COVID-19 trends in the United States

The need to loosen and tighten restrictions may be a reality around the world for months to come.

Rendering of the 2019-nCoV virion. Dan Higgins, MAM/CDC/REUTERS

In a previous Data Insight, we highlighted key indicators to monitor as US states were beginning to reopen their economies and scale back public health and social measures (PHSM). Continuous monitoring and frequent periodic assessments of key indicators allow for data-driven, evidence-based policymaking in the effort to protect residents and resume social and economic activity during the ongoing pandemic. The need to loosen and tighten restrictions may be a reality around the world for months to come. The response to the COVID-19 pandemic is most effective when public health and economic factors are considered in concert with one another, saving both lives and livelihoods.

The pandemic has affected all of the United States, but its impact has been different in both character and magnitude from one city, state or county to the next. The prior Data Insight on resurgence focused on what we can learn by monitoring trends in mobility, surveillance of typical COVID-19 signs and symptoms (syndromic surveillance), case counts, hospitalizations and deaths in the larger context of increased testing capacity and adjusting PHSMs. We normally expect to see an increase in mobility and cases ahead of increases in hospitalizations and deaths, given the lag time that is an inherent in the progression from exposure and infection to illness and death. This lag between exposure and the reported death can be as long as four weeks. In this Data Insight, we examine five US states different geographic and epidemiological characteristics and look specifically at what their COVID-19 indicators show since the states took steps to reopen their economies.

Select states in the US and indicator trends since relaxing of PHSMs began

State Began relaxing PHSMs Mobility Syndromic New Cases Testing Test Positivity Hospitalizations Death
Arizona May 15 Up Up Up Up Up Up Stable
California May 8 Up N/A Up Up Down Up Stable
Maryland May 15 Up N/A Down Up Down Down Down
Oregon May 15 Up Stable Up Up Up Up Stable
Texas May 1 Up N/A Up Up Up Up Up


Arizona began by reopening gyms, swimming pools and spas two days ahead of the expiration of its stay-at-home order on May 15, and subsequently allowed all sectors to reopen state-wide with recommended guidelines on how to operate. Restaurants, for example, were encouraged but not required to operate with reduced capacity and told to “consider offering” masks to front-of-the-house restaurant staff. Spas and massage parlors were not required to work on a reservation-only basis, and the state’s Department of Health Services recommended for people in all sectors to maintain physical distancing to the extent possible. Since reopening, mobility in Arizona has gradually increased from over 50% below baseline to about 25% below baseline.

Arizona’s COVID-like illness (CLI) surveillance systems detected increases in both emergency department visits and hospitalizations for COVID-19 during the week of May 10, the same week lockdown was lifted in that state. They have continued to increase since, up to the most recent data available for the week of June 1, with 6.8% of inpatient hospitalizations and 5.0% of emergency department visits related to COVID-19. These indicators had been decreasing at the start of the state’s lockdown on April 1 to 4.9% and 3.8% respectively just prior to reopening, but have now increased.

When Arizona’s stay-at-home order expired, the state was seeing the highest number of new confirmed cases since the start of the pandemic. The state’s daily new cases had been rising steadily in April and May, but began rising sharply in June. As of June 21, Arizona was reporting the highest rate of new confirmed cases per 1,000 people in the country. While the overall trend in the number of tests performed daily has been increasing gradually since May, the number of cases has risen more sharply than can be accounted for by testing increases alone. Test-positivity, or proportion of tests done each day with a positive result, has continued to increase as well, staying above 15% since early June.

Although it may be too soon to see significant increases in deaths, there have been increases in hospitalizations in parts of the state. The hospitalization data reported to the state is not complete or readily available, with around half of cases missing information on hospitalization status, and a significant lag in reporting. Nevertheless, health officials state that hospitalizations may be “the best way to track COVID-19 trends,” since these numbers, “are not influenced by testing availability or by the addition of new types of tests.” In Maricopa county, hospitalizations started to increase about 10 days after the lockdown was lifted and have continued to increase up to the most recent data available. The state is also at its lowest point in terms of hospital capacity, with 83% of the state’s ICU beds in use as of June 16. As of June 19, cases were continuing to increase.

Source: Washington Post 

The overall epidemiology trends in Arizona are concerning. There is currently no statewide mandate for any PHSMs designed to reduce transmission. The only state action has been to require medical facilities to activate their emergency plans. Overall, there are no reassuring trends in the state’s numbers, and it would be reasonable to anticipate, unfortunately, rising hospitalizations and deaths in the coming weeks.


California’s stay-at-home order was issued on March 19, 2020. In early May, the state began to guide counties through a “Resilience Roadmap” in stages, with Stage 1 corresponding to the strictest restrictions as were issued during the lockdown period. Reopening allowed counties who met certain criteria to advance to Stage 2 as early as May 8, based on their hospitalization metrics, healthcare system readiness, availability of protective equipment for healthcare personnel, testing capacity, and contact tracing capability among others. In Stage 2, approved counties were allowed to gradually reopen lower-risk workplaces including certain retail, offices, manufacturing, personal services, and outdoor museums. Those maintaining public health metric requirements on June 12 were able to reopen some restaurants, zoos, gyms and theaters as part of an extended Stage 2. All vulnerable persons including those over 65 years of age have been encouraged to remain at home as much as possible until the state and its counties are in the 4th and final stage of reopening. California’s mobility remains between 35% and 40% below baseline.

Cases in California have continued to rise, without a two-week decline at any point during the pandemic. Looking more closely, however, the degree to which testing has increased has been in line with the increase in cases. Test positivity has been relatively stable since the start of the state’s phased and gradual reopening, and consistently below 5% since mid-May. Overall, the state reported more than 4,000 cases on June 17, the highest single day total. There are large differences in incidence from county to county, however, with Los Angeles County accounting for almost half of the state’s total cases.

Although in most parts of the state hospitalizations are stable or decreasing, there is an upward trend in the number of confirmed COVID-19 hospitalizations overall. In Sacramento County, a health official was quoted pointing out that some of the new hospitalizations are linked to gatherings happening in homes since reopenings, such as birthday parties and funerals. The current epidemiologic trends do not yet point to a looming significant increase in deaths, and daily deaths in the state have been trending down since late April.

Source: Washington Post 

California was judicious and purposeful in execution of its reopening plan. Nevertheless, adherence to PHSMs will be critical to maintaining the steady state it is in right now, and further protecting its public. On June 18, the Governor announced that he will be requiring residents to wear masks or face coverings in most public indoor settings, and some outdoor settings where physical distancing is not possible. Variable trends among different counties and cities will require nuanced implementation of physical distancing measures.



Maryland began reopening with Phase 1 going into effect on May 15. Governor Hogan allowed each individual county to make its own decisions about reopening and seven of its 24 counties elected to wait until either May 29 or June 1 to begin reopening. These seven counties that delayed make up two thirds of Maryland’s population and more than 80% of its COVID cases so far. Phase 1 allowed manufacturing to reopen and retail, hair salons, and houses of worship to reopen at 50%, all with health and safety precautions. Phase 2 began on June 5 and allowed non-essential businesses to open, personal services businesses at 50%; additional restrictions lifted on June 12th included indoor dining (50% capacity) and outdoor entertainment activities. Face masks remain mandatory inside retail establishments, by restaurant staff, and by both staff and customers in hair salons and other personal services businesses. As in Phase 1, not all counties entered phase 2 at the same time, with Montgomery County and Prince George’s counties near DC (the largest and hardest hit in the state) and Baltimore City, all postponing Phase 2 until June 15 or later.

Mobility is up from the height of the stay-at-home order, with foot traffic to businesses currently 28% below normal compared with 58% below in mid-April. Maryland still ranks 37th in terms of foot traffic to businesses. On a social distancing index created by the University of MD, Maryland is at a 28, the fifteenth highest in the nation, despite being a lot lower than its high of around 60 in April.

Epidemiologic trends indicate that COVID-19 has likely been declining in Maryland since before reopening. During the week of May 11, an average of 888 new cases were reported each day, and 18% of the approximately 6000 daily COVID-19 tests came back positive. By the week of June 15th, cases were down to 372 per day, with test positivity at just over 5%.

Trends in hospitalizations and deaths were similar. The week of May 11, there were an average of 1,522 people in the hospital and 50 deaths per day. By the week of June 15, hospitalizations had dropped by more than 50% to 672 and deaths to 15 per day.

While Maryland has been trending downward steadily, its daily rate of cases is still the 13th highest in the country. Similarly, while the number of tests has gone up since mid-May, its test positivity remains above 5%.

Source: Washington Post 

To date, reopening in Maryland has not changed the state’s downward trajectory in COVID-19 cases. Reopening has been cautious with localities able to opt for a slower reopening. Mandates on face masks in retail and other service settings continue, and business are expected to conform to health and safety compliance. The most populous and hardest hit counties in Maryland only began opening in late Maye or early June. With the further postponement of Phase 2 in three of the four biggest counties, it may be too soon to see increases in cases, let alone hospitalizations or deaths.



Oregon’s approach to reopening its economy has taken local factors into consideration, with counties each having to apply individually to move through three phases of reopening. Counties meeting specific criteria, including a 14-day decline in hospital admissions for COVID-19, a target for emergency department visits related to COVID, a specified testing capacity per 10,000 residents per week, and a minimum contact tracing workforce, are able to put forth an application to the state for approval to progress through reopening. Most counties were approved to enter the first phase of reopening on May 15, which allowed reduced-capacity reopening of gyms, restaurants and personal care services and permitted gatherings of up to 25 people. Most counties were also approved to progress to Phase 2 on June 5, allowing for reopening of recreational sports, entertainment venues such as bowling alleys and movie theaters, and increased capacity at some sectors opened in Phase 1. On June 12, however, the Governor placed a 7 day pause on all further reopenings due to factors discussed in more detail below.

The overall number of cases of COVID-19 has been low in Oregon, with the 11th lowest number of cases in the continental US, and 3rd lowest cases per capita. Despite its low numbers, Oregon began to see an increase in its number of cases out of proportion to its testing changes in late May, although this rise was not apparent in syndromic surveillance. The state’s test positivity has also risen, from 1.4% in late May to greater than 4% in mid-June, again showing that testing increases alone do not account for the rise in the number of cases. During this time, there has been an overall increase in the number of cases that cannot be linked or traced back to an already known case, supporting the presence of ongoing community transmission. What may add nuance to the increases seen in the state, however, is that some of the newly reported cases are associated with a relatively large cluster from a single church in Union county; as of June 16, 236 people associated with the church had tested positive. The church is reported to have held services in April and May despite limits on gatherings during this time, and to have also hosted a wedding and a graduation ceremony, each with 100 or more persons in attendance.

The number of patients hospitalized, number of patients in the ICU, and number of patients on ventilators in Oregon had all decreased steadily through the end of May, but began to rise after June 1, shortly after the increases in cases emerged. The number of daily deaths has remained low in June: between 0 and 4. The small number of cases overall in Oregon may not translate to a significant increase in death trends, particularly if safer distancing is used and efficient contact tracing is deployed to limit further spread.

Source: Washington Post 

Although the current trends in the state are concerning, Oregon is one of two states to place a pause on advancement through its reopening phases, using data for action, protecting its residents from ongoing transmission, and awaiting more reassuring trends in its COVID-19 indicators.



Texas was among the first US states to begin a phased state-wide reopening, with malls, museums, theaters, and libraries allowed to reopen at a reduced operating capacity and with additional protocols in place on May 1. At the time of initial reopening, Texas had not seen a two-or-more-week decline in cases or deaths at any point since the start of the pandemic. Incrementally, the Governor in Texas allowed for additional sectors to open and increased operating capacity for those sectors that had opened earliest. Texas also allowed for further increased operating capacity in rural areas with the lowest incidence of cases. As of June 3rd, nearly every non-essential sector in Texas had been allowed to reopen at 50% operating capacity, including in-person summer schools, outdoor stadiums and overnight recreational camps. Some sectors, including restaurants, were allowed to progress to 75% operating capacity on June 12. Mobility in Texas has returned to 20% below baseline.

Texas has also experienced an increase in its cases out of proportion to the increase in its testing capacity. Texas has been setting records for the number of new daily confirmed cases. On June 20, the state reported 4,272 new cases, almost double the number of new cases ever reported during the pandemic. The average new cases reported in mid-June were more than double the average new cases reported in mid-May, while the daily tests were only 20-30% higher comparing the same time points. Texas’ test positivity has also increased steadily since May 26, rising from around 4% to nearly 7% over three weeks. Meanwhile, the number of hospitalizations has been increasing steadily since May 26, with a new daily record for COVID-19 hospitalizations each day from June 12 to June 21.

Lagging this increase in cases and hospitalizations, the number of deaths may have also already started to increase. On June 17, Texas reported more than 40 deaths in a single day for the first time since May 27. The 7-day average for deaths has been increasing since June 12.

Source: Washington Post 

Although the governor’s initial plan was to examine epidemiologic trends prior to advancing the state through its reopening, no such action has been taken. On June 12, substantial increases in cases and case positivity were already apparent, indicating increased viral transmission. No pause or changes were made to the original schedule for reopening.


The United States has the most cases and deaths from COVID-19 in the world and has had persistently stable rates of 20,000-25,000 new confirmed cases per day since early May. The overall plateau masks large variations by state, with about half of states showing declining transmission and the other half with increasing or stable transmission as of mid-June 2020. Understanding trends at the local level is critical in the coming months to inform appropriate implementation of public health and social measures. As discussed in this Insight, multiple pieces of data and an understanding of how they fit together are needed to accurately understand the COVID-19 risk in a state or jurisdiction.

Moving forward, states and counties are more likely to be able to manage COVID-19 if they routinely monitor key indicators such as percent positivity, number of unlinked infections, and effectiveness of contact tracing. This data should be available for local (e.g. county or zip-code) levels, so that response measures can be fine-tuned and based on risk of transmission. States and counties should also use a phased approach to relaxing measures, with low-risk activities relaxed first and sufficient time between phases to assess transmission trends. Pausing or tightening measures may be warranted if the disease situation worsens, particularly if hospital capacity may become overwhelmed, but should be as targeted as possible. Common sense and scientifically proven measures to reduce transmission, including washing hands, watching your distance and wearing a mask should be standard practice at all times.

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