Bayesian inference for the onset time and epidemiological characteristics of emerging infectious diseases.

Background: Emerging infectious diseases pose a significant threat to global public health. Timely detection and response are crucial in mitigating the spread of such epidemics. Inferring the onset time and epidemiological characteristics is vital for accelerating early interventions, but accurately predicting these parameters in the early stages remains challenging. Methods: We introduce a Bayesian inference method to fit epidemic models to time series data based on state-space modeling, employing a stochastic Susceptible-Exposed-Infectious-Removed (SEIR) model for transmission dynamics analysis. Our approach uses the particle Markov chain Monte Carlo (PMCMC) method to estimate key epidemiological parameters, including the onset time, the transmission rate, and the recovery rate. The PMCMC algorithm integrates the advantageous aspects of both MCMC and particle filtering methodologies to yield a computationally feasible and effective means of approximating the likelihood function, especially when it is computationally intractable. Results: To validate the proposed method, we conduct case studies on COVID-19 outbreaks in Wuhan, Shanghai and Nanjing, China, respectively. Using early-stage case reports, the PMCMC algorithm accurately predicted the onset time, key epidemiological parameters, and the basic reproduction number. These findings are consistent with empirical studies and the literature. Conclusion: This study presents a robust Bayesian inference method for the timely investigation of emerging infectious diseases. By accurately estimating the onset time and essential epidemiological parameters, our approach is versatile and efficient, extending its utility beyond COVID-19.

Measles outbreak investigation in Tocha district, southwestern Ethiopia: an unmatched case-control study.

Background: Measles continues to be a public health challenge in Ethiopia. Rumors of suspected measles were notified on April 8, 2023 from Tocha district. We conducted an assessment to describe measles outbreak and determine risk factors for measles infection in the Tocha district of the Dawuro zone, Southwest Ethiopia. Methods: We conducted a 1:2 unmatched case-control studies from April to May 2023. We took all 147 cases registered on line list for descriptive analyses. We used a total of 74 randomly selected cases and 147 controls for case-control part. Any person in Tocha district with laboratory-confirmed measles IgM antibody; or any suspected person epidemiologically linked to confirmed measles cases from March 23 to April 26 2023, were included in the case. Neighborhood who did not fulfill this standard case definition were included in controls. Data were collected using standardized questionnaires deployed on Kobo Collect. Descriptive analyses were conducted using Epi info version 7.2.5.0. The analyses were performed using Statistical Package for Social Science (SPSS) version 26. Binary logistic regression analyses were utilized to select candidate variables. We conducted multiple logistic regression analysis to identify determinants of measles infection at a p value ≤0.05 with 95% confidence interval. Results: The overall attack rate of 22.64/10,000 for general population and 104.59/10,000 among under-five children were attributed to the outbreak with a case fatality rate of 2.72%. Vaccine coverage in the last year and this year were 73.52 and 53.88%, respectively, while vaccine effectiveness in the district was 79%. Poor house ventilation (AOR = 3.540, 95% CI: 1.663-7.535) and having contact history with the case (AOR = 2.528, 95% CI: 1.180-4.557) were positively related to measles infection while being previously vaccinated for measles (AOR = 0.209, 95% CI: 0.180-4.577) reduce risk of measles infections. Conclusion: The highest attack rate was observed among children under 5 years of age, with a case fatality rate of 2.72%. Vaccination coverage was less than what expected to develop herd immunity. Strategies to increase vaccination coverage and strengthening surveillance systems for rumor identification and early responses to prevent person to person transmission are recommended.

Measles outbreak investigation in Berhet District, North Shewa, Ethiopia.

Introduction: Measles, though usually self-limiting, can have severe consequences influenced by factors such as vaccination and nutrition, notably vitamin A deficiency and malnutrition. Despite progress, contextual changes and implementation issues have hampered efforts, resulting in increased outbreaks and cases of measles. This study seeks to pinpoint outbreak features, risk factors, and strategies for preventing and controlling measles. Methods: A descriptive cross-sectional study and a 1:2 unmatched case-control study design were employed. All 101 suspected measles cases listed on the line-list were included in the descriptive research, with 60 measles patients and 120 controls included in the case-control investigation. Line-list data were cleaned and analyzed using a pivot table in Microsoft Excel 2016. Subsequently, the data were cleaned, entered into Epi Info 7.2, and exported to SPSS 26 for analysis. Results: Twenty cases occurred per 10,000 individuals. Men accounted for 67.3% of cases, with ages ranging from 5 months to 45 years and mean and standard deviations of 9.6 and 7.6, respectively. Age group of 5-14 years comprised 57.4% of cases, followed by 1-4 years with 24.8%. Being unvaccinated against measles showed an adjusted odds ratio (AOR) of 12.06 (95% CI: 3.12-46.52). Travel history to regions with active cases had an AOR of 5.73 (95% CI: 1.78-18.38). Contact with a measles patient showed an AOR of 10.3 (95% CI: 3.48-30.5). Understanding the measles transmission mechanism had an AOR of 0.164 (95% CI: 0.049-0.55), and awareness of the disease's preventability had an AOR of 0.233 (95% CI: 0.67-0.811). All factors were independently associated with the illness. Conclusion: This outbreak affected a broader age range with a high attack rate, mainly in the age group of 5-14-years. Over 35% of cases lacked measles vaccination, indicating low administrative vaccine coverage. Factors contributing to the outbreak include lack of measles vaccination, travel to areas with active disease, contact with cases, and insufficient knowledge of measles transmission and prevention strategies among mothers and caregivers.

Giardioza (Lamblioza) w Polsce w 2021 roku. / Giardasis (Lambliasis) in Poland in 2021.

INTRODUCTION: Giardiosis is a parasitic disease caused by the protozoa Giardia lamblia (also known as Giardia intestinalis and Giardia duodenalis), which causes gastrointestinal symptoms. Infection usually occurs through the ingestion of contaminated water/food or through contact with an infected person. In Poland, giardiasis is notifiable disease, acoording to the EU deffinition implement in the polish surveillance system. AIM OF THE STUDY: The aim of this study is to asses epidemiological situation of giardiasis in Poland in 2021 and compare it to the previous years. MATERIALS AND METHODS: The assessment of the epidemiological situation of giardiasis in Poland in 2021 was performed on the basis of data from the annual bulletins "Infectious diseases and poisoning in Poland" for the years 2008-2021, data on individual cases collected for the purposes of epidemiological surveillance in the EpiBaza system and data from food-born outbreak investigations recorded in the Registry of Epidemic Outbreaks (ROE). RESULTS: In 2021, 559 cases of giardiasis were reported in Poland (558 confirmed case, 1 probable case). There was an increase in the number of reported cases in comparision to 2020 by 56% and decrease to 2019 by 29%. Cases of giardiasis were reported in all voivodeships, with the highest incidence rate in Podlaskie voivodeship (9.1/100 000), incidence rate for Poland was 1.5/100 000. Giardiasis was diagnosed in patiens in all age group, the largest group of patiens were children (age groups 0-4 and 5-9). The hospitalization rate of patients diagnosed with giardiasis was 9.7% and was lower than in 2020, when it was 12.4%. As in previous years, no deaths from giardiasis were reported. CONCLUSIONS: The number of cases of giardiasis has increased compared to 2020, but has not reached pre-pandemic levels. As in previous years, differences in the incidence by age and sex of people with the disease were noted when comparing data reported from Poland and EU/EEA countries.

Measles in Poland in 2021. / Odra w Polsce w 2021 roku.

INTRODUCTION: Measles is one of the most contagious childhood diseases, and the behavior also occurs in adults. This is a multi-year vaccination covered by an elimination program coordinated by the World Health Organization (WHO). Elimination of measles in the country is conditional on a 95% incidence of infection with two victims, monitoring the epidemiological situation, registering all suspected cases of measles, and monitoring by the WHO Reference Laboratory. In our country, the Department of Virology of the NIZP PZH-PIB in Warsaw serves as the head of the Department of Virology. OBJECTIVES: The aim of this study was to evaluate epidemiological indicators of measles in Poland in 2021 compared to previous years, taking into account the impact of the COVID-19 pandemic. MATERIAL AND METHODS: The assessment of the epidemiological situation was based on a review of data from the bulletin, "Infectious Diseases and Poisons in Poland in 2021" (5), and the assessment of the immunization status of the population was based on data from the bulletin, "Immunization in Poland in 2021" (6). Classification of cases was made based on the definition used in the 2021 surveillance (7). Data from the epidemiological surveillance system "EpiBase" were also used. RESULTS: In 2021, 13 measles cases were registered in Poland (incidence 0.03 per 100,000), 44.8% less than in 2020 and 80% less than the median in 2014-2018. In 2021, the highest incidence was recorded at 0.32 per 100,000 children aged 0-4 years. 6 patients (46.2%) were hospitalized; no deaths due to measles were reported. 32 suspected measles cases were recorded, with over a hundred cases expected. Vaccination status of children aged 3 with the first dose was 90.8%, and the second dose was given to children at the age of 9. - 84.6%. CONCLUSIONS: Epidemiological indicators of measles in 2021 in Poland compared to 2020 have decreased. A similar trend observed throughout Europe. This is related to the extinguishment of outbreaks that occurred before the pandemic, mainly in 2019.

Salmonellosis in Poland in 2021. / Salmonelozy w Polsce w 2021 roku.

AIM: The aim of the article is to present and assess the epidemiological situation of salmonellosis in Poland in 2021, in relation to previous years. MATERIAL AND METHODS: The assessment of the epidemiological situation of salmonellosis in Poland was made on the basis of individual data on salmonellosis cases, entered by sanitary-epidemiological stations into the EpiBaza System, data on outbreaks caused by Salmonella bacilli from the Registry of Epidemic Outbreaks System (ROE), as well as on the basis of aggregated data published in the annual bulletins "Infectious Diseases and Poisoning in Poland" (NIPH NIH - NRI, GIS, Warsaw), including information sent by laboratories of sanitary-epidemiological stations, data from the article on the epidemiological situation of salmonellosis in Poland in 2020 and data from the Demographic Research Department of the Central Statistical Office. RESULTS: In 2021, in Poland sanitary-epidemiological stations registered 8,294 cases of salmonellosis - 8,014 cases of intestinal salmonellosis and 280 extra-intestinal salmonellosis, including 190 cases of salmonellosis septicemia. The incidence rate for total salmonellosis was 21.7/100,000 population, for intestinal salmonellosis 21.0, for salmonellosis septicemia 0.50, and 0.23 per 100,000 population for other extra-intestinal infections of salmonellosis etiology. The reported 7,988 cases were classified as confirmed and 306 as probable. There were 5,127 hospitalizations due to salmonellosis, mainly children and the elderly. The peak of the incidence was registered in July. The highest incidence rate of salmonellosis in 2021 was recorded in the Podkarpackie voivodeship (39.8/100,000 population), the lowest in the Swietokrzyskie voivodeship (10.7/100,000 population). The highest incidence of intestinal salmonellosis was registered in the age group 0-4 years, accounting for 44.2% of the total number of cases. Among extra-intestinal infections, almost 62% of cases occurred in people aged 60+. In 2021, sanitary-epidemiological stations were detected and reported 229 outbreaks of food poisoning caused by Salmonella bacilli, 75% of them was Enteritidis serotype. In 2021, the most frequently isolated serotypes were S. Enteritidis 72%, S. Typhimurium (2%) and S. Infantis (0.5%). The serotype was not determined in 24.3% of cases. There were 24 imported cases of salmonellosis from different regions of the world. Due to Salmonella infection 11 people died in 2021. Laboratories of sanitary-epidemiological stations performed 438,183 tests for the presence of Salmonella and Shigella bacilli among humans, 92% of these tests concerned people working in contact with food. CONCLUSIONS: In 2021, there was an increase in the number of salmonellosis cases in Poland, compared to 2020. It can therefore be concluded that the COVID-19 pandemic did not have a long-term impact on reducing the number of Salmonella infections. At the same time, despite the increase, the situation of salmonellosis in Poland has not fully returned to the state before the COVID-19 pandemic.The area where we observe a significant difference, is the percentage of hospitalizations, which is the lowest in 2021 since 1998. It can be assumed, that one of the reasons for this, could be a stricter qualification of people with milder symptoms for hospital treatment, in favour of outpatient care.

Listeriosis in Poland in 2012-2021. / Listerioza w Polsce w latach 2012-2021.

AIM: The aim of the study is to present and evaluate the epidemiological situation of listeriosis in Poland in the years 2012-2021. MATERIAL AND METHODS: The analysis material consisted of data from individual epidemiological case reports on listeriosis submitted to the Department of Epidemiology of Infectious Diseases and Surveillance of the NIPH NIH - NRI by state sanitaryepidemiological stations in the form of paper questionnaires (2012-2019) and in the electronic form through the EpiBaza system (2020 and 2021), as well as aggregated data from the bulletin "Infectious Diseases and Poisoning in Poland". RESULTS: Between 2012 and 2021, a total of 896 cases of listeriosis were registred in Poland. The median incidence was 0.23 per 100,000 population, which was an increase by 52.2% compared to the previous 5-year period (2007-2011). Every year, more than 90% of cases were hospitalized. The highest percentage of patients were in the age group >60 years old (65.5%). From 2012 to 2019 (in the years when information on cases was collected on a paper form), a total of 275 deaths of patients from listeriosis were recorded (38.4% of all reported cases). According to data from the EpiBaza system, in 2020 and 2021 there were 5 (8.33%) and 25 (20.83%) deaths due to listeriosis. A total of 92.1% of patients with listeriosis had significant predisposing factors for the occurrence of this disease, most of which were associated with neoplasia and heart disease and were present in half of all cases. As part of routine surveillance, no epidemic outbreak associated with Listeria monocytogenes infection was reported in Poland in the years 2012-2021.A total number of 49 pregnant women with listeriosis were reported during described period. Between 2012 and 2021, 37 cases of congenital listeriosis were reported. The median of incidence was 1.07/100 thousand live births, a decrease of 26% compared to the previous 5-year period (2007-2011). Of all congenital infections in newborns, 12 deaths (32.43%) were reported. CONCLUSIONS: The epidemiology of listeriosis is changing both in the EU/EEA countries and in Poland: the incidence is increasing and the distribution of cases in different age groups is changing, affecting primarily the elderly, especially those with predisposing diseases. Although 2020 tere was a decrease in the number of cases at EU level, possibly related to the COVID-19 pandemic, the overall trend of listeriosis cases isincreasing. The clinical condition has a significant impact on the course of L. monocytogenes infection: in healthy people, infection is usually asymptomatic. The disease primarily affects immunocompromised people. In contrast, infection of pregnant women can lead to premature birth, miscarriage, meningitis and neonatal sepsis with mortality rate of 20-30%. The growing trend in listeriosis is alarming and requires greater attention in terms of prevention and control of the disease.

Epidemiological and etiological investigations of hand, foot, and mouth disease in Jiashan, northeastern Zhejiang Province, China, during 2016 to 2022.

Background: Hand, foot, and mouth disease (HFMD) is a common infectious disease in children. Enterovirus A71 (EV71) and coxsackievirus A16 (CA16) have been identified as the predominant pathogens for several decades. In recent years, coxsackievirus A6 (CA6) and coxsackievirus A10 (CA10) have played increasingly important roles in a series of HFMD outbreaks. We performed a retrospective analysis of the epidemiology of HFMD and the spectrum of different viral serotypes, to elucidate the genetic and phylogenetic characteristics of the main serotypes in the Jiashan area during 2016 to 2022. Methods: Descriptive epidemiological methods were used to analyze the time and population distribution of HFMD in Jiashan during 2016 to 2022 based on surveillance data. Molecular diagnostic methods were performed to identify the viral serotypes and etiological characteristics of HFMD. Phylogenetic analyses was based on VP1 region of CA16 and CA6. Results: The average annual incidence rate of HFMD fluctuated from 2016 to 2022. Children aged 1-5 years accounted for 81.65% of cases and boys were more frequently affected than girls. Except when HFMD was affected by the COVID-19 epidemic in 2020 and 2022, epidemics usually peak in June to July, followed by a small secondary peak from October to December and a decline in February. Urban areas had a high average incidence and rural areas had the lowest. Among 560 sample collected in Jiashan, 472 (84.29%) were positive for enterovirus. The most frequently identified serotypes were CA6 (296, 52.86%), CA16 (102, 18.21%), EV71 (16, 2.86%), CA10 (14, 2.50%) and other enteroviruses (44, 7.86%). There were 71 and 142 VP1 sequences from CA16 and CA6, respectively. Substitution of N218D, A220L and V251I was detected in CA16 and may have been related to viral infectivity. Phylogenetic analysis showed that CA16 could be assigned to two genogroups, B1a and B1b, while all the CA6 sequences belonged to the D3a genogroup. Conclusion: CA6 and CA16 were the two major serotypes of enteroviruses circulating in the Jiashan area during 2016 to 2022. Continuous and comprehensive surveillance for HFMD is needed to better understand and evaluate the prevalence and evolution of the associated pathogens.

A Coupled Statistical and Deterministic Model for Forecasting Climate-Driven Dengue Incidence in Selangor, Malaysia.

The mosquito-borne dengue virus remains a major public health concern in Malaysia. Despite various control efforts and measures introduced by the Malaysian Government to combat dengue, the increasing trend of dengue cases persists and shows no sign of decreasing. Currently, early detection and vector control are the main methods employed to curb dengue outbreaks. In this study, a coupled model consisting of the statistical ARIMAX model and the deterministic SI-SIR model was developed and validated using the weekly reported dengue data from year 2014 to 2019 for Selangor, Malaysia. Previous studies have shown that climate variables, especially temperature, humidity, and precipitation, were able to influence dengue incidence and transmission dynamics through their effect on the vector. In this coupled model, climate is linked to dengue disease through mosquito biting rate, allowing real-time forecast of dengue cases using climate variables, namely temperature, rainfall and humidity. For the period chosen for model validation, the coupled model can forecast 1-2 weeks in advance with an average error of less than 6%, three weeks in advance with an average error of 7.06% and four weeks in advance with an average error of 8.01%. Further model simulation analysis suggests that the coupled model generally provides better forecast than the stand-alone ARIMAX model, especially at the onset of the outbreak. Moreover, the coupled model is more robust in the sense that it can be further adapted for investigating the effectiveness of various dengue mitigation measures subject to the changing climate.

DeepDynaForecast: Phylogenetic-informed graph deep learning for epidemic transmission dynamic prediction.

In the midst of an outbreak or sustained epidemic, reliable prediction of transmission risks and patterns of spread is critical to inform public health programs. Projections of transmission growth or decline among specific risk groups can aid in optimizing interventions, particularly when resources are limited. Phylogenetic trees have been widely used in the detection of transmission chains and high-risk populations. Moreover, tree topology and the incorporation of population parameters (phylodynamics) can be useful in reconstructing the evolutionary dynamics of an epidemic across space and time among individuals. We now demonstrate the utility of phylodynamic trees for transmission modeling and forecasting, developing a phylogeny-based deep learning system, referred to as DeepDynaForecast. Our approach leverages a primal-dual graph learning structure with shortcut multi-layer aggregation, which is suited for the early identification and prediction of transmission dynamics in emerging high-risk groups. We demonstrate the accuracy of DeepDynaForecast using simulated outbreak data and the utility of the learned model using empirical, large-scale data from the human immunodeficiency virus epidemic in Florida between 2012 and 2020. Our framework is available as open-source software (MIT license) at github.com/lab-smile/DeepDynaForcast.

Generative Bayesian modeling to nowcast the effective reproduction number from line list data with missing symptom onset dates.

The time-varying effective reproduction number Rt is a widely used indicator of transmission dynamics during infectious disease outbreaks. Timely estimates of Rt can be obtained from reported cases counted by their date of symptom onset, which is generally closer to the time of infection than the date of report. Case counts by date of symptom onset are typically obtained from line list data, however these data can have missing information and are subject to right truncation. Previous methods have addressed these problems independently by first imputing missing onset dates, then adjusting truncated case counts, and finally estimating the effective reproduction number. This stepwise approach makes it difficult to propagate uncertainty and can introduce subtle biases during real-time estimation due to the continued impact of assumptions made in previous steps. In this work, we integrate imputation, truncation adjustment, and Rt estimation into a single generative Bayesian model, allowing direct joint inference of case counts and Rt from line list data with missing symptom onset dates. We then use this framework to compare the performance of nowcasting approaches with different stepwise and generative components on synthetic line list data for multiple outbreak scenarios and across different epidemic phases. We find that under reporting delays realistic for hospitalization data (50% of reports delayed by more than a week), intermediate smoothing, as is common practice in stepwise approaches, can bias nowcasts of case counts and Rt, which is avoided in a joint generative approach due to shared regularization of all model components. On incomplete line list data, a fully generative approach enables the quantification of uncertainty due to missing onset dates without the need for an initial multiple imputation step. In a real-world comparison using hospitalization line list data from the COVID-19 pandemic in Switzerland, we observe the same qualitative differences between approaches. The generative modeling components developed in this work have been integrated and further extended in the R package epinowcast, providing a flexible and interpretable tool for real-time surveillance.

Candida auris in Greek healthcare facilities: Active surveillance results on first cases and outbreaks from eleven hospitals within Attica region.

BACKGROUND: Candida auris was sporadically detected in Greece until 2019. Thereupon, there has been an increase in isolations among inpatients of healthcare facilities. AIM: We aim to report active surveillance data on MALDI-TOF confirmed Candida auris cases and outbreaks, from November 2019 to September 2021. METHODS: A retrospective study on hospital-based Candida auris data, over a 23-month period was conducted, involving 11 hospitals within Attica region. Antifungal susceptibility testing and genotyping were conducted. Case mortality and fatality rates were calculated and p-values less than 0.05 were considered statistically significant. Infection control measures were enforced and enhanced. RESULTS: Twenty cases with invasive infection and 25 colonized were identified (median age: 72 years), all admitted to hospitals for reasons other than fungal infections. Median hospitalisation time until diagnosis was 26 days. Common risk factors among cases were the presence of indwelling devices (91.1 %), concurrent bacterial infections during hospitalisation (60.0 %), multiple antimicrobial drug treatment courses prior to hospitalisation (57.8 %), and admission in the ICU (44.4 %). Overall mortality rate was 53 %, after a median of 41.5 hospitalisation days. Resistance to fluconazole and amphotericin B was identified in 100 % and 3 % of tested clinical isolates, respectively. All isolates belonged to South Asian clade I. Outbreaks were identified in six hospitals, while remaining hospitals detected sporadic C. auris cases. CONCLUSION: Candida auris has proven its ability to rapidly spread and persist among inpatients and environment of healthcare facilities. Surveillance focused on the presence of risk factors and local epidemiology, and implementation of strict infection control measures remain the most useful interventions.

Outbreak of severe community-acquired bacterial infections among children in North Rhine-Westphalia (Germany), October to December 2022.

PURPOSE: In late 2022, a surge of severe S. pyogenes infections was reported in several European countries. This study assessed hospitalizations and disease severity of community-acquired bacterial infections with S. pyogenes, S. pneumoniae, N. meningitidis, and H. influenzae among children in North Rhine-Westphalia (NRW), Germany, during the last quarter of 2022 compared to long-term incidences. METHODS: Hospital cases due to bacterial infections between October and December 2022 were collected in a multicenter study (MC) from 59/62 (95%) children's hospitals in NRW and combined with surveillance data (2016-2023) from the national reference laboratories for streptococci, N. meningitidis, and H. influenzae. Overall and pathogen-specific incidence rates (IR) from January 2016 to March 2023 were estimated via capture-recapture analyses. Expected annual deaths from the studied pathogens were calculated from national death cause statistics. RESULTS: In the MC study, 153 cases with high overall disease severity were reported with pneumonia being most common (59%, n = 91). IRs of bacterial infections declined at the beginning of the COVID-19 pandemic and massively surged to unprecedented levels in late 2022 and early 2023 (overall hospitalizations 3.5-fold), with S. pyogenes and S. pneumoniae as main drivers (18-fold and threefold). Observed deaths during the study period exceeded the expected number for the entire year in NRW by far (7 vs. 0.9). DISCUSSION: The unprecedented peak of bacterial infections and deaths in late 2022 and early 2023 was caused mainly by S. pyogenes and S. pneumoniae. Improved precautionary measures are needed to attenuate future outbreaks.

Neurovascular Complications of Iatrogenic Fusarium solani Meningitis.

A multinational outbreak of nosocomial fusarium meningitis occurred among immunocompetent patients who had undergone surgery with epidural anesthesia in Mexico. The pathogen involved had a high predilection for the brain stem and vertebrobasilar arterial system and was associated with high mortality from vessel injury. Effective treatment options remain limited; in vitro susceptibility testing of the organism suggested that it is resistant to all currently approved antifungal medications in the United States. To highlight the severe complications associated with fusarium infection acquired in this manner, we report data, clinical courses, and outcomes from 13 patients in the outbreak who presented with symptoms after a median delay of 39 days.

Factors associated with extent of COVID-19 outbreaks: A prospective study in a large hospital network.

BACKGROUND: The COVID-19 pandemic has generated numerous hospital outbreaks. This study aimed to identify factors related to the extent of nosocomial COVID-19 outbreaks in the largest French public health institution. METHODS: An observational study was conducted from July 2020 to September 2021. Outbreaks were defined as at least 2 cases, patients and/or health care workers (HCWs), linked by time and geographic location. Logistic regression was performed to identify risk factors for large outbreaks among nine variables: variant, medical ward, COVID-19 vaccination rate and incidence among HCWs and Paris population, number of weekly COVID-19 tests among HCWs and the positivity rate, epidemic waves. RESULTS: Within 14 months, 799 outbreaks were identified: 450 small ones (≤6 cases) and 349 large ones (≥7 cases), involving 3,260 patients and 3,850 HCWs. In univariate analysis, large outbreaks were positively correlated to geriatrics wards, COVID-19 incidence, and rate of weekly positive tests among HCWs; and negatively correlated to intensive care units, variant Delta, fourth wave, vaccination rates of the Paris region's population and that of the HCWs. In multivariate analysis, factors that remained significant were the type of medical ward and the vaccination rate among HCWs. CONCLUSIONS: Intensive care unit and high vaccination rates among HCWs were associated with a lower risk of large COVID-19 outbreaks, as opposed to geriatric wards, which are associated with a higher risk.

From "Immunity Debt" to "Immunity Theft"-How COVID-19 Might Be Tied to Recent Respiratory Disease Surges.

This Medical News story discusses the relationship between the COVID-19 pandemic and recent increases in other respiratory diseases.