COVID-19 control in low-income settings and displaced populations: what can realistically be done?

Modelling predictions [1] suggest that uncontrolled COVID-19 epidemics will result in 7.0 billion infections and 40 million deaths globally this year, with the impact expected to be most severe in low-income settings and forcibly displaced populations [2]. Three mechanisms could determine this: (i) higher transmissibility due to larger household sizes [3], intense social mixing [4] between the young and elderly [5], overcrowding in urban slums and displaced people’s camps, inadequate water and sanitation, and specific cultural and faith practices such as mass prayer gatherings, large weddings and funerals during which super-spreading events might propagate transmission disproportionately [6]; (ii) higher infection-to-case ratios and progression to severe disease due to the virus’ interaction with highly prevalent co-morbidities, including non-communicable diseases (NCDs; prevalence of hypertension and diabetes is often higher in low- than high-income settings [7, 8], with a far lower treatment coverage [9]), undernutrition, tuberculosis [10, 11] and HIV¹⁰; and (iii) higher case-fatality due to a dire lack of intensive care capacity, especially outside large cities. Moreover, extreme pressure on curative health services could result in indirect impacts resulting from disrupted care for health problems other than COVID-19 [12]. These risks are exacerbated by the inadequacy of pandemic plans that enable public health systems to respond [13] adequately and without delay. While it remains to be seen if these risk factors can be counterbalanced by younger age distributions, on balance we believe that, given current evidence and plausible reasoning, drastic action is required immediately to protect the world’s most fragile populations from this unfolding threat. We present here our views on the challenges of current containment focused approaches contrasted to more realistic, economically and socially amenable interventions, to limit COVID-19 transmission even in the most resource-constrained settings.

In recent months low-income and crisis-affected countries have followed a global pattern of attempting to interrupt further importation of COVID-19 from abroad through border closures. Examples from China, South Korea and Singapore [14] suggest that this approach may enable containment at least for some time; it is, however, very resource-intensive, and will inevitably require widespread testing and meticulous contact tracing [15]. It is doubtful that these measures are replicable in low-income and crisis settings, where inadequate surveillance and less-than-sufficient testing may initially obfuscate the true extent of locally driven transmission.

Current mathematical modelling forecasts [16] predict that even stringent lockdowns, similar to those implemented in Europe, would be unlikely to prevent cases from surging well beyond these countries’ existing hospitalisation capacity. Despite this, low-income countries are increasingly adopting population wide physical distancing strategies, where all residents except essential workers are asked to stay at home. This presents a difficult balance for low-income countries where the social and economic cost of population-wide physical distancing and travel restrictions, if sustained over a long period, could be very harmful for fragile, export-dependent economies and stretch livelihoods beyond people’s coping ability, in turn dis-incentivising adherence to control measures. In crises, both a lack of trust between populations and national authorities and on-going conflict can undermine a sweeping, one-size-fits-all strategy [17], especially if applied coercively. In short, a draconian containment strategy may be useful for a limited time to allow countries to better prepare, but risks failing beyond a horizon of weeks.

Of the three mechanisms we describe above, two (higher infection severity and case-fatality) appear less tractable for the time being. Some interventions to mitigate secondary impacts could help and should be pursued quickly (e.g. avoiding treatment interruptions for NCDs, TB and HIV by supplying patients with several months of medication through community health workers or dedicated clinics that can reach these patients; intermittent presumptive treatment to reduce other co-morbidities; freeing up health care capacity by postponing non-essential services). Options for improving oxygen therapy in low-resource settings could be explored [18]. However, there appears to be little realistic prospect of scaling up intensive care to the levels required for COVID-19, where demand in a typical low-income setting for critical care beds, even in the mitigated scenarios, is predicted to outstrip supply by a factor of 25 [19]. Isolation of cases in dedicated, but not high-intensity wards might offer neither clinical benefit nor meaningful transmission reductions, as most transmission would still be attributable [20] to low-risk infections [21] and the proportion of the infectiousness period spent pre-admission [22, 23], e.g. among household members. Moreover, without sufficient training and infection control supplies, such facilities would pose a major threat to the health of clinicians, already a very scarce resource in most low-income and crisis settings. However for the majority of LICs, where testing is not widely available, syndromic diagnosis could also result in inadvertent mixing and thus cross-transmission between true COVID-19 cases and patients with other acute respiratory infections.

By contrast, the mechanism of higher transmissibility appears more amenable to economically and socially feasible interventions, even in the most resource-constrained settings. Here too, however, a range of possible strategies may be considered. In order for population-wide physical distancing measures, increasingly being pursued in low-income settings, to realistically achieve sufficient impact on their own, these would require most non-essential workers to work from home or not at all, a strategy ill-suited to the economies and remote-working capability of low-income settings. Moreover, this must be sustained over a long period, until a vaccine, treatment or both are available at scale. We thus suggest that, where dispersive strategies targeting the general population are difficult to implement, enforce and/or sustain [24‐26], leading to ongoing transmission among low-risk populations [27, 28], it will be crucial to focus resources on maximizing the impact of strategies to protect those most vulnerable to severe outcomes, in essence shielding them to the extent possible from the risk of infection. A recent modelling study [16] of the epidemic in three African countries (representing the range of age distributions on the continent) suggests that a combination of self-isolation, moderate distancing and high-uptake shielding would mitigate bed demand and mortality to a considerable extent.

In Ebola epidemics, isolating the ill into a contaminated ‘red zone’ is mainly needed to protect the healthy. For COVID-19, this paradigm is upturned: from the perspective of the highest risk groups, unless they can be shielded from infection and cared for while shielding, the red zone is everywhere. While stressing that no single approach is likely to fit all low-income or crisis settings, we outline below a set of principles that, implemented together, could support the general aim of protecting those most vulnerable from infection by helping them to live safely, dignifiedly and separately from their families and neighbours for what could be an extended period of time, until COVID-19 can be controlled or vaccine and treatment options become available.

While the targeted approach we have outlined may only be one of several possible interventions, we believe that it may offer a realistic solution for allocating scarce resources to maximise impact in settings where scaling up treatment significantly is unlikely to be an option. Other feasible, high-yield interventions should be undertaken simultaneously, e.g. staying home if sick, limiting public transport use, reducing super-spreading events at funerals or other mass gatherings, promoting hand-washing, soap distribution and/or at least maintaining treatment coverage for risk-factor co-morbidities. Clearly, any shielding strategy would need to be predicated on sound, locally informed behavioural science and monitored for effectiveness, e.g. by measuring transmission or mortality within isolation ‘green zones’ and evaluating its potential under realistic modelling assumptions.

Whenever vaccines, improved therapeutics, or rapid testing for COVID-19 become available, these must be allocated equitably to low-income and crisis-affected populations. Until then, it is imperative that low-resource countries and humanitarian responses plan and roll out evidence-based, long-term strategies to mitigate their COVID-19 epidemics, starting now. Approaches such as containment of importation are likely to have exhausted their potential in the immediate future; not all interventions are of equal value, and the opportunity costs of emphasising one over the other should be considered. The price of inaction may be high. Sub-optimal, inefficient control interventions could, however, be just as costly.