On 24 July, the Croatian Institute of Public Health revised its recommendations on priorities for SARS-CoV-2 testing as well as the procedure regarding close contacts of patients with COVID-19.
1. Procedure with close contacts of a COVID-19 patient
In order to reduce the spread of infection, the aim is to place all close contacts of the patient under medical supervision in quarantine/self-isolation.
Beginning of 14-day quarantine and exceptions in testing:
Close contacts do not need to be tested either at the beginning or during quarantine/self-isolation, unless they develop symptoms of the disease. There is one exception: at the beginning of quarantine/self-isolation, if close contacts of COVID-19 patients have been identified as close contacts three or more days after exposure to the patient and have in the meantime made contact with vulnerable groups, then should be tested.
End of 14 days quarantine and testing:
Upon completion of the 14-day quarantine, if people have not developed symptoms testing is not required unless they are health care workers, staff in nursing homes or any other institution within social welfare system.
If a person in quarantine/self-isolation develops symptoms of a disease compatible with COVID-19, they should be tested for SARS-CoV-2 and, if positive, proceed as a newly infected person.
2. Priority groups for testing are:
a. Symptomatic people who, due primarily to their occupation, have a high potential for spreading the disease to vulnerable groups (healthcare professionals and hospitalized patients, residents and employees of nursing homes)
b. Symptomatic people who, due to their characteristics, have a high potential for infecting a large number of people with a risk of rapid spread of infection and cluster formation (prisoners and prison staff, refugees and asylum seekers, homeless people, members of ethnic/cultural groups)
c. Symptomatic people at increased risk of severe disease and complications: people aged 65 and over, people with chronic diseases
d. Symptomatic persons in cases where a grouping of respiratory diseases is noticed in a health institution, which cannot be interpreted by any other etiology.
e. Health and other professionals at increased risk of spreading the infection among vulnerable groups with confirmed COVID-19 disease for the purpose of confirming their cure and the possibility of returning to work.
f. People who report to the health care system with symptoms of a disease compatible with COVID-19, which cannot be explained by another etiology.
As of August 10, there were 22 test sites in the Republic of Croatia performing RT-PCR analysis of collected samples of COVID-19. All processed samples are entered into a national platform at the Croatian Health Insurance Fund, and this is available to all county public health institutes. County public health institutes submit data on positive cases, sources of infection and hotspots as part of their daily reports to the Croatian Public Health Institute. The Croatian Institute of Public Health also collects information on hotspots, hospital treatment of COVID-19, COVID-19 patients on respirators, and on deaths.
As of September 21, 22 test centers are available in the Republic of Croatia (more information can be found at the following link: https://www.koronavirus.hr/svi-testni-centri-u-republici-hrvatskoj/763)
As of September 21, the Croatian Institute of Public Health had revised their COVID-19 recommendations on SARS-CoV-2 testing priorities, contact monitoring, the end of isolation and self-isolation process. The changes compared to earlier versions are as follows:
• release from isolation is based primarily on the clinical picture and exceptionally on the basis of negative PCR findings;
• isolation of an asymptomatic PCR-positive patient is shortened from 14 to 10 days after taking a swab that is PCR-positive (except in immunocompromised individuals);
• isolation of a patient with a mild or moderate clinical picture is shortened from a minimum of 14 to a minimum of 10 days from the onset of the disease (except in immunocompromised individuals);
• Isolation of a patient with a severe clinical picture (treatment requiring intensive care) or an immunocompromised patient (e.g. patients with chemotherapy malignancies, people receiving high doses of corticosteroids / immunosuppressive drugs due to their underlying diagnosis) regardless of the severity of the clinical picture lasts at least 20 days
• at the end of isolation, health professionals no longer need to have a negative PCR result of a swab before returning to work (except in immunocompromised individuals);
• upon completion of the quarantine for health professionals and social service providers, it is no longer necessary to have a negative PCR result of a swab before returning to work (except for immunocompromised persons);
• if a person has had laboratory-confirmed COVID-19 disease in the last three months, she or he does not need to be tested for COVID 19 if there are no clear symptoms of the disease.
• all measures relating to health professionals and employees of social service providers, apply equally to students who practice in these institutions and to any parents who reside with their child in the hospital
As of September 28, 24 test centers were available in the Republic of Croatia, representing an increase of 2 centers from the previous week. More information on all national test centers can be found at: https://www.koronavirus.hr/svi-testni-centri-u-republici-hrvatskoj/763
On October 26, the Croatian Institute of Public Health revised its recommendations on SARS-CoV-2 testing priorities, contact monitoring, the end of isolation and self-isolation process. The changes compared to earlier versions are as follows:
• The self-isolation of a person who was in close contact with a person infected with COVID-19 is shortened from 14 to 10 days. Exceptions are persons working in institutions for accommodation and stay for the elderly and seriously ill persons and persons with disabilities, in which the quarantine lasts 14 days.
• Criteria for termination of isolation were divided into four categories of patients: patients with mild or moderate clinical picture, patients with severe clinical picture, patients who were immunocompromised and asymptomatic patients with COVID-19.
• The clinical criterion for termination of isolation of a symptomatic patient is a minimum of three consecutive days without fever without the use of antipyretics and a significant improvement in other symptoms.
There are currently 28 test sites in Croatia performing RT-PCR analysis of collected samples of COVID-19. All processed samples are entered into a national platform at the Croatian Health Insurance Fund, and this information is available to all county public health institutes. A new method of testing using rapid antigen tests is being applied in several cities and counties.
Rapid antigen tests are used to diagnose symptomatic individuals in the first five days of illness. If the rapid antigen test is negative within five days of the onset of symptoms, or more than five days have passed since the onset of symptoms, the patient should be tested by using the PCR method. Due to lower sensitivity, this new testing method is not used to exclude COVID-19 disease. A negative result of a rapid antigen test should be confirmed by PCR to rule out false-negative findings.
Different types of tests
In Croatia, PCR tests, antigen rapid tests and serological tests are being used.
With the aim of faster detection and isolation of patients and their contacts, rapid antigen tests are a useful tool because they allow greater testing availability and faster results in conditions when PCR testing capacities as the gold standard of COVID-19 diagnostics are overloaded. They should be used within five days of the onset of the disease. In a situation of widespread circulation of the virus in the population, the positive predictive value of the rapid antigen test is high. Therefore, a positive test result in a person who meets the clinical and epidemiological criteria for COVID-19 is considered sufficient to confirm the diagnosis of the disease.
A negative result of a rapid antigen test must be confirmed by a repeated rapid test after two days or a PCR test performed immediately. Until the results of a repeated rapid test or PCR test arrive, the person should be treated as a probable COVID-19 patient, and their close contacts remain quarantined.
A rapid antigen test can be used in the following situations:
• persons in quarantine / self-isolation who have developed symptoms of a disease compatible with COVID-19
• persons at risk of developing a severe illness and vulnerable groups requiring hospitalization and / or intensive care.
• health professionals regardless of epidemiological history (ie whether they have been in contact with someone who has COVID-19 in order to protect health workers and reduce the risk of nosocomial spread)
• a person who is detected as the first patient with clinical symptoms / signs and is part of a collective (eg school, social care institution, prisons, hospitals) in order to identify the grouping as quickly as possible and stop the spread of the disease.
Rapid tests (e.g. self-administration by students supported by volunteers, etc.) outside health care facilities (e.g. pharmacies, companies, universities, schools, etc.)
When conducting extensive testing with the aim of identifying and isolating infected people in the asymptomatic population, collectives such as schools, companies, military collectives, prisons, homes for the elderly are observed as separate entities.
In such collectives, it is advisable to first test all members of the collective who have symptoms with a rapid antigen test. If more than 10% are positive among those tested with symptoms, the test result can be considered as a confirmation of the disease. In this case, negatives with symptoms should be retested by rapid test after two days or immediately by PCR test, and it is also recommended to test asymptomatic members of the collective by rapid test.
It should be emphasized that each specific situation requires an individual epidemiological assessment and that treatment may differ from the recommendations if there is a medical justification.
Integration of results in the overall information system if rapid tests are performed outside health facilities
Institutions that provide health care through the Croatian Health Insurance Fund have the ability to enter positive and negative results of antigen rapid tests. The results are then being reported to the Croatian Institute of Public Health.
At the national level, the results of PCR tests are primarily being recorded. Currently, there is no systematic solution for monitoring antigen rapid tests.
If the results of the rapid antigen test are positive, the same procedure is performed as for the PCR test. In the case of a positive finding, the infected person remains in isolation until meeting the criteria for ending the isolation, and its close contacts remain in quarantine.
Genetic sequencing of SARS-COV-2 from confirmed cases
As part of the cooperation with ECDC, it was agreed that 10% of random PCR positive samples collected at the level of the Republic of Croatia are sent for sequencing to Germany every 7-10 days.
This method of sequencing is planned until the beginning of April, after which the state will have to find a solution at the national level.
On 26 March 2021, the Croatian Institute of Public Health revised its recommendations on SARS-CoV-2 testing priorities, contact monitoring, and the end of isolation and self-isolation processes for the people who had recovered from COVID-19 or have been vaccinated. The changes compared to earlier versions are as follows:
• The exemption from the need for testing and quarantine after recovery from the disease or vaccination is extended from three to six months.
• The so-called British variant of SARS-CoV-2 has been removed from the list of variants for which the duration of quarantine is 14 days and mandatory testing upon completion of quarantine.
RT_PCR is considered as the “gold standard” of testing. As of April 2021, Croatia has updated its testing strategy to include rapid antigen testing as a diagnostic method, in response to a deteriorating epidemiological situation and limited RT-PCR testing capacities.
Testing is performed in the following situations:
• Suspected COVID-19 infection: people with clinical and / or epidemiological indication (according to ECDC definition)
• In certain cases asymptomatic people (close contacts of COVID-19 patients)
• In certain cases, people at the end of self-isolation and isolation (treatment) - for example, healthcare professionals before returning to work (negative finding is a condition for returning to work)
• In certain cases, people in nursing homes (mostly healthcare professionals)
A suspected case of COVID-19 infection is considered to be when the following criteria are met:
o Acute respiratory infection symptoms that occur in patients who have visited countries 14 days prior to symptom development
o Respiratory infection symptoms in patients that were in close contact with a probable or confirmed case 14 days prior to the symptoms
o Severe acute respiratory infection requiring hospitalization
Testing can be performed at the request of elected primary care physicians, epidemiologists or hospital clinicians (in the case of hospitalized patients).
COVID-19 ambulances are set up throughout Croatia for taking patient samples. They are established in all counties in the Republic of Croatia. In Zagreb they operate within health centers (primary physicians work there in shifts. For the first 14 days these were available around the clock; now they operate every day from 6 am to 8 pm.
A new testing method introduced on 31 March 2020 is drive-in diagnostics. The Andrija Štampar Teaching Institute of Public Health was the first in Croatia to introduce this type of testing. The aim of the new test method is to speed up diagnostics and increase the number of tests. This method of testing means that people do not need to get out of their vehicles, which increases the safety of both the person undergoing the test and the health professional. The test is ordered by primary care physicians (https://www.koronavirus.hr/nzzjz-dr-andrija-stampar-prvi-u-hrvatskoj-uveo-drive-in-dijagnostiku-koronavirusa/355). The General Hospital Pula, the General Hospital Karlovac, the Health Centre Split-Dalmatia County (branch office Makarska), the Health Centre Dubrovnik-Neretva County (branch office Metković), as well as several health centres in Zagreb have also introduced drive-in diagnostics.
Some hospitals have provided special ambulances to enable them to conduct more frequent testing of health professionals on COVID-19.
Croatia has thirteen laboratories to which samples are submitted for analysis:
• University Hospital for Infectious Diseases “Dr. Fran Mihaljevic” (they first started testing)
• Teaching Institute of Public Health “Dr. Andrija Štampar”
• Croatian Institute of Public Health (started with testing on 14 March)
• University Hospital Centre Zagreb
• Clinical Medical Centre Osijek (from 1 April 2020)
• Clinical Hospital Center Rijeka
• University Hospital Centre Split (from 26 March 2020)
• Institute of Public Health of Osijek-Baranja County
• Institute of Public Health of Varazdin County
• Teaching Institute of Public Health of Primorsko-Goranska County (from 24 March 2020)
• Institute of Public Health of the Zadar County
• Institute of Public Health of the Split-Dalmatia County
• Institute of Public Health of the Istrian County
The results of the tests are available within 24 hours.