Infectious Disease Alert Updates
September 1, 2024 7 minutes read
By Carol A. Kemper, MD, FDISA
Medical Director, Infection Prevention, El Camino Hospital, Palo Alto Medical Foundation
Abandoning Universal COVID Admission Screening
SOURCE: Brust KB, Kobayashi T, Diekema DJ. Asymptomatic testing of hospital admissions for SARS-CoV-2: Is it OK to stop? Clin Infect Dis 2024;78:356-360.
For the first few years of the COVID epidemic, hospitals in the United States embraced universal SARS-CoV-2 screening of hospital admissions, including persons asymptomatic for respiratory illness. This seemed an essential measure to prevent nosocomial transmission to healthcare workers (HCWs), visitors, and other patients when rates of community infection were surging and outcomes were poorer. As illogical as it may have been, and recognizing that negative testing on admission or pre-operatively was never a guarantee a patient was not incubating infection, universal screening nonetheless gave HCWs, and specifically proceduralists and surgeons, the assurance that they were relatively protected from nosocomial transmission and could resume their usual duties.
Fast forward to 2024, when COVID infection rates are lower and outcomes are better. Gradually, many healthcare facilities are abandoning universal screening of asymptomatic admissions and pre-op patients. The Society for Healthcare Epidemiology of America (SHEA) recently recommended against universal SARS-CoV-2 screening of asymptomatic admissions.
These authors outlined the rationale for discontinuing universal screening of asymptomatic admissions and the unnecessary isolation of asymptomatic positives, given the current status of COVID.
• The risk of infection generally is lower; test positivity rates generally are 1% to 3%, especially in symptomatic persons. Recent data from California in May 2024 indicated a test positivity rate of 2.5% and hospital admissions were only 1.6 per 100,000 population.
• With the availability of vaccination, immunity from prior infection, and improved treatments, as well as the possible attenuation of circulating virus, outcomes of COVID infection have improved significantly.
• Polymerase chain reaction (PCR) testing was not designed to determine infectiousness, and it is now believed that most persons with asymptomatic infection are not readily contagious.
• Contagiousness generally occurs just prior to the onset of symptoms and peaks at days 2-5; transmission beyond day 5 is unlikely. Where someone is on that timeline is not evident from a positive test — and PCR testing in asymptomatic persons is more likely detecting molecular footprints of a recent infection than catching them just prior to the onset of symptoms.
• A negative test on admission does not guarantee the patient will not develop COVID infection during hospitalization — especially with the lifting of visitor restrictions and masking requirements.
• Universal screening strains laboratory services, isolation rooms, and personal protective equipment.
• Testing on admission may result in delays in admission and necessary procedures.
• Finally, isolation has been demonstrated to cause potential harm and can impede medical care.
• The authors observed that, during a 140-day period, only one case of hospital-onset COVID infection may have been prevented at their facility by screening and isolating 50-100 asymptomatic persons testing positive for SARS-CoV-2 on admission.
The authors concluded that, “We sometimes must (reluctantly) accept some risk for pathogen transmission in healthcare settings when the balance shifts from benefit to harm as a result of our infection prevention interventions.”
That is quite a statement. What these authors did not include in their argument is that the risk of exposure outside of the hospital is much greater than inside the hospital, and most people have themselves abandoned restrictions on their activities, essentially embracing COVID as a “fact of life.” To what extent is a hospital facility required to go to protect an individual from a respiratory virus circulating at ease in the community?
However, for some California-based acute care facilities, there have been repercussions from abandoning universal screening. Notification of COVID exposure still is a California Division of Occupational Safety and Health requirement of hospitals and businesses; infection prevention personnel still are required to perform exposure investigations for nosocomial cases; and exposed HCWs still are required to test at baseline and at day 5, during which they must wear an N95 mask for work activities while they monitor for symptoms. Because HCW masking requirements also have stopped as of April 2024, this results in a whole lot of HCW contacts to investigate and test — with monitoring of symptoms, masking, and follow-up testing. At least two to three times a week, our infection prevention (IP) team is notified of a positive employee or a patient testing positive during hospitalization or at the end of their hospitalization as a requirement for placement in a nursing or rehab facility — and they were not initially screened or placed in isolation. In a phrase, IP and employee health personnel have been left to clean up this mess. Arguably, disease severity and death are greater in patients hospitalized with respiratory syncytial virus (RSV) than with either influenza or COVID, but hospitals are not required to provide RSV exposure investigation/notification or restrict employee activities.
If we are to abandon testing and isolation of asymptomatic patients, as well as visitor restrictions and masking requirements for HCWs and visitors alike, then public health authorities need to acknowledge that nosocomial exposures are inevitable (but unlikely to result in transmission), and exposure notification, exposure investigation, and requirements for exposed asymptomatic HCWs need to be similarly abandoned.
Does Obesity Affect HIV Drug Levels?
SOURCE: Berton M, Bettonte S, Stader F, et al. Antiretroviral drug exposure and response in obese and morbidly obese people with human immunodeficiency virus (HIV): A study combining modeling and Swiss HIV Cohort data. Clin Infect Dis 2024:78:98-110.
As obesity reaches near epidemic status in the United States, these authors posed the relevant question of how weight gain affects antiretroviral (ART) drug blood levels in persons with human immunodeficiency virus (HIV). Using therapeutic drug monitoring (TDM) data from the Swiss HIV Cohort Study, modeling of ART pharmacokinetics was performed for different body mass index (BMI) ranges. The cohort included BMIs ranging from 18.5 kg/m2 to 60 kg/m2. TDM data were excluded for persons younger than 20 years of age or older than 50 years of age to avoid confounding age affects. This data set provided a good range of data for most commonly used antiretrovirals. Obesity reduced the area under the curve (AUC) for most ART agents, although the trough concentrations generally were less affected, which the authors stated was important since failure of therapy most often is related to reductions in trough concentrations
For nonnucleoside reverse transcriptase inhibitors, progressive reductions in AUC were predicted for all three drugs with increasing BMI. In addition, trough concentrations were reduced for all three drugs with increasing BMI, with approximately 40% of those with a BMI > 40 kg/m2 failing to reach target levels. The greatest impact was for etravirine, reaching a > 50% reduction in predicted AUC for individuals with BMI > 50 kg/m2 to 60 kg/m2 Detectable HIV viral loads were not observed more frequently in obese individuals receiving these agents.
For integrase inhibitors, reductions in AUC by more than 25% were predicted for dolutegravir for BMI > 30 kg/m2 and for bictegravir and raltegravir for BMI > 40 kg/m2. However, trough concentrations did not appear to differ for different BMI ranges, and observed detectable HIV viral loads were not increased in obese individuals.
For nucleoside reverse transcriptase inhibitors, obesity lowered the predicted AUC and trough concentrations for tenofovir by > 25% for BMI > 40 kg/m2, and the AUC but not the trough concentration was similarly affected for emtricitabine with BMI > 40 kg/m2.
For protease inhibitors, predicted AUC was decreased by > 25% for darunavir/ritonavir for BMI > 40 kg/m2, although trough concentration again did not appear significantly affected. Higher rates of detectable HIV viral loads were not observed in patients receiving darunavir/ritonavir.
In summary, obesity had the greatest impact on etravirine, and to a lesser degree, rilpivirine, with reductions in both AUC and, more importantly, the trough concentrations, which could risk treatment failure. Dosing modifications may need to be considered for those agents, especially in those with morbid obesity. Further, obesity (BMI > 40 kg/m2) significantly lowered both the AUC and trough concentrations for tenofovir, suggesting that failures may be more likely to occur in obese individuals when using this agent for pre-exposure prophylaxis.
Eat Your Fruits and Vegetables!
SOURCE: Lin HY, Fu Q, Tseng TS, et al. Impact of dietary quality on genital oncogenic human papillomavirus infection in women. J Infect Dis 2023;228:1385-1393.
Data from a large-scale national health and nutrition survey from 2003-2016 were used to examine the risk of genital human papillomavirus (HPV) infection in 10,543 women ages 18-59 years. Nearly two-thirds were non-Hispanic white; nearly two-thirds were married or living with a partner; and 13% reported two or more partners within the previous year. HPV deoxyribonucleic acid (DNA) was collected from self-collected vaginal swabs, and a molecular linear array was used to detect 37 HPV genotypes. In addition, information on demographic factors, sexual behavior, and dietary quality were collected. Dietary quality was measured based on a 2015 Health Eating Index (HEI) that sums 13 different dietary components (including total fruits, including juice, whole fruits, total vegetables, green vegetables, beans, whole grains, dairy, total protein foods, seafood, and plant proteins). A higher score indicates higher quality.
High-risk HPV genotypes, low-risk HPV genotypes, and no HPV were found in 19.2%, 21.5%, and 59.3% of the group, respectively. Higher rates of high-risk HPV genotypes were observed, with decreasing frequency, in those with two or more partners in the previous year (40%), younger age (18-26 years) (31%), never married (30%), low income (28%), current smokers (27%), non-Hispanic Black (27%), and high school education (23%).
In addition, there was a strong association between dietary quality and the risk of high-risk HPV. The mean HEI score was 50.8 for those with high-risk HPV, 51.6 for those with low-risk genotypes, and 54.6 for no HPV (P ≤ 0.001). The frequency of high-risk HPV was only 10.2% for those with a high-quality diet (HEI > 80) vs. 25.2% for those with a poor-quality diet (HEI < 40). After adjusting for several factors, several dietary components stood out in the analysis as significantly associated with lower rates of high-risk HPV: greens and beans, total fruits, and whole fruits. There also was some benefit of whole grains and dairy on the prevalence of low-risk HPV but not high-risk HPV.
The authors theorized that the increase in vitamin C and other immunological benefits of a regular diet including dark green vegetables and beans and fruits may reduce inflammation and enhance the immune system response, facilitating clearance of genital HPV. One wonders if other behaviors associated with ingestion of a regular quality diet also contribute to this improved health outcome. Of course, not only is healthy eating a behavior, it also is increasingly a bigger budget item in households.
Abandoning Universal COVID Admission Screening; Does Obesity Affect HIV Drug Levels? Eat Your Fruits and Vegetables!
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