Yet experts tell us that even with successful vaccines and effective treatment, COVID may never go away. Even if the pandemic is curbed in one part of the world, it will likely continue in other places, causing infections elsewhere. And even if it is no longer an immediate pandemic-level threat, the coronavirus will likely become endemic — meaning slow, sustained transmission will persist.
The coronavirus will continue to cause smaller outbreaks, much like seasonal flu. Whether bacterial, viral or parasitic, virtually every disease pathogen that has affected people over the last several thousand years is still with us, because it is nearly impossible to fully eradicate them.
The only disease that has been eradicated through vaccination is smallpox. Mass vaccination campaigns led by the World Health Organization in the s and s were successful, and in , smallpox was declared the first — and still, the only — human disease to be fully eradicated. So success stories like smallpox are exceptional.
It is rather the rule that diseases come to stay. Take, for example, pathogens like malaria. Since , global programs to eradicate malaria, assisted by the use of DDT and chloroquine, brought some success, but the disease is still endemic in many countries of the Global South. Similarly, diseases such as tuberculosis , leprosy and measles have been with us for several millennia.
An epidemic occurs when an infectious disease spreads rapidly to many people. In , the severe acute respiratory syndrome SARS epidemic took the lives of nearly people worldwide.
The influenza flu pandemic of killed between 20 and 40 million people. It is one of the most devastating pandemics in recorded world history. Consequently, we have forgotten about the threat of epidemics.
This has driven complacency, misunderstanding and an under appreciation of the things that preserve the bubble; vaccines, antibiotics, clean water and herd protection.
When I was a child in the s, epidemics still occurred. We had regular outbreaks of measles, rubella and mumps, whilst skin boils abscesses and impetigo were still common in Northern England where I grew up. Typhoid outbreaks still occurred in the United Kingdom, such as in Aberdeen in and the deadly disease smallpox still stalked the world. Polio was still crippling children and pneumonia was common I was hospitalised with this as a young teenager.
I also caught infectious jaundice almost certainly Hepatitis A , which could not then be diagnosed, keeping me off school for weeks. GPs were freely available to visit the sick daily and hospital wards were run by dominant matrons imposing cleanliness and hygiene.
Everyone was acutely aware of the infection threat. Measles in the United Kingdom occurred regularly as periodic epidemics. The disease is now largely controlled by vaccination in the UK but it has not gone away Source: Public Health England. As health systems were steadily built up over the next decades the immediate threat of infection gradually dissipated in richer countries, due to our increasing ability to control, diagnose and prevent infections. As a consequence — we have forgotten those days.
This is only half the story. Infections and epidemics still rage on in the poorer parts of the world. These are largely invisible to most of us in the richer areas, even though they kill millions of children each year. Malaria, dengue, worm infestations, measles and even diphtheria are still relatively common, particularly where there is social disruption.
Trajectory of the recent cholera outbreak in Yemen A The first wave of the epidemic covering late through to early and B The second devastating huge wave of cholera in Source: World Health Organization. I regularly work and visit these settings to study epidemic cholera, antibiotic resistant typhoid and other diseases.
In our work, we have uncovered hidden typhoid epidemics creeping across Asia and on into Africa. Hundreds of thousands of children have been lost — we know little of this in our richer world. We are frightened and threatened by the invisible foe.
Where is it? What is this coronavirus pathogen and what will it do to me or my loved ones? What should we do? Experts and many, many non-experts are willing to give us advice where there are few, if any, precedents of this type of infection rampaging in a population that lacks immunity. Where is the vaccine to protect us? Finally, some epidemics are neither common-source in its usual sense nor propagated from person to person.
Outbreaks of zoonotic or vectorborne disease may result from sufficient prevalence of infection in host species, sufficient presence of vectors, and sufficient human-vector interaction. Examples Figures 1. Summary of notifiable diseases — United States, MMWR ;48 38 —9. For each of the following situations, identify the type of epidemic spread with which it is most consistent.
Description: Epidemic curve histogram shows the presumed index case of Hepatitis A, followed 4 days later by a steep increase in cases which tapers off to 0. Cases who were food handlers and secondary cases are also shown. Return to text. Description: Histogram shows the number of cases of diarrhea by date of onset.
Arrows also show when water main breaks, a boil water order, and water chlorination occur. Bloody and nonbloody diarrheal illness is indicated by different colors. Overall increases and decreases in cases is easily seen. Description: Histogram shows the number of measles cases peaks around November 23 then declines. It peaks again on December 5 and declines until it peaks a third time.
Description: Histogram shows the number of Shigella cases among staff and attendees in stacked bars. The first case occurs in a staff member on day 1. The number of cases among staff and attendees is seen in relationship to the festival dates. Description: Histogram shows a general increasing trend in the number of reported cases of Lyme disease. In NYC, cases drop to 0 after mosquito control activities are begun in the city.
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