A Tale of Two Pandemics: a plea on World TB Day, 24 March 2020
LIV-TB is a cross-campus collaboration between the Liverpool
School of Tropical Medicine and the University of Liverpool. In the following
post, Dr Tom Wingfield talks about the current TB Pandemic.
It is the worst
of times. We are facing a pandemic.
A quarter of the world’s population is estimated to be infected.
By the end of 2020, it is likely that 10 million people will have fallen ill,
three million will not have been tested and treated, and over 1 million, mostly
vulnerable people, will die.
This pandemic is not caused by the novel coronavirus, SARS-CoV-2,
which leads to COVID-19.
It is caused by tuberculosis (TB).
Yesterday, on World TB Day 2020, and amid this
unprecedented outbreak, we at LIV-TB and others think
it is vital to compare and contrast the TB and COVID-19 pandemics - one old,
one new - to remind ourselves why it’s still time to end TB. We
have written a related comment that has been published here in Lancet
Respiratory Medicine.
So what is a pandemic? A pandemic is defined as
a disease that spreads over a whole country or the whole world. TB and COVID-19
both fit this definition, affecting people across all six continents. No
country is TB free and COVID-19 has now reached more than 180 of the nearly 200
countries on the planet.
There are striking similarities between the two pandemics.
Both are a huge cause of illness and death around the world. TB is the single
biggest infectious diseases killer, ending the lives of 1.2 million people in
2018. This is more than HIV and malaria combined. COVID-19 has infected nearly
250,000 people and caused nearly 10,000 deaths in the first quarter of
2020 alone.
Both cause symptoms
of fever, cough and shortness of breath. In countries with escalating
COVID-19 cases, this is likely to mean that people with TB presenting to
clinics and hospitals may go unrecognised or misdiagnosed. A similar pattern
emerged in West Africa when cases
of malaria were missed during the Ebola outbreak. Another similarity is
that those at higher risk of more severe TB and COVID-19 disease and outcomes
are older people
and those with chronic illnesses. And, as we are discovering for COVID-19,
both diseases lead to significant social impact including stigma, discrimination,
and isolation;
and economic impact related to country
productivity losses and catastrophic
costs to individuals and households.
There are also stark differences, the first being time. TB
has accompanied us for thousands of years even being found in Egyptian
mummies. SARS-CoV-2, on the other hand, is a new coronavirus that has
spread rapidly around the world since December 2019. TB, previously known
as consumption
or The White Plague, is used to being labelled a pandemic. This is the
first COVID-19 pandemic humankind has ever seen. Second, most children with
COVID-19 will
have only mild symptoms. The same cannot be said for TB, which in
2018 killed
one in five of the 1.1 million children who became ill with TB. Finally,
over 90% of TB cases and deaths occur in low- and middle-income countries. In
contrast, Europe has been called the second epicentre of
COVID-19 after China. Among other factors, this may explain why more
funding and person-power will be put into the COVID-19 response in a year than
TB has received in decades. However, modelling studies show us that vulnerable
countries in sub-Saharan Africa and the Americas will soon be dealing with
their own COVID-19 epidemics. We must all act together now to prevent
a catastrophe.
There remain many unknowns. How TB and COVID-19 may interact
is not understood. Put simply, TB rates could go up due to more people coughing
due to COVID-19 who also have TB or go down due to self-isolation and
quarantine. The risk factors for getting COVID-19 and having more severe
disease appear to overlap and be similar to those for TB. These include being older, a
smoker, male,
having other chronic
illnesses such as lung disease, and being poor. Undoubtedly, COVID-19, like
TB, will be associated with the medical
poverty trap, in which poorer people have a higher likelihood of infection,
disease, and adverse outcomes. Also, unemployed people, informal or zero-hour
contract workers, will experience further impoverishment, which increases
TB risk.
The best of times would be to live in a COVID-19 and TB-free
world. But this is a long way off and there is much to do. So, as we work
together to control COVID-19, let's not forget the ongoing TB pandemic; still
the biggest infectious diseases killer. We need to markedly increase funding to
strengthen healthcare systems to address TB and to support research for a
vaccine, better tests and medicines, equitable access to care, and socioeconomic
support for people affected by TB. We need to continue to inform, advocate
for, and empower local communities and to lobby
governments and policymakers, to ensure that TB, as well as COVID-19,
remain high on the global agenda. The lessons we have been taught by pandemics,
old and new, are to be proactive, long-sighted, to plan ahead, and to not
become complacent.
Let's look forward to the best of times.
Read the full
Lancet Respiratory Medicine article.