US flu activity falls, but CDC says COVID-19 may affect data
Laboratory confirmed influenza continues to decrease sharply in the United States, and the number of people visiting clinics with influenza-like illness (ILI) fell last week, according to today's FluView report from the Centers for Disease Control and Prevention (CDC).
But the agency notes that the drop in ILI activity, from 6.3% the previous week to 5.4% the week ending Mar 28, needs to be interpreted cautiously because of the impact of the COVID-19 pandemic.
"Recent changes in healthcare seeking behavior, including increasing use of telemedicine and recommendations to limit emergency department (ED) visits to severe illness, as well as increasing levels of social distancing, are affecting the number of persons with ILI and their reasons for seeking care in outpatient and ED settings," the CDC said.
While the percentage of clinic visits due to ILI remains well above the national baseline of 2.4%, the number of jurisdictions reporting high ILI activity fell from 37 the previous week to 31, and the number of jurisdictions reporting regional or widespread flu activity fell from 49 to 41. The percentage of respiratory specimens testing positive for flu at clinical laboratories fell from 7.3% to 2.1%.
But the hospitalization rate for flu climbed slightly, rising to 67.9 per 100,000 population from 67.3 per 100,000 population the previous week, which is higher than most recent flu seasons. And the percentage deaths attributed to pneumonia and influenza rose from 7.3% to 8.2%, an increase the CDC said is mainly due to pneumonia deaths and may be associated with COVID-19
The impact of the current flu season on children remains significant. The CDC reported seven more pediatric deaths, bringing the total for the season to 162—higher for this time of year than any season since the CDC began reporting flu statistics in 2004-05, except for the 2009 H1N1 pandemic season. The hospitalization rate for children 0 to 4 years old is the highest the CDC has on record for this group, while the hospitalization rate for school-aged children is higher than any recent season aside from 2009.
Testing by public health laboratories shows that 56.9% of the circulating viruses tested since Sep 29, 2019, are influenza A, and 43.1% are influenza B. For the season, 2009 H1N1 is the predominant influenza A virus (92.6%). The most common influenza B virus is the Victoria lineage (98.4%).
The CDC estimates there have been at least 39 million flu illnesses so far this season, with 400,000 hospitalization and 24,000 deaths.
Apr 3 CDC FluView report
Afghanistan, Pakistan, 5 African countries report more polio cases
Seven countries reported new polio cases, including Afghanistan and Pakistan, which both reported more wild poliovirus type 1 (WPV1) cases, according to the latest weekly update from the Global Polio Eradication Initiative (GPEI).
Afghanistan's WPV1 case was reported from Farah province, marking its third of 2020. Pakistan reported 4 cases, one from Sindh province and three from Khyber Pahktunkhwa province, raising its total for the year to 36.
In Africa, five nations reported more circulating vaccine-derived poliovirus type 2 (cVDPV2) cases. Benin reported one case, its first of the year involving a patient from Borgou province, part of a transmission chain linked to the Jigwa outbreak in Nigeria. The Democratic Republic of the Congo (DRC) reported two more cases, both from Kwilu province, lifting its total for the year to four.
In Ethiopia, health officials reported 5 more cases, 4 in Oromiya province one in the Southern Nations, Nationalities, and Peoples' (SNNP) region, increasing the country's 2020 total to 22. Ghana reported 5 more cVDPV2 cases, 3 in Ashanti province and 1 each in Bono and Western North provinces, raising its total for the current year to 8. And Togo reported 5 more cases, 3 in Lomt and 2 in Savanes provinces, increasing its 2020 total to 6.
Apr 2 GPEI update
In other polio developments, the GPEI on Mar 24 called on countries to suspend door-to-door polio vaccination campaigns to help curb the spread of COVID-19, until at least the second half of the year, Science reported yesterday. The report also said World Health Organization (WHO) advisors have also recommended temporarily suspending vaccination for other diseases, except for at clinics and doctors' offices.
Apr 2 Science report
WHO: Vigilance still needed, but no new Ebola cases in DRC
The DRC last reported an Ebola case on Feb 17, according to the WHO yesterday.
"While this is a positive development, there is still a high risk of re-emergence of EVD [Ebola virus disease] given the current challenges related to limited resources amidst other local and global emergencies, continued insecurity and population displacement in previous hotspots, and limited access to some affected communities," the WHO warned in an update on the DRC's largest outbreak, which was first reported in August 2018.
Response workers still received an average of 4,082 alerts of possible infection daily during the last week of March. In total, the outbreak has resulted in 3,453 cases, including 2,273 deaths.
As announced last month, the WHO said an injection of $20 million US is urgently needed to fund response efforts through May.
Apr 2 WHO update