#14,787
While the rapid development of an RT-PCR test for the novel coronavirus has provided doctors and public health officials an important tool in the fight against this epidemic, no lab test is 100% perfect, and there are unanswered questions over the current test's sensitivity and specificity.
- Sensitivity is defined as the ability of a test to correctly identify individuals who have a given disease or condition.
- Specificity is defined as the ability of a test to exclude someone from having a disease or illness.
It isn't known exactly when an infected person - who may be exhibiting no, or few symptoms - will likely begin to test positive. How the patient's samples are taken, and transported to the lab, can affect impact reliability. And viral shedding - at least with MERS-CoV - has been shown to be intermittent, which may sometimes foil lab testing.
In October of 2018, in AJIC:Intermittent Positive Testing For MERS-CoV, we looked at report in the American Journal of Infection Control - that found intermittent (positive-negative-positive) lab results for MERS in a substantial number of cases.
Middle East respiratory syndrome coronavirus intermittent positive cases: Implications for infection control
Sarah H. Alfaraj, MD, Jaffar A. Al-Tawfiq, MD, Ziad A. Memish, MD, FRCPC, FACP, FRCPE, FRCPL
In the days and weeks ahead we should get a much better idea of the reliability of the current 2019-nCoV PCR test, and any other diagnostics that will be developed.
Illustrating the uncertainty, in today's update from Japan's MOH, we get details on two more confirmed cases (#14 & #15) - one of whom tested negative while symptomatic a couple of days ago - but who now tests positive.
We also get details on their 5th asymptomatic detection.
We also get details on their 5th asymptomatic detection.
PATIENT (14, 15) RELATED TO NEW CORONAVIRUS AND OCCURRENCE OF ASYMPTOMATIC PATHOGEN HOLDER (*)
(*) A asymptomatic pathogen holder has no symptoms but is positive for PCR test
Yesterday (January 31), when a Japanese national returned to Japan from Wuhan after a charter trip (Flight 3) at the National Institute of Infectious Diseases conducted a test at 15:00 a.m. on the new coronavirus, two cases of the current new coronavirus-related infection were reported.
One of the two examples (the 14th patient) is one of 15 individuals who were found to have had symptoms during a detailed examination at the National Center for International Medical Research (NCGM). Another example is a asymptomatic pathogen owner.
On January 29th, a medical institution determined that one of the 12 Japanese people who returned to Japan on July 1 and were hospitalized at a medical institution was likely negative for a test of the new coronavirus, and at 15 o'clock today, an additional test of the new coronavirus was reported positive (15th case)
They were returned to Japan by charter flights from Wuhan, and after PCR tests, a new coronavirus was detected. We will certainly conduct an active epidemiological survey including understanding of rich contacts.
Overview
Patient 14
(1) Age: 40Patient 15 Example
(2) Sex: Male
(3) Location: Under investigation
(4) Symptoms, Progress:
On January 31, he returned to Japan on the third flight. I am positive when I have a cough and a fever at 38°C during my medical examination at the National Center for International Medical Research.
(5) Action history:
According to his report, he did not visit the Hainan Market (Hanan Marine Castle) in Wuhan City.
There is no clear contact with pneumonia patients in China.(1) Age: 40Asymptomatic pathogen holder 5 example
(2) Sex: Male
(3) Location: People's Republic of China
(4) Symptoms, Progress:
His cough appeared on January 26. When he returned to Japan on January 29, he found fever and coughing in the 37°C and was hospitalized. The first test is negative. After that, when an additional examination is conducted using sputum, the result is positive.
His symptoms are improving, and as of February 1, his cough remains a little, but he has been dehydrated.
(5) Action history:
According to his report, he did not visit the Hainan Market (Hanan Marine Castle) in Wuhan City.
There is no clear contact with pneumonia patients in China.(1) Age: 30(Others)
(2) Sex: Male
(3) Location: Under investigation
(4) Symptoms, Progress:
On January 31, he returned to Japan on the third flight. I have no symptoms and I'm positive for a test.
(5) Action history:
According to his report, he did not visit the Hainan Market (Hanan Marine Castle) in Wuhan City.
There is no clear contact with pneumonia patients in China.
In the future, we will continue to make efforts to provide accurate information to the public, and we would like you to help us provide accurate information.In addition, we recommend that you refrain from field interviews in terms of protecting the privacy of patients.
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