ABSTRACT
Background: Long-term suppression of SARS-CoV-2 transmission will require context-specific strategies that recognize the heterogeneous capacity of communities to undertake public health recommendations, particularly due to limited access to food, sanitation facilities, and physical space required for self-quarantine or isolation. We highlight the epidemiological impact of barriers to adoption of public health recommendations by urban slum populations in low- and middle-income countries (LMICs) and the potential role of community-based initiatives to coordinate efforts that support cases and high-risk contacts. Methods: Daily case updates published by the National Public Health Institute of Liberia were used to inform a stratified stochastic compartmental model representing transmission of SARS-CoV-2 in two subpopulations (urban poor versus less socioeconomically vulnerable) of Montserrado County, Liberia. Differential transmission was considered at levels of the subpopulation, household versus community, and events (i.e., funerals). Adoption of home-isolation behavior was assumed to be related to the proportion of each subpopulation residing in housing units with multiple rooms, access to sanitation facilities, and access to basic goods like water and food. Percentage reductions in cumulative infection counts, cumulative counts of severe cases, and maximum daily infection counts for each subpopulation were evaluated across intervention scenarios that included symptom-triggered, community-driven efforts to support high-risk contacts and confirmed cases in self-isolation following the scheduled lifting of the state of emergency. Results: Modeled outbreaks for the status quo scenario differed between the two subpopulations, with increased overall infection burden but decreased numbers of severe cases in the urban poor subpopulation relative to the less socioeconomically vulnerable population after 180 days post-introduction into Liberia. With more proactive self-isolation by mildly symptomatic individuals after lifting of the public health emergency, median reductions in cumulative infections, severe cases, and maximum daily incidence were 7.6% (IQR: 2.2%-20.9%), 7.0% (2.0%-18.5%), and 9.9% (2.5%-31.4%) for cumulative infections, severe cases, and maximum daily incidence, respectively, across epidemiological curve simulations in the urban poor subpopulation and 16.8% (5.5%-29.3%), 15.0% (5.0%-26.4%), and 28.1% (IQR: 9.3%-47.8%) in the less socioeconomically vulnerable population. An increase in the maximum attainable percentage of behavior adoption by the urban slum subpopulation, with the provision of support to facilitate self-isolation or quarantine, was associated with median reductions in cumulative infections, severe cases, and maximum daily incidence were 19.2% (IQR: 10.1%-34.0%), 21.1% (IQR: 13.3%-34.2%), and 26.0% (IQR: 11.5%-48.9%), respectively, relative to the status quo scenario. Conclusions: Broadly supported post-lockdown recommendations that prioritize proactively monitoring symptoms, seeking testing and isolating at home by confirmed cases are limited by resource constraints in urban poor communities. Investing in community-based initiatives that determine needs and coordinate needs-based support for self-identified cases and their contacts could provide a more effective, longer-term strategy for suppressing transmission of COVID-19 in settings with prevalent distrust and socioeconomic vulnerabilities.
Subject(s)
COVID-19ABSTRACT
Background: Long-term suppression of SARS-CoV-2 transmission will require context-specific strategies that recognize the heterogeneous capacity of communities to undertake public health recommendations, particularly due to limited access to food, sanitation facilities, and physical space required for self-quarantine or isolation. We highlight the epidemiological impact of barriers to adoption of public health recommendations by urban slum populations in low- and middle-income countries (LMICs) and the potential role of community-based initiatives to coordinate efforts that support cases and high-risk contacts. Methods: Daily case updates published by the National Public Health Institute of Liberia were used to inform a stratified stochastic compartmental model representing transmission of SARS-CoV-2 in two subpopulations (urban poor versus less socioeconomically vulnerable) of Montserrado County, Liberia. Differential transmission was considered at levels of the subpopulation, household versus community, and events (i.e., funerals). Adoption of home-isolation behavior was assumed to be related to the proportion of each subpopulation residing in housing units with multiple rooms, access to sanitation facilities, and access to basic goods like water and food. Percentage reductions in cumulative infection counts, cumulative counts of severe cases, and maximum daily infection counts for each subpopulation were evaluated across intervention scenarios that included symptom-triggered, community-driven efforts to support high-risk contacts and confirmed cases in self-isolation following the scheduled lifting of the state of emergency. Results: Modeled outbreaks for the status quo scenario differed between the two subpopulations, with increased overall infection burden but decreased numbers of severe cases in the urban poor subpopulation relative to the less socioeconomically vulnerable population after 180 days post-introduction into Liberia. With more proactive self-isolation by mildly symptomatic individuals after lifting of the public health emergency, median reductions in cumulative infections, severe cases, and maximum daily incidence were 7.6% (IQR: 2.2%-20.9%), 7.0% (2.0%-18.5%), and 9.9% (2.5%-31.4%) for cumulative infections, severe cases, and maximum daily incidence, respectively, across epidemiological curve simulations in the urban poor subpopulation and 16.8% (5.5%-29.3%), 15.0% (5.0%-26.4%), and 28.1% (IQR: 9.3%-47.8%) in the less socioeconomically vulnerable population. An increase in the maximum attainable percentage of behavior adoption by the urban slum subpopulation, with the provision of support to facilitate self-isolation or quarantine, was associated with median reductions in cumulative infections, severe cases, and maximum daily incidence were 19.2% (IQR: 10.1%-34.0%), 21.1% (IQR: 13.3%-34.2%), and 26.0% (IQR: 11.5%-48.9%), respectively, relative to the status quo scenario. Conclusions: Broadly supported post-lockdown recommendations that prioritize proactively monitoring symptoms, seeking testing and isolating at home by confirmed cases are limited by resource constraints in urban poor communities. Investing in community-based initiatives that determine needs and coordinate needs-based support for self-identified cases and their contacts could provide a more effective, longer-term strategy for suppressing transmission of COVID-19 in settings with prevalent distrust and socioeconomic vulnerabilities.
Subject(s)
COVID-19ABSTRACT
BackgroundAbsolute numbers of COVID-19 cases and deaths reported to date in the sub-Saharan Africa (SSA) region have been significantly lower than those across the Americas, Asia, and Europe. As a result, there has been limited information about the demographic and clinical characteristics of deceased cases in the region, as well as the impacts of different case management strategies. MethodsData from deceased cases reported across SSA through May 10, 2020 and from hospitalized cases in Burkina Faso through April 15, 2020 were analyzed. Demographic, epidemiological, and clinical information on deceased cases in SSA was derived through a line-list of publicly available information and, for cases in Burkina Faso, from aggregate records at the Center Hospitalier Universitaire de Tengandogo in Ouagadougou. A synthetic case population was derived probabilistically using distributions of age, sex, and underlying conditions from populations of West African countries to assess individual risk factors and treatment effect sizes. Logistic regression analysis was conducted to evaluate the adjusted odds of survival for patients receiving oxygen therapy or convalescent plasma, based on therapeutic effectiveness observed for other respiratory illnesses. ResultsAcross SSA, deceased cases for which demographic data are available have been predominantly male (63/103, 61.2%) and over 50 years of age (59/75, 78.7%). In Burkina Faso, specifically, the majority of deceased cases either did not seek care at all or were hospitalized for a single day (59.4%, 19/32); hypertension and diabetes were often reported as underlying conditions. After adjustment for sex, age, and underlying conditions in the synthetic case population, the odds of mortality for cases not receiving oxygen therapy was significantly higher than those receiving oxygen, such as due to disruptions to standard care (OR: 2.07; 95% CI: 1.56 - 2.75). Cases receiving convalescent plasma had 50% reduced odds of mortality than those who did not (95% CI: 0.24 - 0.93). ConclusionInvestment in sustainable production and maintenance of supplies for oxygen therapy, along with messaging around early and appropriate use for healthcare providers, caregivers, and patients could reduce COVID-19 deaths in SSA. Further investigation into convalescent plasma is warranted, as data on its effectiveness specifically in treating COVID-19 becomes available. The success of supportive or curative clinical interventions will depend on earlier treatment seeking, such that community engagement and risk communication will be critical components of the response.