Cancer patients may shed viable COVID-19 virus for 2 months
A New England Journal of Medicine study yesterday of cancer patients with COVID-19 demonstrated viral RNA shedding for up to 78 days and live virus for up to 61 days, suggesting extended infectiousness in patients whose immune system is suppressed.
Live-virus shedding in patients who are not immunocompromised is well-documented, but little is known about how long immunocompromised patients—including those receiving cancer treatments—are contagious. The presence of viral RNA does not always correlate with transmissibility, and previous studies have demonstrated lengthy periods of viral RNA shedding after patients are no longer infectious.
Scientists at Memorial Sloan Kettering Cancer Center collected respiratory samples from 20 cancer patients receiving immune-suppressing therapy from Mar 10 to Apr 20. Nasopharyngeal samples were tested for SARS-CoV-2, the virus that causes COVID-19, using reverse-transcription polymerase chain reaction (RT-PCR). Viral culture of positive swabs was used to assess the presence of infective particles and whole-genome sequencing was conducted for viral samples.
Of the 20 patients, 15 were receiving active treatment or chemotherapy and 11 had severe COVID-19. Viral RNA was detected in the cancer patients up to 78 days after the onset of symptoms (interquartile range [IQR], 24 to 64 days). Viable virus was detected in 71% of initial nasopharyngeal samples and grew in cultures from five patients up to 61 days after symptom onset.
Whole-genome sequencing of viral samples suggested persistent infection with a single viral strain.
"Patients with profound immunosuppression after undergoing hematopoietic stem-cell transplantation or receiving cellular therapies may shed viable SARS-CoV-2 for at least 2 months. The current guidelines for COVID-19 isolation precautions may need to be revised for immunocompromised patients," the study authors wrote.
Dec 1 N Engl J Med study
Outsize COVID-19 burden noted in Hawaii's Pacific Islanders
A report in the International Journal of Infectious Diseases yesterday highlights the disproportionate burden of COVID-19 among Pacific Islanders in Hawaii: They represent 4% of the state population but make up 31% of COVID-19 cases.
Hawaii reported its first confirmed case of COVID-19 on the main island of Oahu on Mar 6. Sharp peaks in cases occurred in March and April, attributed mostly to returning residents and visiting tourists. A mandatory 14-day isolation of all incoming visitors and returning residents on Mar 23 led to a decrease in cases, but transmission rebounded in late July and peaked at the end of August after a stay-at-home order lifted and many non-essential businesses reopened.
As of Oct 30, a total of 15,003 COVID-19 cases have been reported in the state.
Hawaii's multi-ethnic population includes large subpopulations descended from Asians, native Hawaiians, other Pacific Islanders and Europeans, as well as many recent immigrants. Pacific Islanders—80% of whom reside in Honolulu—come primarily from American Samoa, Micronesia, the Marshall Islands, and Palau.
Pacific Islanders had a COVID-19 case rate of 448 per 100,000 people on Jul 17, 7.5 times higher than the combined rate for all other non–Pacific Islanders (59.7 per 100,000). The Pacific Islander case rate increased during every 7-day interval after Jul 17, reaching 31% of the total reported COVID-19 cases as of Oct 30.
Hawaiian Pacific Islanders are younger (median age between 18.5 and 23.7 years), less educated, and have lower per capita incomes than the overall Hawaiian population. They are also more likely to work in frontline service jobs, particularly in the tourist sector.
"Local explanations for the high COVID-19 rates in Pacific Islanders have been inferred from observations that Pacific Islander households in Hawai'i tend to be multi-generational, leading to crowded living quarters," the authors noted. "This makes physical distancing difficult."
Dec 1 Int J Infect Dis study