Serotonin as a potential Long COVID biomarker: The chemical messenger serotonin might play a role in causing Long COVID symptoms, according to a new paper published this week in Cell. Researchers at the University of Pennsylvania and colleagues studied blood samples of people with Long COVID and animal models of the condition. They found that people with Long COVID have reduced levels of serotonin throughout their bodies, and that these reductions are correlated with common Long COVID symptoms such as brain fog and autonomic dysfunction. The study also examines biological mechanisms that could play a role in causing reduced serotonin; it provides new information about how a coronavirus infection could trigger long-term symptoms, as well as potential biomarkers for clinical trials. For more context, see this coverage in STAT News.
Healthcare costs of Long COVID: Another Long COVID study from this week, posted as a preprint in The Lancet: researchers at University College London tracked about 282,000 people with Long COVID over the course of two years, compiling their healthcare costs from National Health System (NHS) data. The study included people diagnosed with Long COVID between January 2020 and January 2023, compared with people who did not have Long COVID but had similar demographic characteristics. Long COVID led to higher healthcare spending, the study found, costing about 3,400 British pounds per patient per year. The researchers also noted that, for people with Long COVID, cost increased progressively over time. These costs are far greater for people in the U.S. where most healthcare is privatized.
Hospital-acquired COVID-19 cases: And another British study: researchers at the U.K. Health Security Agency and London School of Hygiene & Tropical Medicine analyzed data from about 350 British hospitals to estimate the prevalence of hospital-acquired coronavirus infections, or people who got the virus while in the hospital for something else. The team found that hospital-acquired infections represented 95,000 to 167,000 cases between June 2020 and March 2021 (i.e. 1% to 2% of all hospital admissions during this period). The researchers also found that people who got COVID-19 at the hospital were more likely to transmit it to other patients, and that more crowded hospitals with fewer single rooms were more likely to have in-hospital transmission. This study demonstrates a need for better infection control measures in hospitals, such as masking, improved ventilation, etc.
Wastewater surveillance for climate-resilient pathogens: In a new article in Science, researchers at the Rockefeller Foundation and the Santa Fe Institute argue that wastewater surveillance should be expanded on a global scale with a interest in tracking pathogens that are resilient to climate change. Pathogens like cholera, Lyme disease, dengue virus, and Zika virus, which can spread more widely in a warming planet, are posing increased risks to global health, the authors explain. Wastewater surveillance—as a population-level, potentially-quick-responding monitoring tool—can help track these pathogens more quickly than traditional tracking methods that rely on medical facilities sharing individual health data. The authors also explain barriers to global wastewater surveillance such as the cost of these programs and their prevalence so far in higher-income countries, as opposed to in some countries where surveillance may be most needed. Significant investment is necessary to build a truly effective system, they argue.