Key actions to scale back transmission of COVID-19, embody energetic case discovering, care and isolation, contact tracing, and quarantine. Acute Febrile Sickness (AFI) surveillance programs are usually used to raised perceive widespread causes of fever. They might even be successfully leveraged to observe exercise related to SARS-CoV-2 virus an infection as fever could also be a part of the medical presentation of COVID-19. As well as, AFI is an umbrella syndrome that, relying on the case definition in use, can envelop a sub-set of the surveillance inhabitants presenting with influenza-like sickness (ILI) or extreme acute respiratory an infection (SARI), two syndromes historically related to surveillance of respiratory illnesses just like COVID-19. Even in conditions the place AFI surveillance programs enroll sufferers primarily based on an undifferentiated fever (UF) with a case definition that excludes individuals with respiratory signs, there should be a chance to detect circumstances who meet the SARI or ILI case definition throughout the screening or AFI enrollment course of that happens previous to the enrollment of UF circumstances.
Goal of the doc
This doc summarizes CDC’s interim steering for the surveillance of COVID-19 and an infection with extreme acute respiratory syndrome coronavirus 2 (SARS-CoV-2) utilizing present AFI surveillance programs. The doc attracts on surveillance suggestions printed by WHO and CDC, which define case definitions for COVID-19 and accessible reporting mechanisms. It’s meant to enhance efforts to leverage present nationwide and sub-national influenza surveillance programs, notably by way of the World Influenza Surveillance and Response System (GISRS)exterior icon for environment friendly and cost-effective implementation of COVID-19 surveillance.
The combination of COVID-19 in present AFI surveillance programs is meant to:
- Complement, not change, ongoing ILI and SARI or COVID-19 surveillance actions.
- Leverage present AFI surveillance programs for environment friendly and cost-effective implementation of COVID-19 surveillance.
- Help emergency and high-priority investigations by way of the sharing of obtainable workers, materials, provides, reagents, or testing processes.
CDC doesn’t suggest the institution of latest surveillance programs throughout this public well being emergency.
Please seek advice from World Well being Groupexterior icon (WHO) and CDC web sites for additional details about COVID-19 and SARS-CoV-2. Because the COVID-19 pandemic is evolving, and WHO updates world surveillance suggestions for COVID-19exterior icon and steering for GISRS companions, CDC steering will replicate these revisions in its pointers.
Surveillance Targets when Leveraging AFI Surveillance Methods for COVID-19
The general intention is to make use of present AFI surveillance programs for epidemiological and virologic surveillance for COVID-19. Relying on the prevailing programs, a number of of the next targets will be addressed:
- Main Targets
- To watch neighborhood unfold and depth of COVID-19 exercise
- The place can we establish illness exercise?
- What’s the proportion of SARS-CoV-2 optimistic specimens from AFI circumstances assembly the SARI/ILI case definition, and is it growing or reducing over time?
- To know illness severity and spectrum of sickness
- What’s the ratio of outpatient to inpatient circumstances of COVID-19 sickness?
- To know threat components for extreme illness and transmission
- What age teams are most affected? What fraction of COVID-19 circumstances have underlying sickness or different high-risk situations?
- What threat components are related to threat of publicity (for instance, well being care practitioners)?
- To watch for modifications in virus properties
- Are SARS-CoV-2 genetic sequences or virologic traits altering in ways in which would possibly have an effect on transmission, severity, immune correlates of safety, or vaccine growth?
- To watch neighborhood unfold and depth of COVID-19 exercise
- Secondary Targets
- To evaluate the proportion of febrile sufferers with out respiratory signs who check optimistic for SARS-CoV-2 virus
- To conduct future research of sufferers with AFI, together with serologic investigations to evaluate immune response to SARS-CoV-2 an infection
- To guage new SARS-CoV-2 diagnostic or serologic exams
Testing of specimens for SARS-CoV-2 collected by way of present AFI surveillance will assist monitor the development and affect of COVID-19 sickness. This exercise is separate from, however complementary to, efforts to establish COVID-19 circumstances utilizing the individual beneath investigation or suspect case definitions utilized by CDC and WHO, respectively. Surveillance programs could also be employed for situational consciousness, public well being motion, and to know the affect of illness, in addition to for characterizing COVID-19 sickness within the inpatient and outpatient settings.
Relationship to ongoing AFI surveillance actions
Nations that conduct AFI surveillance ought to proceed to take action with out interruption or alteration to the case definition getting used to set off enrollment in surveillance and pattern assortment. No matter whether or not the system enrolls and exams sufferers utilizing a broad AFI case definition or a extra particular UF case definition, CDC suggests the mixing of SARS-CoV-2 RT-PCR testing into present laboratory testing algorithms used for AFI surveillance. The SARS-CoV-2 RT-PCR diagnostic method ought to comply with the identical biosafety, specimen administration and testing pointers as described within the CDC Steerage on integration of COVID-19 in present influenza-like sickness (ILI) or extreme acute respiratory an infection (SARI) sentinel surveillanceexterior icon and the WHO’s Operational issues for COVID-19 surveillance utilizing GISRSpdf iconexterior icon
Concerns for the Interaction between Present AFI Surveillance & SARI/ILI Surveillance
As beforehand talked about, this steering is meant to enhance ongoing efforts to leverage present ILI/SARI surveillance programs for COVID-19 surveillance. The complementary position of AFI surveillance programs on this regard could range amongst nations.
- In nations with poor or no ILI/SARI surveillance, AFI surveillance platforms could present a chance for establishing COVID-19 surveillance.
- In nations with present ILI/SARI surveillance that may successfully be leveraged for COVID-19 surveillance, AFI surveillance programs could also be equally leveraged in a complementary trend as a way to:
- Increase the protection of surveillance to geographical areas or populations not coated by ILI/SARI surveillance
- Reply totally different surveillance questions of nationwide or worldwide significance
- Present entry to extra testing gear and sources
Adaptation of Specimen Assortment Procedures in AFI Surveillance
Relying on the specifics of AFI enrollment and present pattern assortment, the variation of AFI surveillance programs for this function could take one in all three kinds:
- If NP and oropharyngeal (OP) swabs are already being collected from enrolled AFI circumstances, then this exercise ought to proceed, and these samples can type the premise of SARS-CoV-2 RT-PCR testing.
- If NP/OP swabs aren’t already being collected and the surveillance system presently enrolls and exams AFI circumstances on the premise of a broad AFI case definition1, then NP/OP swabs must be collected from the subset of enrolled AFI circumstances assembly the ILI or SARI case definitions, relying on whether or not they’re outpatients or inpatients (see Appendix 1).
- If NP/OP swabs aren’t already being collected and the surveillance system presently enrolls and exams AFI circumstances on the premise of a UF case definition that excludes individuals with respiratory signs, then applicable sufferers assembly the ILI or SARI case definitions must be recognized upstream throughout screening procedures. At that time, NP/OP swabs must be collected from people assembly the ILI or SARI case definitions.
AFI surveillance additionally permits for the opportunity of detecting SARS-CoV-2 amongst sufferers who don’t current with respiratory signs. In all eventualities laid out above, the gathering of NP/OP swabs for SARS-CoV-2 RT-PCR testing from a pattern of AFI or UF circumstances with no respiratory signs might also be thought of as a way to assess the proportion of febrile sufferers with out respiratory signs who check optimistic for SARS-CoV-2.
Steered Sampling Procedures
Testing capability could range relying upon native sources, however nations ought to think about testing a minimal of 35-50 samples per week or as much as 100 samples per week, as check kits allow. In conditions the place testing sources are restricted, there ought to ideally be an a priori allocation of check kits and different laboratory provides for surveillance actions throughout a sure time interval. On this situation, the variety of eligible samples throughout the given time interval will be divided by the variety of accessible exams, as a way to calculate a sampling interval which can be utilized to make a scientific choice of samples to check.
If SARS-CoV-2 is detected throughout an preliminary section of testing, increasing testing to a bigger pattern or to all specimens could also be thought of, as sources permit, to additional consider the frequency of detection.
Specimen Assortment, Packaging and Transport
All procedures outlined within the CDC Steerage on integration of COVID-19 in present influenza-like sickness (ILI) or extreme acute respiratory an infection (SARI) sentinel surveillance or the WHO’s Operational issues for COVID-19 surveillance utilizing GISRS must be adopted for the protected assortment, packaging and transport of NP/OP swabs collected by way of AFI surveillance programs.
WHO recommends utilizing reverse transcription polymerase chain response (RT-PCR) for laboratory affirmationexterior icon of SARS-CoV-2 in respiratory specimens. All procedures outlined within the CDC Steerage on integration of COVID-19 in present influenza-like sickness (ILI) or extreme acute respiratory an infection (SARI) sentinel surveillance or the WHO’s Operational issues for COVID-19 surveillance utilizing GISRS must be adopted for SARS-CoV-2 RT-PCR testing.
Epidemiological Knowledge Assortment
Case investigation kinds utilized in present AFI surveillance must be modified to incorporate COVID-19- particular questions. A lot of the knowledge included on the WHO COVID-19 case investigation typeexterior icon is just like that collected in present AFI surveillance. The minimal knowledge variables are outlined within the CDC Steerage on integration of COVID-19 in present influenza-like sickness (ILI) or extreme acute respiratory an infection (SARI) sentinel surveillance and WHO’s Operational issues for COVID-19 surveillance utilizing GISRS
At a minimal, knowledge ought to embody the date of symptom onset, date of well being care visits, and date of laboratory affirmation. These knowledge will assist nations characterize and monitor COVID-19 exercise over time. Crucial demographic info to know the populations at biggest threat embody age and gender, co-morbidities, being pregnant standing, and different components that will affect severity of illness. Well being standing on the time of reporting and medical course ought to embody details about admission to the intensive care unit (ICU) and the necessity for O2 and air flow. When attainable, outcomes (e.g., recovered, died) must be collected as nicely. All case report kinds ought to embody a novel case identifier, and the laboratory specimen ought to embody the identical distinctive identifier, as is commonplace observe in AFI surveillance.
Further variables particular to COVID-19 could also be added to present nation case report kinds. The place attainable, CDC doesn’t suggest creating totally different kinds for COVID-19 surveillance the place applicable kinds for AFI surveillance exist. Nonetheless, extra COVID-19-specific questions could should be administered to AFI sufferers enrolled for COVID-19 testing. As well as, there could also be a must have a full COVID-19 particular questionnaire used for sufferers the place UF circumstances are being enrolled and no knowledge is presently being collected from the sufferers with respiratory signs.
Weekly Mixture Reporting
Common mixture reporting to nationwide, regional (e.g., Africa CDC) and worldwide (e.g., WHO) ought to happen in keeping with established mechanisms. One choice for nations with SARI/ILI surveillance programs, as outlined within the CDC Steerage on integration of COVID-19 in present influenza-like sickness (ILI) or extreme acute respiratory an infection (SARI) sentinel surveillance, is to submit weekly mixture report back to WHO FluMart, as beneficial by WHO. WHO has integrated reporting for COVID-19 into the FluMart platform, and requests that GISRS companions share knowledge on testing for SARS-CoV-2. Questions relating to reporting in FluNet or FluID could also be directed to email@example.com. Different reporting channels could range relying on the nation and the reporting programs accessible.
Weekly mixture experiences ought to at minimal embody the variety of AFI specimens examined for COVID-19 and the variety of those who check optimistic by the week of pattern assortment (the numbers of specimens with detrimental and inconclusive outcomes will also be reported if accessible). Every week, it is very important monitor which specimens are being examined (e.g., all specimens from circumstances assembly the ILI/SARI case definitions, specimens from circumstances with out respiratory signs, solely influenza-negative samples, or a subset of both). The variety of specimens examined and the related outcomes will also be damaged down by case definition (e.g., ILI, SARI, others), illness severity or consequence.
Alternatives for Future Testing in AFI Surveillance
As extra is discovered about COVID-19 and new diagnostic applied sciences are developed, future alternatives for added testing of samples collected by way of AFI surveillance programs must be thought of.
The pre-existing procedures to gather blood and/or serum by way of AFI surveillance programs current a chance for serological testing, which can assist to guage the proportion of the inhabitants that has been uncovered to SARS-CoV-2 and reply different fundamental surveillance questions. Serological exams can search for the presence of particular antibodies, usually IgM or IgG, made in response to an infection. The antibodies detected by the serological check can point out whether or not PCR optimistic sufferers had an immune response to SARS-CoV-2, or if asymptomatic sufferers have antibodies indicating a previous or current an infection. If procedures aren’t already in place to take action, AFI surveillance applications considering conducting serological research sooner or later could think about biobanking blood and/or serum specimens for future use. As obligatory, present AFI protocols and affected person consent kinds must be amended to incorporate easy, versatile language that will permit for the storage and future testing of specimens.
AFI surveillance programs may additionally be used to guage novel diagnostics. These may embody serological assays, extra molecular assays, and point-of-care fast exams.
Monitoring the Implementation of those Pointers
These pointers will proceed to be refined as extra is discovered about COVID-19 and SARS-CoV-2. Monitoring their implementation and incorporating classes discovered will even be necessary on this effort. All nations implementing these pointers are requested to seek the advice of with CDC’s Epidemiology, Informatics, Surveillance, and Laboratory Department within the Division of World Well being Safety of the Heart for World Well being (POC: Olga Henao, firstname.lastname@example.org) for coordination of technical help requests and assortment of related info for monitoring implementation of actions.