Browsing by Author "Hookham, Lauren (57223236861)"

Background: Arboviruses are increasingly affecting Europe, partly due to the effects of climate change. This increase in range and impact emphasises the need to improve preparedness for emerging arboviral infections that often co-circulate and might have overlapping clinical syndromes. We aimed to strengthen surveillance networks for four clinically relevant arboviruses in southeast Europe. Methods: This study reports an in-depth analysis of the MERMAIDS-ARBO prospective observational study in adults (ie, aged ≥18 years) hospitalised with an arbovirus-compatible disease syndrome in 21 hospitals in seven countries in southeast Europe over four arbovirus seasons (May 1–Oct 31, 2016–19) to obtain arbovirus prevalence outcomes. The main objectives of the MERMAIDS-ARBO study, describing the clinical management and outcomes of four arboviruses endemic to southeast Europe, including Crimean–Congo haemorrhagic fever virus (CCHFV), tick-borne encephalitis virus (TBEV), Toscana virus, and West Nile virus (WNV), are reported elsewhere. In this analysis, given the challenges associated with arbovirus diagnostics, we developed a diagnostic algorithm accounting for serology outcomes and sample timing to study arbovirus prevalence in southeast Europe. Serum samples were collected on days 0, 7, 28, and 60 after hospital admission and tested for anti-CCHFV IgG and IgM antibodies with ELISAs (confirmed with an indirect immunofluorescence test) and for IgG and IgM antibodies specific to TBEV, Toscana virus, and WNV with custom-printed protein microarrays (confirmed with virus neutralisation tests). All acute-phase samples were tested by PCR for all four viruses. Descriptive analyses were performed for virus-reactive cases by geography and year, and possible factors (eg, age, sex, and insect bites) associated with virus reactivity were assessed. Findings: Of 2896 individuals screened, 913 were eligible for inclusion, of whom 863 (514 men, 332 women, and 17 unknown) had samples sent to the study reference laboratories and were included in molecular and serological analyses. Some individuals had insufficient clinical data to be included in the clinical analysis, but met the eligibility criteria for and were included here. Serum sampling was incomplete (eg, samples missing from one or more timepoints or no data on time since symptom onset) for 602 (70%) patients, and the timing of collection was often heterogeneous after symptom onset up to 40 days (average median delay of 5–6 days across all timepoints), affecting the ability to diagnose arbovirus infection by serology. By use of an interpretation table incorporating timing and completeness of sampling, one (<1%) participant had a confirmed recent infection with CCHFV, ten (1%) with TBEV, 40 (5%) with Toscana virus, and 52 (6%) with WNV. Most acute confirmed infections of Toscana virus were found in Albania (25 [63%] of 40), whereas WNV was primarily identified in Romania (36 [69%] of 52). Albania also had the highest overall Toscana virus seropositivity (168 [60%] of 282), mainly explained by patients confirmed to be exposed or previously exposed (104 [62%] of 168). Patients without antibodies to WNV or Toscana virus were significantly younger than patients with antibodies (mean difference –8·48 years [95% CI –12·31 to –4·64] for WNV, and –6·97 years [–9·59 to –4·35] for Toscana virus). We found higher odds of Toscana virus reactivity in men (odds ratio 1·56 [95% CI 1·15 to 2·11]; p=0·0055), WNV reactivity with mosquito bites versus no mosquito bites (2·47 [1·54 to 3·97]; p=0·0002), and TBEV reactivity with tick bites versus no tick bites (2·21 [1·19 to 4·11]; p=0·018). Interpretation: This study shows that despite incomplete and heterogeneous data, differential diagnosis of suspected arbovirus infections is possible, and the diagnostic interpretation algorithm we propose could potentially be used to strengthen routine diagnostics in clinical settings in areas at risk for arboviral diseases. Our data highlight potential hotspots for arbovirus surveillance and risk factors associated with these particular arbovirus infections. Funding: European Commission and Versatile Emerging infectious disease Observatory. Translations: For the Greek, Albanian, Romanian, Bosnian, Serbian, and Croatian translation of the summary see Supplementary Materials section. © 2025 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license

Background: Arboviruses have expanded into new regions in Europe, yet data indicate gaps in disease notifications and a risk of further spread. We aimed to report on prevalence, clinical management, and outcomes of endemic arbovirus infections in southeast Europe. Methods: In this prospective observational study (MERMAIDS-ARBO), we enrolled adults (age ≥18 years) hospitalised with an arbovirus-compatible disease syndrome within 21 days of symptom onset across 21 hospitals in seven countries in southeast Europe over four arbovirus seasons (May 1–Oct 31, during 2016–19). We obtained data from case report forms completed by site investigators on admission and discharge. Participants were excluded if they had non-infectious CNS disorders, symptoms of another confirmed cause, an identified focal source of infection, or symptoms caused by recurrence of a pre-existing condition. The primary outcome was the proportion of participants with confirmed or probable acute infections with West Nile virus (WNV), tick-borne encephalitis virus (TBEV), Crimean–Congo haemorrhagic fever virus (CCHFV), or Toscana virus (TOSV), per reference laboratory criteria. Secondary outcomes were the proportions of patients treated with antivirals, antibiotics, or corticosteroids; the proportion of patients requiring intensive care; hospital length of stay; and mortality. Findings: Of 2896 adults screened for eligibility, 929 were recruited and 913 met protocol-defined eligibility criteria (median age 43·1 years [IQR 29·5–59·7]; 550 [60%] men, 361 [40%] women, and two [<1%] with missing data). 530 (58%) participants presented with suspected meningitis, encephalitis, or both, and 318 (35%) with fever plus myalgia, fever plus arthralgia, or both. 820 (90%) reported no international travel within 21 days before symptom onset. 727 (80%) were administered antibiotics, 379 (42%) corticosteroids, and 222 (24%) antivirals. The median length of hospital stay was 9 days (IQR 6–14), and 113 (12%) required intensive care. Of 847 participants with a reference laboratory sample who met full eligibility criteria for analysis, 110 (13%) were diagnosed with 114 confirmed or probable acute arbovirus infections (four had coinfections or cross-reactivity): one (<1%) with CCHFV, 16 (2%) with TBEV, 44 (5%) with TOSV, and 53 (6%) with WNV. There was one death (<1%) of an individual with WNV. Of the 110 participants, 49 (45%) had a local clinician-attributed arbovirus discharge diagnosis. Interpretation: Our data highlight the need to strengthen arbovirus surveillance systems for the early detection of emerging and re-emerging outbreaks, including investments to increase awareness of arbovirus infections among clinicians, to improve access to specialist diagnostics, and to develop effective and accessible vaccines and treatments to protect populations and health systems in southeast Europe. Funding: European Commission and Versatile Emerging infectious disease Observatory. Translations: For the Greek, Albanian, Romanian, Bosnian, Serbian, and Croatian translation of the summary see Supplementary Materials section. © 2025 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license