COVID-19 Alaska Weekly Case Update: Sept. 13 -19, 2020

COVID-19 Weekly Case Update

 

Alaska Department of Health and Social Services Weekly Case Analysis
September 13-19, 2020

 

Case trends and predictions

  • Overall, new cases in Alaska are increasing. The daily state case rate as of September 19 is 10.2 cases per 100,000 people averaged over the last 14 days, so the state alert level is now high. This is up from 8.7 last week and 7.9 the week before.
  • The reproductive number, a measure of contagion, is currently estimated to be approximately 1. A reproductive number of 1 means that each person who is diagnosed with COVID-19 gives it on average to one other person. A reproductive number of more than 1 means that the epidemic is growing, and the goal is to have enough people wear masks, stay at least 6 feet from others, and stay home and get tested when they are sick that Alaska’s reproductive number decreases to well below 1. Our reproductive number was below 1 as recently as late August. 
  • An updated model epidemic curve predicts Alaska’s cases will continue to rise over the next week. Until two weeks ago, cases had been predicted to decrease. One week ago, cases were now expected to double every 62 days, with a daily projected growth rate of 1.12%. This projection has improved slightly, with cases now expected to double around every 190 days, with a daily projected growth rate of 0.37%.  
  • Nonresident cases, which peaked in late July, decreased over August and continue to downtrend. 
  • Data for COVID-19 in Alaska healthcare workers are now available, although limited as not all cases have an occupation reported. About half of the 260 cases reported in healthcare workers may have been acquired at work; others were related to travel, household or community exposure. 8 hospitalizations among healthcare workers are reported and no deaths.  

  • Alaska continues to have both the fewest COVID-19 related deaths and the fewest COVID-19 related deaths per capita of any US state.

 

Regional trends

  • Juneau City and Borough now has the highest rate of viral transmission, having increased its rate to 16.3, continuing the rise from 13.4 last week and 6.3 the week before.
  • Fairbanks North Star Borough has the second highest rate of viral transmission with a case rate of 15.9, a slight decrease from 17.1 the week before. 
  • The Northwest Region had the steepest increase this week among communities with high transmission, with a rate now at 15.6 from 10.7 the previous week. 
  • Anchorage Municipality remains in the high transmission category and has again improved slightly from last week. 
  • The Y-K Delta region increased from 6.0 to 8.4, remaining within the intermediate zone.
  • The Interior Region, Mat-Su and Northern Southeast Region also saw increases this week. 
  • Other regions’ case rates downtrended this week.

 

Regional case trends

Behavioral Health Region

Average new cases Aug 16 - 29

Average new cases Aug 23- Sept 5

Average new cases  Aug 30- Sept 12

Average new cases Sept 5- Sept 19

Anchorage Municipality

12.6

14.1

13.5

13.2

Fairbanks North Star Borough

10.8

13.7

17.1

15.9

Interior Region except Fairbanks North Star Borough

7.9

4.3

2.7

3.1

Juneau City and Borough

5.1

6.3

13.4

16.3

Kenai Peninsula Borough

5.8

2.9

2.2

1.8

Matanuska-Susitna Region

6.2

4.9

4.3

4.7

Northern Southeast Region

6.3

5.2

2.1

3.1

Northwest Region

12.7

11.0

10.7

15.6

Southern Southeast Region

6.1

5.2

2.5

Insufficient data; low case rate

Southwest Region

1.7

2.3

4.2

3.5

Yukon-Kuskokwim Delta Region

7.3

7.6

6.0 

8.4

Statewide

7.0

7.9

8.7

10.2

 

 

New cases, hospitalizations and deaths

  • This week saw 558 new cases in Alaskans, an increase from last week’s 513 new cases, for a total of 6,836 cumulative cases in Alaskans. 4,610 of those are considered active, or 67%, an increase from 65% last week, as 2,226 Alaskans are thought to have recovered or completed their isolation period. Data on recovery lags data on new cases and may not be up to date. 
  • Cumulative hospitalizations increased to 262 with 16 new this week, slightly more than the increase of 14 last week.
  • Deaths among Alaska residents increased by 1 to 45 total. 
  • There were 16 nonresident cases identified this week, for a total of 931.  

How COVID-19 spreads in Alaska

  • The majority of new infections among Alaskans are from community spread, not from travel. Most Alaskans get the virus from someone they work, socialize, or go to school with.
  • Many cases do not have a clear source, meaning that contact tracers have not been able to identify where the person got the virus. This could mean that there are cases in our communities that we do not know about. 
  • Many Alaskans who are diagnosed with COVID-19 report that they went to social gatherings, community events, church services and other social venues while they were contagious but before they knew they had the virus.
  • The distribution of cases among people of different races and ethnicities has not changed significantly since last week.
  • Cases continue to increase most rapidly in young adult Alaskans, especially those aged 20-29. 

 

 

Distribution of cases compared to population distribution and distribution of cases, hospitalizations and deaths by race and ethnicity

Includes data from all cases reporting one or more races. Based on these data, American Indian and Alaska Native as well as Native Hawaiian and Pacific Islander populations are disproportionately affected. One factor limiting interpretation is that a greater proportion of tests from the Alaska Native Tribal Health system currently have race indicated than tests from other sources, which may mean that cases in Alaska Native People are more likely to be reported as such than cases in people who receive care through non-tribal health systems. However, this should not significantly impact Native Hawaiian and Pacific Islander population case counts. Currently, cases in this population are nearly five times what would be expected based on estimated population (6.8% vs 1.4%). 

 

If race or ethnicity is not identified with the initial test, contact tracers will attempt to collect this information, but these data are often delayed resulting in many cases (currently 3,072, or 45%) still labeled under investigation or unknown. Additionally, people who are hospitalized or have died with COVID-19 are more likely to have a race identified.

 

Race 

Percent of Alaska population*

Number of cases

Percent of cases of those for whom a race is known

In cases of that race/ethnicity, percent who were/are hospitalized

In cases of that race or ethnicity, percent who have died

American Indian and Alaska Native

15.6%

1205

32%

6.6% 

1.3% 

Asian

6.5%

157

4.2%

9.6% 

1.9% 

Black/African American

3.7%

225

6.0%

3.6% 

0.4%

Hispanic ethnicity**

7.3%

317

12.0%***

4.1%

0.3%

Multiple races

7.5%

241

6.4%

2.19%

0%

Native Hawaiian and Pacific Islander

1.4%

257

6.8%

16.7% 

1.9% 

White

65.3%

1,477

39.0%

4.9%

1.2%

Other

 

202

 

3.5% 

0%

Unknown or not yet identified

 

3,072

 

1.0% 

0.1%

All cases for which a race is known

 

3,764

 

6.1%

1.1%

All cases

 

6,836

 

3.8% 

0.7%

*Based on US Census Bureau 2019 estimates: https://www.census.gov/quickfacts/AK

**By federal convention, ethnicity is not mutually exclusive of race, so cases identifying Hispanic ethnicity are also counted under a race category.  

***Reports the percent of cases of those for whom an ethnicity is known.

 

Testing trends

  • Testing increased at a steady rate throughout May, June and July, but starting in mid-August, increases have slowed.
  • Alaska has the capacity to continue expanding testing. DHSS can assist in materials for setting up new testing sites and is pursuing all avenues for expanding testing. 

 

 

Positivity rates

  • The statewide test positivity rate, calculated by dividing the number of positive tests by the total number of tests performed over a given period of time, averaged over the past seven days, increased from 2% to 2.3% over this last week. Statewide test positivity has not been above 3% since April, and has never exceeded 3.5%. 
  • This is significantly better than the current national average test positivity rate of 4.6%. In comparison to other states, Alabama currently has a positivity rate of 14.2% and South Dakota, 16.6%, while New York, which peaked at 50.7% in early April, has greatly expanded testing since then and currently has a positivity rate of 0.9%. Source: Johns Hopkins
  • Of boroughs or census areas in the high risk zone, the reported test positivity rate is currently highest in the Fairbanks North Star Borough, with a rate of 4.8%, improved from 5.3% last week. The North Slope Borough has a positivity rate of 3.5%, and the Juneau City and Borough’s positivity rate is 1.6%. 
  • Test positivity is a good measure of whether testing is adequate in a given area, since it is affected by the number of tests performed as well as the number of new cases in an area. However, because it depends so much on the number of tests performed, it tells us more about whether we are doing enough testing than about how much virus is spreading in a community. It is also affected by any delays in reporting, since positive tests are sometimes reported faster than negative tests. For example, one region currently has a reported 100% test positivity rate- but only reported one test total in the last week, so this likely represents a lag in test reporting rather than a very high positivity rate. A case rate can give good information about how much virus is spreading in a community, as long as the test positivity is low, so these measures can work together to help us understand the spread of virus in a community. A community test positivity rate under 5% is currently generally accepted as being low enough to estimate that a community’s case rate is reasonably accurate.  
  • In late August, Alaska led the nation in most tests per capita and continues to be among the top 3 states in tests per capita. 

 

COVID-19 in Alaska healthcare workers

  • 260 cases of COVID-19 were reported in Alaskans working in healthcare. These data are limited because occupation is not always known. 
  • Of these, 51% likely were exposed to the virus at work, while 29% acquired the virus because of a contact within their household or through community spread, and 3% acquired the virus through out of state travel. The remaining 17% did not have a known exposure that could be determined. 
  • Healthcare workers included in these data are physicians, nurses, pharmacists, dentists, nursing aides, EMTs, first responders, behavioral health professionals, and others working in inpatient and outpatient health care. 29% of the 260 cases reported did not have an occupation specified and listed only healthcare. Of the 260 healthcare workers with COVID-19, approximately 20% worked in a hospital, 23% in a long term care, rehab or assisted living facility, 13% in outpatient medicine, dentistry or therapies, 14% in another setting and 30% did not have a work site specified. 
  • Of the 260 cases in healthcare workers identified, 8 required hospitalization. There were no deaths reported. 

 

Health care capacity

  • Hospital bed occupancy statewide remains steady. Hospitalizations peaked in early August and have plateaued since then. Ventilator capacity remains adequate overall, although the number of patients with confirmed or suspected COVID-19 who are requiring ventilators increased to 13. Hospital data includes inpatient beds and ventilators located all around the state, including some in smaller hospitals without ICU capacity. Hospital beds do not necessarily represent staffed beds, as staffing can change quickly, particularly if a community has many health workers impacted by COVID-19. 

What Alaskans should do 

  • Anyone with even one new symptom of COVID-19 (fever, chills, cough, shortness of breath, difficulty breathing, fatigue, muscle aches, body aches, headache, new loss of taste or smell, sore throat, congestion, runny nose, nausea, vomiting, or diarrhea), even if it is very mild, should get tested for COVID-19 right away. Tests are most accurate in the first few days of symptoms, and if the test is positive, getting tested right away helps contact tracers move as quickly as possible. 
  • Alaskans can help contact tracers work to slow the spread of COVID-19 by answering the phone promptly if contacted and providing accurate information.
  • Alaskans should avoid gatherings, wear masks when around any non-household member, keep six feet of distance from anyone not in their household and wash hands frequently to slow community transmission of COVID-19.

Further information