News Scan for Apr 10, 2018

Superbugs in nursing homes
;
Lassa fever continues
;
Malaria net effectiveness

Study finds high rate of MDRO colonization in new nursing home patients

Nearly 57% of short-stay nursing home residents harbor multidrug-resistant organisms (MDROs) near the time of admission and at discharge, according to University of Michigan researchers.

In a longitudinal cohort study published yesterday in Clinical Infectious Diseases, the researchers evaluated MDRO colonization prevalence in 651 recently admitted nursing facility (NF) patients from November 2013 through May 2016. Patients at six NFs in southeast Michigan were enrolled within 14 days of admission and followed for up to 6 months. The researchers evaluated for MDRO prevalence upon enrollment, MDRO acquisition and loss during their stay, prevalence upon discharge, and identified risk factors for colonization.

The results showed that 56.8% of the patients were colonized with an MDRO at enrollment: 16.1% with methicillin-resistant Staphylococcus aureus (MRSA), 33.2% with vancomycin-resistant enterococci (VRE), and 32% with resistant gram-negative bacilli (R-GNB). Risk factors for colonization at enrollment included prolonged hospitalization, functional disability, antibiotic use, or device use.

Among the 456 patients with one or more follow-up sampling visits, the incidence rate per 1,000 patient-days for new MDRO acquisition was 3.4 from MRSA, 8.2 for VRE, and 13.6 for R-GNB. MDRO colonization at discharge was 56.4%: 18.4% for MRSA, 30.3% for VRE, and 33.6% for R-GNB. More than half of the patients discharged to the community (52.4%) and 70.9% of those readmitted to a hospital were colonized with one or more MDROs at discharge.

The authors of the study say the findings illustrate the potential for NFs to be a reservoir for MDROs that can then spread between institutions and within community healthcare settings. They suggest that patients with long prior hospitalizations and other risk factors for MDRO colonization should be targets for aggressive prevention efforts.
Apr 9 Clin Infect Dis study


Nigeria records more Lassa cases, including in healthcare worker

In its latest outbreak update, the Nigerian Centre for Disease Control (NCDC) confirmed eight new cases of Lassa fever, including three deaths. There are now 408 confirmed  and 9 probable cases in Nigeria's largest-ever Lassa outbreak.

One of the new cases involves a healthcare worker from Ebonyi state, the NCDC said, bringing the total healthcare workers infected during this outbreak to 27. Ebonyi, Edo, and Ondo are the hardest-hit states, with 81% of confirmed Lassa cases. Lassa is typically transmitted through contact with rodents, but person-to-person transmission can occur when someone comes into contact with infected bodily fluids.

Since the outbreak began in January, the NCDC has recorded 101 deaths in confirmed cases, and 9 deaths in probable cases. The case-fatality rate in confirmed cases is 24.8%

According to the latest update from the World Health Organization's African Regional Office, Lassa cases have declined slightly in recent weeks, but the peak transmission period is not over yet.
Apr 8 NCDC update

Apr 6 WHO African Regional Office bulletin

 

Study: Despite resistance, insecticide nets effective against malaria

Despite rising rates of antimalarial resistance, insecticide mosquito nets remain effective and should still be used in malaria-endemic regions, according to a new study published in Lancet Infectious Diseases.

In 2016, researchers estimated that more than 50% of people in sub-Sarahan Africa sleep under pyrethroid-treated long-lasting insecticidal nets, making the net one of the most common vector-control tools used in much of the Southern Hemisphere.

To conduct the new study, researchers tracked both mosquito resistance rates and malaria incidence in communities in Benin, Cameroon, India, Kenya, and Sudan in which pyrethroid long-lasting insecticidal nets were the main vector-control tool.

From 2012 to 2016, the researchers sampled 80,000 mosquitoes for resistance, and followed 40,000 children for clinical incidence. Despite varying levels of resistance rates, net users had a lower risk of infection in all countries except Sudan.

"We found no evidence that clinical incidence differed between high and low resistance clusters for all locations and timepoints combined," the authors wrote. "We found no evidence of an association between infection prevalence or clinical incidence with higher pyrethroid resistance."

In all countries but Sudan, net users had a significantly lower risk of infection than did non-users.

The authors said that net use should be encouraged in malaria-endemic countries, but cautioned that net users still had high rates of malaria infection rates, ranging from 0.8%  in India to 50.8% in Benin. Other interventions, including spraying, should be used in these areas to reduce malaria transmission, they added.

In an accompanying commentary on the study, Emmanuel Chanda, PhD, the project office for vector control operations in the World Health Organization's African Regional Office said, "The authors of this study make a substantial contribution to dispelling the misconception that resistance renders nets ineffective, and are cognisant of challenges of confounders, including constraints for resistance management. The conclusions drawn are pertinent to malaria control and elimination efforts."
Apr 9 Lancet Infect Dis study
Apr 9 Lancet Infect Dis commentary

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