Andrea Matucci

Background: Data on tick-borne diseases (TBDs) in Italy are fragmented. This study aimed to describe tick-borne pathogens (TBPs) and TBDs observed in a hospital in Italy and to assess the correlation between TBPs and human disease. Methods: A prospective observational study was conducted in a single hospital between March 2024 and January 2025. Inclusion criteria were: individuals ≥ 8 years of age and consent to study participation. Data and blood samples were collected at baseline (T0), and 12–18 weeks later (T1). Ticks collected at T0 were pooled and analyzed by real-time PCR. Serological and molecular tests were used for TBD diagnosis. Results: Ninety-three individuals (median age 39 years; 52.7% female) were enrolled. The pathogens most frequently detected in the tick pools were Rickettsia spp. (15.1%) and Borrelia spp. (7.5%). Sixteen participants (17.2%) developed TBD-compatible symptoms, but TBD was confirmed in only four cases: Lyme borreliosis (n = 2), scalp eschar and neck lymphadenopathy after tick bite (SENLAT, n = 1), and tick-borne encephalitis (TBE, n = 1). Concordance between TBP detection and the corresponding TBD development in humans was observed in only two cases (2.1%). Conclusions: The low concordance between pathogens detected in participant-level tick pools and confirmed human tick-borne disease supports the limited clinical value of tick testing in this setting.

Acute gastroenteritis is a common condition with a wide and often indistinguishable etiology, requiring laboratory support for an accurate diagnosis. Classical diagnostic methods, including stool culture and antigen-based tests, are limited by restricted pathogen coverage and variable sensitivity. In the present study, 548 stool samples from patients with suspected gastroenteritis were tested using the QIAstat-Dx Gastrointestinal Panel 2 and compared with stool culture and rotavirus/adenovirus antigen tests. The molecular panel showed a positivity rate of 50.4%, consistently higher than stool culture (12.6%) and antigen assays (12.3% for rotavirus and 4.4% for adenovirus). The most frequently detected pathogens included enteropathogenic Escherichia coli (15.3%), Campylobacter spp. (12.0%), and enteroaggregative E. coli (10.2%). Agreement between methods was good for bacterial pathogens but low for viral targets. Discordant viral results were often associated with low antigen cut-off index values and multiple pathogen detections by the molecular panel, suggesting potential limitations of antigen-based assays. Overall, the QIAstat-Dx Gastrointestinal Panel 2 improves pathogen detection and provides rapid, comprehensive diagnostic information, while a combined approach with conventional methods may represent the most appropriate strategy for optimizing patient management.

This study aimed primarily to evaluate the performance of two Conformité Européenne—In Vitro Diagnostic (CE-IVD) multiplex real-time PCR (rt-PCR) assays for the molecular identification of tick-borne pathogens (TBPs) of human interest on ticks removed from human skin and collected through a citizen science-based approach. As a secondary objective, the aggregated results were used to describe tick species distribution, developmental stages, and seasonal TBP circulation in 2024 in the considered area. The comparison was conducted on 116 tick samples collected in 2024 voluntarily delivered to a hospital in northeastern Italy. Detected TBPs were further confirmed with in-house-validated PCR methods and, where applicable, resolved to the species level. Clinically relevant pathogen species were identified as single infections or coinfections. Overall, 33.6% of tick samples tested positive for at least one TBP, and 6.9% showed coinfections. Kit B exhibited a higher detection rate for Borrelia spp. and Rickettsia spp. targets, partly reflecting its broader diagnostic specificity, while statistically significant differences in cycle threshold values were observed for Anaplasma phagocytophilum detection. The most frequently involved ticks were Ixodes ricinus nymphs, and the most represented area was Verona province. Late spring and early summer were identified as the periods with the highest tick conferment and pathogen diversity. Overall, the results support the use of multiplex real-time PCR commercial kits combined with citizen science-based tick collection as an effective approach for both diagnostic screening and regional surveillance of circulating ticks and TBPs.

Sustained by urbanization, globalization and climate change, infectious diseases transmitted by arthropod vectors, such as mosquitoes, ticks and sandflies, are emerging or resurging in Europe, including Italy. There are limited therapeutic treatments and vaccines for most arthropod-borne pathogens, thus monitoring and control of vectors remains the most-effective prevention strategy. Supported by a country-wide initiative that aims at providing strategic guidance for preventing vector-borne diseases in Italy, including suirveillance and control initiatives that results in the acquistion of a large number of field samples, we conceived a digital repository of samples from arthropod vectors and their metadata to promote their sharing among the scientific community. We built a relational database called RAV-IT, accessible at https://mosqit.unipv.it/. Currently, RAV-IT aggregates seventeen Italian institutions and hosts nearly two thousand vector samples and their metadata, which can be viewed and requested for research purposes. RAV-IT is interactive and can accept further samples from any users. RAV-IT is a non-profit repository that is expected to enhance resource sharing for research on arthropod vectors.

An unprecedented outbreak of Oropouche virus (OROV) is occurring in the Americas, characterized by thousands of confirmed cases and a wide geographical spread, including areas outside the Amazon Basin. Little is known about this neglected arbovirus regarding its pathophysiological aspects and potentially different transmission modes. This study describes the clinical course of a man who returned from a trip to Cuba and presented to our hospital 4 days after the onset of febrile symptoms. The patient was diagnosed with Oropouche fever and was followed for 177 days after the onset of symptoms. We performed a longitudinal investigation of the samples collected from several body sites (whole blood, serum, urine, and semen) with the aim of providing further insights into OROV infection dynamics, using the detection of antigenomic RNA as a marker of active viral replication. Clinical samples that were longitudinally collected over the course of OROV infection showed consistently higher amounts of antigenomic RNA compared to genomic RNA, even after viral clearance from serum. Moreover, our case study showed the persistence of OROV RNA in serum of less than 15 days from the onset of symptoms, as compared to up to one month in urine, three months in semen, and four months in whole blood. Our study suggests that Oropouche virus may persist in an actively replicating state in different body sites for long periods of time, with important implications for transmission dynamics. Furthermore, our results provide a diagnostic indication, suggesting that serum is inferior to both urine and whole blood as preferred diagnostic samples. Further studies are needed to determine the pathogenetic implications of these findings, as they have been derived from a single case and must be confirmed using a larger number of cases.

In an epidemiologic investigation of Enterovirus (EV) infections in a Verona hospital, September 2022–September 2024, we detected EV-C105 in six pediatric patients with upper respiratory symptoms between March and May 2023. The primary objective was to describe the local incidence of EV cases. The secondary objective was to perform Sanger’s genomic characterization and the whole-genome sequencing (WGS) of EV-C105. The proportion of positive EV results was calculated based on routine molecular method testing. An available cohort of 114 underwent Sanger sequencing, and the six EV-C105 were characterized with WGS. Overall, 96% EV results were from the upper respiratory tract. The total proportion of positives in children was 83%. Out of the typed 114, 90% were Rhinoviruses and 9%, EVs. Notably, six pediatric cases were EV-C105, placing together in a unique cluster with 99% of nucleotides belonging to the European lineage with the highest Average Nucleotide Identity, including EV-C104, EV-C109, and EV-C118. Our data describes the first cluster indicating that EV-C105 incidence may be higher than previously estimated. However, a limitation for affirming this hypothesis is the lack of a more in-depth epidemiological investigation on a larger case series with the possibility of including data from coordinated laboratories.

Our study wanted to describe the kinetics of serological and adaptive immune responses in mpox patients. Methods: Fourteen patients with laboratory-confirmed mpox were tested at different time points after the symptom onset. An immunofluorescence assay was performed to evaluate the seroconversion kinetics of specific IgA, IgM, and IgG. Moreover, the characterization of the adaptive immunological profile of T- and B-cells was performed. Results: The antibody kinetics revealed the faster and more effective seroconversion of specific IgA than IgM. Moreover, we detected an increase in Active memory B cells and CD8+ cells in the early phases of infection, and a reduction in CD4+ T-cells in the mpox patients with respect to the controls and found the presence of higher levels of Treg cells in the HIV+ patients in the early phase of infection. Conclusion: Our data highlight the relevance of specific IgA testing early after the symptom onset, suggesting a possible role as a marker in early diagnosis, especially in close contact subjects. Furthermore, the different maturation states of effector cells in HIV+ patients, together with high Treg levels, may lead us to better understand the role of MPXV-HIV co-infection and identify potential cellular markers to monitor the excessive immune activation involved in mpox disease progression.

On 27 May 2024, the Cuban Ministry of Health reported the first outbreak of Oropouche fever on the island. The etiologic agent, Oropouche virus (OROV), is a poorly understood arbovirus that has been known since the 1960s and represents a public health burden in Latin America. We report the whole-genome characterization of the first European OROV isolate from a returning traveler from Cuba with Oropouche fever-like symptoms. The isolate was obtained from the patient’s serum; whole-genome sequencing was performed by next-generation sequencing, followed by phylogenetic analysis and genetic variability studies. The analysis showed that the most closely related sequence was from the French Guiana 2020 outbreak. Interestingly, our isolate is a reassortant virus, included in a highly supported monophyletic clade containing recent OROV cases (Brazil 2015–Colombia 2021), separated from the other four previously known genotypes. More deeply, it was found to be included in a distinct branch containing the sequences of the Brazil 2022–2024 outbreak. The reassortment event involved the S and L segments, which have high similarity with sequences belonging to a new cluster (here defined as OROV_SCDC_2024), while the M segment shows high similarity with older sequences. These results likely describe the viral strain responsible for the current outbreak in Cuba, which may also reflect the ongoing outbreak in Latin America. Further studies are needed to understand how OROV evolves towards traits that facilitate its spread and adaptation outside its original basin, and to track its spread and evolution in the European continent.

Background: Oropouche virus (OROV) is a segmented RNA virus belonging to the genus Orthobunyavirus in the family Peribunyaviridae. Herein, an in-house droplet digital PCR (ddPCR) assay was used for the detection and quantification of OROV. Methods: The ddPCR reaction was assessed as duplex assay using the human housekeeping gene RPP30. Limit of detection (LoD) analysis was performed in whole blood, serum, and urine. The assay was executed on a total of 28 clinical samples (whole blood n = 9, serum n = 11, and urine n = 8), of which 16 specimens were tested positive at the routine molecular diagnostics (endpoint and real-time PCRs). Results: The LoD of the ddPCR performed using 10-fold serial dilution of OROV detected up to 1 cp/µL in all the biological matrices. Compared to the routine molecular diagnostics, the ddPCR assay showed 100% sensitivity for whole blood and serum and 75% for urine, highlighting higher positive rate of ddPCR. Conclusion: We have established a quantitative RNA detection method of OROV with high sensitivity and specificity based on ddPCR. This test is capable of quantitatively monitoring the viral load of OROV and can contribute, in addition to laboratory diagnosis, to shed light on the pathogenesis, filling in the knowledge gaps of this neglected disease and to the vector control programs.

Oropouche fever is caused by Oropouche virus (OROV), transmitted primarily through the bite of infected midges, particularly of the genusCulicoides. The virus is mainly circulating in Central and South America where several countries reported an ongoing outbreak. We report here two imported cases of OROV infection identified in Italy, late May–early June 2024. These cases indicate that in the shadow of a massive dengue outbreak in the Americas, the Oropouche outbreak might be more widespread than previously estimated.