Factors predicting kidney damage in Puumala virus infected patients in Southern Denmark

Vascular dysfunction in hemorrhagic viral fevers: opportunities for organotypic modeling

The hemorrhagic fever viruses (HFVs) cause severe or fatal infections in humans. Named after their common symptom hemorrhage, these viruses induce significant vascular dysfunction by affecting endothelial cells, altering immunity, and disrupting the clotting system. Despite advances in treatments, such as cytokine blocking therapies, disease modifying treatment for this class of pathogen remains elusive. Improved understanding of the pathogenesis of these infections could provide new avenues to treatment. While animal models and traditional 2D cell cultures have contributed insight into the mechanisms by which these pathogens affect the vasculature, these models fall short in replicatingin vivohuman vascular dynamics. The emergence of microphysiological systems (MPSs) offers promising avenues for modeling these complex interactions. These MPS or 'organ-on-chip' models present opportunities to better mimic human vascular responses and thus aid in treatment development. In this review, we explore the impact of HFV on the vasculature by causing endothelial dysfunction, blood clotting irregularities, and immune dysregulation. We highlight how existing MPS have elucidated features of HFV pathogenesis as well as discuss existing knowledge gaps and the challenges in modeling these interactions using MPS. Understanding the intricate mechanisms of vascular dysfunction caused by HFV is crucial in developing therapies not only for these infections, but also for other vasculotropic conditions like sepsis.

Dynamics of Puumala hantavirus outbreak in Black Sea Region, Turkey

BACKGROUND

Some of the hantavirus species in Euro-Asia cause haemorrhagic fever with renal syndrome (HFRS) in humans. The first documented human hantavirus infection in Turkey was diagnosed in 2009. This report describes the dynamics of the first hantavirus outbreak that emerged in humans in the Western Black Sea Region of Turkey.

METHODS

All the suspected cases of hantavirus infection were admitted to the Infectious Diseases and Clinical Microbiology Department at the Zonguldak Bülent Ecevit University Hospital in Zonguldak, Turkey. The patients were carefully interviewed, examined and evaluated using routine laboratory tests and hantavirus diagnostic tools. Hantavirus-reactive antibodies (IgM and IgG) in serum samples were detected via enzyme immune assay (EIA) and immunofluorescence assay (IFA) in the acute and convalescence stages of the disease. The presence of hantavirus ribonucleic acid (RNA) was analysed via reverse transcription polymerase chain reaction (RT-PCR) in serum and urine samples. A focus reduction neutralization test (FRNT) was performed to confirm specific hantavirus serotypes. In addition, a case-control study was conducted to identify possible risk factors for hantavirus transmission in the outbreak area. A control group was composed of asymptomatic individuals who were seronegative for hantavirus IgM and IgG and living in the outbreak area.

RESULTS

A total of 55 suspected cases of hantavirus infection were admitted to the inpatient clinic between February and June of 2009. Twenty-four patients were diagnosed with acute HFRS via EIA or IFA. In 22 of the 24 infected patients, Puumala virus (PUUV) was identified as the causative hantavirus type by detecting IgM in the acute stage and an increase in the IgG level in follow-up serum samples. PUUV was also verified as the infecting agent by FRNT in two of the 24 cases. Among the 24 laboratory-confirmed HFRS cases, 21 (87.5%) were males and 3 (12.5%) were females, and the mean age was 45.92 years (standard deviation ± 16.90 years). Almost all these individuals were living in villages or rural areas. The 24 HFRS cases were matched with 26 healthy controls for statistical analyses and according to binary logistic regression analysis, and dealing with rodent control activities in gardens or in annexes of their homes (p = 0.021 and Odds ratio [OR] = 17.11) and being male (p = 0.019 and OR = 22.37) were detected as statistically significant risk factors for hantavirus infection. The most commonly observed clinical complaints were fatigue (95.8%), shivering (91.7%), fever (87.1%), headache (70.8%) and nausea (70.8%). Haemodialysis was required for four patients (16.7%). Except for the first case diagnosed with acute hantavirus infection, no patient died. The mean delay time to hospital admission from initiation of symptoms was 5.3 days, the mean duration of febrile days was 2.6 days, and the mean duration of hospital stay was 8.5 days.

CONCLUSION

Hantaviruses are circulating in Turkey and causing sporadic or epidemic infection in humans. Additional investigations are needed to better understand the dynamics of hantaviruses in this country.

Platelet Distribution Width at First Day of Hospital Admission in Patients with Hemorrhagic Fever with Renal Syndrome Caused by Hantaan Virus May Predict Disease Severity and Critical Patients' Survival

Thrombocytopenia is one of the main characteristics of hemorrhagic fever with renal syndrome (HFRS). This study aimed to evaluate the associations of platelet distribution width (PDW) with the disease severity and critical patients' survival of HFRS. The demographics, clinical data, and white blood cell and platelet parameters including PDW in 260 patients hospitalized for HFRS were analyzed. The results showed that PDW on the first day (PDW1) was positively associated with the disease severity (p = 0.005). Multiple regression analysis showed that in addition to age (odds ratio [OR], 1.091; 95% confidence interval [CI], 1.015-1.172) and occurrence of sepsis (OR, 22.283; 95% CI, 2.985-166.325), PDW1 (OR, 0.782; 95% CI, 0.617-0.992) was a risk factor of the mortality, having an area under the receiver operating characteristic curve of 0.709 (95% CI, 0.572-0.846, p = 0.013) for predicting mortality, with a sensitivity of 70% and a specificity of 67% at a cutoff of 16.5 fL, in patients with critical HFRS. These results suggest the potential of PDW at the first day of hospitalization as a valuable parameter for evaluating the severity of HFRS and a moderate parameter for predicting the prognosis of critical HFRS patients. A prospective study in large patient population is needed to validate these findings.

Bioclinical Test to Predict Nephropathia Epidemica Severity at Hospital Admission

We conducted a multicenter, retrospective cohort study of hospitalized patients with serologically proven nephropathia epidemica (NE) living in Ardennes Department, France, during 2000-2014 to develop a bioclinical test predictive of severe disease. Among 205 patients, 45 (22.0%) had severe NE. We found the following factors predictive of severe NE: nephrotoxic drug exposure (p = 0.005, point value 10); visual disorders (p = 0.02, point value 8); microscopic or macroscopic hematuria (p = 0.04, point value 7); leukocyte count >10 × 10⁹ cells/L (p = 0.01, point value 9); and thrombocytopenia <90 × 10⁹/L (p = 0.003, point value 11). When point values for each factor were summed, we found a score of <10 identified low-risk patients (3.3% had severe disease), and a score >20 identified high-risk patients (45.3% had severe disease). If validated in future studies, this test could be used to stratify patients by severity in research studies and in clinical practice.