areas, and can be considered as a first-line diagnostic test in the Emergency Room setting.

SARS-CoV-2 microfluidic antigen point-of-care testing in Emergency Room patients during COVID-19 pandemic.

In Emergency Room, Point-of-care antigen testing for SARS-CoV-2 antigen can expedite clinical strategies for patient management. We tested 1,232 consecutive patients during Italian second wave peak using the recent LumiraDx microfluidic assay. This assay showed high concordance (96.9 %), sensitivity and specificity compared to molecular testing, being highly valuable.

Urgent need of rapid tests for SARS CoV-2 antigen detection: Evaluation of the SD-Biosensor antigen test for SARS-CoV-2.

At the time of writing, FIND has listed four CE-marked SARSCoV-2 antigen tests. We evaluated the recently CE-approved rapid POCT SD-Biosensor for SARS-CoV-2 nucleoprotein detection in nasopharyngeal secretions from 330 patients admitted to the Emergency Room for a suspect of COVID-19 and travelers returning home from high risk countries. Sensitivity, specificity, accuracy, negative and predictive values were consistent with the use of the test to mass-screening for SARS-CoV-2 surveillance.

HIV-1 detection in the olfactory mucosa of HIV-1-infected participants.

OBJECTIVE: HIV infection chronically affects the central nervous system (CNS). Olfactory mucosa is a unique site in the respiratory tract that is directly connected to the CNS; thus we wanted to evaluate olfactory mucosa as a surrogate of CNS sampling. DESIGN: We conducted a preliminary study examining HIV populations and susceptible cells in the olfactory mucosa. METHODS: Olfactory mucosa was sampled by minimally invasive brushing. Cerebrospinal fluid (CSF) analyses were performed as per routine clinical procedures. Olfactory marker protein, CD4+, CD8+, and trans-activator of transcription (TAT) expressions were assessed by immunohistochemistry. Plasma, CSF, and olfactory mucosa HIV-RNA were quantified using the Cobas AmpliPrep/Cobas TaqMan assay, whereas HIV proviral DNA was evaluated on peripheral blood mononuclear cell and olfactory mucosa. HIV-1 env deep sequencing was performed for phylogenetic analysis. RESULTS: Among ART-naive participants, 88.2% (15/17), and among ART-treated participants, 21.4% (6/28) had detectable HIV-RNA in samples from their olfactory mucosa; CSF escape was more common in patients with olfactory mucosa escape (50 vs. 7.9%; P = 0.010). Olfactory mucosa samples contained few cells positive for CD4, CD8, or HIV-DNA, and no HIV TAT-positive cells, indicating that this approach efficiently samples virions in the olfactory mucosa, but not HIV-infected cells. Yet, using a deep sequencing approach to phylogenetically compare partial HIV env genes in five untreated participants, we identified distinct viral lineages in the OM. CONCLUSIONS: The results of this study suggest that nasal brushing is a well tolerated and useful technique for sampling the olfactory mucosa. HIV-RNA was detected in most naïve and in some treated patients, warranting larger longitudinal studies.

Laboratory findings in Zika infection: The experience of a reference centre in North-West Italy.

BACKGROUND: Zika virus (ZIKV) remains a public health concern due to its association with fetal malformation and neurologic disease. OBJECTIVE: To report a reference centre experience on ZIKA virus (ZIKV) infection in travelers from epidemic countries from January 1 to September, 30, 2016 in Italy North-West (a geographic area covering 4.424 million inhabitants, corresponding to almost 73% of Italy North-West area). STUDY DESIGN: One hundred and twelve febrile travelers were studied to rule out a tropical fever [e.g. malaria, dengue (DENV), chikungunya (CHIKV), West Nile (WNV) and ZIKV]. Molecular tests for detecting ZIKV RNA were applied on serum or urine as well as IgG and IgM specific serology. RESULTS: ZIKV was the most frequent "tropical infection (11.6%) with 12 infected travelers and one sexual partner of an infected traveler. At the time of the diagnosis, ZIKV RNA was detected in the blood from 9 patients (69%) within 7 days from symptom onset; afterwards, the virus was detected only in urine (5 patients) and ZIKV IgM was reactive in 9 patients (69%). Travelers with ZIKV infection tested negative for DENV, CHIKV, WNV and malaria and completely recovered. Other infections identified in travelers were DENV (5 patients, 4.5%), CHIKV (1, 0.9%), malaria (Plasmodium vivax, 1, 0.9%), measles (1, 0.9%) and tuberculosis (1, 0.9%). CONCLUSIONS: The etiologic diagnosis of a febrile illness in travelers where ZIKV is endemic is highly desirable as they are sentinel of a challenging epidemiology including the risk of autochthonous transmission in non endemic countries where the competent or carrier vector is present.

Evaluation of the performance of a new automated HIV combination assay.

BACKGROUND: More and more countries test for HIV infection using combination assays that simultaneously detect p24 antigen and HIV antibodies. OBJECTIVE: To assess the performance of a new HIV combo assay: LIAISON® XL murex HIV Ab/Ag HT. STUDY DESIGN: The assays were examined with a total of 3090 samples that included 769 selected HIV antibody-negative samples, 1849 unselected HIV samples, 15 HIV-1 p24 Ag reference samples, 90 primary HIV-1 infection (PHI) samples, 167 HIV-1 antibody-positive samples (well characterized of groups M and O), 95 HIV-1 antibody-positive samples and 105 HIV-2 antibody-positive samples. RESULTS: The specificity of the LIAISON® XL murex HIV Ab/Ag HT was 99.7%. The analytical sensitivity of Ag p24 of the LIAISON® XL murex HIV Ab/Ag HT was 0.58IU/mL and 9.93pg/mL when using WHO and French national standards, respectively. All screened HIV subtypes was identified by this assay. Also, 90 PHI specimens were detected by this screening assay. CONCLUSION: The sensitivity and specificity of the LIAISON® XL murex HIV Ab/Ag HT assay are high. Hence the assay offers automated high-throughput screening with ability to detect primary infection.

Cerebrospinal fluid viral load and neopterin in HIV-positive patients with undetectable viraemia.

BACKGROUND: Cerebrospinal fluid (CSF) HIV RNA is commonly used as a marker of compartmental antiviral activity in HIV-positive patients. Undetectable CSF HIV RNA levels have been associated with low CSF neopterin levels and better neurocognitive performances. The aim of this study was to analyse the prevalence and predictors of non-detectable CSF HIV RNA using a commercial assay. METHODS: In adult HIV-positive HAART-treated patients with confirmed plasma HIV RNA <50 copies/ml, CSF HIV RNA (with Roche Amplicor Assay) and neopterin were measured. RESULTS: 112 adult patients were included. Plasma and CSF HIV RNA were non-detectable (target not detected [TND]) in 29 (25.9%) and 36 (32.1%) patients, respectively. CSF TND was observed more frequently in patients with plasma TND (P=0.005, OR=3.87). CSF neopterin levels were associated with age (rho =0.333, P=0.002) and current (rho= -0.272, P=0.015) and nadir (rho =-0.240, P=0.038) CD4+ T-lymphocytes; the lowest CSF neopterin concentration was observed in patients with CSF TND versus other viral load strata (0.62 mg/dl versus 0.78 mg/dl; P=0.048). CONCLUSIONS: Efficaciously treated HIV-positive patients with detectable plasma HIV RNA might imperfectly control CSF viral replication. Prospective studies addressing the management and neurocognitive consequences of CSF low-level viraemia are warranted.

First external quality assurance program of the Italian HLA-B*57:01 Network assessing the performance of clinical virology laboratories in HLA-B*57:01 testing.

BACKGROUND: Since the HLA-B*57:01 allele is strongly associated with abacavir hypersensitivity reaction, testing for the presence of HLA-B*57:01 is mandatory before administration of abacavir. While HLA-B*57:01 testing is usually provided by pharmacogenetics, genetics or blood transfusion services, clinical virology laboratories can be an optimal opportunity for HLA-B*57:01 testing since they receive blood samples for routine HIV monitoring and have the expertise for convenient and less expensive PCR-based point mutation assays. OBJECTIVES: The Italian HLA-B*57:01 Network gathers accredited clinical virology laboratories offering HLA-B*57:01 testing in Italy with the aim to share protocols, test new methods, develop and maintain external quality assurance (EQA) programs. STUDY DESIGN: A panel of 9HLA-B*57:01-positive and 16HLA-B*57:01-negative frozen blood samples were blindly distributed to 10 units including 9 clinical virology laboratories and one reference pharmacology laboratory. Each laboratory was free to use its own routine method for DNA extraction and HLA-B*57:01 testing. RESULTS: DNA was extracted by automated workstations in 6 units and by manual spin columns in 4. Eight units used the Duplicα Real Time HLA-B*57:01 kit by Euroclone and two units used two different PCR homemade protocols. All the 10 units correctly identified all the 25 samples. CONCLUSIONS: The first HLA-B*57:01 EQA program run in Italy showed that clinical virology units are equipped and proficient for providing HLA-B*57:01 testing by inexpensive assays easy to integrate into their routine.

Predominance of hepatitis C virus Q80K among NS3 baseline-resistance-associated amino acid variants in direct-antiviral-agent-naïve patients with chronic hepatitis: single-centre experience.

In the era of direct-acting antiviral agents (DAAs), hepatitis C virus (HCV) genotyping tests at baseline are controversial. The HCV NS3-Q80K polymorphism is associated with resistance to the recently approved NS3 inhibitor simeprevir (SMV) when combined with PEG-interferon and ribavirin (PEG-IFN/RBV) and alternative therapy should be considered for patients with baseline Q80K. The aim of this study was to provide an estimate of Q80K prevalence at baseline in a study group of 205 DAA-naïve patients (21% of them with HIV coinfection) using NS3 full-population direct sequencing to detect resistance-associated amino acid variants (RAVs). NS3 RAVs were identified in 56 patients (27.3%). Q80K was the most frequently reported one (41%), in both HIV/HCV-coinfected and HCV-monoinfected patients, but it was only detectable in cases of HCV-subtype 1a infection. Therefore, in clinical practice, an NS3-Q80K genotyping test prior to simeprevir plus PEG-IFN/RBV treatment is highly recommended.

HIV-1 Very Low Level Viremia Is Associated with Virological Failure in Highly Active Antiretroviral Treatment-Treated Patients.

The aim of this study was to evaluate the impact of HIV-1 very low-level viremia (<50 copies/ml) on the 2-year risk of virological failure. A retrospective analysis including HIV-positive patients presenting two consecutive HIV RNA below 50 copies/ml (outpatient clinic in Italy, first semester of 2010) was performed. HIV RNA was measured through real time polymerase chain reaction (PCR) assay CAP/CTM HIV-1 version 2.0 (detection limit: 20 copies/ml) and stratified as undetectable RNA ("Target Not Detected", TND), <20 copies/ml, 20-50 copies/ml. After 96 weeks virological failure was defined as two consecutive viral loads above 50 copies/ml. Log-rank tests and a multivariate Cox proportional hazard model were used for univariate and multivariate analysis. A total of 1,055 patients (71.4% male, 87.4% white, aged 46.7 years) were included: nadir and current CD4 cell counts were 203 cells/mm(3) (106-292) and 554 cells/mm(3) (413-713.5). HIV RNA was undetectable in 781 patients (74%), <20 copies/ml in 190 patients (18%) and 20-50 copies/ml in 84 patients (8%). Virological failure was observed in 81 patients (7.7%); at multivariate analysis detectable RNA at baseline (p=0.017), HCV infection (p=0.020), more than three pills in the regimen (p=0.003), and duration of HIV RNA <50 copies/ml below 2 years (p<0.001) were independently associated with virological failure. In 14 patients newly selected resistance-associated mutations were observed. Undetectable HIV RNA by real-time PCR is significantly associated with a lower 2-year risk of virological failure along with Ab HCV negativity, longer viral control, and lower pill burden. Studies investigating the management of residual viremia under antiretroviral treatment are warranted.

Etiological diagnosis of bloodstream infections through a multiplex real-time polymerase chain reaction test in pediatric patients: a case series from a tertiary Italian hospital.

BACKGROUND: The outcome of bloodstream infections (BSIs) is strongly related to microbiological diagnosis. Several factors may reduce blood culture (BC) diagnostic yield in pediatric BSIs, making the application of molecular methods quite promising. METHODS: Multiplex real-time polymerase chain reaction (PCR) tests (the LightCycler Septifast Test MGRADE by Roche Diagnostics--LC-SF) performed in the tertiary centre of Regina Margherita Children's Hospital (Turin, Italy) over a 3-year period were retrospectively evaluated. Results of the LC-SF test were compared with those of BC (Automated Bact/Alert 3D, Biomerieux) collected at a close time point. RESULTS: 545 LC-SF tests were collected from 289 patients (183 males, median age 6.8 years, interquartile range (IQR) = 2.7-13.1); 163 had congenital or acquired immunodeficiency. In 515 cases (94.5%) the LC-SF test was performed with ongoing empirical antimicrobial therapy. Etiological definition was achieved in 111 BSI cases (20.4%). Both LC-SF and BC identified the responsible pathogen in 39 episodes. The LC-SF test alone gave a positive result in 29 septic episodes; BC alone permitted the etiological diagnosis in 43 episodes, but isolates were not included in the LC-SF master list in 10 cases. A 26% increase in bacterial identification chances due to the LC-SF test was documented. Cohen's kappa test indicated a moderate strength of agreement (0.49) between LC-SF tests and BCs closely collected. CONCLUSIONS: BC remains the gold standard for the etiological diagnosis of BSIs, but PCR methods proved to be a valuable adjunctive diagnostic tool in pediatric BSIs, especially in children receiving empirical chemotherapy.

Combination of conventional blood cultures and the SeptiFast molecular test in patients with suspected sepsis for the identification of bloodstream pathogens.

We evaluated performances of the molecular test SeptiFast (SF) for the detection of agents of bloodstream infection (BSI) in patients with suspected sepsis, the majority of them under antibiotic treatment and at high prevalence of HIV-1 infection (10.5%). Matched SF and blood culture (BC) samples (n=1186) from 1024 patients were studied. Two hundred fifty-one episodes of BSI out of 1144 were identified with the combined methods (22%). SF identified more episodes of BSI than BC: 206 versus 176 (χ(2)=7.008, P=0.0081) and a significantly higher number of Gram-negative bacteria than BC (77 versus 53, χ(2)=9.12; P=0.0025), as well as of polymicrobial infections (χ(2)=4.50, P=0.0339). In conclusion, SF combined with BC improved the diagnosis of sepsis, especially in immunocompromised patients.

Recent outbreak of aseptic meningitis in Italy due to Echovirus 30 and phylogenetic relationship with other European circulating strains.

BACKGROUND: Enteroviruses (EVs) are common human viral pathogens, causing a variety of diseases, including aseptic meningitis. Recently, EV aseptic meningitis outbreaks have been reported across Europe, but, in Italy, knowledge of recent EV molecular epidemiology is very limited. OBJECTIVES: We report an outbreak of EV aseptic meningitis in 10 adults in North-Western Italy, from October to November 2012. Patients were parents or close relatives of children <5 years old attending the same class of a nursery school, suffering from a mild febrile upper respiratory disease. Phylogenetic relationship with other European circulating strains was analyzed updating E30 circulation in Italy in recent years. STUDY DESIGN: EVs were detected from cerebrospinal fluid (CSF) specimens with a real-time reverse transcription polymerase chain reaction and virus isolation was achieved from rectal and pharyngeal swabs. For cluster definition and phylogenetic studies, viral VP1 region was directly amplified and sequenced from CSF. RESULTS: EVs were identified in CSF from all patients and from rectal and pharyngeal swabs in 7 of them. Direct sequencing of CSF revealed the presence of the same Echovirus 30 (E30) in all patients and phylogenetic analysis identified it as a diverging clade within E30 genotype VII, the most recent strain circulating in UK, Finland and Denmark since 2006. CONCLUSION: Molecular techniques allowed the rapid identification and typing of E30 from CSF. Phylogenetic analysis revealed that the cluster might be due to a new E30 variant within the genotype VII currently circulating in Europe, thus updating the epidemiology of EV circulation in Italy.

A(H1N1)pdm09 hemagglutinin D222G and D222N variants are frequently harbored by patients requiring extracorporeal membrane oxygenation and advanced respiratory assistance for severe A(H1N1)pdm09 infection.

BACKGROUND: In patients with A(H1N1)pdm09 infection, severe lung involvement requiring admission to intensive care units (ICU) has been reported. Mutations at the hemagglutinin (HA) receptor binding site (RBS) have been associated with increased virulence and disease severity, representing a potential marker of critical illness. OBJECTIVES: To assess the contribution of HA-RBS variability in critically ill patients, A(H1N1)pdm09 virus from adult patients with severe infection admitted to ICU for extracorporeal membrane oxygenation support (ECMO) during influenza season 2009-2011 in Piemonte (4·2 million inhabitants), northwestern Italy, was studied. PATIENTS AND METHODS: We retrospectively analyzed HA-RBS polymorphisms in ICU patients and compared with those from randomly selected inpatients with mild A(H1N1)pdm09 disease and outpatients with influenza from the local surveillance program. RESULTS: By HA-RBS direct sequencing of respiratory specimens, D222G and D222N viral variants were identified in a higher proportion in ICU patients (n=8/24, 33·3%) than in patients with mild disease (n=2/34, 6%) or in outpatients (n=0/44) (Fisher's exact test P<0·0001; OR 38·5; CI 95% 4·494-329·9). Eleven ICU patients died (42%), three of them carrying the D222G variant, which was associated with RBS mutation S183P in two. D222G and D222N mutants were identified in upper and lower respiratory samples. CONCLUSIONS: A(H1N1)pdm09 HA substitutions D222G and D222N were harbored in a significantly higher proportion by patients with acute respiratory distress for A(H1N1)pdm09 severe infection requiring ICU admission and ECMO. These data emphasize the importance of monitoring viral evolution for understanding virus-host adaptation aimed at the surveillance of strain circulation and the study of viral correlates of disease severity.

Clinical impact of A/H1/N1/09 influenza in patients with cirrhosis: experience from a nosocomial cluster of infection.

A/H1N1/09 influenza is associated with a high risk of complications in patients with chronic diseases, but data on morbidity and mortality in patients with cirrhosis are limited. A cluster of A/H1N1/09 infection in 48 patients admitted to a Gastro-Hepatology Unit is reported. Nosocomial spread, clinical outcome, and viral characteristics of A/H1N1/09 strains from a study group of 48 inpatients (21 and 27 with and without cirrhosis, respectively) were compared with those from a control group of 44 outpatients with mild influenza-like illness and without cirrhosis. A/H1N1/09 infection was confirmed in 8/48 (17%) inpatients. A/H1N1/09 infection rate did not differ in patients with and without cirrhosis (4/21, 19%; 4/27, 15%), but three patients with cirrhosis died of pneumonia and acute respiratory distress syndrome, with fungal or bacterial superinfection in two cases, despite antiviral treatment. None of patients without cirrhosis died. Viral sequences showed the presence of hemagglutinin mutation D222G in two out of three fatal cases and S183P in seven out of eight infected patients. These mutants were not detected in the outpatients group. Even if A/H1N1/09 infection rate in hospitalized patients with and without cirrhosis was not significantly different, cirrhosis and D222G/S183P substitutions were significantly associated with severe disease and poor outcome, also suggesting fungal or bacterial superinfection and portal hypertension as risk factors for A/H1N1/09 disease severity in patients with cirrhosis. Vaccination, preventive and early treatment and a strict control of nosocomial spread should be activated carefully in patients with cirrhosis during epidemics influenza.

Performance of genotypic tropism testing on proviral DNA in clinical practice: results from the DIVA study group.

OBJECTIVE: The DIVA study is aimed at setting up a standardized genotypic tropism-testing on proviral-DNA for the routine clinical diagnostic-laboratory. METHODS: Twelve local centres and 5 reference centres (previously cross-validated) were identified. For inter-center validation-procedure, 60 peripheral-blood mononuclear cells (PBMCs) aliquots from 45 HAART-treated patients were randomly chosen for population V3 sequencing on proviral-DNA at local HIV centre and at reference-laboratory. Viral tropism was predicted by Geno2Pheno algorithm (False Positive Rate [FPR] = 20%) as proposed by the European-Guidelines. Quantification of total HIV-1 DNA was based on a method described by Viard (2004). RESULTS: Quantification of HIV-1 DNA was available for 35/45 (77.8%) samples, and gave a median value of 598 (IQR:252- 1,203) copies/10 PBMCs. A total of 56/60 (93.3%) samples were successfully amplified by both the reference and the local virological centers. The overall concordance of tropism prediction between local and reference centers was 54/56 (96.4%). Results of tropism prediction by local centers were: 33/54 (61.1%) R5 and 21/54 (38.9%) X4/DM. CONCLUSION: There was high concordance in the genotypic tropism prediction based on proviral DNA among different virological centers throughout Italy. Our results are in line with other European studies, and support the use of genotypic tropism testing on proviral DNA in patients with suppressed plasma HIV-1 RNA candidate to CCR5-antagonist treatment.

Diagnosis of dengue fever in North West Italy in travelers from endemic areas: a retrospective study.

BACKGROUND: Domestic outbreaks of Dengue (DENV) fever from imported cases have to be considered a possible risk in non-endemic countries where Dengue vectors are present, such as in Italy. OBJECTIVE: To review imported acute/recent DENV infections in a one-year survey in a North West Italy region where the presence of Aedes albopictus is documented. STUDY DESIGN: We retrospectively reviewed laboratory and clinical records of Italian febrile travelers from Dengue endemic areas referring to the local reference Centre for Infectious Disease, covering a population of about 4 million people. RESULTS: Acute/recent DENV infection was identified in 15 out of 91 travelers from endemic areas (16.5%) including 12 primary and 3 secondary infections; in 6 patients the virus was detectable in blood according to molecular real-time Polymerase Chain Reaction-based assays: in 9 patients the diagnosis of DENV infection was accomplished by the combination of specific IgM reactivity, high IgG titers, IgG seroconversion from negative to positive and increasing (four-fold) IgG titers in paired serum samples. Two cases of DENV infections were imported from South Egypt in patients travelling together, confirming the importance of returning travelers as sentinels of a rapidly changing epidemiology in specific geographic areas. CONCLUSIONS: Our findings outline the high rate of imported Dengue infection in North West Italy and emphasize the need for a continued Dengue surveillance in non-endemic countries as well as a careful evaluation and follow-up of febrile patients returning from Dengue endemic countries.