scholarly journals Bayesian estimation of Lassa virus epidemiological parameters: implications for spillover prevention using wildlife vaccination

2019 ◽  
Author(s):  
Scott L. Nuismer ◽  
Christopher H. Remien ◽  
Andrew Basinski ◽  
Tanner Varrelman ◽  
Nathan Layman ◽  
...  
Keyword(s):  
West Africa ◽  
Surveillance Data ◽  
Model Parameters ◽  
Lassa Virus ◽  
Vaccination Programs ◽  
Public Health Burden ◽  
Health Burden ◽  
Human Infections ◽  
Rodent Populations ◽  
Epidemiological Parameters

AbstractLassa virus is a significant burden on human health throughout its endemic region in West Africa, with most human infections the result of spillover from the primary rodent reservoir of the virus, the natal multimammate mouse,M. natalensis. Here we develop a Bayesian methodology for estimating epidemiological parameters of Lassa virus within its rodent reservoir and for generating probabilistic predictions for the efficacy of rodent vaccination programs. Our approach uses Approximate Bayesian Computation (ABC) to integrate mechanistic mathematical models, remotely-sensed precipitation data, and Lassa virus surveillance data from rodent populations. Using simulated data, we show that our method accurately estimates key model parameters, even when surveillance data are available from only a relatively small number of points in space and time. Applying our method to previously published data from two villages in Guinea estimates the time-averagedR0of Lassa virus to be 1.658 and 1.453 for rodent populations in the villages of Bantou and Tanganya, respectively. Using the posterior distribution for model parameters derived from these Guinean populations, we evaluate the likely efficacy of vaccination programs relying on distribution of vaccine-laced baits. Our results demonstrate that effective and durable reductions in the risk of Lassa virus spillover into the human population will require repeated distribution of large quantities of vaccine.Author SummaryLassa virus is a chronic source of illness throughout West Africa, and is considered to be a threat for widespread emergence. Because most human infections result from contact with infected rodents, interventions that reduce the number of rodents infected with Lassa virus represent promising opportunities for reducing the public health burden of this disease. Evaluating how well alternative interventions are likely to perform is complicated by our relatively poor understanding of viral epidemiology within the reservoir population. Here we develop a novel statistical approach that couples mathematical models and viral surveillance data from rodent populations to robustly estimate key epidemiological parameters. Applying our method to existing data from Guinea yields well-resolved parameter estimates and allows us to simulate a variety of rodent vaccination programs. Together, our results demonstrate that rodent vaccination alone is unlikely to be an effective tool for reducing that public health burden of Lassa fever within West Africa.

scholarly journals Bridging the gap: Using reservoir ecology and human serosurveys to estimate Lassa virus spillover in West Africa

2021 ◽  
Vol 17 (3) ◽  
pp. e1008811
Author(s):  
Andrew J. Basinski ◽  
Elisabeth Fichet-Calvet ◽  
Anna R. Sjodin ◽  
Tanner J. Varrelman ◽  
Christopher H. Remien ◽  
...  
Keyword(s):  
Machine Learning ◽  
West Africa ◽  
Human Population ◽  
Risk Model ◽  
Lassa Virus ◽  
Training Models ◽  
Infection Dynamics ◽  
Wildlife Vaccination ◽  
Risk Forecast ◽  
Human Infections

Forecasting the risk of pathogen spillover from reservoir populations of wild or domestic animals is essential for the effective deployment of interventions such as wildlife vaccination or culling. Due to the sporadic nature of spillover events and limited availability of data, developing and validating robust, spatially explicit, predictions is challenging. Recent efforts have begun to make progress in this direction by capitalizing on machine learning methodologies. An important weakness of existing approaches, however, is that they generally rely on combining human and reservoir infection data during the training process and thus conflate risk attributable to the prevalence of the pathogen in the reservoir population with the risk attributed to the realized rate of spillover into the human population. Because effective planning of interventions requires that these components of risk be disentangled, we developed a multi-layer machine learning framework that separates these processes. Our approach begins by training models to predict the geographic range of the primary reservoir and the subset of this range in which the pathogen occurs. The spillover risk predicted by the product of these reservoir specific models is then fit to data on realized patterns of historical spillover into the human population. The result is a geographically specific spillover risk forecast that can be easily decomposed and used to guide effective intervention. Applying our method to Lassa virus, a zoonotic pathogen that regularly spills over into the human population across West Africa, results in a model that explains a modest but statistically significant portion of geographic variation in historical patterns of spillover. When combined with a mechanistic mathematical model of infection dynamics, our spillover risk model predicts that 897,700 humans are infected by Lassa virus each year across West Africa, with Nigeria accounting for more than half of these human infections.

Determining Ancestry between Rodent- and Human-Derived Lassa Virus Sequences in Endemic Foci within West Africa: Indications of Reverse Zoonosis

2019 ◽  
Author(s):  
Ayodeji Olayemi ◽  
Adetunji Samuel Adesina ◽  
Thomas Strecker ◽  
N’Faly Magassouba ◽  
Elisabeth Fichet-Calvet
Keyword(s):  
West Africa ◽  
Lassa Virus

Detection of Flaviviral-Like DNA Sequences in Aedes aegypti (Diptera: Culicidae) Collected From Argentina

2021 ◽  
Author(s):  
Melisa B Bonica ◽  
Dario E Balcazar ◽  
Ailen Chuchuy ◽  
Jorge A Barneche ◽  
Carolina Torres ◽  
...  
Keyword(s):  
Public Health ◽  
Aedes Aegypti ◽  
Dna Sequences ◽  
Immature Stages ◽  
Public Health Burden ◽  
The Past ◽  
Health Burden ◽  
The World ◽  
Aegypti Genome ◽  
Dengue Epidemics

Abstract Diseases caused by flaviviruses are a major public health burden across the world. In the past decades, South America has suffered dengue epidemics, the re-emergence of yellow fever and St. Louis encephalitis viruses, and the introduction of West Nile and Zika viruses. Many insect-specific flaviviruses (ISFs) that cannot replicate in vertebrate cells have recently been described. In this study, we analyzed field-collected mosquito samples from six different ecoregions of Argentina to detect flaviviruses. We did not find any RNA belonging to pathogenic flaviviruses or ISFs in adults or immature stages. However, flaviviral-like DNA similar to flavivirus NS5 region was detected in 83–100% of Aedes aegypti (L.). Despite being previously described as an ancient element in the Ae. aegypti genome, the flaviviral-like DNA sequence was not detected in all Ae. aegypti samples and sequences obtained did not form a monophyletic group, possibly reflecting the genetic diversity of mosquito populations in Argentina.

Tuberculosis and notifiable skin diseases amongst a representative cohort of refugees in Germany (2014–16)

2020 ◽  
Author(s):  
Patrick D Dissmann ◽  
Felix Koehring ◽  
Florian Fischer
Keyword(s):  
Public Health ◽  
Infectious Diseases ◽  
Skin Diseases ◽  
Absolute Number ◽  
Federal State ◽  
Head Lice ◽  
Public Health Burden ◽  
Health Burden ◽  
Representative Cohort ◽  
Screening Result

Abstract Until now, systematic surveillance for infectious diseases in refugees is still missing. For that reason, this study aims at illustrating the prevalence of tuberculosis (TB) and notifiable skin diseases in a representative cohort of refugees in Lippe, a district of the federal state of North Rhine-Westphalia, Germany. We collected data on notifiable communicable diseases (TB, scabies, and head lice) from refugees (n = 8946) based on a medical screening after their arrival from October 2014 until May 2016. Data were analysed using descriptive and bivariate methods. Overall, we found 63 of 8764 screened refugees to have an abnormal TB screening result (0.72%). Of 8946 screened refugees, only 51 individuals were found to have scabies (0.57%) and a further 49 were tested positive for head lice (0.55%). The absolute number of TB cases indicate only a moderate public health burden. However, communicable skin diseases can become a problem in crowded holding camps, where they can cause local outbreaks.

scholarly journals COVID-19-related anxiety disorder in Iraq during the pandemic: an online cross-sectional study

2020 ◽  
Vol 27 (1) ◽  
Author(s):  
Saad Kazim Karim ◽  
Perjan Hashim Taha ◽  
Nazar Mohammad Mohammad Amin ◽  
Habeeb Shuhaib Ahmed ◽  
Miami Kadhim Yousif ◽  
...  
Keyword(s):  
Public Health ◽  
Mental Health ◽  
Anxiety Disorder ◽  
Health Care Professionals ◽  
Communicable Disease ◽  
Health Anxiety ◽  
Psychological State ◽  
Academic Degree ◽  
Public Health Burden ◽  
Health Burden

Abstract Background The COVID-19 outbreak is an unprecedented global public health burden, which popped up in China in late 2019 to early 2020 and distributed worldwide rapidly. Indeed, this pandemic transmission has raised global physical and mental health concerns. Mental health issues that concur with this public health emergency may pose anxiety, depression, and posttraumatic stress disorder. In Iraq, there are no registered known data on the psychological consequence of the public during the communicable disease outbreak. The ongoing study aims to address the paucity of these data as an appraisal of the mental health burden represented by anxiety disorder related to the global COVID-19 era. Results Among the 1591 Iraqi respondents, 788 (49.5%) accounted for having health anxiety over the current home restriction situation. Younger ages experienced more COVID-19-related health anxiety compared to older ages. Females reported higher health anxiety compared to males (57.7% vs 42.3%). The health care professionals reported 20.9% health anxiety. The Iraqi southern population displayed more health anxiety compared to the northern and middle portions. This work showed about half of the respondents were spending over 60 min focusing on news of COVID-19. We found that 80 to 90% carrying out preventive efforts and home quarantine against COVID-19 infection. Interestingly, participants experienced fear from the risk of COVID-19 infection, whether more or equal to a level of war scare, in 70.1% of the sample. Conclusions In Iraq, during the COVID-19 pandemic, nearly half of the respondents have health anxiety. Southern Iraqi cities displayed higher rates of anxiety. Also, being female, younger ages, holding an academic degree, or being a college student are associated with more prominent degrees of anxiety. Furtherly, it is important to adopt strategies for public health education and prevention and alerting future governmental responses focusing on psychological state impact among the general population.

scholarly journals Research output and the public health burden of cancer: is there any relationship?

2016 ◽  
Vol 23 (2) ◽  
pp. 75 ◽  
Author(s):  
F.M. Patafio ◽  
S.C. Brooks ◽  
X. Wei ◽  
Y. Peng ◽  
J. Biagi ◽  
...  
Keyword(s):  
Public Health ◽  
Clinical Trials ◽  
Cancer Mortality ◽  
Research Funding ◽  
Research Output ◽  
Cancer Site ◽  
Relative Distribution ◽  
Public Health Burden ◽  
The Public ◽  
Health Burden

Purpose The relative distribution of research output across cancer sites is not well described. Here, we evaluate whether the volume of published research is proportional to the public health burden of individual cancers. We also explore whether research output is proportional to research funding.Methods Statistics from the Canadian and American cancer societies were used to identify the top ten causes of cancer death in 2013. All journal articles and clinical trials published in 2013 by Canadian or U.S. authors for those cancers were identified. Total research funding in Canada by cancer site was obtained from the Canadian Cancer Research Alliance. Descriptive statistics and Pearson correlation coefficients were used to describe the relationship between research output, cancer mortality, and research funding.Results We identified 19,361 publications and 2661 clinical trials. The proportion of publications and clinical trials was substantially lower than the proportion of deaths for lung (41% deaths, 15% publications, 16% clinical trials), colorectal (14%, 7%, 6%), pancreatic (10%, 7%, 5%), and gastroesophageal (7%, 5%, 3%) cancers. Conversely, research output was substantially greater than the proportion of deaths for breast cancer (10% deaths, 29% publications, 30% clinical trials) and prostate cancer (8%, 15%, 17%). We observed a stronger correlation between research output and funding (publications r = 0.894, p < 0.001; clinical trials r = 0.923, p < 0.001) than between research output and cancer mortality (r = 0.363, p = 0.303; r = 0.340, p = 0.337).Conclusions Research output is not well correlated with the public health burden of individual cancers, but is correlated with the relative level of research funding.

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