COVID-19 (novel coronavirus): What we know, what we don’t know, and how we can plan within our communities

March 5, 2020

Andrew Lover, MS MPH PhD Dept. of Biostatistics and Epidemiology [email protected]

School of Public Health and Health Sciences Updated Mar 7; v1.1. Overview

1. Some background 2. The virus and epidemiology 3. Response measures and community preparedness 4. Q & A

School of Public Health and Health Sciences 2 Disclaimers

All opinions in this talk are my personal views, and do not represent those of the Department of Biostatistics and Epidemiology; the School of Public Health and Health Sciences; or UMass-Amherst.

Guidance is being rapidly updated; always consult your local, state and federal authorities for the most up-to-date information. (mass.gov and cdc.gov)

General note: most/many current studies are preprints and are not yet peer reviewed; and data change hourly/daily.

School of Public Health and Health Sciences 3 Terminology

§ Coronaviruses are a small class of human pathogens; four of which cause ‘normal’ respiratory infections. § Two others may cause severe infections: SARS-CoV, and MERS-CoV. MERS-CoV § Original name (Jan 2020): Wuhan flu or novel coronavirus-2019 § Current standard (allows for expansion) § Illness: COVID-19 (“coronavirus disease”) § Virus: SARS-CoV-2 § This structure parallels HIV/AIDS

School of Public Health and Health Sciences 4 Population-level metrics

§ Endemic: The constant presence of a disease or infectious agent within a given geographic area or population group § Epidemic: The occurrence in a community or region of cases of an illness clearly in “excess of normal expectancy” (preferred) § Outbreak: An epidemic limited to localized increase in the incidence of a disease (avoid)

§ Pandemic: An epidemic occurring over a very wide area, crossing international boundaries and usually affecting a large number of people (national or global), but no specific criteria

School of Public Health and Health Sciences 5 The first signal…. (Dec 2019)

School of Public Health and Health Sciences 6 Ancient history….

Jan 23. Jan 30.

School of Public Health and Health Sciences 7 Current status § We’ve moved from a handful of infections in Central China to this, in 8-9 weeks.

Source: JHU https://gisanddata.maps.arcgis.com/apps/opsdashboard/index.html

School of Public Health and Health Sciences 8 Describing individuals

§ Susceptible: uninfected, but able to become infected if exposed § Infectious: infected and able to transmit the infection to other susceptible individuals § Immune: possessing cell-mediated or humoral antibody protection against an infection § Infected/ill/clinical case: presence of clinical signs (not synonymous with infected) § Subclinical (latent) infection: presence of infectious agent but absence of clinical disease § Carrier: implies a protracted infected state with shedding of the infectious agent. Carriers may be diseased, recovering, or healthy.

School of Public Health and Health Sciences 9 The ID Epi Iceberg (why is surveillance difficult?)

Symptoms Data quality

- Generally good - Severe Clinical - Moderate disease - Generally good

- Mild? Subclinical - Moderate to poor disease

- Poor without - None? specific studies

- None. - Very poor

School of Public Health and Health Sciences 10 The epidemiological triad

§ A dynamic system, with many modifiable components.

Human host • Age and sex • Behavior • Nutritional status • Health status Agent Environment

• Infectivity • Weather • Pathogenicity • Housing • Virulence • Geography • Immunogenicity • Occupational setting • Antigenic stability • Political situation • Survival • Infrastructure

School of Public Health and Health Sciences 11 Quantifying infections

How fast? Attack rate -----> (number with clinical illness / number exposed) x 100

How serious? Case fatality ratio (ability to cause death in clinical cases) -----> (number of deaths / number with clinical disease) x 100

Infection fatality ratio (ability to cause death in all infections) -----> (number of deaths / number infected) x 100

School of Public Health and Health Sciences 12 Reproductive number R0

The basic reproductive number, R0, the mean number of individuals directly infected by an infectious case through the total infectious period, when introduced into a fully susceptible population.

probability of transmission per contact

R0 = p • c • d duration of infectiousness

contacts per unit time

Infections will….. disappear, if R < 1 become endemic, if R ~ 1 become epidemic, if R > 1

School of Public Health and Health Sciences 13 Reproductive number R0- II

§ Useful summary statistic, but context-specific, and modifiable. § Some examples: Seasonal influenza: ~ 1.2 EBV disease: ~ 2.2 (2014) COVID-19: 2.3; 1.2-3.5; & others. Measles: 7.7 to 18 (various studies)

COVID-19: https://www.ncbi.nlm.nih.gov/pubmed/32097725

School of Public Health and Health Sciences 14 COVID-19 Epidemiology

School of Public Health and Health Sciences 15 Is it “Just the flu”?

COVID-19 Seasonal influenza § No one has any immunity. § High levels of diverse partial § Case fatality rate estimates: immunity in the community. 1.0 to 2.5% (?). § Case fatality rate: 0.1%. § Many severe cases requiring § Some severe cases (ca. 1.1% critical care (20-25%). for current season). § No vaccine; no antivirals. § Annual vaccine; multiple § Novel pathogen, with no antiviral regimens. clinical or epidemiological § Well-studied pathogens, with evidence-base. decades of clinical and epidemiological guidance. Updated Mar 7: source https://www.cdc.gov/flu/about/burden/preliminary-in-season-estimates.htm

School of Public Health and Health Sciences 16 Model-based estimates (LSHTM)

§ Reporting systems and data completeness varies, so biases are probable. https://cmmid.github.io/

School of Public Health and Health Sciences 17 Most comprehensive data to date

School of Public Health and Health Sciences 18 Case demographics

§ From WHO-China Joint report, based on 55,924 laboratory-confirmed cases:

§ Age: median 51 years (range: 2 days-100 years old). § Vast majority of cases (77.8%) between 30–69 years. § 51.1% are male. § 21.6% are farmers or laborers.

School of Public Health and Health Sciences 19 Joint Mission report- Case fatality ratio Cases of Daily Number Number

WHO-China Joint Mission report Feb 2020 Days Since First Case https://reliefweb.int/report/china/report-who-china-joint-mission-coronavirus-disease-2019-covid-19

School of Public Health and Health Sciences 20 Joint Mission report- spectrum of illness Cases of Daily Number Number

WHO-China Joint MissionDays Since report First FebCase 2020 https://reliefweb.int/report/china/report-who-china-joint-mission-coronavirus-disease-2019-covid-19

School of Public Health and Health Sciences 21 COVID-19 Symptoms

§ From WHO-China Joint mission report, based on 55,924 laboratory-confirmed cases:

§ Reported symptoms (all non-specific): fever (87.9%), dry cough (67.7%), fatigue (38.1%), sputum production (33.4%), shortness of breath (18.6%), sore throat (13.9%), headache (13.6%), myalgia or arthralgia (14.8%), chills (11.4%), nausea or vomiting (5.0%), nasal congestion (4.8%), diarrhea (3.7%), bloody sputum (0.9%), and conjunctival congestion (0.8%).

§ Symptom onset: mean of 5-6 days after reported exposure (range 1-14 days).

School of Public Health and Health Sciences 22 China CDC; (JAMA, 2020) Cases of Daily Number Number

Days Since First Case

School of Public Health and Health Sciences 23 Droplets versus airborne transmission

Droplets “Airborne spread has not been reported for COVID-19 and it is not Aerosol believed to be a major driver of transmission based on available evidence…”

WHO-China Joint Mission report Feb 2020 Close contact/ droplet range: ~ 6 ft.

Image: https://bmcinfectdis.biomedcentral.com/articles/10.1186/s12879-019-3707-y

School of Public Health and Health Sciences 24 What we don’t know

§ R0 in dense urban settings outside of Asia. § CFR with all outcomes measured. § CFR in weak health systems with limited critical care facilities. § Size of the asymptomatic/subclincial populations. § Basis and implications of low infections in children. § Potential for reinfection. § Clinical predictors of severity (triage) and optimal treatment protocols. § Potential for long-term impacts (sequelae).

School of Public Health and Health Sciences 25 Community measures- a.k.a things you can do right now

School of Public Health and Health Sciences 26 Every epidemic is unique

§ The global and national evidence-base for planning and response is based on influenza and not COVID-19.

§ Seasonal influenza ≠ influenza pandemic § SARS/COVID-19 ≠ influenza pandemic

§ However, there are important lessons and commonalities.

School of Public Health and Health Sciences 27 General response options

Transmission interventions • Infection control Non- Contact interventions pharmaceutical • Social distancing interventions (NPIs) • Quarantine/isolation • Closure of schools/business etc. ------Vaccines • Longer-term Antiviral drugs • Several COVID-19 studies underway

School of Public Health and Health Sciences 28 Flattening the epicurve

https://preventepidemics.org/coronavirus/?=undefined

School of Public Health and Health Sciences 29 Step-by-step layers of preparation

1. Normal things we all should (but maybe don’t) do during flu season (“Rules from preschool”)

2. Simple planning and discussions in your household and neighborhood (EASY)

3. Think and strategize for potential longer-term impacts (Slightly less easy)

Days Since First Case

School of Public Health and Health Sciences 30 Goals of community measures/NPIs

1. Delay onset 2. Reduce peak burden on health sector/ infrastructure 3. Decrease total cases, mortality and overall health impacts.

https://www.cdc.gov/flu/pandemic-resources/national-strategy/severity-assessment- framework.html Days Since First Case

School of Public Health and Health Sciences 31 Interim CDC guidance (Mar. 3)

(Now------> “Rules from preschool”)

Before a COVID-19 outbreak occurs in your community- Plan During a COVID-19 outbreak in your community- Act After a COVID-19 outbreak in your community- Follow Up

https://www.cdc.gov/coronavirus/2019-ncov/community/index.html

School of Public Health and Health Sciences 32 Rules from preschool

§ Wash your hands (often and well) § Always use a tissue (or your sleeve) when sneezing/coughing § Avoid touching your face § Don’t share utensils, water bottles, etc. § Stay home if you’re sick § Wipe down/disinfect common surfaces § Keep a distance from people who are sick § Avoid handshakes and close contact where possible

Adapted from https://www.cdc.gov/coronavirus/2019- ncov/community/index.html

School of Public Health and Health Sciences 33 The details- hand hygiene

§ Steps are here -----> § And sing! Seriously.

Wet Soap Scrub § Use lots of soap, and wash longer than you think. § Soap and water are best, Rinse Dry Turn the but if not available, use Water OOfff

alcohol-based gel (60% on How long should I As long as it the label). wash? takes to sing your ABC’s! Special thanks to the Tacoma-Pierce County Health Department - Food and Community Safety Program, Tacoma WA County Health Department - Food and Community Safety Program, Tacoma Special thanks to the Tacoma-Pierce

https://www.cdc.gov/handwashing/when-how-handwashing.html

School of Public Health and Health Sciences 34 The details

§ Wash them: § After eating § After using the bathroom § After sneezing or coughing § Whenever they’re dirty

https://www.cdc.gov/handwashing/when-how-handwashing.html

School of Public Health and Health Sciences 35 Infection control- facemasks

§ There are two types of masks

• Surgical masks trap droplets (helping others if you are sick).

• N95 masks can decrease exposure with proper fit (if others are sick in close proximity).

School of Public Health and Health Sciences 36 Infection control- facemasks

§ Stockpiling may cause shortages that directly impact front-line health staff, putting entire communities at risk.

https://www.cdc.gov/coronavirus/2019-ncov/about/prevention- treatment.html (March 3)

School of Public Health and Health Sciences 37 CDC: near-term planning

§ Talk to the people who need to be in your plan. (today) § Consider some extra groceries; and any essential medicines. § Plan to help anyone at risk for serious complications (elderly, immunosuppressed, lung disease, etc.). § Create an emergency contact list, including local response. § Get a flu buddy (‘pandemic pal’) especially if you live by yourself. In the event of local transmission ------> Call each other daily; and if anyone is sick- twice daily, and have an agreed-upon plan for food/medicine etc.

Adapted from: https://www.cdc.gov/coronavirus/2019-ncov/community/home/get-your-household-ready-for-COVID-19.html https://www.cdc.gov/nonpharmaceutical-interventions/pdf/gr-pan-flu-com-faith-org-serv-vul-pop.pdf (2017)

School of Public Health and Health Sciences 38 CDC: in the event of local transmission

§ Stay home from school/work if sick; limit close contacts. § Put your household plan into action. § Continue all the preschool rules. § Use a separate bathroom and bedroom for sick household members where possible. § Inform school/workplace of changes in schedule. § Plan for disruptions in childcare and school schedules. § Call your flu buddy. § Stay informed & take care of everyone’s emotional health.

Adapted from: https://www.cdc.gov/coronavirus/2019-ncov/community/home/get-your-household-ready-for-COVID-19.html https://www.cdc.gov/nonpharmaceutical-interventions/pdf/gr-pan-flu-com-faith-org-serv-vul-pop.pdf

School of Public Health and Health Sciences 39 How well does it work? (Joint Mission Report)

1. Epi investigations; viral isolation; and diagnostic development

2. Mandated reporting; fever. checks; 3. Case cluster detection; isolation and quarantine; traffic restrictions; developing evidence- public messaging; plus aggressive case based interventions; finding and contact tracing. mitigating impacts.

School of Public Health and Health Sciences 40 Longer-term considerations

School of Public Health and Health Sciences 41 Definitions

§ Isolation § Separation of persons with symptoms § Often in hospital settings § Applied at individual-level

§ Quarantine § Restricted movement of persons with possible or presumed exposure § Applied at the individual or community-level § May be voluntary or mandatory

School of Public Health and Health Sciences 42 Potential impacts on healthcare systems

§ Potential for staffing and bed shortages (especially if there is nosocomial transmission). § Shortages of key supplies and equipment; masks, anti-viral drugs (if available), ventilators. § Vaccine development is always uncertain, and bottlenecks are possible (8-10 months). § If there is widespread transmission, people may be taken care of at home by family members.

School of Public Health and Health Sciences 43 Potential social distancing measures

§ Alternative to quarantine: “reverse quarantine” § aka “shelter in place” or “snow days” § Persons (presumably) not exposed remove themselves from the general population § Sharply decreases the frequency of contacts and mixing § May be aimed at work, community, or school settings

School of Public Health and Health Sciences 44 Constantly updated resources UMass https://www.umass.edu/coronavirus

Mass DPH https://www.mass.gov/resource/information-on-the- outbreak-of-coronavirus-disease-2019-covid-19

US CDC https://www.cdc.gov/coronavirus/2019-nCoV/summary.html

WHO https://www.who.int/emergencies/diseases/novel- coronavirus-2019/advice-for-public

School of Public Health and Health Sciences 45 Q and A session

School of Public Health and Health Sciences 46