High habitat richness reduces the risk of tick-borne encephalitis in Europe: A multi-scale study

Background

The natural transmission cycle of tick-borne encephalitis (TBE) virus is enhanced by complex interactions between ticks and key hosts strongly connected to habitat characteristics. The diversity of wildlife host species and their relative abundance is known to affect transmission of tick-borne diseases. Therefore, in the current context of global biodiversity loss, we explored the relationship between habitat richness and the pattern of human TBE cases in Europe to assess biodiversity's role in disease risk mitigation.

Methods

We assessed human TBE case distribution across 879 European regions using official epidemiological data reported to The European Surveillance System (TESSy) between 2017 and 2021 from 15 countries. We explored the relationship between TBE presence and the habitat richness index (HRI1) by means of binomial regression. We validated our findings at local scale using data collected between 2017 and 2021 in 227 municipalities located in Trento and Belluno provinces, two known TBE foci in northern Italy.

Findings

Our results showed a significant parabolic effect of HRI on the probability of presence of human TBE cases in the European regions included in our dataset, and a significant, negative effect of HRI on the local presence of TBE in northern Italy. At both spatial scales, TBE risk decreases in areas with higher values of HRI.

Interpretation

To our knowledge, no efforts have yet been made to explore the relationship between biodiversity and TBE risk, probably due to the scarcity of high-resolution, large-scale data about the abundance or density of critical host species. Hence, in this study we considered habitat richness as proxy for vertebrate host diversity. The results suggest that in highly diverse habitats TBE risk decreases. Hence, biodiversity loss could enhance TBE risk for both humans and wildlife. This association is relevant to support the hypothesis that the maintenance of highly diverse ecosystems mitigates disease risk.

HIV screening of migrants in the autonomous Province of Trento (north of Italy)

Abstract

Migrants have accounted for more than 40% of new HIV diagnoses in Europe in 2022. Among the population of asylum seekers currently present in the Trento Province, screening for HIV infection is poorly carried out for various reasons. Here we report our experience about screening for HIV infection in asylum seekers present in that area using rapid self HIV-testing.

The COVID-19 vaccination in 4,772 pregnant women in the province of Trento (North-East Italy). Characteristics of vaccinated women

OBJECTIVES

to investigate vaccine uptake among pregnant women during the 2nd and 3rd trimester of pregnancy. To describe the factors influencing vaccine uptake during pregnancy, comparing sociodemographic and clinical characteristics of pregnant women who were vaccinated during the 2nd or 3rd trimester with those who were not vaccinated, despite having the indication for vaccination.

DESIGN

observational study with a cross-sectional approach and prevalence estimation in the population of women who gave birth in the study period, through record linkages between the ministry information flow Birth assistance certificate, the Regional vaccination register and the Italian flow for SARS-CoV-2 infections.

SETTING AND PARTICIPANTS

the study included all the 4,772 pregnant women living in Trentino (north-east Italy), who were in the 2nd or 3rd trimester of pregnancy between the 5th May 2021 and the 28th February 2022 and who delivered in Trentino.

MAIN OUTCOME MEASURES

vaccine uptake among pregnant women during the 2nd and 3rd trimester of pregnancy. Results: 33.3% of pregnant women got vaccinated with at least one dose of vaccine during the 2nd or 3rd trimester of pregnancy. Independent factors associated with vaccine uptake in the 2nd or 3rd trimester were the mother's citizenship, educational level, occupational status and age.

CONCLUSIONS

the proportion of women who received at least one dose of COVID-19 vaccine during pregnancy was low. The results are important to start efficient actions to promote vaccination in pregnant women, particularly in the most vulnerable ones (unemployed, foreigners and with a low educational level), who appear to be less vaccinated frequently.

Correlation between airborne pollen data and the risk of tick-borne encephalitis in northern Italy

Tick-borne encephalitis (TBE) is caused by a flavivirus that infects animals including humans. In Europe, the TBE virus circulates enzootically in natural foci among ticks and rodent hosts. The abundance of ticks depends on the abundance of rodent hosts, which in turn depends on the availability of food resources, such as tree seeds. Trees can exhibit large inter-annual fluctuations in seed production (masting), which influences the abundance of rodents the following year, and the abundance of nymphal ticks two years later. Thus, the biology of this system predicts a 2-year time lag between masting and the incidence of tick-borne diseases such as TBE. As airborne pollen abundance is related to masting, we investigated whether inter-annual variation in pollen load could be directly correlated with inter-annual variation in the incidence of TBE in human populations with a 2-year time lag. We focused our study on the province of Trento (northern Italy), where 206 TBE cases were notified between 1992 and 2020. We tested the relationship between TBE incidence and pollen load collected from 1989 to 2020 for 7 different tree species common in our study area. Through univariate analysis we found that the pollen quantities recorded two years prior for two tree species, hop-hornbeam (Ostrya carpinifolia) and downy oak (Quercus pubescens), were positively correlated with TBE emergence (R² = 0.2) while a multivariate model with both tree species better explained the variation in annual TBE incidence (R² = 0.34). To the best of our knowledge, this is the first attempt at quantifying the correlation between pollen quantities and the incidence of TBE in human populations. As pollen loads are collected by widespread aerobiological networks using standardized procedures, our study could be easily replicated to test their potential as early warning system for TBE and other tick-borne diseases.

Anti-SARS-CoV-2 antibodies persistence after natural infection: a repeated serosurvey in Northern Italy

INTRODUCTION

To evaluate the decline of antibodies induced by SARS-CoV-2 infection, the individuals resident in 5 municipalities of the Autonomous Province of Trento, Northern Italy, who resulted IgG positive for anti-SARS-CoV-2 nucleocapsid (NC) in May 2020, were tested four months later.

METHODS

Anti-SARS-CoV-2 NC antibodies were detected using the Abbott SARS-CoV-2 IgG assay. Samples that gave a negative result were re-tested using the Liaison SARS-CoV-2 IgG assay to assess anti-spike (S) S1/S2 antibodies. The fifty-percent tissue culture infective dose (TCID50) neutralizing assay was performed on a subgroup of formerly positive sera. Statistical analysis was performed by STATA version 16.1 (STATA Corp., College Station, Texas, USA).

RESULTS

Overall, 480 out of 1159 participants became seronegative for anti-NC IgG antibodies. Age above 70 years and cough were associated with persistent anti-NC IgG levels. Most anti-NC IgG negative sera were positive for anti-S IgG (77.9%). The neutralization assay showed high concordance with anti-S antibodies positivity.

CONCLUSION

In conclusion, a decline of anti-NC IgG values was recorded four months after the first evaluation. A high proportion of anti-NC seronegative individuals were positive for anti-spike IgG antibodies, which appear to persist longer and to better correlate with neutralization activity.

The risk of symptomatic infection during a second COVID-19 wave, in SARS-CoV-2 seropositive individuals

We analyzed 221 coronavirus disease 2019 cases identified between June 2020 and January 2021 in 6074 individuals screened for immunoglobulin G antibodies in May 2020, representing 77% of residents of 5 Italian municipalities. The relative risk of developing symptomatic infection in seropositive participants was 0.055 (95% confidence interval, .014–.220).

Prevalence of SARS-CoV-2 IgG antibodies in an area of northeastern Italy with a high incidence of COVID-19 cases: a population-based study

Objectives

A seroprevalence study of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was conducted in a high-incidence area located in northeastern Italy.

Methods

All citizens above 10 years of age resident in five municipalities of the Autonomous Province of Trento, with the highest incidence of coronavirus disease 2019 (COVID-19) cases, were invited to participate in the study. Among 6098 participants, 6075 sera and a standardized questionnaire administered face-to-face were collected between 5 May and 15 May 2020 and examined. Symptomatic individuals and their family contacts were tested by RT-PCR. Anti-SARS-CoV-2 antibodies were detected using an Abbott SARS-CoV-2 IgG assay, which was performed on the Abbott Architect i2000SR automated analyser. Seroprevalence was calculated as the proportion of positive results among the total number tested. A multivariable logistic regression model was performed to assess the relationship between seropositive versus seronegative individuals for a set of explanatory variables.

Results

A total of 1402 participants were positive for IgG antibodies against SARS-CoV-2, with a prevalence of 23.1% (1402/6075). The highest prevalence was found in the age class 40–49 years. Overall, 34.4% (2096/6098) of the participants reported at least one symptom. The ratio between reported cases identified by molecular test and those with seropositive results was 1:3, with a maximum ratio of about 1:7 in the age group <20 years and a minimum around 1:1 in those >70 years old. The infection fatality rate was 2.5% (35/1402). Among the symptoms, anosmia and ageusia were strongly associated with seropositivity.

Conclusions

The estimated seroprevalence of 23% was three-fold higher than the number of cases reported in the COVID-19 Integrated Surveillance data in the study area. This may be explained in part by a relatively high number of individuals presenting mild or no illness, especially those of younger age, and people who did not seek medical care or testing, but who may contribute to virus transmission in the community.

Surveillance of childhood overweight: comparison of "OKkio alla SALUTE" survey and general paediatrics data in the Province of Trento

Estimates of childhood overweight and obesity for the Province of Trento provided by the 2014 "OKkio alla SALUTE" survey (Italian national surveillance system for weight and nutrition in children) were compared with estimates provided by paediatric health forms. The Province of Trento is the only region that makes use of the information gathered through these forms, which are completed by primary care paediatricians as part of the 6-year health evaluation. OKkio alla SALUTE data for children, obtained from students enrolled in the third year of primary school in 2014 (845 children aged 8-9 years), were compared with data collected at the age of 6 for cohorts born in 2006, evaluated in 2012-2013 (3101 subjects). The following prevalence figures were obtained from OKkio alla SALUTE and the 6-year paediatrician evaluation respectively: overweight, 17.4% vs 11.7%; obese, 4.1% vs 4.5%; severely obese, 1.4% vs 1.0%. The two information sources provide similar estimates, suggesting the potential for their integrated use.