Fractional Dynamics of Vector-Borne Infection with Sexual Transmission Rate and Vaccination

New fractional operators have the aim of attracting nonlocal problems that display fractal behaviour; and thus fractional derivatives have applications in long-term relation description along with micro-scaled and macro-scaled phenomena. Formulated by fractional operators, the formulation of a dynamical system is used in applications for the description of systems with long-range interactions. Vector-borne illnesses are one of the world’s most serious public health issues with a large economic impact on the nations that are impacted. Population increase, urbanization, globalization, and a lack of public health infrastructure have all had a role in the introduction and reemergence of vector-borne illnesses during the last four decades. The control of these infections are important to lessen the economic burden of vector-borne diseases in infected regions. In this research work, we formulate the transmission process of Zika virus with the impact of sexual incidence rate and vaccination in terms of mathematics. We presented the fundamental theory of fractional operators Caputo–Fabrizio (CF) and Atangana–Baleanu (AB) for the analysis of the proposed system. We examine our system of Zika infection and determined the endemic indicator through a next-generation matrix technique. The uniqueness and existence of the solution has been investigated through fixed point theory. Accordingly, a numerical method has been introduced to investigate the dynamical nature of the system and make a comparison of the outcomes of the operators. The impact of different input factors has been conceptualized through dynamical behaviour of the system. We observed that lowering the index of memory, the fractional system provides accurate results about the recommended Zika dynamics and dramatically reduces infected people. It has been proved that high efficacy of a vaccine can lower the level of infection. Moreover, the impact of other parameters on the system of Zika virus infection are highlighted through numerical results.

Download Full-text

Impact of public health interventions to curb SARS-CoV-2 spread assessed by an evidence-educated Delphi panel and tailored SEIR model

Journal of Public Health ◽

10.1007/s10389-021-01566-2 ◽

2021 ◽

Author(s):

Bernd Brüggenjürgen ◽

Hans-Peter Stricker ◽

Lilian Krist ◽

Miriam Ortiz ◽

Thomas Reinhold ◽

...

Keyword(s):

Public Health ◽

Transmission Rate ◽

Latency Period ◽

Policy Decision ◽

Sensitivity Analyses ◽

Delphi Panel ◽

Time Step ◽

Seir Model ◽

Health Policy Decision ◽

The Impact

Abstract Aim To use a Delphi-panel-based assessment of the effectiveness of different non-pharmaceutical interventions (NPI) in order to retrospectively approximate and to prospectively predict the SARS-CoV-2 pandemic progression via a SEIR model (susceptible, exposed, infectious, removed). Methods We applied an evidence-educated Delphi-panel approach to elicit the impact of NPIs on the SARS-CoV-2 transmission rate R0 in Germany. Effectiveness was defined as the product of efficacy and compliance. A discrete, deterministic SEIR model with time step of 1 day, a latency period of 1.8 days, duration of infectiousness of 5 days, and a share of the total population of 15% assumed to be protected by immunity was developed in order to estimate the impact of selected NPI measures on the course of the pandemic. The model was populated with the Delphi-panel results and varied in sensitivity analyses. Results Efficacy and compliance estimates for the three most effective NPIs were as follows: test and isolate 49% (efficacy)/78% (compliance), keeping distance 42%/74%, personal protection masks (cloth masks or other face masks) 33%/79%. Applying all NPI effectiveness estimates to the SEIR model resulted in a valid replication of reported occurrence of the German SARS-CoV-2 pandemic. A combination of four NPIs at consented compliance rates might curb the CoViD-19 pandemic. Conclusion Employing an evidence-educated Delphi-panel approach can support SARS-CoV-2 modelling. Future curbing scenarios require a combination of NPIs. A Delphi-panel-based NPI assessment and modelling might support public health policy decision making by informing sequence and number of needed public health measures.

Download Full-text

Potential for transmission of Elizabethkingia anophelis by Aedes albopictus and the role of microbial interactions in Zika virus competence

10.1101/702464 ◽

2019 ◽

Author(s):

MG Onyango ◽

AF Payne ◽

J Stout ◽

C Dieme ◽

L Kuo ◽

...

Keyword(s):

Zika Virus ◽

Inhibitory Effect ◽

Microbial Interactions ◽

Morbidity And Mortality ◽

Source Of Infection ◽

Vector Borne ◽

Complex Relationships ◽

The Impact ◽

First Time ◽

Transmission Barrier

AbstractElizabethkingia anophelis has been the cause of four outbreaks with significant morbidity and mortality. Its transmission routes remain unknown and no point source of infection has been identified. Here we show that E. anophelis can be found in the saliva of Aedes mosquitoes, suggesting the novel possibility of vector-borne transmission of this bacterium. We additionally characterized diverse microbial communities in Aedes midguts, salivary glands and saliva. To the best of our knowledge, this represents the first description of the microbiome of Aedes saliva. Further, we demonstrate that increased abundance of E. anophelis is associated with decreased susceptibility and replication of Zika virus (ZIKV) in the midgut of Aedes mosquitoes, suggesting a novel transmission barrier for arboviruses transmitted by Aedes mosquitoes. Together, these results demonstrate the complex relationships between the mosquito, the midgut microbial community and arboviruses and offer insights into the epidemiology and control of emerging bacterial and viral pathogens.Author SummaryElizabethkingia anophelis has in the recent past caused outbreaks different parts of the world resulting both in morbidity and mortality. Until now, to the best of our knowledge, no study has been able to demonstrate that this bacterium can be transmitted by mosquitoes. We have demonstrated for the first time that Elizabethkingia anophelis is present in the saliva of both infected and non-infected Aedes mosquitoes. Further, we have shown that it confers an inhibitory effect on Zika virus establishment in the midguts of Aedes mosquitoes. Together, these results potentially display the potential for vector borne transmission of E. anophelis as well as a novel transmission barrier of ZIKV. Lastly, we have for the first time characterized salivary microbes of Aedes mosquitoes necessitating the investigation of the impact of salivary microbes in severity of disease in vertebrate hosts.

Download Full-text

THE IMPACT OF GLOBAL WARMING ON THE PUBLIC HEALTH INCREASING THE BACTERIAL CAUSING INFECTIOUS DISEASES PERFORMED BY EXPERIMENT: VECTOR-BORNE DISEASES INSECTS, TAIF, KSA

International Journal of Research -GRANTHAALAYAH ◽

10.29121/granthaalayah.v5.i5.2017.1836 ◽

2017 ◽

Vol 5 (5) ◽

pp. 42-53

Author(s):

Sherifa Mostafa M. Sabra ◽

Samar Ahamed

Keyword(s):

Public Health ◽

Global Warming ◽

Infectious Diseases ◽

Vector Borne Diseases ◽

The Public ◽

Colony Forming Unit ◽

Tapinoma Sessile ◽

Vector Borne ◽

The Mean ◽

The Impact

The search conducted on "The impact of global warming (GW) on the public health (PH) increasing the bacterial causing infectious diseases (IDs) performed by experiment: Vector-borne diseases (VBDs) insects, Taif, KSA", the experiment used ants (Taif Tapinoma sessile), prepared, arranged appropriate nests and adjusted the temperature at (20, 25, 30, 35, 40 and 45°C), for a week of each zone. It revealed the behaviour as (normal, semi-normal and ab-normal), the mean of mortality rates were between (0-53.3%). The bacterial contents measured by the turbidity indicated the presence of multiplication, were between (0.109-0.328). The bacterial growth degrees by sings were between (+ - +++++) and percent between (12-100%). Colony Forming Unit/ml (CFU/ml) confined between (1.8X102-15.0X102)/mL. Through this experiment it turned out the GW had a significant role on the PH, helped the proliferation of bacterial pathogens that caused IDS. The conclusion wiped from the experiment that the extent degrees of GW disadvantages on the PH. The PH workers must take the "Preventive Health Prophylaxis Measures" (PHPMs) to protect the individuals from IDs by eliminating the VBDs of various types, monitoring the immunological situation of individuals, provided the vaccinations of IDs and preparing for complete PHPMs against any changes in the PH.

Download Full-text

Zika virus: A newly emergent vector-borne public health threat in the Americas

10.7287/peerj.preprints.1781v1 ◽

2016 ◽

Cited By ~ 1

Author(s):

Sujit Pujhari ◽

Jason L. Rasgon

Keyword(s):

Public Health ◽

Birth Defects ◽

Zika Virus ◽

Human Population ◽

Focused Attention ◽

New Disease ◽

Conspiracy Theories ◽

Transmission Cycle ◽

Public Health Threat ◽

Vector Borne

Zika virus is a newly emergent mosquito-borne flavivirus. Once almost ignored epidemiologically, recent major outbreaks and links to neurological birth defects have focused attention on this neglected pathogen. We review the discovery, biology and symptomatology of Zika virus, what is known and not known about the mosquitoes that transmit the virus, conspiracy theories currently hampering control efforts, and potential avenues of Zika control. It is likely that Zika virus is here to stay in the Americas, so a thorough understanding of the complete epidemiological transmission cycle and potential effects on the human population will be critical for managing this new disease in the coming years.

Download Full-text

Concern and Attitudes Toward Zika Virus in Jarabacoa, Dominican Republic: A Cross-Sectional Study

Global Journal of Health Science ◽

10.5539/gjhs.v10n12p1 ◽

2018 ◽

Vol 10 (12) ◽

pp. 1

Author(s):

Gregory Black ◽

Eric Hasenkamp ◽

Nicholas Johnson ◽

Rosanna Ianiro ◽

Ricardo Izurieta ◽

...

Keyword(s):

Public Health ◽

Health Education ◽

Dominican Republic ◽

Zika Virus ◽

Public Health Education ◽

Medical Provider ◽

Cross Sectional Survey ◽

Cross Sectional ◽

Contraception Use ◽

Vector Borne

BACKGROUND & OBJECTIVES: The Zika virus, a member of the flavivirus genus, is an emerging threat to many tropical regions of the world. This study was designed to assess the level of knowledge, attitudes and concern in regards to the Zika virus in the community of Jarabacoa, Dominican Republic, with the hopes of guiding future efforts toward public education and prevention of future public health threats. METHODS: A cross-sectional survey was conducted in the rural communities of Jarabacoa during October 2016 and October 2017. Individuals completed a 14-point survey evaluating: level of concern towards Zika (1=no concern, 3=neutral, 5=extremely concerned), knowledge level of the disease, use of personal protection against the virus, how people initially heard about the disease and contraception use. RESULTS: Overall, women were more concerned than men about contracting the virus (p<.001, CI -2.510, -0.826). Of the respondents (N=138), 66% learned about Zika from the TV/news and 24.6% from their medical provider. 5% knew Zika was contracted from blood and 2% from pregnancy, and only 17% of respondents knew that it was contracted through sex. For protection from Zika, only 8% used condoms. Of the women trying to get pregnant, none knew Zika could be transmitted through sex. CONCLUSION: This study revealed that women were more concerned about the Zika virus than men and that knowledge about the virus was limited. In general, people are protecting themselves against vector borne transmission but not non-vector borne modes of transmission such as sexual intercourse. Also, public health education is lacking. Further studies are needed with more male participants, focus on contraception and social media’s effect on public health education.

Download Full-text

Effects of climate change on the spread of zika virus: a public health threat

Reviews on Environmental Health ◽

10.1515/reveh-2017-0042 ◽

2018 ◽

Vol 33 (1) ◽

pp. 31-42 ◽

Cited By ~ 8

Author(s):

Hina Asad ◽

David O. Carpenter

Keyword(s):

Public Health ◽

Climate Change ◽

South America ◽

Zika Virus ◽

Human Disease ◽

Human Population ◽

Viral Disease ◽

Health Concerns ◽

Public Health Threat ◽

Vector Borne

Abstract Zika is a vector-borne viral disease transmitted to humans primarily by Aedes aegypti mosquitoes. The increased climate instability has contributed to the emergence of infections carried by mosquitoes like dengue, chikungunya and zika. While infection with the zika virus is not new, the recent epidemic of microcephaly in Brazil and other countries in South America resulting from the infection of pregnant women with the zika virus raise a number of serious public health concerns. These include the question of how climate change affects the range of zika vectors, what can we do to shorten the length of mosquito season, how and why the symptoms of zika infection have changed and what can be done to reduce the burden of human disease from this infection? Another important question that needs to be answered is what are the factors that caused the zika virus to leave the non-human primates and/or other mammals and invade the human population?

Download Full-text

Optimal public health intervention in a behavioural vaccination model: the interplay between seasonality, behaviour and latency period

Mathematical Medicine and Biology A Journal of the IMA ◽

10.1093/imammb/dqy011 ◽

2018 ◽

Vol 36 (3) ◽

pp. 297-324

Author(s):

Bruno Buonomo ◽

Rossella Della Marca ◽

Alberto d’Onofrio

Keyword(s):

Public Health ◽

Side Effects ◽

Perceived Risk ◽

Transmission Rate ◽

Minimum Principle ◽

Public Health Intervention ◽

Latency Period ◽

Vaccine Uptake ◽

Optimal Time ◽

The Impact

AbstractHesitancy and refusal of vaccines preventing childhood diseases are spreading due to ‘pseudo-rational’ behaviours: parents overweigh real and imaginary side effects of vaccines. Nonetheless, the ‘Public Health System’ (PHS) may enact public campaigns to favour vaccine uptake. To determine the optimal time profiles for such campaigns, we apply the optimal control theory to an extension of the susceptible-infectious-removed (SIR)-based behavioural vaccination model by d’Onofrio et al. (2012, PLoS ONE, 7, e45653). The new model is of susceptible-exposed-infectious-removed (SEIR) type under seasonal fluctuations of the transmission rate. Our objective is to minimize the total costs of the disease: the disease burden, the vaccination costs and a less usual cost: the economic burden to enact the PHS campaigns. We apply the Pontryagin minimum principle and numerically explore the impact of seasonality, human behaviour and latency rate on the control and spread of the target disease. We focus on two noteworthy case studies: the low (resp. intermediate) relative perceived risk of vaccine side effects and relatively low (resp. very low) speed of imitation. One general result is that seasonality may produce a remarkable impact on PHS campaigns aimed at controlling, via an increase of the vaccination uptake, the spread of a target infectious disease. In particular, a higher amplitude of the seasonal variation produces a higher effort and this, in turn, beneficially impacts the induced vaccine uptake since the larger is the strength of seasonality, the longer the vaccine propensity remains large. However, such increased effort is not able to fully compensate the action of seasonality on the prevalence.

Download Full-text

Zika virus: A newly emergent vector-borne public health threat in the Americas

10.7287/peerj.preprints.1781 ◽

2016 ◽

Author(s):

Sujit Pujhari ◽

Jason L. Rasgon

Keyword(s):

Public Health ◽

Birth Defects ◽

Zika Virus ◽

Human Population ◽

Focused Attention ◽

New Disease ◽

Conspiracy Theories ◽

Transmission Cycle ◽

Public Health Threat ◽

Vector Borne

Download Full-text

Evolution of disease transmission rate during the course of SARS-COV-2: Patterns and determinants

10.21203/rs.3.rs-44647/v1 ◽

2020 ◽

Author(s):

Jie Zhu ◽

Blanca Gallego

Keyword(s):

Public Health ◽

Disease Transmission ◽

Reproduction Number ◽

Transmission Rate ◽

Region Of Interest ◽

Health Interventions ◽

Transmission Model ◽

Public Health Interventions ◽

Containment Measures ◽

The Impact

Abstract To date, many studies have argued the potential impact of public health interventions on flattening the epidemic curve of SARS-CoV-2. Most of them have focused on simulating the impact of interventions in a region of interest by manipulating contact patterns and key transmission parameters to reflect different scenarios. Our study looks into the evolution of the daily effective reproduction number during the epidemic via a stochastic transmission model. We found this measure (although model-dependent) provides an early signal of the efficacy of containment measures. This epidemiological parameter when updated in real-time can also provide better predictions of future outbreaks. Our results found a substantial variation in the effect of public health interventions on the dynamic of SARS-CoV-2 transmission over time and across countries, that could not be explained solely by the timing and number of the adopted interventions. This suggests that further knowledge about the idiosyncrasy of their implementation and effectiveness is required. Although sustained containment measures have successfully lowered growth in disease transmission, more than half of the 101 studied countries failed to maintain the effective reproduction number close to or below 1. This resulted in continued growth in reported cases. Finally, we were able to predict with reasonable accuracy which countries would experience outbreaks in the next 30 days.

Download Full-text

Dynamics of Zika virus outbreaks: an overview of mathematical modeling approaches

PeerJ ◽

10.7717/peerj.4526 ◽

2018 ◽

Vol 6 ◽

pp. e4526 ◽

Cited By ~ 11

Author(s):

Anuwat Wiratsudakul ◽

Parinya Suparit ◽

Charin Modchang

Keyword(s):

Public Health ◽

Mathematical Models ◽

Real World ◽

Zika Virus ◽

Real World Data ◽

World Data ◽

Vector Borne Diseases ◽

Complex Models ◽

Vector Borne ◽

Simple Models

BackgroundThe Zika virus was first discovered in 1947. It was neglected until a major outbreak occurred on Yap Island, Micronesia, in 2007. Teratogenic effects resulting in microcephaly in newborn infants is the greatest public health threat. In 2016, the Zika virus epidemic was declared as a Public Health Emergency of International Concern (PHEIC). Consequently, mathematical models were constructed to explicitly elucidate related transmission dynamics.Survey MethodologyIn this review article, two steps of journal article searching were performed. First, we attempted to identify mathematical models previously applied to the study of vector-borne diseases using the search terms “dynamics,” “mathematical model,” “modeling,” and “vector-borne” together with the names of vector-borne diseases including chikungunya, dengue, malaria, West Nile, and Zika. Then the identified types of model were further investigated. Second, we narrowed down our survey to focus on only Zika virus research. The terms we searched for were “compartmental,” “spatial,” “metapopulation,” “network,” “individual-based,” “agent-based” AND “Zika.” All relevant studies were included regardless of the year of publication. We have collected research articles that were published before August 2017 based on our search criteria. In this publication survey, we explored the Google Scholar and PubMed databases.ResultsWe found five basic model architectures previously applied to vector-borne virus studies, particularly in Zika virus simulations. These include compartmental, spatial, metapopulation, network, and individual-based models. We found that Zika models carried out for early epidemics were mostly fit into compartmental structures and were less complicated compared to the more recent ones. Simple models are still commonly used for the timely assessment of epidemics. Nevertheless, due to the availability of large-scale real-world data and computational power, recently there has been growing interest in more complex modeling frameworks.DiscussionMathematical models are employed to explore and predict how an infectious disease spreads in the real world, evaluate the disease importation risk, and assess the effectiveness of intervention strategies. As the trends in modeling of infectious diseases have been shifting towards data-driven approaches, simple and complex models should be exploited differently. Simple models can be produced in a timely fashion to provide an estimation of the possible impacts. In contrast, complex models integrating real-world data require more time to develop but are far more realistic. The preparation of complicated modeling frameworks prior to the outbreaks is recommended, including the case of future Zika epidemic preparation.

Download Full-text