Skip to main content
SearchLoginLogin or Signup

The potential impact of intervention strategies on COVID-19 transmission in Malawi: A mathematical modelling study (lay summary)

This is a lay summary of the article published under the DOI: 10.1101/2020.10.06.20207878

Published onApr 30, 2023
The potential impact of intervention strategies on COVID-19 transmission in Malawi: A mathematical modelling study (lay summary)
·

Researchers predicted more Covid-19 burden in Malawi than in China

Researchers reported that Covid-19 infected patients are more likely to die in Malawi than in China, possibly because of the status of their population and hospitals. The government can use this information to manage effects Covid-19. 

During the outbreak of Covid-19 in 2020, many countries imposed lockdowns. However, depending on each country’s local conditions, a lockdown was not always feasible, and people did not always comply. At the time, many decision-makers also used mathematical models and predictions to determine how other potential interventions, such as wearing masks or improving hospital capacity, might help curb the impact of Covid-19.

In this study, researchers used mathematical models to look at the impact of Covid-19 and lockdowns in Malawi. They also wanted to predict if increasing hospital capacities would improve the situation.

They used existing data from China and from Malawi.

The researchers reported more deaths, especially among younger people, in Malawi than in China. They said interventions that were implemented, for example, people standing 2 metres apart, people not going to work and restrictions on taxis and buses, could save 3 100 lives. With those interventions, the researchers estimated about 4 deaths per 1 000 people in 250 days.

They said if the elderly could be given extra protection from the virus many deaths could be avoided, and ICU admissions reduced by half. They also suggested that if at least 60% of the population could wear masks, Covid-19 could be controlled.

The researchers reported that if a Covid-19 medicine that could reduce death rates by 65%, and reduce the number of very sick people by 80%, could be found, the death rate could be reduced to just 2.55%.

The researchers predicted that most infections would occur among those aged below 20 years, but would result in only 1.3% deaths in the same age group. They estimated more deaths among those aged above 70.

The researchers said lockdown for long periods could reduce infections, and reduce deaths to just about 1 person in 1 000 people. They said infections would still occur after lockdown if other interventions are not implemented. 

The researchers said imposing a lockdown in Malawi may not be possible because many people are poor and need to go out and work. But if hospital beds with oxygen could be increased by half, that would reduce the death rate.  

This study tried to predict the impact of Covid-19 interventions in Malawi, thereby contributing to global efforts to combat the disease.

Abstract

Background COVID-19 mitigation strategies have been challenging to implement in resource-limited settings such as Malawi due to the potential for widespread disruption to social and economic well-being. Here we estimate the clinical severity of COVID-19 in Malawi, quantifying the potential impact of intervention strategies and increases in health system capacity.

Methods The infection fatality ratios (IFR) in Malawi were estimated by adjusting reported IFR for China accounting for demography, the current prevalence of comorbidities and health system capacity. These estimates were input into an age-structured deterministic model, which simulated the epidemic trajectory with non-pharmaceutical interventions. The impact of a novel therapeutic agent and increases in hospital capacity and oxygen availability were explored, given different assumptions on mortality rates.

Findings The estimated age-specific IFR in Malawi are higher than those reported for China, however the younger average age of the population results in a slightly lower population-weighted IFR (0.48%, 95% uncertainty interval [UI] 0.30% – 0.72% compared with 0.60%, 95% CI 0.4% – 1.3% in China). The current interventions implemented, (i.e. social distancing, workplace closures and public transport restrictions) could potentially avert 3,100 deaths (95% UI 1,500 – 4,500) over the course of the epidemic. Enhanced shielding of people aged ≥ 60 years could avert a further 30,500 deaths (95% UI 17,500 – 45,600) and halve ICU admissions at the peak of the outbreak. Coverage of face coverings of 60% under the assumption of 50% efficacy could be sufficient to control the epidemic. A novel therapeutic agent, which reduces mortality by 0.65 and 0.8 for severe and critical cases respectively, in combination with increasing hospital capacity could reduce projected mortality to 2.55 deaths per 1,000 population (95% UI 1.58 – 3.84).

Conclusion The risks due to COVID-19 vary across settings and are influenced by age, underlying health and health system capacity.

Disclaimer

This summary is a free resource intended to make African research and research that affects Africa, more accessible to non-expert global audiences. It was compiled by ScienceLink's team of professional African science communicators as part of the Masakhane MT: Decolonise Science project. ScienceLink has taken every precaution possible during the writing, editing, and fact-checking process to ensure that this summary is easy to read and understand, while accurately reporting on the facts presented in the original research paper. Note, however, that this summary has not been fact-checked or approved by the authors of the original research paper, so this summary should be used as a secondary resource. Therefore, before using, citing or republishing this summary, please verify the information presented with the original authors of the research paper, or email [email protected] for more information.

Connections
A Reply to this Pub
The potential impact of intervention strategies on COVID-19 transmission in Malawi: A mathematical modelling study
Description

AbstractBackgroundCOVID-19 mitigation strategies have been challenging to implement in resource-limited settings such as Malawi due to the potential for widespread disruption to social and economic well-being. Here we estimate the clinical severity of COVID-19 in Malawi, quantifying the potential impact of intervention strategies and increases in health system capacity.MethodsThe infection fatality ratios (IFR) in Malawi were estimated by adjusting reported IFR for China accounting for demography, the current prevalence of comorbidities and health system capacity. These estimates were input into an age-structured deterministic model, which simulated the epidemic trajectory with non-pharmaceutical interventions. The impact of a novel therapeutic agent and increases in hospital capacity and oxygen availability were explored, given different assumptions on mortality rates.FindingsThe estimated age-specific IFR in Malawi are higher than those reported for China, however the younger average age of the population results in a slightly lower population-weighted IFR (0.48%, 95% uncertainty interval [UI] 0.30% – 0.72% compared with 0.60%, 95% CI 0.4% – 1.3% in China). The current interventions implemented, (i.e. social distancing, workplace closures and public transport restrictions) could potentially avert 3,100 deaths (95% UI 1,500 – 4,500) over the course of the epidemic. Enhanced shielding of people aged ≥ 60 years could avert a further 30,500 deaths (95% UI 17,500 – 45,600) and halve ICU admissions at the peak of the outbreak. Coverage of face coverings of 60% under the assumption of 50% efficacy could be sufficient to control the epidemic. A novel therapeutic agent, which reduces mortality by 0.65 and 0.8 for severe and critical cases respectively, in combination with increasing hospital capacity could reduce projected mortality to 2.55 deaths per 1,000 population (95% UI 1.58 – 3.84).ConclusionThe risks due to COVID-19 vary across settings and are influenced by age, underlying health and health system capacity.Summary BoxWhat is already known?As COVID-19 spreads throughout Sub-Saharan Africa, countries are under increasing pressure to protect the most vulnerable by suppressing spread through, for example, stringent social distancing measures or shielding of those at highest risk away from the general population.There are a number of studies estimating infection fatality ratio due to COVID-19 but none use data from African settings. The estimated IFR varies across settings ranging between 0.28-0.99%, with higher values estimated for Europe (0.77%, 95% CI 0.55 – 0.99%) compared with Asia (0.46%, 95% CI 0.38 – 0.55).The IFR for African settings are still unknown, although several studies have highlighted the potential for increased mortality due to comorbidities such as HIV, TB and malaria.There are a small number of studies looking at the impact of non-pharmaceutical interventions in Africa, particularly South Africa, but none to date have combined this with country-specific estimates of IFR adjusted for comorbidity prevalence and with consideration to the prevailing health system constraints and the impact of these constraints on mortality rates.What are the new findings?After accounting for the health system constraints and differing prevalences of underlying comorbidities, the estimated infection fatality ratio (IFR) for Malawi (0.48%, 95% uncertainty interval 0.30% – 0.72%) is within the ranges reported for the Americas, Asia and Europe (overall IFR 0.70, 95% CI 0.57 – 0.82, range 0.28 – 0.89).Introducing enhanced shielding of people aged ≥ 60 years could avert up to 30,500 deaths (95% UI 17,500 – 45,600) and significantly reduce demand on ICU admissions.Maintaining coverage of face coverings at 60%, under the assumption of 50% efficacy, could be sufficient to control the epidemic.Combining the introduction of a novel therapeutic agent with increases in hospital capacity could reduce projected mortality to 2.55 deaths per 1,000 population (95% UI 1.58 – 3.84).What do the new findings imply?Adjusting estimates of COVID-19 severity to account for underlying health is crucial for predicting health system demands.A multi-pronged approach to controlling transmission, including face coverings, increasing hospital capacity and using new therapeutic agents could significantly reduce deaths to COVID-19, but is not as effective as a theoretical long-lasting lockdown.

Comments
0
comment
No comments here
Why not start the discussion?