Passengers from the cruise ship MV Hondius are tested for the Andes virus every week during the quarantine period. This way, infections are detected quickly and in case of a positive result, persons can be treated immediately. Testing also helps prevent the possible further spread of the virus. The risk that the virus will continue to spread among the general population is still very low.
Testing upon arrival in the Netherlands
Upon their arrival in the Netherlands, a blood sample was taken from the repatriated passengers. The National Institute for Public Health and the Environment (RIVM) and Erasmus MC have tested these samples in the laboratory. This is part of the protocol to find out at an early stage whether people have the Andes virus or have had it before.
Testing during quarantine
Throughout the entire quarantine period, testing for the Andes virus is repeated every week. If a person has the Andes virus, they usually develop symptoms within one to six weeks. That is why the quarantine period lasts six weeks. If a person develops health issues during the quarantine period, that person will be tested again.
Types of tests
Two types of tests are being done: a PCR test every week and a serology test. In a PCR test, saliva, urine and blood can be tested in the laboratory to see if they contain the RNA of the Andes virus. If the virus is present, it means that the person is currently infected with the Andes virus.
The serology test checks the blood for antibodies against the Andes virus. These antibodies show whether a person has been exposed to the virus. Antibodies remain detectable for longer than RNA. This makes it possible to determine whether a person has been infected, even if the infection is no longer present.
Laboratory testing of samples
RIVM and Erasmus MC test the samples collected in the Netherlands in laboratories suitable for this purpose. Having two organisations perform both tests provides additional assurance about the results of the tests.
Negative test result
If the PCR result is negative, the person is not currently infected with the Andes virus. Because the time between exposure and infection is long with the Andes virus, a test performed the following week can still show that a person is infected with the Andes virus. After six weeks, the risk of someone still testing positive is very low. That is why the person may then be released from quarantine.
Positive test result
If the PCR result is positive, it means the person is infected with the Andes virus. The Municipal Health Service (GGD) will then keep an extra close eye on this person's health and consult with doctors at the nearby university hospital.