As of 8/15/21, there are 20,110 cases with a second positive molecular test 90 or more days after a previous positive test, including 188 deaths (0.9%).
Thank you,
California Department of Public Health
We appreciate your patience, here is the information you requested. As always, if you need to attribute this information, please attribute to the California Department of Public Health.
QUESTION 1: Can CDPH provide an update on COVID-19 reinfection? In early June you reported 14,022 cases with a second positive molecular test 90 or more days after a previous positive test, including 171 deaths (1.21%). Do you have an update on those figures?
CDPH RESPONSE: Using a cut off of 90 days, only 0.43% of cases (16,311 out of 3,772,470 reported cases as of 7/20/21) have a reported second positive molecular test 90 or more days after a previous positive molecular test. Out of the 16,311 cases, 193 (1.18%) cases died.
Some reinfection is expected, but these data suggest that reinfection is rare. This is consistent with information from CDC When You Can be Around Others After You Had or Likely Had COVID-19 | CDC.
QUESTION 2: In March you also reported 2 confirmed cases of reinfection. Are you still tracking those? How many deaths are among the 14,022 cases?
CDPH RESPONSE: As we stated previously, the process for confirmation of reinfection based on strain differences is difficult and not scalable. There is currently no standard definition for reinfection based on other criteria. CDPH is analyzing different options and continues to find that reinfection is rarely reported. In addition, CDC is working to develop an alternative definition for reinfection.
Thank you,
California Department of Public Health, Office of Communications
www.cdph.ca.gov
www.covid19.ca.gov
Out of the 14,022 cases, there were 171 deaths (1.21%).
As we stated previously, the process for confirmation of reinfection based on strain differences is difficult and not scalable. CDPH is analyzing different options and continues to find that reinfection is rarely reported. Using a cut off of 90 days, only 0.38% of cases (14,022 out of 3,685,032 reported cases as of 5/30/21) have a reported second positive molecular test 90 or more days after a previous positive molecular test. Some reinfection is expected, but these data suggest that reinfection is rare. This is consistent with information from CDC (When You Can be Around Others After You Had or Likely Had COVID-19 | CDC).
Thank you,
California Department of Public Health, Office of Communications
www.cdph.ca.gov
www.covid19.ca.gov
The CDPH response to your question:
QUESTION 1: About a month ago, CDPH confirmed that California had 2 confirmed cases and 127 suspected cases of COVID-19 reinfection. Could you please provide an update on those figures?
CDPH RESPONSE: The numbers referred to in your previous inquiry were part of a pilot looking for reinfection based on differences in infecting strains. That effort showed that, consistent with published literature, reinfection can occur, but is rare. In addition, the pilot showed that the process for confirmation of reinfection based on strain differences is difficult and not scalable. At this time, that pilot is no longer active and CDPH is pursuing efforts to measure the number of people who have repeat positive tests at different time intervals. This approach is expected to be useful at a larger scale and more sustainable. Results from this analysis are still in development.
Additionally, wanted to make sure you saw Dr. Mark Ghaly’s discussion last Friday with the Sacramento Press Club. The link is here and Dr. Ghaly mentions breakthrough cases at about the 10-minute mark.
Thank you,
California Department of Public Health, Office of Communications
www.cdph.ca.gov
www.covid19.ca.gov
The CDPH response to your question.
QUESTION: Is there also a count for the number of suspected reinfections? For example, cases where someone tested positive with an interval of at least 90 days, or where samples from the first infection are no longer available to confirm or rule out reinfection.
CDPH RESPONSE: The California Department of Public Health (CDPH) is investigating ways to collaborate with local and state partners to leverage existing surveillance reporting tools to characterize the incidence of suspected cases of reinfection. Between September 9, 2020 and February 11, 2021, CDPH consulted on 129 cases that were reported as possible reinfections from local health departments. During that time, only two were determined to be true reinfections based on whole genome sequencing. Since that time CDPH has not confirmed any further cases of reinfection. Our data is consistent with what has been shown in the literature, which is that although reinfections are likely rare, they can occur.
Thank you,
California Department of Public Health, Office of Communications
www.cdph.ca.gov
www.covid19.ca.gov
We would like to include additional information. According to the CDC, reinfection is rare. However, it is important to remember that confirming a reinfection can be challenging, and some reinfection is expected. We urge Californians to continue to take steps to prevent the spread of disease, including people who have had COVID-19 in the past. These steps include wearing a mask when out in public, avoiding gathering especially indoors, avoiding crowds, frequent hand washing, and getting vaccinated when it’s your turn.
Sincerely,
CDPH, Office of Communications
The CDPH response to your question.
QUESTION: In January you answered a few questions about confirmed cases of COVID-19 reinfection. At the time there were only two confirmed reinfections. Have any other cases been confirmed since then or is the number still two?
CDPH RESPONSE: No additional reinfection cases have been confirmed.
Thank you,
California Department of Public Health, Office of Communications
www.cdph.ca.gov
www.covid19.ca.gov
Your patience is appreciated. Please find the CDPH response to your questions below.
QUESTION 1: When you say reinfection has been confirmed, that means samples from both episodes were subject to genomic sequencing, to rule out they were caused by the same infection?
CDPH RESPONSE: Yes, genomic sequencing of samples from both infections confirmed reinfection. Samples from both the first and the second infection were sequenced and were different strains.
QUESTION 2: I understand you cannot provide any personal details, but can you provide any of the following, non-identifying details?
1. The number of days between both episodes
2. Symptoms during the 1st episode (or a description, such as mild, moderate, or serious)
3. Symptoms during the 2nd episode (or a description)
4. Whether the two patients recovered
CDPH RESPONSE: For both cases, the time between infections was greater than four months apart. The patients had symptoms during both episodes of infection. Due to the low case counts, demographic data and clinical elements that may be used to identify individuals cannot be shared in order to protect patient privacy.
Please see the following statement in response to your questions.
The state has confirmed two cases where individuals have been reinfected with COVID-19. In order to protect patient privacy, CDPH cannot provide additional details about these situations or individuals.
Reinfection with COVID-19 is rarely reported. To date, out of more than 3 million cases, only two cases with reinfection have been confirmed in California. Nevertheless, it is important to recognize that reinfection can happen, and that everyone needs to take steps to prevent the spread of disease, including people who have had COVID-19 in the past. These steps include staying at home as much as possible, wearing a mask, avoiding gathering especially indoors, avoiding crowds, frequent hand washing, and getting vaccinated when eligible and available.
You may attribute it to:
Corey Egel
Assistant Deputy Director, Office of Communications
California Department of Public Health
Thank you.
The California Department of Public Health – Office of Communications
Please see our responses to your questions below.
Question 1: How many suspected cases have been found in California? Have any deaths been reported?
CDPH Response: The California Department of Public Health (CDPH) conducts a full review of all available clinical and diagnostic data when alerted about a possible reinfection case. Assessment of a case for reinfection requires a detailed review of all available clinical and diagnostic data. While there are a small number of cases under investigation, currently there are no confirmed cases of reinfection in California.
Question 2: Do you have a criteria to find possible reinfections (for example, is there a minimum interval or an absence of symptoms between the episodes)?
CDPH Response: CDPH uses the CDC’s Common Investigation Protocol for Investigating Suspected SARS-CoV-2 Reinfection as guidance. Detailed investigative criteria are listed in this protocol.
Question 3: Will any of the suspected cases be subject to genomic sequencing to confirm or rule out reinfection? If so, have any been confirmed to date?
CDPH Response: CDPH has been using genomic sequencing to evaluate cases of reinfection and our approach to evaluating these cases is consistent with the CDC’s Common Investigation Protocol for Investigating Suspected SARS-CoV-2 Reinfection. Please refer to this protocol for investigative criteria and laboratory guidance, including use of genomic analysis in these cases. Please see response to question #1 regarding the second question.
Question 4: Are reinfections (either confirmed or suspected) counted as new cases?
CDPH Response: At this time, CDPH is not reporting those who test positive a second time as a new case. Any repeat positive tests results are added to the patient’s initial positive incident. This methodology is consistent with the position statement and case definition for COVID-19 from the Council of State and Territorial Epidemiologists (CSTE, see https://www.cste.org/news/520707/CSTE-Interim-Position-Statement-Update-to-COVID-19-Case-Definition.htm) which cites minimal evidence for re-infection.
Sincerely,
CDPH, Office of Public Affairs