Mathematical modelling of the Ebola virus disease = I-Model yeziBalo yesifo Segciwane Le-Ebola.

Abstract

Despite the numerous modelling efforts to advise public health physicians to understand the dynamics of the Ebola virus disease (EVD) and control its spread, the disease continued to spread in Africa. In the current thesis, we systematically review previous EVD models. Further, we develop novel mathematical models to explore two important problems during the 2018-2020 Kivu outbreak: the impact of geographically targeted vaccinations (GTVs) and the interplay between the attacks on Ebola treatment centres (ETCs) and the spread of EVD. In our systematic review, we identify many limitations in the modelling literature and provide brief suggestions for future work. Our modelling findings underscore the importance of considering GTVs in areas with high infections. In particular, we find that implementing GTVs in regions with high infections so that the total vaccinations are increased by 60% decreases the cumulative cases by 15%. On the other hand, we need to increase the vaccinations to more than 1000% to achieve the 15% decrease in EVD cases if we implement GTVs in areas with low infections. On the impact of the attacks on ETCs, we find that due to the attacks on ETCs, the cumulative cases increased by more than 17% during the 2018-2020 Kivu outbreak. We also find that when 10% of the hospitalised individuals flee the attacks on ETCs after spending only three days under treatment, the cumulative cases increased by more than 30% even if these individuals all returned to the ETCs three days later. On the other hand, if only half of these individuals returned to ETCs for treatment, the cumulative cases increase by approximately 50%. Further, when these patients spend one more day in the community, after which they all return to ETCs, the cumulative cases rise by an additional 10%. Global sensitivity analysis also confirmed these findings. To conclude, our literature systematic review is used to identify many critical factors which were overlooked in previous EVD models. Our modelling findings show that the attacks on ETCs can be destructive to the efforts of EVD response teams. Hence, it is important for decision-makers to tackle the reasons for community distrust and address the roots of the hostility towards ETCs. We also find that GTVs can be used to contain the spread of EVD when ring vaccinations, contact tracing and antiviral treatments cannot successfully control the spread of EVD.

Iqoqa.

Naphezu kwemizamo eminingi yokumodela okuhloswe ngayo ukweluleka izikhulu zezempilo zomphakathi ukuthi ziqonde amandla egciwane lesifo se-Ebola (EVD) futhi zilawule ukusakazeka kwaso, lesi sifo saqhubeka nokusabalala e-Afrikha. Kulo mbhalo weziqu zobudokotela, sibuyekeza ngokuhlelekile amamodeli angaphambilini e-EVD futhi sithuthukise amamodeli ezibalo amasha ukuze sihlole izinkinga ezimbili ezibalulekile ngesikhathi sokubheduka kwesifo eKivu ngonyaka wezi-2018-2020: umthelela wemigomo eqondiswe ngokwendawo (GTVs) kanye nokuhlangana phakathi kokuhlaselwa kwezindawo ezelapha i-Ebola (ETCs) kanye ukusabalala kwe-EVD. Ukubuyekeza kwethu okuhlelekile kuveza imikhawulo embalwa ezincwadini zokumodela ezikhona futhi kunikeza iziphakamiso zomsebenzi wesikhathi esizayo. Okutholakele kugcizelela ukubaluleka kokucabangela ama-GTV ezindaweni ezinamazinga aphezulu okutheleleka. Ngokukhethekile, sithola ukuthi ukusebenzisa ama-GTV ezifundeni ezinamazinga aphezulu okutheleleka—njengokuthi isamba sokugoma sikhuphuke ngo-60%—kwehlisa isibalo sezifo ngo-15%. Ngokuphambene, imigomo idinga ukukhuphuka ngaphezu kuka-1000% ukuze kuzuzwe ukwehla okungu-15% ezimweni ze-EVD uma ama-GTV esetshenziswa ezindaweni ezinamazinga aphansi okutheleleka. Mayelana nomthelela wokuhlaselwa kwama-ETC, sithola ukuthi lokhu kuhlasela kwenyuse amacala anqwabelene ngaphezu kuka-17% ngesikhathi sokubheduka kwesifo e-Kivu ngo-2018-2020. Ukwengeza, lapho u-10% wabantu abasesibhedlela bebalekela ukuhlaselwa kwama-ETC ngemva kokuchitha izinsuku ezintathu kuphela belashwa, amacala anqwabelene akhuphuka ngaphezu kuka-30%, ngisho noma laba bantu bebuyela kuma-ETC ezinsukwini ezintathu kamuva. Uma ngabe uhhafu walaba bantu ubuyela kuma-ETC ukuze bathole ukwelashwa, izimo ezikhulayo zikhuphuka cishe ngo-50%. Ngaphezu kwalokho, lapho lezi ziguli zichitha usuku olulodwa ngaphezulu emphakathini, ngemva kwalokho zonke zibuyela kuma-ETC, amacala akhulayo akhuphuka ngo-10%. Ukuphetha, ukubuyekezwa kwezincwadi zethu kukhomba izici ezimbalwa ezibalulekile ezinganakwa kumamodeli angaphambilini e-EVD. Okutholakele kokumodela kwethu kubonisa ukuthi ukuhlaselwa kwama-ETC kungakhinyabeza kakhulu imizamo yamaqembu okuphendula e-EVD. Ngakho-ke, kubalulekile ukuthi abenzi bezinqumo babhekane nezizathu zokungathembeki komphakathi kanye nezimpande zobutha kuma-ETC. Ngaphezu kwalokho, sithola ukuthi ama-GTV angaqukatha ngempumelelo ukusabalala kwe-EVD lapho ukugonywa okuzungezile, ukulandelelwa kokuthintana, kanye nokwelashwa ngezidambisigciwane kunganele ukulawula ukusabalala kwesifo.