#14,846
Japan's MOH has announced 2 new positive coronavirus cases in evacuees who returned to Japan in late January - both whom initially tested negative for the virus - only to fall ill and test positive more than a week later.
- The first patient, a man in his 40s, returned on January 30th and initially tested negative, but was diagnosed after a second test on Monday.
- The second patient, a man in his 50s who returned first Japanese evacuation flight on January 29, previously twice tested negative for the virus, only to test positive on Feb 10th.
It is not unusual, or unexpected, that people can test negative in the early stages of infection, before symptoms appear. The second case, however, continued to test negative after a fever and cough appeared.
We've seen similar problems with testing for MERS-CoV (see AJIC :Intermittent Positive Testing For MERS-CoV) and it is one of the reasons why it requires two consecutive negative tests to rule out a MERS infection.
Accuracy of these tests can also depend on how the samples are collected, and how they are transported to the lab. The most common (and least invasive) sampling method for respiratory infections is via a Nasophyaryngeal (NP) swab.The CDC's interim recommendations for specimen collection for MERS are more rigorous, calling for `Collection of all three specimen types (not just one or two of the three), lower respiratory, upper respiratory and serum specimens for testing using the CDC MERS rRT-PCR assay is recommended.'
Based on the MOH reports below, it appears they are collecting samples by throat swabs in Japan.
About outbreak of patient associated with new coronavirus (24th case)
At around 18:00 yesterday (February 10), the Health Follow-up Center reported a case of this new type of coronavirus-related infection.
This patient is a resident of Saitama Prefecture, a Japanese who returned on January 30 on a charter flight (second flight) from Wuhan City. Coronavirus was detected.
It is the 24th case in Japan where the outbreak of patients with infectious diseases related to the new coronavirus was confirmed.
We will carry out proactive epidemiological investigations on this matter, including the identification of close contacts.
Outline(1) Age: 40's
(2) Gender: Male
(3) Residence: Saitama
(4) Symptoms, progress:
- January 30 Returned to Japan on the second charter flight.
- On the same day, when she moved from the airport and was consulted at the National Center for Global Health and Medicine, she underwent a PCR test but was negative.
- February 1 Returned to home with hope because he returned with his children. Waiting at home.
- February 8 Fever 39.5 degrees.
- February 9 Taking over-the-counter medications and relieving fever to 37.2 degrees.
- February 10 morning Visited a medical institution in Saitama prefecture. Chest X-ray shows pneumonia in both middle and lower lung fields.
- On the same day, a specimen (throat swab) was collected, and a PCR test was performed at the Regional Health Research Institute and the result was positive. Hospitalized at a medical institution in Saitama prefecture.
(5) Behavioral history:
- February 11 Fever in the 38 degrees range.
- Two family members are suspected of close contact. Under detailed investigation.
- According to his report, he has not stopped by the seafood market in Wuhan (South China Seafood).
- No clear contact with pneumonia patients has been identified in China.
About outbreak of patient associated with new type coronavirus (the 25th case)
At around 21:00 yesterday (February 10), Chiba Prefecture reported a case of infectious disease associated with this new type of coronavirus.
This patient was a Japanese who returned on January 29 on a charter flight (first flight) from Wuhan, Hubei Province. A new coronavirus was detected as a result of PCR performed at the National Institute of Infectious Diseases.
It is the 25th case in Japan of outbreaks of patients with a new coronavirus-related infection.
We will carry out proactive epidemiological investigations on this matter, including the identification of close contacts.
Outline
(1) Age: 50's
(2) Gender: Male
(3) Place of residence: People's Republic of China (Wuhan City, Hubei Province)
(4) Symptoms and progress:
- January 29 Returned to Japan on the first charter flight, National International Medical Service He was examined at a research center and stayed at a hotel in Chiba Prefecture.
- January 30 The result of PCR test at the National Institute of Infectious Diseases was negative.
- February 7 Fever (38.5 ° C), cough, and other symptoms appeared, and she was transported to a medical institution in Chiba Prefecture and hospitalized.
- Feb. 8, PCR test was negative at a local health research institute in Chiba Prefecture, but the patient was hospitalized. Feb.
(5) Action history:
- 10 Since the symptoms did not improve, a PCR test was performed again at the National Institute of Infectious Diseases and the test was positive.
- According to his report, he has not stopped at the seafood market in Wuhan (South China Seafood City).
- No clear contact with pneumonia patients has been identified in China. After January 30, she has not left her guest room until she was transported to a medical institution.
A reminder that as good as lab tests generally are, `no' doesn't always mean no.
