Scientists have detailed the first known locally-transmitted case in the US of the novel coronavirus infection, COVID-19, tracing it to a man who contracted the disease from his wife travelling from Wuhan, China. The study has been published in the journal The Lancet.
According to the researchers, person-to -person transmission of the deadly coronavirus, SARS-CoV-2, occurred between the two people with prolonged, unprotected exposure while the first patient showed symptoms.
They said despite active monitoring and testing of 372 contacts of both cases, no further transmission was detected.
The study noted that on January 23, 2020, Illinois reported the US state Chicago’s first laboratory-confirmed case, or index case, of COVID-19 in a woman in her 60s returning from Wuhan, China in mid-January, 2020.
Subsequently, the first evidence of secondary transmission in the US was reported on January 30, when her husband, who had not travelled outside the US but had frequent, close contact with his wife since her return, tested positive.
Following this, public health authorities conducted an intensive epidemiologic investigation of the two confirmed cases.
In the research, the scientists report the clinical and laboratory features of both patients and the assessment and monitoring of several hundred individuals with potential exposure to SARS-CoV-2. In total, they identified 372 individuals as potential contacts with 347 of them actively monitored after confirmation of exposure to the woman or her husband on or after the day of symptom onset. This included 152 community contacts, and 195 healthcare professionals, the study mentioned. There were 25 people that had insufficient contact information to complete active monitoring, the scientists said.
Assessing the data, the researchers observed that on December 25, 2019, the female patient travelled to Wuhan where she visited a hospitalised relative and other family members with undiagnosed respiratory illness. On her return to the US on January 13, 2020, the study noted that she experienced six days of mild fever, fatigue, and cough before being hospitalised with pneumonia and testing positive for SARS-CoV-2.
Prior to hospitalisation she was living with her husband who has chronic obstructive pulmonary disease (COPD) and chronic cough, it said. These conditions, the researchers said, made it difficult to determine the timing of his symptom onset related to COVID-19. Eight days after his wife was admitted to hospital, the husband was also hospitalised with worsening shortness of breath and coughing up blood, and also tested positive for SARS-CoV-2, according to the study.
The scientists said both patients recovered, and were discharged to home isolation, which was lifted 33 days after the woman returned from Wuhan, following two negative tests for SARS-CoV-2 taken 24 hours apart.
This report suggests that person-to-person transmission of SARS-CoV-2 might be most likely to occur through unprotected, prolonged exposure to an individual with symptomatic COVID-19.
Healthcare facilities should rapidly triage and isolate individuals suspected of having COVID-19, and notify infection prevention services and local health departments for support in testing, management, and containment efforts.
Individuals who think they might have been exposed to COVID-19, and experiencing a fever, cough, shortness of breath, or other symptoms consistent with COVID-19 should call their healthcare provider before seeking help so that appropriate preventive actions can be taken.