Health Emergencies

Countries around the world face a perfect storm of converging threats. Covid is the latest but far from the last health emergency the world will face.
Covid is the most recent health emergency, but one of only a many in recent years. On average, one new pathogen with substantial potential for human harm is discovered every year.
The Global Health Security Agenda is an important initiative to reduce global risk. But outbreaks and epidemics of HIV, Zika, Ebola, drug-resistant bacteria, cholera, and more demonstrate our ongoing vulnerability to microbial onslaught and sneak attack. The articles in this section outline some of those risks - and some succesful responses that are important to learn from.

Featured Article

Frieden TR, Tappero JW, Dowell SF, Hien NT, Guillaume FD, Aceng JR. Safer countries through global health security. Lancet 2014;383(9919):764-6.

At the launch of the Global Health Security Agenda - An Outline of Needs

Selected articles with summary and commentary

Global Health Security

Shahpar C, Lee CT, Wilkason C, Buissonnière M, McClelland A, Frieden TR. Protecting the world from infectious disease threats: now or never. BMJ Glob Health. 2019;4(4):e001885.

Health cannot be protected by Ministries of Health alone.16 Many sectors need to be involved in order to increase and sustain investment,17 build long-term capacity and implement policies affecting health in the food, security and animal sectors. In many countries, the JEE was the first opportunity for these sectors to work together. This group should continue to collaborate in order to prioritise which gaps to fill first, begin implementation, increase domestic financing and monitor progress. High-level support (eg, from presidential or prime minister offices) is essential for countries to take action. Engagement by journalists and civil society can convey that increased health security is essential.18 This support can help counter the pattern of a temporary surge of activity followed by waning interest, as typically seen after a major outbreak.
For the first time in history, the world has an in-depth understanding of how prepared most countries are to deal with epidemic diseases and of what must be done to improve preparedness. To save lives, funded, prioritised, well-planned actions must be implemented at scale as soon as possible, supported by a network of partners working together to support countries to step up their capacities to prevent, detect and respond to public health threats and make the world safer.

Redd SC, Frieden TR. CDC’s evolving approach to emergency management.* Health Security. 2017;1:1-12.

We reviewed experience from 2009 through 20017, drawing lessons from the H1N1 influenza pandemic, Ebola, Zika, and many tother emergencies. Our fundamental conclusion: the best emergency preparation is getting everyday systems to work well to find, stop, and prevent health threats, with the ability to scale these systems up quickly and robustly.

Frieden TR, Schuchat A, Petersen LR. Zika virus 6 months later. JAMA 2016;316:1443-1444.

The Zika epidemic was the most complex emergency CDC had faced. It required involvement of a broad range of expertise: virology, entomology, vector control, reproductive health, birth defects, laboratory development, pathology, and more. We're still learning about how to control it, and why the impact was so different in different places.

Tappero JW, Thomas MJ, Kenyon TA, Frieden TR. Global health security agenda: building resilient public health systems to stop infectious disease threats. Lancet 2015;385:1889-91.

This collection of artilces outlines the rationale and needs for the Global Health Security Agenda. The world now has a good sense of what is needed, where, how to address these needs, and how much it will cost to do so. What's lacking is action to meet these needs - with money, technical support, and strengthening operational capacities.


Frieden TR, Das-Douglas M, Kellerman SE, Henning KJ. Applying public health principles to the HIV epidemic. N Engl J Med 2005;353:2397-2402. and Frieden TR, Foti KE, Mermin J. Applying public health principles to the HIV epidemic – How are we doing? NEJM 2015;373(23):2281-7.

In 2005, I called for the application of public health principles to the HIV epidemic (table below). This was highly controversial at the time. Since then, the view has been widely accepted and applied, and we review the substantial, although far from complete progress, since, and concluded that, "The combination of patient empowerment, community engagement, clinical excellence, and public health focus on outcomes and impact could make management of HIV infection a model for combating other chronic diseases."
Difference between HIV and other infectious diseases outline in our 2005 article.

Torian LV, Wiewel EW, Liu K, Sackoff JE, Frieden TR. Risk factors for delayed initiation of medical care after diagnosis of human immunodeficiency virus. Arch Intern Med 2008;168:1181-1187.

Delay in diagnosis of HIV results in both avoidable illness in the person diagnosed, and increased risk of spread to others. Addressing the root causes of delayed diagnosis and treatment is essential to controlling the HIV epidemic.


Frieden TR, Damon IK. Ebola in West Africa – CDC’s role in epidemic detection, control, and prevention. EID 2015;21(11):1897-1905. and Frieden TR, Damon I, Bell BP, Kenyon T, Nichol S. Ebola 2014—new challenges, new global response and responsibility. NEJM 2014;371(13):1177-80.

The Ebola epidemic was the most challenging emergency of my 15 years leading public health programs. Thousands of CDC staff worked for years in West Africa to help end the epidemic. Although as I said publicly early on, it was never "in the cards" for Ebola to spread widely in the United States, the epidemic caused a degree of fear and politicization in the public and by politicians that foreshadowed the deadly errors made in the US response to Covid in 2020.
Time matters! The RITE (Rapid Isolation and Treatment of Ebola) strategy helped stop Ebola.
Martin Meltzer's model of Ebola is one of the greatest modeling stories in public health history - and not widely enough known. Samantha Power's book outlines the impact his worst-case scenario had within the United States government and global community. But less well appreciated is the fact that his projection of what would happen with fast, effective action matched what did happen stunningly well, as shown in this figure below.
Meltzer's model predicted - with stunning accuracy - what happened with effective action to stop Ebola.
I outlined this in a brief (2 minute) video that I wish more people would watch - because models have been so poorly understood and used during the Covid pandemic.
About Ebola, we made one specific and one general conclusion.
"The Ebola virus is a formidable enemy. If a single case is missed, a single contact becomes ill and isn't isolated, or a single lapse in infection control or funeral-practice safety occurs, another chain of transmission can start."
"We believe that stopping outbreaks in a way that leaves behind stronger systems to identify, stop, and prevent future health threats is a moral imperative."

Haiti including cholera

Periago MR, Frieden TR, Tappero JW, De Cock KM, Aasen B, Andrus JK. Elimination of cholera transmission in Haiti and the Dominican Republic. Lancet 2012;379:193-286.

It's possible to eliminate cholera from Haiti and the Dominican Republic - but requires persistence and political commitment.

Dowell SF, Tappero JW, Frieden TR. Public health in Haiti – challenges and progress. NEJM 2011;364(4):300-301.

The earthquake and cholera epidemic were devastating, and even before these events, Haiti had, by far, the worst health status of any country in the hemisphere. But it would be a mistake to fail to recognize the many areas where dedicated health workers and community volunteers have made substantial progress. This progress demonstrates that more progress is definitely possible.
Note: The earthquake also resulted in the death of Diana Caves, a dedicated and inspiring CDC staffer who was in the country on a short-term assignment to help improve prevention and control of HIV. This was the one death in the line of duty which occurred in my time as CDC director from 2009-2017. I will never forget meeting with her family to inform them. We established an award to recognize staff early in their career.

Drug-resistant bacteria

Rapid increase in drug-resistant tuberculosis in New York City - a symptom of program failure
Antibiotics have saved millions of lives, but drug-resistance threatens to usher in a post-antibiotic time. In April of 1991, acting on a tip from an alert clinician, I conducted a study of every patient in New York City with tuberculosis. The results were alarming, and resulted in a substantial increase in funding and attention. We were ultimately able to control the outbreak, which was largely driven by spread in hospitals, and was the largest outbreak of multi-drug resistant tuberculosis the United States has experienced. Another bacteria, vancomycin-resistant enterocci, didn't spread widely. In 1990, while an infectious disease fellow, I wrote of the widespread inappropriate use of antibiotics.

Frieden TR, Sterling T, Pablos-Mendez A, et al. The emergence of drug resistant tuberculosis in New York City. N Engl J Med 1993;328:521-526.

Frieden TR, Munsiff SS, Low DE, et al. Emergence of vancomycin-resistant enterococci in New York City. Lancet 1993;342:76-79

Nivin B, Nicholas P, Gayer M, Frieden TR, Fujiwara PI. A continuing outbreak of multidrug-resistant tuberculosis, with transmission in a hospital nursery. Clin Infect Dis 1998;26:303-307.

Frieden TR, Mangi R. Inappropriate use of oral ciprofloxacin.* JAMA 1990;264:1438-1440.


Writing with Dr. Tedros, now WHO Director General, and others, we outlined a way forward to control of malaria, tuberculosis, and HIV.

Frieden TR, Teklehaimanot A, Chideya S, Farmer P, Kim JY, Raviglione MC. A road map to control malaria, tuberculosis, and human immunodeficiency virus/AIDS. * Arch Intern Med 2009;169:1650-2.

World Trade Center / Health Registries

I became health commissioner in January, 2002, when the World Trade Center remains were still burning. We established a registry to track health effects and facilitate benefits for survivors and those suffering from the health, including mental health, complications. Rapid creation of health registries to better understand and support those effected by health emergencies is an important public health function, and must be done quickly and sensitively.

Farfel M, Digrande L, Brackbill R, Prann A, Cone J, Friedman S, Walker DJ, Pezeshki G, Thomas P, Galea S, Williamson D, Frieden TR, Thorpe L. An overview of 9/11 experiences and respiratory and mental health conditions among World Trade Center Health Registry enrollees. J Urban Health 2008;85:880-909.

Vitamins and infections

There's a long and interesting history of the interaction of nutrition and infection. In the early 1900s, anti-tuberculosis activists helped to create milk stations so children could receive wholesome milk as a nutritional supplement. During my training as an Epidemic Intelligence Service Officer of the Centers for Disease Control, I documented that vitamin A levels were low among children in New York City with measles. This resulted in a new recommendation to provide vitamin A to young children with measles in the United States.
While working in India, we gradually realized that tuberculosis has substantial seasonality: there is a much higher rate in cold weather in the north of the country, but no seasonality in the south of the country which doesn't have a winter season. (I was memorably informed that Chennai has three seaons: hot, hotter, and hottest.) The figure below is striking in showing this. Very high seasonality in the cold winter months in the north, and none in the hot winter months in the south. The reasons for this seasonality are not yet definitively known, but vitamin D deficiency in the colder months, when people are inside more, is a leading and plausible hypothesis, for which there is increasing evidence.
Seasonality of tuberculosis, India: gradient colder to warmer climates - none in the hot south.

Frieden TR, Sowell AL, Henning KJ, Huff DL, Gunn RA. Vitamin A levels and measles severity: New York City.* Am J Dis Child 1992;146:182-186.

Thorpe LE, Frieden TR, Laserson KF, Wells G, Khatri GR. Seasonality in tuberculosis, India: is it real and what does it tell us?* Lancet 2004;364:1613-1614.

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