Tuesday 3 March 2020

The best defense against disturbing new diseases

The global fight against coronavirus depends on the health systems of the world’s most vulnerable communities.

The 2019 novel coronavirus has caused a public-health emergency in China, a global economic superpower. Like many in my field, I worry that if and when the emergent virus takes root in poorer countries that are already tackling outbreaks of other pathogens, it could wreak havoc of an even larger magnitude.

I am a physician who concentrates on outbreak preparedness against new infectious diseases, both in the United States and in countries with far fewer resources. My work—currently in western and equatorial Africa and previously in Asia and Latin America—has convinced me that global defenses against new infectious diseases are only as strong as the health systems in the poorest communities all around the world. The specifics of new diseases matter less than whether those communities can, with international support, build the resilience to face common (and uncommon) threats.

When I landed in Uganda a couple of weeks ago, the airport in Entebbe was screening for Ebola virus disease, because of the continuing outbreak in the neighboring Democratic Republic of Congo, and also for the novel coronavirus, known as 2019-nCoV. That same week, a number of other diseases also threatened people living in the region. The Ugandan public-health authorities were simultaneously dealing with outbreaks of Crimean-Congo hemorrhagic fever and yellow fever.

Last week, World Health Organization Director-General Tedros Adhanom Ghebreyesus declared 2019-nCoV a public-health emergency of international concern. The potential harm to low- and middle-income countries was high on his list of concerns. His agency subsequently identified 13 African countries at high risk for transmission of 2019-nCoV due to direct links or high-volume travel from China. The damage the new epidemic might cause in Africa is not only a function of the disease itself (which currently is thought to have a mortality rate of about 2 percent), but also of how it could combine with other health threats and disrupt trade, travel, and educational endeavors on the continent. In countries that have already struggled to contend with other infections, the 2019-nCoV epidemic could lie over the public-health landscape like a heavy blanket, overburdening the already sparse health-care systems with yet more illnesses and deaths. In time, the novel coronavirus will likely become part of the tapestry of common diseases, but not before it exacts direct costs from poor communities—while also diverting money and energy, much like Ebola did, from health threats that are more familiar but still potentially lethal.

The last two Ebola outbreaks—in West Africa from 2013 to 2016 and now in the Democratic Republic of Congo—have devastated the affected countries. If any good has come of those events, it’s that they have also led to improvements in many African countries’ capacity to tackle emerging infectious diseases, bringing in investment in diagnostic capacity and national coordination.

Nigeria, for example, has improved its national laboratory that tests infectious-disease specimens. That nation’s improved detection capabilities have improved surveillance not just of Ebola, but also of Lassa fever and of the growing incidence of monkeypox and other infectious diseases. There is greater regional leadership; the Africa Centers for Disease Control and Prevention—a.k.a. Africa CDC—has emerged as both a coordinator of and advocate for more resources and has led the efforts to conduct diagnostic testing for 2019-nCoV in multiple countries across the continent.

Meanwhile, teams in the Democratic Republic of Congo and neighboring countries have had recent practice in tracing the contacts of patients who might have been exposed to a dangerous pathogen, and the countries in the region have shown incredible success in working together to control the current Ebola outbreak across multiple borders. Congo recently successfully conducted the first clinical trial in history to take place in the middle of both an armed-conflict zone and an Ebola outbreak. Its experience has added to global knowledge about how to deploy experimental treatments for other emerging diseases in resource-limited settings.

Some countries have used the emergency-coordination structures they employed for Ebola response and have been able to adapt them to rapid response for the novel coronavirus. Programs such as the Global Health Security Agenda, a multicountry initiative established in the aftermath of the 2013–2016 Ebola epidemic, have improved the centralized public-health capacities in many low-income countries. Despite all these advances, though, the magnitude of health threats that poorer countries face remains vastly greater than their capacity to handle them unaided.    

The new coronavirus is also not the same challenge as Ebola. Whereas Ebola transmission requires close contact with an infected person’s bodily fluids, 2019-nCoV is thought to be transmitted—potentially before patients even show symptoms of infection—through respiratory droplets created by coughing or sneezing. The 2019-nCoV epidemic could unfortunately result in a much greater number of cases, despite having a lower mortality rate, and may test aspects of public-health resilience in ways that Ebola didn’t. It will exacerbate some of the greatest weaknesses of crowded low-resource health-care facilities, including their inability to quickly identify and isolate patients who may have early symptoms resembling those of other common diseases. Coronavirus will spread through hospitals where high-quality infection control is extremely challenging and where, in most cases, testing for even regular respiratory viruses such as influenza is not conducted (unless it’s part of national surveillance studies).

Many of the challenges above are those aspects of health care that are closer to the patient. While recent initiatives have improved disease surveillance and other public-health planning, the health-care delivery system has seen fewer advances. In every epidemic, hospitals and clinics have the potential to serve as amplifiers for infection. The recent Ebola outbreak in Congo is a case in point: About 18 percent of those cases were thought to be a result of transmission within a health-care setting. In other words, patients were exposed to pathogens when they sought medical care.

To anyone who has worked in low-resource settings, this is not a surprise. In many poor regions, personal-protective equipment (PPE), such as masks, gloves, and other clothing, is in short supply. Maintaining the levels of infection control that prevail in the United States and Europe requires training and support largely unavailable to health-care workers who are already overwhelmed by too many patients. During Ebola outbreaks, the same health-care workers, after a limited amount of instruction, are expected to put on and take off complicated masks and protective clothing without getting infected. 

As the scope of 2019-nCoV widens, these workers will have to compete with the rest of the world for supplies and try to use them in a consistent way across what will likely be a huge patient load. As one of my Ugandan physician colleagues remarked, “It also doesn’t help that it seems like every hospital portrayed in the media is taking care of coronavirus patients with different types of PPE. It’s leading to a lot of confusion about how these recommendations should be translated to resource-limited settings.”

Currently, there are no confirmed cases of 2019-nCoV in Africa, but multiple people suspected of infection, based on their travel history and symptoms, have been identified at the borders of a growing number of African countries. If the cases start to occur within the borders of these countries—and without obvious links to known sources of infection—properly diagnosing those infected will be extraordinarily difficult.

If the 2019-nCoV epidemic spreads around the world, rich countries may decide to test incoming travelers who display compatible symptoms. In poor communities, identifying those carrying the virus will be even harder. To test routinely for the large number of patients expected from the most pessimistic predictions about the 2019-nCoV epidemic, a herculean burden will need to be placed on national laboratories. Most important, a large-scale testing policy will require health-care workers to treat patients, collect all these individual samples, and ship them to central laboratories because no bedside rapid diagnostic tests are currently available for 2019-nCoV virus. In the face of competing needs from diseases with much higher mortality rates, how realistic is such a proposal?

The 2019-nCoV acute respiratory disease may manifest profoundly differently in poor regions of the world. Currently, older patients and those with chronic ailments seem to get more severely ill from coronavirus and are at higher risk of death. In the developing world, 2019-nCoV could conceivably yield more severe disease and higher mortality rates because of underlying malnutrition and other concurrent infections (as we see with tuberculosis and influenza). These concerns are relevant in the United States too. A patient’s history of smoking could make novel coronavirus infection worse. The indoor and outdoor pollution to which many poor communities are exposed might have an effect, too. As scientific discovery moves forward, will rich countries spend the resources needed to answer the questions important to poor communities all around the world?

If a greater number of sicker patients require hospitalization for 2019-nCoV acute respiratory disease, patients admitted with other conditions suffer as well, as space becomes scarce and health-care workers are pulled in all directions. Many hospitals operating in rich countries faced shortages of intensive-care beds during prior pandemics like H1N1 and SARS. They had to work together and improvise ways of caring for a large number of critically ill patients. Such planning will be even more crucial in low-resource areas.

Nearly 90 previously unknown human pathogens have been discovered since 1980. Emergent diseases sometimes bring new attention and new resources; the Bill and Melinda Gates Foundation, for instance, recently made a major contribution to help tackle the novel coronavirus. Still, the central lessons of 2019-nCoV and Ebola are the same: Temporary support in the aftermath of an epidemic is not a substitute for much greater investment by the international community in health care in the most vulnerable countries all around the globe. The advent of 2019-nCoV should push us to look beyond specific diseases and toward how we can improve health care more generally—and contain the next pandemic before it starts.

(Source: The Atlantic)

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