Asymptomatic and symptomatic COVID-19 patients show similar shedding patterns
Patients with confirmed asymptomatic COVID-19 infections shed virus at similar levels to those who are experiencing symptoms, underscoring the importance of public health actions to control the spread of the virus, researchers from South Korea reported yesterday in JAMA Internal Medicine.
Their cohort study involved 303 patients who were isolated at a community treatment center in Cheonan in March. Health workers carefully tracked patients' symptoms during isolation. Among the group, 193 (63.7%) had symptoms at the start of isolation and 21 (19.1%) of the asymptomatic patients went on the develop symptoms. Also, the health workers conducted reverse transcription polymerase chain reaction (RT-PCR) tests on lower and upper respiratory tract samples on multiple days at doctor discretion.
Cycle threshold values for SARS-CoV-2 were similar for both asymptomatic and symptomatic patients. Viral shedding lasted about 17 days in asymptomatic patients and 19.5 days for symptomatic and presymptomatic patients.
Researchers noted that the testing method didn't gauge infectiousness but said people with confirmed infections should be isolated regardless of symptoms, and they emphasized that symptom-based screening may substantially underreport cases.
Aug 6 JAMA Intern Med abstract
Ebola infects 3 more in latest DRC outbreak, 77 total, with 33 deaths
Three more Ebola cases have been confirmed in the Democratic Republic of Congo (DRC) Equateur province outbreak, raising the total to 77, the World Health Organization (WHO) African regional office said today on Twitter.
One more death was reported, lifting the fatality count to 33. It's unclear if the death involved one of the latest confirmed patients.
The outbreak, the country's 11th involving Ebola, was first detected in early June and is occurring in the same area as a 2018 outbreak that lasted a few months and totaled 54 cases, 33 of them fatal. The WHO said the latest outbreak is concerning, because it is occurring across a wide geographic area with some of the illnesses occurring in Mbandaka, the provincial capital that has travel connections to Kinshasa and neighboring countries.
In the African regional office's weekly health emergencies and outbreaks report, the WHO said the outbreak response is challenged by a lack of resources for investigations in Mbandaka and case management in hard-to-reach places. It noted that the treatment facility in Bikoro is full, and that six confirmed cases in four different locations remain in the community. So far, more than 18,800 people have been vaccinated.
Aug 7 WHO African regional office tweet
Aug 6 WHO African regional office weekly report
Four countries report more polio cases
Four countries reported more polio cases last week, including Pakistan, Cameroon, Chad, and the Democratic Republic of Congo (DRC), according to the latest weekly update from the Global Polio Eradication Initiative (GPEI).
Pakistan reported three more wild poliovirus type 1 (WPV1) cases, one each from Khyber Pakhtoon, Punjab, and Sindh provinces, raising the total for the year to 63.
In Africa, Cameroon reported one circulating vaccine-derived poliovirus type 2 (cVDPV2) case, its fourth ever. The case was detected in Est province, marking its third polio case of 2020.
Chad reported three more cVDPV2 cases, one each from Ndjamena, Sila, and Tandjile provinces, raising the country's number for 2020 to 62 from two different outbreaks. One of them is linked to Nigeria's Jigawa state outbreak.
Meanwhile, the DRC reported two more cVDPV2 cases, one from Kwango province and one from Kwilu province, putting the country's total for the year at 22.
Aug 7 GPEI weekly update
Avian flu outbreaks hit poultry in Australia, Russia, and Vietnam
Three countries reported new highly pathogenic avian influenza outbreaks, which involved three different strains: H7N7, H5N8, and H5N1, according to the latest notifications from the World Organization for Animal Health (OIE).
Australia, which recently reported H7N7 on a layer farm in Lethbridge in Victoria, reported the virus at a second layer farm in the same area. The latest outbreak began on Aug 5, killing 190 of 355,000 susceptible birds, which included free-range, caged, and barn-based poultry. Depopulation is under way. So far the source isn't known, but contact with wild species may have played a role.
Elsewhere, Russia reported two outbreaks involving H5N8 in backyard poultry. The investigation also turned up the virus in a wild duck found at a lake near the village right before the outbreaks began. The virus struck flocks at two different sites in Chelyabinskaya oblast in events that began on July 28. The virus killed 129 of 186 susceptible birds, and the birds—including chicken, ducks, and geese—were slated for culling. Russia reported its last outbreak involving the strain in 2005.
And in Asia, Vietnam reported a new outbreak involving H5N1, which began on July 23 and affected village birds in Tra Vinh province, killing 200 of 1,040 poultry. The surviving birds were destroyed to curb the spread of the virus. Vietnam reported its last outbreak in early June.
Aug 7 OIE report on H7N7 in Australia
Aug 4 OIE report on H5N8 in Russia
Aug 7 OIE report on H5N1 in Vietnam