SARS-CoV-2 infections among pregnant women, 2020, Finland-Cross-testing of neutralization assays.

We studied the development of the severe acute respiratory syndrome-related coronavirus (SARS-CoV-2) pandemic in southern Finland in 2020 and evaluated the performance of two surrogate immunoassays for the detection of neutralizing antibodies (NAbs). The data set consisted of 12 000 retrospectively collected samples from pregnant women in their first trimester throughout 2020. All the samples were initially screened for immunoglobulin G (IgG) with SARS-CoV-2 spike antibody assay (EIM-S1, Euroimmun) followed by confirmation with nucleocapsid antibody assay (Architect SARS-CoV-2, Abbott). Samples that were reactive (positive or borderline) with both assays were subjected to testing with commercial surrogate immunoassays of NeutraLISA (EIM) and cPassTM (GenScript Biotech Corporation) by using pseudoneutralization assay (PNAbA) as a golden standard. No seropositive cases were detected between January and March. Between April and December, IgG (EIM-S1 and Abbott positive) and NAb (PNAbA positive) seroprevalences were between 0.4% and 1.4%. NeutraLISA showed 90% and cPass 55% concordant results with PNAbA among PNAbA negative samples and 49% and 92% among PNAbA positive samples giving NeutraLISA better specificity but lower sensitivity than cPass. To conclude, seroprevalence in pregnant women reflected that of the general population but the variability of the performance of serological protocols needs to be taken into account in inter-study comparison.

High Epstein-Barr virus capsid antigen IgG level associates with the carriership of CD8+ T cell somatic mutations in the STAT3 SH2 domain.

High carrier prevalence of STAT3 SH2 domain somatic mutations was recently discovered in CD8+ T cells. We found these low-allele-fraction clones in 26% of donors, without difference between multiple sclerosis (MS) patients and controls. Here we tested whether anti-viral antibodies associate with the carriership of these mutant clones. We compared antibody responses against common viruses in mutation carriers vs. non-carriers. Plasma samples of 152 donors (92 MS patients, 60 controls) were analyzed for antibodies against cytomegalovirus (CMV), Epstein-Barr virus (EBV), human herpesvirus-6A and parvovirus B19. The mutation carrier status associated with EBV VCA IgG level (p = 0.005) and remained significant after logistic regression (p = 0.036). This association was contributed similarly by MS patients and controls. These results suggest that EBV contributes to the generation or growth of these clones. The pathogenic role of the STAT3 mutant clones in MS is presently unclear, but their detailed characterization warrants further study.

A Combination of N and S Antigens With IgA and IgG Measurement Strengthens the Accuracy of SARS-CoV-2 Serodiagnostics.

BACKGROUND: Primary diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is based on detection of virus RNA in nasopharyngeal swab samples. In addition, analysis of humoral immunity against SARS-CoV-2 has an important role in viral diagnostics and seroprevalence estimates. METHODS: We developed and optimized an enzyme immunoassays (EIA) using SARS-CoV-2 nucleoprotein (N), S1 and receptor binding domain (RBD) of the viral spike protein, and N proteins from SARS, Middle East respiratory syndrome (MERS), and 4 low-pathogenic human CoVs. Neutralizing antibody activity was compared with SARS-CoV-2 IgG, IgA, and IgM EIA results. RESULTS: The sensitivity of EIA for detecting immune response in COVID-19 patients (n = 101) was 77% in the acute phase and 100% in the convalescent phase of SARS-CoV-2 infection when N and RBD were used as antigens in IgG and IgA specific EIAs. SARS-CoV-2 infection significantly increased humoral immune responses against the 229E and NL63 N proteins. S1 and RBD-based EIA results had a strong correlation with microneutralization test results. CONCLUSIONS: The data indicate a combination of SARS-CoV-2 S1 or RBD and N proteins and analysis of IgG and IgA immunoglobulin classes in sera provide an excellent basis for specific and sensitive serological diagnostics of COVID-19.

Molecular Epidemiology and Evolutionary Trajectory of Emerging Echovirus 30, Europe.

In 2018, an upsurge in echovirus 30 (E30) infections was reported in Europe. We conducted a large-scale epidemiologic and evolutionary study of 1,329 E30 strains collected in 22 countries in Europe during 2016-2018. Most E30 cases affected persons 0-4 years of age (29%) and 25-34 years of age (27%). Sequences were divided into 6 genetic clades (G1-G6). Most (53%) sequences belonged to G1, followed by G6 (23%), G2 (17%), G4 (4%), G3 (0.3%), and G5 (0.2%). Each clade encompassed unique individual recombinant forms; G1 and G4 displayed >2 unique recombinant forms. Rapid turnover of new clades and recombinant forms occurred over time. Clades G1 and G6 dominated in 2018, suggesting the E30 upsurge was caused by emergence of 2 distinct clades circulating in Europe. Investigation into the mechanisms behind the rapid turnover of E30 is crucial for clarifying the epidemiology and evolution of these enterovirus infections.

Lymphocytic Choriomeningitis Virus Infections and Seroprevalence, Southern Iraq.

Acute febrile neurological infection cases in southern Iraq (N = 212) were screened for lymphocytic choriomeningitis virus (LCMV). Two LCMV IgM-positive serum samples and 2 cerebrospinal fluid samples with phylogenetically distinct LCMV strains were found. The overall LCMV seroprevalence was 8.8%. LCMV infections are common and associated with acute neurological disease in Iraq.

Range Expansion of Bombali Virus in Mops condylurus Bats, Kenya, 2019.

Previously identified only in Sierra Leone, Guinea, and southeastern Kenya, Bombali virus-infected Mops condylurus bats were recently found ¼750 km away in western Kenya. This finding supports the role of M. condylurus bats as hosts and the potential for Bombali virus circulation across the bats' range in sub-Saharan Africa.

Evaluation of commercial and automated SARS-CoV-2 IgG and IgA ELISAs using coronavirus disease (COVID-19) patient samples.

Antibody-screening methods to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) need to be validated. We evaluated SARS-CoV-2 IgG and IgA ELISAs in conjunction with the EUROLabworkstation (Euroimmun, Lübeck, Germany). Overall specificities were 91.9% and 73.0% for IgG and IgA ELISAs, respectively. Of 39 coronavirus disease patients, 13 were IgG and IgA positive and 11 IgA alone at sampling. IgGs and IgAs were respectively detected at a median of 12 and 11 days after symptom onset.

Specialist laboratory networks as preparedness and response tool - the Emerging Viral Diseases-Expert Laboratory Network and the Chikungunya outbreak, Thailand, 2019.

We illustrate the potential for specialist laboratory networks to be used as preparedness and response tool through rapid collection and sharing of data. Here, the Emerging Viral Diseases-Expert Laboratory Network (EVD-LabNet) and a laboratory assessment of chikungunya virus (CHIKV) in returning European travellers related to an ongoing outbreak in Thailand was used for this purpose. EVD-LabNet rapidly collected data on laboratory requests, diagnosed CHIKV imported cases and sequences generated, and shared among its members and with the European Centre for Disease Prevention and Control. Data across the network showed an increase in CHIKV imported cases during 1 October 2018-30 April 2019 vs the same period in 2018 (172 vs 50), particularly an increase in cases known to be related to travel to Thailand (72 vs 1). Moreover, EVD-LabNet showed that strains were imported from Thailand that cluster with strains of the ECSA-IOL E1 A226 variant emerging in Pakistan in 2016 and involved in the 2017 outbreaks in Italy. CHIKV diagnostic requests increased by 23.6% between the two periods. The impact of using EVD-LabNet or similar networks as preparedness and response tool could be improved by standardisation of the collection, quality and mining of data in routine laboratory management systems.

Bombali Virus in Mops condylurus Bat, Kenya.

Bombali virus (genus Ebolavirus) was identified in organs and excreta of an Angolan free-tailed bat (Mops condylurus) in Kenya. Complete genome analysis revealed 98% nucleotide sequence similarity to the prototype virus from Sierra Leone. No Ebola virus-specific RNA or antibodies were detected from febrile humans in the area who reported contact with bats.

Zika Virus Infection with Prolonged Maternal Viremia and Fetal Brain Abnormalities.

The current outbreak of Zika virus (ZIKV) infection has been associated with an apparent increased risk of congenital microcephaly. We describe a case of a pregnant woman and her fetus infected with ZIKV during the 11th gestational week. The fetal head circumference decreased from the 47th percentile to the 24th percentile between 16 and 20 weeks of gestation. ZIKV RNA was identified in maternal serum at 16 and 21 weeks of gestation. At 19 and 20 weeks of gestation, substantial brain abnormalities were detected on ultrasonography and magnetic resonance imaging (MRI) without the presence of microcephaly or intracranial calcifications. On postmortem analysis of the fetal brain, diffuse cerebral cortical thinning, high ZIKV RNA loads, and viral particles were detected, and ZIKV was subsequently isolated.

Detection of novel tick-borne pathogen, Alongshan virus, in Ixodes ricinus ticks, south-eastern Finland, 2019.

The newly identified tick-borne Alongshan virus (ALSV), a segmented Jingmen virus group flavivirus, was recently associated with human disease in China. We report the detection of ALSV RNA in Ixodes ricinus ticks in south-eastern Finland. Screening of sera from patients suspected for tick-borne encephalitis for Jingmen tick virus-like virus RNA and antibodies revealed no human cases. The presence of ALSV in common European ticks warrants further investigations on its role as a human pathogen.

Fatal Tick-Borne Encephalitis Virus Infections Caused by Siberian and European Subtypes, Finland, 2015.

In most locations except for Russia, tick-borne encephalitis is mainly caused by the European virus subtype. In 2015, fatal infections caused by European and Siberian tick-borne encephalitis virus subtypes in the same Ixodes ricinus tick focus in Finland raised concern over further spread of the Siberian subtype among widespread tick species.

Serological survey of Seewis virus antibodies in patients suspected for hantavirus infection in Finland; a cross-reaction between Puumala virus antiserum with Seewis virus N protein?

Puumala virus (PUUV, carried by Myodes glareolus) co-circulates with Seewis virus (SWSV, carried by Sorex araneus) in Finland. While PUUV causes 1000-3000 nephropathia epidemica (NE) cases annually, the pathogenicity of SWSV to man is unknown. To study the prevalence of SWSV antibodies in hantavirus fever-like patients' sera, we used recombinant SWSV nucleocapsid (N) protein as the antigen in ELISA, immunofluorescence assay (IFA) and immunoblotting. While characterizing the recombinant SWSV N protein, we observed that a polyclonal rabbit antiserum against PUUV N protein cross-reacted with SWSV N protein and vice versa. We initially screened 486 (450 PUUV-seronegative and 36 PUUV-seropositive) samples sent to Helsinki University Hospital Laboratory for PUUV serodiagnosis during 2002 and 2007 in an SWSV N protein IgG ELISA. In total, 4.2 % (19/450) of the PUUV-seronegative samples were reactive in the SWSV N protein IgG ELISA and none of the tested samples [43 PUUV-seronegative (weakly reactive in the SWSV IgG ELISA) and 15 random] were reactive in the SWSV N protein IgM ELISA. None of the IgG reactions could be confirmed by IFA or immunoblotting. Furthermore, among the 36 PUUV-seropositive samples three were reactive in SWSV N protein IgG and ten in SWSV N protein IgM ELISA. One PUUV-seropositive sample reacted with SWSV N protein in IFA and four in immunoblotting. Finally, we applied competitive ELISA to confirm that the observed reactivity was due to cross-reactivity rather than a true SWSV response. In conclusion, no evidence of SWSV infection was found among the 486 samples studied; however, we did demonstrate that PUUV antiserum cross-reacted with shrew-borne hantavirus N protein.

Stress-related eating, obesity and associated behavioural traits in adolescents: a prospective population-based cohort study.

BACKGROUND: Stress-related eating is associated with unhealthy eating and drinking habits and an increased risk of obesity among adults, but less is known about factors related to stress-driven eating behaviour among children and adolescents. We studied the prevalence of stress-related eating and its association with overweight, obesity, abdominal obesity, dietary and other health behaviours at the age of 16. Furthermore, we examined whether stress-related eating is predicted by early-life factors including birth size and maternal gestational health. METHODS: The study population comprised 3598 girls and 3347 boys from the Northern Finland Birth Cohort 1986 (NFBC1986). Followed up since their antenatal period, adolescents underwent a clinical examination, and their stress-related eating behaviour, dietary habits and other health behaviours were assessed using a postal questionnaire. We examined associations using cross-tabulations followed by latent class analysis and logistic regression to profile the adolescents and explain the risk of obesity with behavioural traits. RESULTS: Stress-related eating behaviour was more common among girls (43%) than among boys (15%). Compared with non-stress-driven eaters, stress-driven eaters had a higher prevalence of overweight, obesity and abdominal obesity. We found no significant associations between stress-eating and early-life factors. Among girls, tobacco use, shorter sleep, infrequent family meals and frequent consumption of chocolate, sweets, light sodas and alcohol were more prevalent among stress-driven eaters. Among boys, the proportions of those with frequent consumption of sausages, chocolate, sweets, hamburgers and pizza were greater among stress-driven eaters. For both genders, the proportions of those bingeing and using heavy exercise and strict diet for weight control were higher among stress-eaters. Besides a 'healthy lifestyle' cluster, latent class analysis revealed two other patterns ('adverse habits', 'unbalanced weight control') that significantly explained the risk of overweight among boys and girls. CONCLUSIONS: Stress-related eating is highly prevalent among 16-year-old girls and is associated with obesity as well as adverse dietary and other health behaviours among both genders, but intrauterine conditions are seemingly uninvolved. In terms of obesity prevention and future health, adolescents who use eating as a passive way of coping could benefit from learning healthier strategies for stress and weight management.

Evidence of Ljungan virus specific antibodies in humans and rodents, Finland.

Ljungan virus (LV, genus Parechovirus, family Picornaviridae) is considered currently to be a rodent-borne virus. Despite suggested human disease associations, its zoonotic potential remains unclear. To date, LV antibody prevalence in both humans and rodents has not been studied. In this study, two different LV immunofluorescence assays (LV IFAs) were developed with LV genotypes 1 (LV strain 87-012G) and 2 (LV strain 145SLG), and cross-neutralization and -reaction studies were carried out with LV strain 145SLG. Finally, a panel of 37 Finnish sera was screened for anti-LV antibodies using two different LV IFAs (LV 145SLG and LV 87-012G) and a neutralization (NT) assay (LV 145SLG), and 50 samples from Myodes glareolus by LV IFA (LV 145SLG). The LV seroprevalence study showed 38% and 18% positivity in humans and M. glareolus, respectively. LV IFAs and NT assays were compared, and the results were in good agreement. The data are the first evidence of humans and rodents coming into contact with LV in Finland. Additional studies are required in order to acquire a better understanding of the prevalence, epidemiological patterns and possible disease association of LV infections.

Serological Evidence of Exposure to Onyong-Nyong and Chikungunya Viruses in Febrile Patients of Rural Taita-Taveta County and Urban Kibera Informal Settlement in Nairobi, Kenya.

Several alphaviruses, such as chikungunya (CHIKV) and Onyong-nyong (ONNV), are endemic in Kenya and often cause outbreaks in different parts of the country. We assessed the seroprevalence of alphaviruses in patients with acute febrile illness in two geographically distant areas in Kenya with no previous record of alphavirus outbreaks. Blood samples were collected from febrile patients in health facilities located in the rural Taita-Taveta County in 2016 and urban Kibera informal settlement in Nairobi in 2017 and tested for CHIKV IgG and IgM antibodies using an in-house immunofluorescence assay (IFA) and a commercial ELISA test, respectively. A subset of CHIKV IgG or IgM antibody-positive samples were further analyzed using plaque reduction neutralization tests (PRNT) for CHIKV, ONNV, and Sindbis virus. Out of 537 patients, 4 (0.7%) and 28 (5.2%) had alphavirus IgM and IgG antibodies, respectively, confirmed on PRNT. We show evidence of previous and current exposure to alphaviruses based on serological testing in areas with no recorded history of outbreaks.

Evolutionary Relationships of Ljungan Virus Variants Circulating in Multi-Host Systems across Europe.

The picornavirus named 'Ljungan virus' (LV, species Parechovirus B) has been detected in a dozen small mammal species from across Europe, but detailed information on its genetic diversity and host specificity is lacking. Here, we analyze the evolutionary relationships of LV variants circulating in free-living mammal populations by comparing the phylogenetics of the VP1 region (encoding the capsid protein and associated with LV serotype) and the 3Dpol region (encoding the RNA polymerase) from 24 LV RNA-positive animals and a fragment of the 5' untranslated region (UTR) sequence (used for defining strains) in sympatric small mammals. We define three new VP1 genotypes: two in bank voles (Myodes glareolus) (genotype 8 from Finland, Sweden, France, and Italy, and genotype 9 from France and Italy) and one in field voles (Microtus arvalis) (genotype 7 from Finland). There are several other indications that LV variants are host-specific, at least in parts of their range. Our results suggest that LV evolution is rapid, ongoing and affected by genetic drift, purifying selection, spillover and host evolutionary history. Although recent studies suggest that LV does not have zoonotic potential, its widespread geographical and host distribution in natural populations of well-characterized small mammals could make it useful as a model for studying RNA virus evolution and transmission.

Molecular detection and phylogenetic analysis of Borrelia miyamotoi strains from ticks collected in the capital region of Finland.

Borrelia miyamotoi is an emerging pathogen that shares high similarity with relapsing fever Borrelia, but has an atypical clinical presentation. Within the framework of tick-borne disease surveillance in Finland, human serum samples suspected for tick-borne encephalitis (n=974) and questing ticks (n=739) were collected from the capital region in Finland to determine the prevalence of B. miyamotoi. All tested human samples were negative and 5 (0.68 %) Ixodes ricinus ticks were positive for B. miyamotoi. Partial sequencing of the flagellin (flaB) gene of 3 positive samples and 27 B. miyamotoi-positive tick samples obtained from previous studies across Finland were amplified, sequenced, and included in the phylogenetic analysis. The phylogenetic tree revealed that most B. miyamotoi strains isolated from ticks in Finland share high similarity with other European strains, including strains related to human infection. Possible disease transmission may occur during exposure to tick bites. A single strain collected from an I. persulcatus tick in Pajujärvi grouped with an outlier of B. miyamotoi strains isolated from Russia and Far East Asian countries. Further studies should investigate the pathogen's role in human infection in Finland. Another important finding is the occurrence of I. persulcatus ticks (8%) collected by crowdsourcing from the coastal southern part of Finland. This suggests a regular introduction and a possible wide expansion of this tick species in the country. This could be associated with transmission of new pathogens.

SARS-CoV-2 infections among healthcare workers at Helsinki University Hospital, Finland, spring 2020: Serosurvey, symptoms and risk factors.

BACKGROUND: Exposure, risks and immunity of healthcare workers (HCWs), a vital resource during the SARS-CoV-2 pandemic, warrant special attention. METHODS: HCWs at Helsinki University Hospital, Finland, filled in questionnaires and provided serum samples for SARS-CoV-2-specific antibody screening by Euroimmun IgG assay in March-April 2020. Positive/equivocal findings were confirmed by Abbott and microneutralization tests. Positivity by two of the three assays or RT-PCR indicated a Covid-19 case (CoV+). RESULTS: The rate of CoV(+) was 3.3% (36/1095) and seropositivity 3.0% (33/1095). CoV(+) was associated with contact with a known Covid-19 case, and working on a Covid-19-dedicated ward or one with cases among staff. The rate in the Covid-19-dedicated ICU was negligible. Smoking and age <55 years were associated with decreased risk. CoV(+) was strongly associated with ageusia, anosmia, myalgia, fatigue, fever, and chest pressure. Seropositivity was recorded for 89.3% of those with prior documented RT-PCR-positivity and 2.4% of those RT-PCR-negative. The rate of previously unidentified cases was 0.7% (8/1067) and asymptomatic ones 0% (0/36). CONCLUSION: Undiagnosed and asymptomatic cases among HCWs proved rare. An increased risk was associated with Covid-19-dedicated wards. Particularly high rates were seen for wards with liberal HCW-HCW contacts, highlighting the importance of social distancing also among HCWs.