View source for Non-pharmaceutical intervention (epidemiology)

{{Short description|Methods that do not involve pharmaceuticals that reduce epidemic spread}}
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{{About|the specific use of the term in [[epidemiology]]|the general concept|Non-pharmacological intervention}}
In [[epidemiology]], a '''non-pharmaceutical intervention''' (NPI) is any method used to reduce the spread of an [[epidemic]] disease without requiring [[Medication|pharmaceutical drug]] treatments. Examples of non-pharmaceutical interventions that reduce the spread of infectious diseases include [[Face masks during the COVID-19 pandemic|wearing a face mask]] and [[Quarantine|staying away from sick people]].<ref name="auto">{{Citation |last=von Csefalvay |first=Chris |title=Modeling the control of infectious disease |date=2023 |url=https://linkinghub.elsevier.com/retrieve/pii/B9780323953894000153 |work=Computational Modeling of Infectious Disease |pages=173–215 |access-date=2023-03-05 |publisher=Elsevier |language=en |doi=10.1016/b978-0-32-395389-4.00015-3 |isbn=978-0-323-95389-4}}</ref>

The [[US Centers for Disease Control and Prevention]] (CDC) points to personal, community, and environmental interventions.<ref>{{Cite web|date=2019-06-11|title=Nonpharmaceutical Interventions (NPIs) {{!}} CDC|url=https://www.cdc.gov/nonpharmaceutical-interventions/index.html|access-date=2020-04-16|website=www.cdc.gov|language=en-us}}</ref> NPIs have been recommended for pandemic influenza at both local<ref name=":1">{{cite journal | vauthors = Bell D, Nicoll A, Fukuda K, Horby P, Monto A, Hayden F, Wylks C, Sanders L, van Tam J | display-authors = 6 | title = Non-pharmaceutical interventions for pandemic influenza, national and community measures | journal = Emerging Infectious Diseases | volume = 12 | issue = 1 | pages = 88–94 | date = January 2006 | pmid = 16494723 | pmc = 3291415 | doi = 10.3201/eid1201.051371 }}</ref> and global levels<ref>{{cite journal | vauthors = Bell D, Nicoll A, Fukuda K, Horby P, Monto A, Hayden F, Wylks C, Sanders L, Van Tam J | display-authors = 6 | title = Non-pharmaceutical interventions for pandemic influenza, international measures | journal = Emerging Infectious Diseases | volume = 12 | issue = 1 | pages = 81–7 | date = January 2006 | pmid = 16494722 | pmc = 3291414 | doi = 10.3201/eid1201.051370 }}</ref> and studied at large scale during the [[2009 swine flu pandemic]]<ref>{{cite journal | vauthors = Mitchell T, Dee DL, Phares CR, Lipman HB, Gould LH, Kutty P, Desai M, Guh A, Iuliano AD, Silverman P, Siebold J, Armstrong GL, Swerdlow DL, Massoudi MS, Fishbein DB | display-authors = 6 | title = Non-pharmaceutical interventions during an outbreak of 2009 pandemic influenza A (H1N1) virus infection at a large public university, April-May 2009 | journal = Clinical Infectious Diseases | volume = 52 Suppl 1 | issue = suppl_1 | pages = S138-45 | date = January 2011 | pmid = 21342886 | doi = 10.1093/cid/ciq056 | url = https://academic.oup.com/cid/article/52/suppl_1/S138/501065 | doi-access = free }}</ref> and the [[COVID-19 pandemic]].<ref>{{cite journal | vauthors = Imai N, Gaythorpe KA, Abbott S, Bhatia S, van Elsland S, Prem K, Liu Y, Ferguson NM | display-authors = 6 | title = Adoption and impact of non-pharmaceutical interventions for COVID-19 | journal = Wellcome Open Research | volume = 5 | pages = 59 | date = 2020-04-02 | pmid = 32529040 | pmc = 7255913 | doi = 10.12688/wellcomeopenres.15808.1 | doi-access = free }}</ref><ref>{{Cite web|title=Report 9 - Impact of non-pharmaceutical interventions (NPIs) to reduce COVID-19 mortality and healthcare demand|url=http://www.imperial.ac.uk/medicine/departments/school-public-health/infectious-disease-epidemiology/mrc-global-infectious-disease-analysis/covid-19/report-9-impact-of-npis-on-covid-19/|access-date=2020-04-16|website=Imperial College London|language=en-GB}}</ref><ref name=autogenerated2>{{Cite journal|url=|doi=10.1016/j.jobb.2021.08.003|title=A solution scan of societal options to reduce transmission and spread of respiratory viruses: SARS-CoV-2 as a case study|year=2021|last1=Sutherland|first1=William J.|last2=Taylor|first2=Nigel G.|last3=Aldridge|first3=David C.|last4=Martin|first4=Philip|last5=Rhodes|first5=Catherine|last6=Shackelford|first6=Gorm|last7=Beard|first7=Simon|last8=Belfield|first8=Haydn|last9=Bladon|first9=Andrew J.|last10=Brick|first10=Cameron|last11=Christie|first11=Alec P.|last12=Dobson|first12=Andrew P.|last13=Downey|first13=Harriet|last14=Hood|first14=Amelia S.C.|last15=Hua|first15=Fangyuan|last16=Hughes|first16=Alice C.|last17=Jarvis|first17=Rebecca M.|last18=MacFarlane|first18=Douglas|last19=Morgan|first19=William H.|last20=Mupepele|first20=Anne-Christine|last21=Marciniak|first21=Stefan J.|last22=Nelson|first22=Cassidy|last23=ó Héigeartaigh|first23=Seán|last24=Rios Rojas|first24=Clarissa|last25=Sainsbury|first25=Katherine A.|last26=Smith|first26=Rebecca K.|last27=Sundaram|first27=Lalitha S.|last28=Thornton|first28=Ann|last29=Watkins|first29=John|last30=White|first30=Thomas B.|journal=Journal of Biosafety and Biosecurity|volume=3|issue=2|pages=84–90|pmid=34541465|pmc=8440234|display-authors=1}}</ref> NPIs are typically used in the period between the emergence of an epidemic disease and the deployment of an effective vaccine.<ref name=":0">{{Cite book |url=https://apps.who.int/iris/bitstream/handle/10665/329438/9789241516839-eng.pdf|title=Non-pharmaceutical public health measures for mitigating the risk and impact of epidemic and pandemic influenza|publisher=[[World Health Organization]]|year=2019|isbn=978-92-4-151683-9|access-date=2020-11-25|archive-url=https://web.archive.org/web/20201118063803/https://apps.who.int/iris/bitstream/handle/10665/329438/9789241516839-eng.pdf|archive-date=2020-11-18|url-status=live}}</ref>

== Types ==
Choosing to stay home to prevent the spread of symptoms of a potential sickness, covering coughs and sneezes, and washing one's hands regularly, are all examples of non-pharmaceutical interventions.<ref name="cdc.gov">{{Cite web|url=https://www.cdc.gov/nonpharmaceutical-interventions/personal/index.html|title = Personal NPIs: Everyday Preventive Actions &#124; Nonpharmaceutical Interventions &#124; CDC|date = 26 August 2019}}</ref> Another example is when administrators of schools, workplaces, community areas, etc., take proper preventive actions and remind people to take precautions when need be in order to avoid the spread of disease.<ref name="cdc.gov"/> Most NPIs are simple, requiring little effort to put into practice, and, if implemented correctly, have the potential to save lives.

=== Personal protective measures ===
{{See also|Personal protective equipment}}
[[File:8210-Cropped.jpg|thumb|upright=1.0|An [[N95 respirator]]]]
==== Hand hygiene ====
{{excerpt|Hand washing|only=paragraph}}

==== Respiratory etiquette ====
{{excerpt|Source control (respiratory disease)|Potentially ineffective methods of source control|only=paragraphs}}

==== Face masks ====
{{Main|Source control (respiratory disease)|N95 respirator}}
{{excerpt|Source control (respiratory disease)|Contrast with personal protective equipment|only=paragraphs|hat=0}}

=== Environmental measures ===
{{see also|Non-pharmaceutical intervention (epidemiology)#Engineering controls}}
[[File:Open window Harlow Museum & Walled Gardens, Essex 01 darker.jpg|upright=0.9|thumb|An open window can reduce infection by increasing ventilation, a cheap NPI]]

==== Surface and object cleaning ====
Germs can survive outside the body on hard surfaces for periods ranging from hours to weeks, depending on the virus and environmental conditions. The disinfection of high-touch surfaces with substances such as bleach or alcohol kills germs, preventing indirect contact transmission. Dirty surfaces should be washed before the use of disinfectant.<ref name=":0" /><ref>{{Cite web |date=2020-02-11|title=Coronavirus Disease 2019 (COVID-19) - Environmental Cleaning and Disinfection Recommendations|url=https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/cleaning-disinfection.html|access-date=2020-11-26|website=Centers for Disease Control and Prevention|language=en-us}}</ref>

==== Ultraviolet lights ====
[[Ultraviolet germicidal irradiation|Ultraviolet]] (UV) light can be used to destroy micro-organisms that exist in the environment. The installation of UV light fixtures can be costly and time consuming; it is unlikely that they could be used at the outbreak of an epidemic. There are possible health concerns involving UV light, as it may cause cancer and eye problems. The WHO does not recommend its use.<ref name=":0" />

==== Increased ventilation ====
Increased ventilation of a room through opening a window or through mechanized ventilation systems may reduce transmission within the room. Although opening a window may introduce allergens and air pollution, or, in some climates, cold air, it is overall a cheap and effective type of intervention, and its advantages probably outweigh its disadvantages.<ref name=":0" />

==== Modifying humidity ====
Viruses such as [[influenza]] and [[coronavirus]] thrive in cold, dry environments, and increasing the humidity of a room may reduce their transmission.<ref>{{cite journal | vauthors = Mecenas P, Bastos RT, Vallinoto AC, Normando D | title = Effects of temperature and humidity on the spread of COVID-19: A systematic review | journal = PLOS ONE | volume = 15 | issue = 9 | pages = e0238339 | date = 2020-09-18 | pmid = 32946453 | pmc = 7500589 | doi = 10.1371/journal.pone.0238339 | bibcode = 2020PLoSO..1538339M | doi-access = free }}</ref> Higher humidity, however, may cause [[mold]] and [[mildew]], which may in turn cause respiratory problems. [[Humidifier]]s are also expensive and will probably be in short supply at the start of an epidemic.<ref name=":0" />

=== Social distancing measures ===
{{Main|Social distancing}}
{{See also|Stay-at-home order}}
[[File:Bruce Westerman getting covid-19 test - 5.29.20.jpg|thumb|upright=1.0|[[COVID-19]] testing]]
==== Contact tracing ====
{{excerpt|Contact tracing|only=paragraph}}

==== Isolation of sick individuals ====
{{excerpt|Isolation (health care)|only=paragraph}}

==== Quarantine of exposed individuals ====
{{Main|Quarantine}}
Quarantine involves the voluntary or imposed confinement of potentially non-ill persons who have been exposed to an illness, regardless of whether they have contracted it. Quarantine will often happen at home, but it may happen elsewhere, such as aboard ships (maritime quarantine) or airlines (onboard quarantine). Like isolation of sick individuals, forced quarantine of exposed individuals brings with it ethical concerns, although in this case the concerns may be greater; quarantine involves restricting the movement of those who may otherwise be well, and in some cases may even cause them greater risk if they are quarantining with the sick person to whom they were exposed, such as a sick family member or roommate with whom they live. Like isolation, quarantine brings with it financial risk, because of work absenteeism.<ref name=":0" />

==== School measures and closures ====
[[File:Wikimedia Meet example using Jitsi.png|thumb|upright=0.9|[[Teleconferencing]] is a way of facilitating the NPI measure of [[remote learning]] and [[remote work]]]]
{{Main article|Distance education}}
Measures taken involving schools range from making changes to operations within schools to complete school closures. Lesser measures may involve reducing the density of students, such as by distancing desks, cancelling activities, reducing class sizes, or staggering class schedules. Sick students may be isolated from the greater student body, such as by having them stay at home or otherwise segregate them from other students.

More drastic measures include class dismissal, in which classes are cancelled but the school stays open to provide childcare to some children, and complete school closure. Both measures may be either reactive or proactive: In a reactive case, the measure takes place after an outbreak has occurred in the school; in a proactive case, the measure takes place in order to prevent spread within the community.

Closures of schools may affect the families of affected children, especially low-income families. Parents may be forced to miss work to care for their children, affecting financial stability; children may also miss out on free school meals, causing nutritional concerns. Long absences from schools because of closures can also have negative effects on students' education.<ref name=":0" />

However, in the months following the onset of the [[COVID-19]] pandemic, instead of closures, [[remote learning]] was turned to as an intervention against infection by [[SARS-CoV-2]] in the days before vaccines.<ref>{{Cite news |last=Lieberman |first=Mark |date=2020-07-22 |title=COVID-19 & Remote Learning: How to Make It Work |url=https://www.edweek.org/technology/covid-19-remote-learning-how-to-make-it-work/2020/07 |access-date=2024-07-24 |work=Education Week |language=en |issn=0277-4232}}</ref>

==== Workplace measures and closures ====
{{Main|Remote work}}
Measures taken in the workplace include: [[remote work]]; [[paid leave]]; staggering shifts such that arrival, exit, and break times are different for each employee; reduced contact; and extended weekends.

Workplace closure is a more drastic measure. The financial effect of workplace closure on both the individual and the economy can be severe. When [[remote work]] is not possible, such as in essential services, businesses may not be able to comply with guidelines. In one simulation study school closure coupled with 50% absenteeism in the workplace would have had the highest financial impact of all the scenarios studied, although some studies have found that the combination would be effective in reducing both the [[attack rate]] and the height of an epidemic.

One benefit of workplace closure is that when used in conjunction with school closures they avoid the need for parents to make childcare arrangements for children who are staying away from school.

The WHO recommends workplace closure in the case of extraordinarily severe epidemics and pandemics.<ref name=":0" />

==== Avoiding crowding ====
Avoiding crowding may involve: avoiding crowded areas such as shopping centres and transportation hubs; closing public spaces and banning large gatherings, such as sports events or religious activities; or setting a limit on small gatherings, such as limiting them to no more than a few people. There are negative consequences to the banning of gatherings; banning cultural or religious activities, for example, may prevent access to support in a time of crisis. Gatherings also allow sharing of information, which can provide comfort and reduce fear.

The WHO recommends this intervention in moderate and severe epidemics and pandemics.<ref name=":0" />

=== Travel-related measures ===
[[File:NO road sign 150.svg|thumb|upright=0.8|Travel restrictions are another type of NPI]]
==== Travel advice ====
{{Main|Travel advice}}Travel advice involves notifying potential travelers that they may be entering a zone that is affected by a disease outbreak. It allows informed decisions to be made before travel, and it increases awareness when the traveler is in the destination country. Public awareness campaigns have been used in the past for areas affected by infectious diseases such as [[Dengue virus|dengue]], [[malaria]], [[Middle East respiratory syndrome–related coronavirus|Middle East respiratory syndrome]], and [[Influenza A virus subtype H1N1|H1N1]] influenza. Although such awareness campaigns may reduce exposure among those traveling abroad, they may cause economic impact, owing to reduced travel in countries about which the advice has been issued. Overall, this intervention type is considered both feasible and acceptable.<ref name=":0" />

==== Entry and exit screening ====
Entry and exit screening involves screening travelers at [[Port of entry|ports of entry]] for symptoms of illness. Measures include: health declarations, in which travelers make a declaration that they have not recently had symptoms of illness; visual inspections of the traveler; and the use of [[non-contact thermography]], in which a device such as a [[thermographic camera]] is used to measure the traveler's body temperature, in order to determine if they have a fever. Such a method may be circumvented by the traveler through the use of [[antipyretic]]s before travel in order to reduce fever. More intensive measures such as [[molecular diagnostics]] and [[Point-of-care testing|point-of-care]] [[Rapid antigen test|rapid antigen detection tests]] may also be used, but they carry a high resource cost and may not be applicable to a large number of travelers. A substantial number of resources may be needed in order to train staff and acquire equipment.

Although there is probably no harm to the traveler by the use of this type of intervention, a limitation of it is that travelers may be asymptomatic on arrival and symptoms may not show until several days after entry, at which point they may have already exposed others to their illness. There are also ethical concerns involving invading the privacy of the traveler. Screening is considered by the WHO to be both acceptable and feasible, though they did not recommend its use in the case of influenza outbreak due to its inefficacy in identifying asymptomatic individuals.<ref name=":0" />

==== Internal travel restrictions ====
Travel within a country may be restricted in order to delay the spread of disease. Restriction of travel within a country is likely to slow the spread of disease, but not prevent it entirely. Its use would be most effective at the start of a localized and extraordinarily severe pandemic for only a short period of time. It would only be effective if the measures were strict: while a 90% restriction was projected to delay spread by one or two weeks, a 75% restriction saw no effect. An analysis of the spread of influenza in [[United States|America]] following complete airline closures due to the [[September 11 attacks]] saw reduced spread by 13 days compared with previous years.

Restricting travel brings both ethical, and in many countries, legal challenges. [[Freedom of movement]] is considered in many places to be a human right, and its restriction may have an adverse effect, particularly among vulnerable populations, such as migrant workers and those traveling to seek medical attention. Although 37% of the Member States of the WHO included internal travel restrictions as part of their pandemic preparedness plan as of 2019, some of those countries may face legal challenges in implementing them, because of their own laws. Such restrictions may also bring economic effects because of disruption in the supply chain.<ref name=":0" />

==== Border closure ====
Border closure is a measure that involves complete or severe restriction of travel across [[border]]s. This had a beneficial effect in delaying the spread of cases of influenza during the 1918 influenza pandemic, and was predicted to delay epidemic spread between [[Hong Kong]] and [[mainland China]] by 3.5 weeks. While border closure is expected to slow the spread of infection, it is not expected to reduce the duration of an epidemic. Strict border closure in island nations could be effective, although supply chain problems may cause adverse disruptions.

Supply chain problems due to border closure are likely to cause disruption of essential goods, such as food and medications, as well as serious economic effects. They may have adverse effects on the daily lives of individuals. Border closure also has serious ethical implications, because, like internal travel restrictions, it involves restricting the movements of individuals. It should only be used as a voluntary measure to the maximum extent possible. There may also be stigmatization of individuals from affected areas.

Border closure would be most feasible at the very start of a pandemic. The WHO recommended it only in extraordinary circumstances, and asked that they be notified by any nation implementing it.<ref name=":0" />

== 1918 influenza pandemic ==
{{Further|Spanish flu}}
[[File:Precaution during the Spanish Influenza Epidemic would not permit anyone to ride on the street cars without wearing a mask, Seattle, Washington (ca.1918). Original from Library of Congress. Digitally enhanced by rawpixel. (50636591896).jpg|thumb|Early use of face masks during the Spanish flu]]
Non-pharmaceutical interventions were widely adopted during the 1918 flu outbreak – most famously, the radical quarantine of [[Gunnison, Colorado]] resulted in sparing the town the worst of the earlier waves of the pandemic.<ref name="auto"/> Interventions used included the wearing of face masks, isolation, quarantine, personal hygiene, use of disinfectants, and limits on public gatherings. At the time, the science behind NPIs was new, and was not applied consistently in every area. Retroactive studies on the outbreak have shown that the measures were effective in mitigating the spread of the infection.<ref>{{Cite web|title=The 1918 Flu Pandemic: Why It Matters 100 Years Later {{!}} Blogs {{!}} CDC|url=https://blogs.cdc.gov/publichealthmatters/2018/05/1918-flu/|url-status=live|archive-url=https://web.archive.org/web/20211223010523/https://blogs.cdc.gov/publichealthmatters/2018/05/1918-flu/|archive-date=2021-12-23|access-date=2021-12-22|website=Centers for Disease Control and Infection|date=14 May 2018 |language=en-us}}</ref><ref>{{Cite journal|last1=Markel|first1=Howard|last2=Lipman|first2=Harvey B.|last3=Navarro|first3=J. Alexander|last4=Sloan|first4=Alexandra|last5=Michalsen|first5=Joseph R.|last6=Stern|first6=Alexandra Minna|last7=Cetron|first7=Martin S.|date=2007-08-08|title=Nonpharmaceutical Interventions Implemented by US Cities During the 1918-1919 Influenza Pandemic|journal=JAMA|volume=298|issue=6|pages=644–654|doi=10.1001/jama.298.6.644|pmid=17684187 |issn=0098-7484|doi-access=free}}</ref>

The use of non-pharmaceutical interventions during the 1918 flu pandemic also gave rise to new societal concerns. There was a growing awareness of "overreacting" and "under-reacting" among U.S. public health authorities, and these opposing perspectives often added to the uncertainties inherent in the epidemic. Likewise, public perceptions varied with respect to adherence to public health guidelines, giving rise to terms such as "mask slackers" and "careless consumptives."<ref>{{Cite journal |last=Tomes |first=Nancy |date=2010 |title="Destroyer and Teacher": Managing the Masses During the 1918–1919 Influenza Pandemic |journal=Public Health Reports |volume=125 |issue=Suppl 3 |pages=48–62 |doi=10.1177/00333549101250S308 |issn=0033-3549 |pmc=2862334 |pmid=20568568}}</ref>

== COVID-19 ==
{{See also|Face masks during the COVID-19 pandemic|COVID-19 lockdowns}}[[COVID-19]] is a disease caused by the [[SARS-CoV-2]] virus, which spread from China, creating a [[COVID-19 pandemic|pandemic]].<ref>Li LQ, Huang T, Wang YQ, Wang ZP, Liang Y, Huang TB, Zhang HY, Sun W, Wang Y. COVID-19 patients' clinical characteristics, discharge rate, and fatality rate of meta-analysis. J Med Virol. 92(6):577-583. 2020.</ref> Several [[COVID-19 vaccine]]s are now being used, 6.54 billion doses having been administered worldwide as of 12 October 2021.<ref>{{cite journal |title=Coronavirus (COVID-19) Vaccinations – Statistics and Research|url=https://ourworldindata.org/covid-vaccinations|access-date=12 October 2021|journal=Our World in Data|date=5 March 2020|last1=Ritchie|first1=Hannah|author1-link=Hannah Ritchie |last2=Mathieu|first2=Edouard|last3=Rodés-Guirao|first3=Lucas|last4=Appel|first4=Cameron|last5=Giattino|first5=Charlie|last6=Ortiz-Ospina|first6=Esteban|last7=Hasell|first7=Joe|last8=MacDonald|first8=Bobbie|last9=Beltekian|first9=Diana|last10=Roser|first10=Max|author10-link=Max Roser }}</ref>

In the early stages of the COVID-19 pandemic, before vaccines had been developed, NPIs were key in mitigating infections and reducing COVID-19-related mortality. Some NPIs remained in place or were reinstituted for a time after vaccine rollout.<ref>{{cite news |last1=Anon |title=Coronavirus: Israel reimposes masks amid new virus fears |work=BBC News |date=25 June 2021 |url=https://www.bbc.co.uk/news/world-middle-east-57594155 |access-date=12 October 2021}}</ref> One report identified over 500 specific NPIs for controlling transmission and spread of the [[SARS-CoV-2]] virus; most of these have been tried in practice.<ref name=autogenerated2 /> Evidence suggests that highly effective strategies include closing schools and universities,<ref name=autogenerated1>{{Cite journal|url=|doi=10.1126/science.abd9338 |issn=0036-8075|title=Inferring the effectiveness of government interventions against COVID-19|year=2021|last1=Brauner|first1=Jan M.|last2=Mindermann|first2=Sören|last3=Sharma|first3=Mrinank|last4=Johnston|first4=David|last5=Salvatier|first5=John|last6=Gavenčiak|first6=Tomáš|last7=Stephenson|first7=Anna B.|last8=Leech|first8=Gavin|last9=Altman|first9=George|last10=Mikulik|first10=Vladimir|last11=Norman|first11=Alexander John|last12=Monrad|first12=Joshua Teperowski|last13=Besiroglu|first13=Tamay|last14=Ge|first14=Hong|last15=Hartwick|first15=Meghan A.|last16=Teh|first16=Yee Whye|last17=Chindelevitch|first17=Leonid|last18=Gal|first18=Yarin|last19=Kulveit|first19=Jan|journal=Science|volume=371|issue=6531|pmid=33323424|pmc=7877495|hdl=10044/1/86864 }}</ref> banning large gatherings,<ref name=autogenerated1 /> and wearing face masks.<ref>{{Cite journal|url=|doi = 10.1001/jama.2021.1505 |issn=0098-7484|title = Effectiveness of Mask Wearing to Control Community Spread of SARS-CoV-2|year = 2021|last1 = Brooks|first1 = John T.|last2 = Butler|first2 = Jay C.|journal = JAMA|volume = 325|issue = 10|pages = 998–999|pmid = 33566056|pmc = 8892938 |s2cid = 231868838}}</ref>

=== Engineering controls ===
{{see also|Workplace hazard controls for COVID-19}}
[[File:OC Fairground HVAC vent.jpg|thumb|upright=0.9|Upgrades to [[HVAC]] systems are an example of a non-pharmaceutical intervention for the prevention of disease, and should be designed to reach at least 5 [[air changes per hour]] (12 in hospitals)]]
NPIs are still key to mitigating infections. NPIs, which include engineering controls under the [[Hierarchy of hazard controls]], do not require compliance with [[Personal protective equipment|PPE]] mandates, or require administrative changes, like lockdowns, to prevent the spread of disease ''among the general public.''
{{excerpt|Workplace hazard controls for COVID-19|General workplace guidelines|only=paragraphs|hat=0}}
==== Proposed controls ====
{{excerpt|Workplace hazard controls for COVID-19|Proposed controls|hat=0}}

== See also ==
* [[Flatten the curve]]

== References ==
<references />

== External links ==
* [https://www.cdc.gov/nonpharmaceutical-interventions/index.html Nonpharmaceutical Interventions] on [[Centers for Disease Control and Prevention]]

{{Concepts in infectious disease|state=expanded}}
{{COVID-19 pandemic}}

[[Category:Epidemiology]]
[[Category:Centers for Disease Control and Prevention]]
[[Category:Public health]]
[[Category:Medical hygiene]]