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

Our weekly wrap-up of antimicrobial stewardship & antimicrobial resistance scans

UK study finds sharp rise in infective endocarditis

Incidence of infective endocarditis in the United Kingdom has increased markedly since 1998, but the increase does not appear to be linked to 2008 guidelines aimed at reducing antibiotic prophylaxis before dental procedures, UK researchers reported yesterday in BMC Medicine.

To measure and model trends in national incidence of infective endocarditis from April 1998 through March 2017, the researchers used data from Hospital Episode Statistics (HES), which contains details of all inpatient admissions to National Health Service (NHS) hospitals in England, and used three different sets of inclusion criteria and a range of regression models to identify the most likely date for a change in trends. They also looked at secondary diagnostic codes in HES data and national laboratory data to identify infective endocarditis caused by oral streptococcal species, which would be more likely to be associated with dental procedures.

The results shows that infective endocarditis incidence increased from 22.2 to 41.3 per million population in 1998 to 42.0 to 67.7 in 2017 depending on inclusion criteria. The most likely dates for a change in incidence trends ranged from September 2001 (uncertainty interval August 2000 to May 2003) to May 2015 (March 1999 to January 2016), depending on inclusion criteria and statistical model used.

For the proportion of infective endocarditis cases associated with streptococci, the most likely change points ranged from October 2008 (March 2006 to April 2010) to August 2015 (September 2013–November 2015), but those associated with oral streptococci decreased in proportion after the change point. Smoothed trends showed no notable changes in trend around the guideline date.

"Although we find no evidence that the withdrawal of dental antibiotic prophylaxis has increased cases of infective endocarditis, we do find that infective endocarditis has continued to increase rapidly in England, with incidence roughly doubling over the 20 years of the study," the authors wrote. "Further research should focus on determining the true cause of this increase."
Apr 2 BMC Med study

Review highlights use of critical antibiotics in veterinary medicine

A new paper published yesterday in the Journal of Antimicrobial Chemotherapy by an international group of veterinarians highlights the lack of valid and effective alternatives for several classes of medically important antibiotics that are commonly used to treat infections in food-producing and companion animals.

In 2018, the World Health Organization (WHO) recommended that drugs classified as highest priority critically important antimicrobials (HP-CIAs) for human medicine not be used for treatment of food-producing animals with clinically diagnosed infectious disease, due to concerns about rising antibiotic resistance, the risk of resistance spreading from animals to humans, and a desire to maintain the effectiveness of these drugs for human infections. The WHO identified five classes of antimicrobials as HP-CIAs: extended-spectrum cephalosporins, macrolides and ketolides, glycopeptides, polymyxins, and quinolones.

But data on how often these drugs are used in livestock production, and what disease they are used to treat, is lacking. To outline the diseases for which HP-CIAs are most commonly used in food-producing (pigs, cattle, and poultry) and companion animals (horses, dogs, and cats), and highlight areas where effective alternatives may be lacking, members of the European Society of Clinical Microbiology and Infectious Diseases Study Group for Veterinary Microbiology reviewed 20 articles and reports identified through a literature review.

The review found that HP-CIAs are most commonly used for enteric and respiratory infections in pigs, cattle, and poultry. The most common indications for dogs and cats are urogenital infections, while horses receive HP-CIAs most frequently for respiratory infections. The review also found that there are no valid and effective alternatives to colistin and macrolides for certain enteric infections in pigs and respiratory pathogens in cattle. In addition, effective, legal, and convenient alternatives are lacking for managing common infections in cats, some enteric and respiratory infections in poultry, and multidrug-resistant infections in all companion animal species.

The authors conclude, "Although the panel of potential alternatives to antimicrobials has grown substantially in recent years, more research is needed to develop and validate effective and sustainable non-antimicrobial strategies, especially for managing the disease conditions identified by this review."
Apr 2 J Antimicrob Chemother abstract

Review finds dearth of data on antibiotic stewardship in Africa

Originally published by CIDRAP News Apr 2

A literature review by Nigerian and UK researchers found only a handful of studies on antimicrobial stewardship programs (ASPs) in African countries, highlighting the paucity of data on ASP implementation on the continent, according to a paper published yesterday in the Journal of Global Antimicrobial Resistance.

The review of five electronic databases found 13 studies published that met the criteria for inclusion. Seven were conducted in South Africa, three in Kenya, and one each in Sudan, Tanzania, and Egypt. The studies mainly assessed the effectiveness of the interventions using process measures, including change in total antibiotic consumption, cost savings, appropriateness of prescribing and reduction in antibiotic encounters, and compliance with antibiotic guidelines. In some of the studies, change in mortality, 30-day readmission, and surgical-site infection rate were also assessed.

Of the studies reviewed, 6 reported overall reduction in antibiotic use, 3 reported improvements in antibiotic appropriateness and reduction in antibiotic encounters, 2 reported improved compliance with antibiotic guidelines, 2 reported cost savings, and 2 reported decreases in surgical-site infection rates. Non-significant change in mortality and 30-day readmission rate were reported in 2 studies.

Despite the paucity of data, the authors say the findings indicate the ASP interventions were associated with improvements in antibiotic use and demonstrate that ASPs can be implemented in other African countries.

"Whilst the continent faces a myriad of challenges which impact on effective healthcare delivery and implementation of health programmes, such as ASPs, all included studies reported improvement in outcome measures (e.g., decrease in antibiotic consumption, compliance with antibiotic policy, reduction in surgical site infections) following the antimicrobial stewardship interventions," they write. "Other African countries can emulate these examples."
Apr 1 J Glob Antimicrob Resist study

Study examines antibiotic options for injection drug users

Originally published by CIDRAP News Apr 2

Injection drug users with invasive infections who leave the hospital before completing intravenous (IV) antibiotics fare better when offered oral antibiotic therapy on discharge, researchers from Washington University in St. Louis School of Medicine reported today in Clinical Infectious Diseases.

The retrospective, single-center study looked at a cohort of injection drug users admitted to an academic medical center with an invasive bacterial or fungal infection. While infectious disease physicians recommend 4 to 6 weeks of IV antibiotic therapy for such patients, for a variety of reasons, injection drug users frequently leave the hospital against medical advice (AMA) before completing therapy, and significant controversy exists among infectious disease specialists over antibiotic treatment strategies in these situations.

The study compared three different treatment strategies in 293 injection drug users who had severe invasive infections: a full course of inpatient IV antibiotics, a partial course of IV antibiotics without oral antibiotics on AMA discharge, and a partial course of IV antibiotics with oral antibiotics on AMA discharge. The primary outcome was 90-day all-cause readmission rates.

The results showed that 90-day all cause readmission rates were highest among injection drug users who did not receive oral antibiotic therapy on AMA discharge (n = 46, 68.7%), compared with inpatient IV (43, 31.5%) and partial oral antibiotics (27, 32.5%). In a multivariate analysis, 90-day readmission risk was higher among injection drug users who did not receive oral antibiotic therapy on AMA discharge (adjusted hazard ratio [aHR], 2.32; 95% confidence interval [CI], 1.41 to 3.82) and not different among those prescribed oral antibiotic therapy on AMA discharge (aHR, 0.99; 95% CI, 0.62 to 1.62) compared with those who completed IV therapy. Surgical source control (aHR, 0.57; 95% CI, 0.37 to 0.87) and addiction medicine consultation (aHR, 0.57; 95% CI, 0.38 to 0.86) were both associated with reduced readmissions.

The authors say the study supports the concept of multifaceted, holistic management of injection drug users with invasive infections who cannot complete prolonged IV therapy.

"Additional studies specifically evaluating the role and impact of health navigators, case managers, therapists and addiction medicine providers are needed to identify key bundle components while containing costs," they write. 
Apr 2 Clin Infect Dis abstract

Study ties kids' MRSA skin infections to household colonization

Originally published by CIDRAP News Mar 31

A study of 150 households has found that recurrent methicillin-resistant Staphylococcus aureus skin and other soft-tissue infections (MRSA SSTIs) may be associated with persistent MRSA colonization of household members and contamination of environmental surfaces, US researchers reported yesterday in JAMA Pediatrics.

In the study, researchers from the Washington University School of Medicine in St. Louis and the University of Chicago investigated factors associated with persistent S aureus colonization and recurrent SSTI among 150 households with children with MRSA SSTIs, making a total of five quarterly visits over a 12-month period to conduct surveys and obtain swab samples from household members, pets, and environmental surfaces. Molecular testing was performed on all S aureus samples to identify the particular strain of the bacteria, and multivariable generalized mixed-effect logistic regression models were used to asses factors associated with persistent S aureus personal colonization, environmental contamination, and interval SSTI.

Of 540 participants who completed all five samplings, 213 (39%) were persistently colonized with S aureus, most often in the nostrils and with the same strain that infected the index patient at enrollment. Nine pets (8%) were persistently colonized with S aureus. Participants reporting interval intranasal mupirocin application were less likely to experience persistent colonization (odds ratio [OR], 0.44; 95% credible interval [CrI], 0.30 to 0.66), whereas increasing strain-specific environmental contamination pressure was associated with increased individual persistent colonization (OR, 1.17; 95% CrI, 1.06 to 1.30). Strains with higher colonization pressure (OR, 1.47; 95% CrI, 1.25 to 1.71) and MRSA strains (OR, 1.57; 95% CrI, 1.16 to 2.19) were more likely to persist.

Seventy-six index patients (53%) and 101 household contacts (19%) reported interval SSTIs. Individuals persistently colonized with MRSA (OR, 1.56; 95% CrI, 1.17 to 2.11), those with a history of SSTI (OR, 2.55; 95% CrI, 1.88 to 3.47), and index patients (OR, 1.54; 95% CrI, 1.07 to 2.23) were more likely to report an interval SSTI.

"Our analyses suggest that long-term eradication and SSTI prevention measures should be targeted at both the personal and the household levels, pairing personal decolonization with environmental hygiene interventions associated with reduced contamination," the authors wrote.
Mar 30 JAMA Pediatr abstract

Review supports oral step-down antibiotics for heart infections

Originally published by CIDRAP News Mar 30

A review of published research going back nearly 70 years suggests oral antibiotic step-down therapy is at least as effective as IV-only antibiotics for treating infective endocarditis (IE), US researchers reported today in JAMA Internal Medicine.

The review identified 21 observational or quasi-experimental studies and three randomized controlled trials (RCTs) that focused on the effectiveness of antibiotics administered orally for part of the therapeutic course in patients with IE. None of the observational studies found oral step-down therapy to be inferior to IV-only therapy, with patients on oral step-down therapy achieving cure rates of 77% to 100%. Three observational studies in particular found that patients treated with oral step-down therapy had lower mortality rates than those treated with IV-only therapy.

Results were similar in the three RCTs, which showed that oral step-down therapy was at least as effective as IV-only therapy in left-sided, right-sided, and prosthetic valve IE. The largest of the three trials found that, after 3.5 years of follow up, rates of treatment failure (26% vs 38%; hazard ratio [HR], 0.64; 95% CI, 0.45 to 0.91) and mortality (16% vs 27%; HR, 0.57; 95% CI, 0.37 to 0.87) were significantly lower in patients who received oral step-down antibiotics compared with those received IV-only therapy.

The authors say the findings challenge the long-held dogma that treatment of IE requires IV antibiotic strategies and indicate that oral step-down therapy should be incorporated into clinical practice, especially since prolonged IV therapy is associated with higher risk of adverse events.

"Oral antibiotic step-down therapy is intrinsically safer than prolonged intravenous therapy owing to the elimination of the risk of complications from the indwelling line," they write. "Thus, absent any data suggesting the superiority of intravenous therapy, any meaningful data supporting the efficacy of modern oral antibiotic therapy for IE creates equipoise, which allows for a reasonable consideration of oral therapy for this disease in well-selected patients."
Mar 30 JAMA Intern Med abstract

Study finds high carriage of MDR bacteria in Ghanaian infants

Originally published by CIDRAP News Mar 30

A study of two neonatal intensive care units (NICUs) in Ghana found that half of the newborn babies screened were carrying multidrug-resistant gram-negative (MDR GN) bacteria, researchers reported last week in Open Forum Infectious Diseases.

As part of an ongoing study of infection control interventions against neonatal sepsis and MDR GN carriage, a team of researchers from Ghana, Sweden, and Denmark conducted a cross-sectional study of two NICUs in Accra from September 2017 through January 2018. To determine the prevalence of MDR GN carriage, they cultured swabs collected from newborns and the hospital environment and performed antibiotic susceptibility testing. They also obtained blood cultures isolates from infants who had sepsis, and performed molecular analysis of those isolates, to determine the proportion and source of GN bloodstream infections (BSIs).

A total of 276 GN isolates were collected from 175 of 228 (76.8%) screened newborns. The three most common organisms isolated were Klebsiella spp. (41.7%, 115/276), Escherichia coli (26.4%, 73/276), and Enterobacter spp. (12.3%, 34/276). The carriage rate of MDR GN bacteria among screened neonates was 49.6% (113/228), while 46.1% (105/228) carried third-generation cephalosporin-resistant organisms. Among Klebsiella species, 75.6% (87/115) expressed extended-spectrum beta-lactamase (ESBL) enzymes and 15.6% (18/115) expressed carbapenemase enzymes. The carriage rate MDR GN bacteria increased with duration of hospitalization and was strongly associated with antibiotic use.

Overall, 7% (16/228) of the screened neonates developed GN BSIs, 13 of which were MDR. Whole-genome sequencing of isolates from two infants who had ESBL-producing K pneumoniae BSIs showed similarity between the carriage and the bloodstream isolates, and further analysis also found similarities with K pneumoniae isolates from the hospital environment.

The authors of the study say the findings highlight the need to improve antibiotic use and infection prevention and control practices in NICUs in low-resource settings.
Mar 28 Open Forum Infect Dis abstract