ASP Scan (Weekly) for Dec 29, 2017

News brief

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

Review challenges the 'static vs cidal' dogma

Data from high-quality, randomized controlled trials show that bactericidal antibiotics are not intrinsically superior to bacteriostatic antibiotics, researchers from the University of Southern California School of Medicine report in a new paper in Clinical Infectious Diseases.

To test the common belief that bactericidal antibiotics (agents that kill or eliminate bacteria) are more effective than bacteriostatic antibiotics (agents that halt bacterial growth), the researchers conducted a systematic review of all randomized controlled trials published from January 1985 through September 2017 that compared clinical outcomes of bactericidal versus bacteriostatic antibiotics when treating serious or life-threatening invasive infections. They identified 56 trials to include in the review.

Of the 56 trials identified, 49 (81%) found no significant difference in efficacy between bacteriostatic and bactericidal agents, including for potentially highly lethal infections, such as typhoid fever, pneumonia, plague, or bacteremia. Furthermore, six of the trials showed that the bacteriostatic agent was more effective than the bactericidal agents.

Only one trial, comparing tigecycline with imipenem for the treatment of ventilator-associated pneumonia, found that a bactericidal agent was superior in efficacy. But pharmacologic analysis of that trial determined that the inferiority of the bacteriostatic agent (tigecycline) was based on the dose being too low; when the dose of tigecycline was doubled, efficacy was similar to imipenem.

The authors of the review say the available data suggest that other drug characteristics, such as optimal dosing, pharmacokinetics, and tissue penetration may be more important drivers of clinical efficacy.

"While it seems intuitive that antibiotics that more rapidly kill bacteria should be more clinically effective, a systematic review of randomized controlled trials does not support this assertion," the authors write. "It is time to abandon the notion that bactericidal agents are intrinsically more effective than bacteriostatic agents."
Dec 26 Clin Infect Dis abstract

 

Study probes role of portable medical equipment in pathogen spread

A small study conducted at a Veteran's Affairs hospital in Texas suggests that portable medical equipment (PME) could play an important role in the transmission cycle of healthcare-associated infections, researchers from the Texas Veterans Health Care System reported yesterday in BMC Infectious Diseases.

In the study, research staff observed different patient-care events over six different 24-hour periods on six different hospital units. The observers followed one healthcare worker for their entire shift, documenting every time they touched a patient or a surface—including hard surfaces, bedding, and PME such as computers on wheels (COW), vitals machines, and IV infusion pumps. Each encounter was recorded as a sequence of events and analyzed using sequence analysis. The purpose of the study was to investigate the patterns and sequence of touch events among healthcare workers, patients, surfaces, and equipment in the hospital environment.

The most commonly touched items in patient rooms were the patients with 850 touches, COW (634), bedrails (375), and IV pumps. Sequence analysis revealed that touching the patient and then the bedrail was the most common sub-sequence (occurring in 28.1% of all sequences). Touching the COW and then the patient was the most common sub-sequence between PME and patient (22.6% of all sequences), followed by touching the patient and then the COW (20.4% of all sequences), and touching the patient and then the IV pump (16.1% of all sequences).

The researchers also observed that hand hygiene was below expectations and that gloves were used in only about half the encounters. In addition, 5 of 48 COWs (10.4%) were contaminated with methicillin-resistant Staphylococcus aureus.

"PME, particularly COW and IV pump, are highly touched items and were common in sub-sequences that involved the patient, possibly contributing to higher pathogen transmission risk," the authors write. "Disinfection of PME, preferably in between patient interactions, may potentially be necessary, along with optimal hand hygiene, to reduce the possibility of transmission between patients."
Dec 28 BMC Infect Dis study

 

Study finds steady increase in antibiotic use in Chinese hospitals

Originally published by CIDRAP News Dec 28

Despite efforts to improve antibiotic use, total antibiotic consumption in China's tertiary hospitals showed a significant upward trend from 2011 through 2015, according to a study yesterday in PLoS One.

In the study, investigators from Peking University retrospectively analyzed aggregated monthly surveillance data on antibiotic sales to 468 hospitals in 28 provinces in China over the 5-year period, which coincided with a 3-year national regulatory campaign (2011-2014) to control total antibiotic use in the country's secondary and tertiary hospitals. Antibiotic consumption was expressed in defined daily doses per 1,000 inhabitants per day (DID), and population weighted antibiotic consumption patterns in China were compared with European countries using indicators from the European Surveillance of Antimicrobial Consumption (ESAC).

Total antibiotic consumption, including all specific antibiotic classes except macrolides, significantly climbed over the study period, from an average of 7.97 DID in 2011 to 10.08 DID in 2015. The most frequently used antibiotics were cephalosporins, which accounted for 28.6% of total consumption, followed beta-lactam-beta-lactamase inhibitor combinations (20%), macrolides (17.4%), and fluoroquinolones (10.5%). Antibiotics in parenteral form accounted for nearly half of all antibiotics consumed.

Analysis of regional distribution of antibiotic consumption showed that eastern regions of the country used more antibiotics than western regions when using census population as a denominator. Comparison of antibiotic use in China with ESAC data from 2012 showed that there was higher consumption of third- and fourth-generation cephalosporins and fluoroquinolones in China than in 75% of the 29 European countries.

The authors of the study say more research is needed on the appropriateness of antibiotic prescriptions in Chinese hospitals to help reduce the risk of antibiotic resistance. China is estimated to be the second largest consumer of antibiotics in the world.
Dec 27 PLoS One study

News Scan for Dec 29, 2017

News brief

UAE reports MERS in Omani camel worker

The United Arab Emirates (UAE) on Dec 11 reported another MERS-CoV infection, in a man from Oman whose asymptomatic case was found during screening when he was transporting camels, some of them infected, into the UAE, according to a Dec 22 update from the World Health Organization (WHO).

The 39-year-old man is in home isolation in Oman, and so far his contacts have tested negative for Middle East respiratory syndrome coronavirus (MERS-CoV).

On Dec 2, the man transported camels through the Al Ain-Mezyed entry point at the border with Oman. Ten dromedary camels were screened for MERS-CoV, and five tested positive. Veterinary officials are investigating camels on the affected farm, and infected camels have been quarantined. The infection marks the fifth MERS-CoV case to be detected in the UAE this year. The WHO said so far globally it has received reports of 2,122 MERS-CoV illnesses, at least 740 of them fatal.
Dec 22 WHO statement

In a related development, Saudi Arabia's Ministry of Health (MOH) today reported that a patient has died from the disease, a 50-year-old man from Al Bukayriyah. The Saudi man is not a health worker and had an underlying health condition. All told, Saudi Arabia has reported 1,760 cases, 713 of them fatal. Three people are still being treated for their infections.
Dec 29 Saudi MOH statement

 

Polio case reported in Pakistan; DRC notes pair of vaccine-derived cases

In its latest weekly report, the Global Polio Eradication Initiative (GPEI) said Pakistan has reported one more wild poliovirus type 1 (WPV1) case and the Democratic Republic of Congo (DRC) has reported two more vaccine-derived poliovirus type 2 (cVDPV2) cases.

Pakistan's case, which GPEI noted in a brief advance report last week, involves a patient from Balochistan province, who had a Nov 13 paralysis onset. Pakistan has now reported eight WPV1 cases for 2017.

The DRC's two new cVDPV2 cases are from different districts in Tanganika province and had Nov 9 and Nov 19 paralysis onsets. The new illnesses lift the DRC's number of cVDPV2 cases for 2017 to 12.
Dec 29 GPEI update

 

H5N6 reassortant turns up in Switzerland

In the latest avian flu outbreak development, Switzerland reported its first detection of a new highly pathogenic H5N6 reassortant, as South Korea reported two more outbreaks on duck farms and Hong Kong reported a second recent detection in a wild bird, according to separate reports from the World Organization for Animal Health (OIE). Also, Russia reported its first outbreak involving highly pathogenic H5N2, and Saudi Arabia reported the spread of H5N8 to poultry farms beyond the Riyadh region.

Switzerland's detection involves a wild swan found sick near Lake Biel, not far from the French border, according to a government report translated and posted by Avian Flu Diary (AFD), an infectious disease news blog. The OIE report said the bird was found on Dec 18 and that preliminary test results from the Friedrich-Loeffler Institute suggest the virus is related to H5N8 and H5N6 strains recently detected in Europe. In mid December, identification of the reassortant in the Netherlands marked the first detection in Europe.

Also, South Korea reported two more H5N6 outbreaks that began on Dec 26, both on duck farms in previously affected South Jeolla province. The events led to the culling of nearly 27,000 birds. And Hong Kong today said H5N6 was detected in a black-faced spoonbill found dead on Dec 21 in a wetland park, its second report this week of the virus in a wild bird.
Dec 29 OIE report on H5N6 in Switzerland
Dec 28 AFD post on
H5N6 in Switzerland
Dec 28 OIE report on
H5N6 in South Korea
Dec 29 OIE report on
H5N6 in Hong Kong

In news about other strains, a recent outbreak on a commercial poultry farm in Russia's Kostroma Oblast that was recently attributed to highly pathogenic H5N8 has now been linked to highly pathogenic H5N2, the country's agriculture ministry said in an OIE report today.

Meanwhile, Saudi Arabian officials said H5N8 has been linked to an outbreak at a poultry facility in Al Ahsa in Eastern province, about 186 miles east of Riyadh province, where the virus was first confirmed in poultry earlier this month, according to a government report translated and posted by AFD.
Dec 29 OIE report on H5N2 in Russia
Dec 28 AFD
post

Stewardship / Resistance Scan for Dec 29, 2017

News brief

Review challenges the 'static vs cidal' dogma

Data from high-quality, randomized controlled trials show that bactericidal antibiotics are not intrinsically superior to bacteriostatic antibiotics, researchers from the University of Southern California School of Medicine report in a new paper in Clinical Infectious Diseases.

To test the common belief that bactericidal antibiotics (agents that kill or eliminate bacteria) are more effective than bacteriostatic antibiotics (agents that halt bacterial growth), the researchers conducted a systematic review of all randomized controlled trials published from January 1985 through September 2017 that compared clinical outcomes of bactericidal versus bacteriostatic antibiotics when treating serious or life-threatening invasive infections. They identified 56 trials to include in the review.

Of the 56 trials identified, 49 (81%) found no significant difference in efficacy between bacteriostatic and bactericidal agents, including for potentially highly lethal infections, such as typhoid fever, pneumonia, plague, or bacteremia. Furthermore, six of the trials showed that the bacteriostatic agent was more effective than the bactericidal agents.

Only one trial, comparing tigecycline with imipenem for the treatment of ventilator-associated pneumonia, found that a bactericidal agent was superior in efficacy. But pharmacologic analysis of that trial determined that the inferiority of the bacteriostatic agent (tigecycline) was based on the dose being too low; when the dose of tigecycline was doubled, efficacy was similar to imipenem.

The authors of the review say the available data suggest that other drug characteristics, such as optimal dosing, pharmacokinetics, and tissue penetration may be more important drivers of clinical efficacy.

"While it seems intuitive that antibiotics that more rapidly kill bacteria should be more clinically effective, a systematic review of randomized controlled trials does not support this assertion," the authors write. "It is time to abandon the notion that bactericidal agents are intrinsically more effective than bacteriostatic agents."
Dec 26 Clin Infect Dis abstract

 

Study probes role of portable medical equipment in pathogen spread

A small study conducted at a Veteran's Affairs hospital in Texas suggests that portable medical equipment (PME) could play an important role in the transmission cycle of healthcare-associated infections, researchers from the Texas Veterans Health Care System reported yesterday in BMC Infectious Diseases.

In the study, research staff observed different patient-care events over six different 24-hour periods on six different hospital units. The observers followed one healthcare worker for their entire shift, documenting every time they touched a patient or a surface—including hard surfaces, bedding, and PME such as computers on wheels (COW), vitals machines, and IV infusion pumps. Each encounter was recorded as a sequence of events and analyzed using sequence analysis. The purpose of the study was to investigate the patterns and sequence of touch events among healthcare workers, patients, surfaces, and equipment in the hospital environment.

The most commonly touched items in patient rooms were the patients with 850 touches, COW (634), bedrails (375), and IV pumps. Sequence analysis revealed that touching the patient and then the bedrail was the most common sub-sequence (occurring in 28.1% of all sequences). Touching the COW and then the patient was the most common sub-sequence between PME and patient (22.6% of all sequences), followed by touching the patient and then the COW (20.4% of all sequences), and touching the patient and then the IV pump (16.1% of all sequences).

The researchers also observed that hand hygiene was below expectations and that gloves were used in only about half the encounters. In addition, 5 of 48 COWs (10.4%) were contaminated with methicillin-resistant Staphylococcus aureus.

"PME, particularly COW and IV pump, are highly touched items and were common in sub-sequences that involved the patient, possibly contributing to higher pathogen transmission risk," the authors write. "Disinfection of PME, preferably in between patient interactions, may potentially be necessary, along with optimal hand hygiene, to reduce the possibility of transmission between patients."
Dec 28 BMC Infect Dis study

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