Becker's Hospital Review

124 CMO / CARE DELIVERY A timeline of emerging infectious diseases in history By Mackenzie Bean T he world has entered "a pandemic era" in which humans' im- pact on the environment may cause new infectious diseases to emerge more frequently, Anthony Fauci, MD, and his colleague David Morens, MD, wrote in an article for Cell. Dr. Fauci, director of the National Institutes of Allergy and Infectious Disease, and Dr. Morens, a senior advisor at the NIAID, said activi- ties like deforestation, overfishing and urban crowding can disrupt the natural ecosystem, which may be a contributing factor to the emer- gence of diseases. "e COVID-19 pandemic is yet another reminder, added to the rap- idly growing archive of historical reminders, that in a human-domi- nated world, in which our human activities represent aggressive, dam- aging and unbalanced interactions with nature, we will increasingly provoke new disease emergences," they wrote. Drs. Fauci and Morens shared the following timeline of key emerging and reemerging infectious diseases that have spread across the globe: Note: Most mortality figures represent estimates. 430 BCE — e Plague of Athens killed about 100,000 people and is the first transregional pandemic in recorded history. e exact disease that caused this plague is unknown. 541 — e Plague of Justinian killed 30 million to 50 million people and was caused by the bacteria Yersinia pestis. 1340s — "Black Death," a bubonic plague caused by Yersinia pestis, killed about 50 million people. 1494 — Syphilis, a pandemic brought to Europe from the Ameri- cas, has killed more than 50,000 people and is caused by the bacteria Treponema pallidum. c. 1500 — Tuberculosis is an ancient disease that became a pandemic in the Middle Ages and has killed millions. 1520 — Smallpox, caused by the bacteria Variola major, has killed about 3.5 million people. 1793-1798 — Yellow fever killed about 25,000 people in colonial America in what is referred to as "e American Plague." 1832 — e 1832 cholera pandemic killed about 18,402 people, spreading across Asia, Europe and the Americas. 1918 — Spanish flu killed about 50 million people and caused addi- tional pandemics in 1957, 1968 and 2009. 1976 - 2020 — Ebola has killed 15,258 people and caused 29 epidem- ics since it was first detected in 1976. 1981 — Acute hemorrhagic conjunctivitis is a derivative of pink eye that was first recognized in 1969 and caused a pandemic in 1981. 1981 — HIV/AIDS have killed about 37 million people since it was first identified in 1981. It is considered an ongoing pandemic. 2002 — SARS killed 813 people in what health experts call a "near-pan- demic" in 2002. 2009 — H1N1 "swine flu" killed 284,000 people in what was the cen- tury's fih flu pandemic. 2014 — Chikungunya is a mosquito-borne virus that was first iden- tified in 1952 and became pandemic in 2014. Deaths from this virus are uncommon. 2015 — Zika is a type of flavivirus that has existed for decades. It wasn't until 2015 that the mosquito-borne virus spread pandemically, likely due to a virus mutation. n COVID-19 patients test positive for 3 weeks, UPMC analysis finds By Mackenzie Bean A systemwide analysis of COVID-19 retesting data at University of Pennsylvania Medical Center found patients generally tested positive for three weeks, the Pittsburgh-based health system said Aug. 10. Researchers analyzed the results of more than 30,000 nucleic acid polymerase chain reaction COVID-19 tests performed between March 3 and May 3 across the sys- tem's 40 hospitals and 700 physician offices. Of these tests, 485 were repeated. Of 74 patients who initially tested positive and were re- tested, about half still were positive. The median time between the first test and a repeat positive was 18 days, while the median time for a negative result upon retest- ing was 23 days. Based on this finding, researchers said PCR tests may remain positive for about 21 days. Another 418 patients initially tested negative and were retested. Of these, 96.4 percent were still negative after the second test. Only 15 patients first tested negative and then positive. Researchers said the data was not collected through a formal clinical trial process. Testing differed based on clinician discretion, so researchers could not calculate a true false-positive rate. The research was published Aug. 10 in Infection Control & Hospital Epidemiology. n

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