Beijing battles coronavirus cluster as pandemic hampers flu tracking

Wholesale food market in Hong Kong
Wholesale food market in Hong Kong

estherpoon / iStock

As the global COVID-19 total nears 8 million cases, Chinese health officials are investigating a large COVID-19 cluster that appears to be linked to a large wholesale market in Beijing, amid worries that overburdened public health systems are losing visibility on what's happening with flu.

The global total today reached 7,973,302 cases, and 434,793 people have died from their infections, according to the Johns Hopkins online dashboard.

Global total climbs by 100,000 cases a day

At a media briefing today, World Health Organization (WHO) Director-General Tedros Adhanom Ghebreyesus, PhD, alluded to the rapid increase in cases, noting that it took 2 months to reach the first 100,000 cases.

"For the past 2 weeks, more than 100,000 new cases have been reported almost every single day," he said. Nearly 75% of the recent cases are from 10 countries, mostly in the Americas and South Asia, but COVID-19 activity is increasing in Africa, eastern Europe, central Asia, and the Middle East.

Even countries that have suppressed transmission need to be alert for possible resurgence, Tedros said.

Officials probe source of Beijing cluster

A new cluster reported last week in Beijing, its first cases in more than 50 days, has now grown to more than 100 confirmed cases, Tedros said, and the source and extent of the outbreak are under investigation.

The WHO said in a June 13 statement that officials from China's National Health Commission and the city of Beijing have briefed the WHO China country office on the cluster, noting that the first case-patient became ill on June 9.

Several patients were identified though six of the city's fever clinics, and early investigations revealed that some of the first patients with symptoms had links to the Xinfadi market—said to be Asia's biggest wholesale food market—where samples from humans in the environment yielded 45 positive people, all with asymptomatic infection, and 40 positive environmental samples. One other asymptomatic individual was identified in a close contact of a confirmed case.

The WHO said genetic sequencing is under way to clarify the origin of the virus and the links between cases.

Today, the Beijing Center for Disease Control reported 36 more symptomatic cases and 6 more asymptomatic people. The outbreak prompted city officials to order security checkpoints for several Beijing districts, cancel schools, and order people to be tested, Reuters reported.

At the affected market, SARS-CoV-2, the virus that causes COVID-19, was found on cutting boards for processing imported salmon, though experts from China quoted in China Daily said the potential salmon source is extremely unlikely.

A researcher for the China Center for Disease Control said an initial analysis of two early cases suggests that the SARS-CoV-2 strain is different than the one found in China and might reflect a mutated strain from Europe. But he said more testing is needed to confirm the origin of the virus.

At today's briefing, Mike Ryan, MD, who leads the WHO's health emergencies program, said the foodborne possibility is a hypothesis that should be explored, but he noted that the virus primarily spreads through the respiratory route.

Maria Van Kerkhove, PhD, the WHO's technical lead for COVID-19, said clusters are notable, and investigations help identify the conditions that brought the cases together and offer an opportunity to better understand how the disease transmits.

COVID-19 demands slow flu tracking

At today's media briefing, Tedros said the pandemic burden is creating difficult challenges for global flu surveillance activities. He said the well-established Global Influenza Surveillance and Response System (GISRS) has been in operation since 1952 and has been strengthened over the past 8 years, but it now faces significant challenges, with pandemic demands leading to suspensions or declines in flu surveillance as well as a sharp drop in sharing flu information and viruses.

"Compared with the last three years, we’ve seen a dramatic decrease in the number of specimens tested for influenza globally," he said, adding that WHO Collaborating Centers have seen a 62% drop in virus shipments, and GISAID has seen a 94% decline in the number of flu virus sequences uploaded to its sharing database. Repurposed staff and supplies, overburdened labs, and transport restrictions are among the reasons for the drop in flu surveillance activities.

Tedros warned that the disruptions may have short- and long-term effects, including the loss of capacity to detect and report new flu viruses that have pandemic potential. And the WHO also depends on the latest information about flu viruses to make annual vaccine strain recommendations. "The Southern Hemisphere flu season is already under way. There is no time to lose," he said.

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