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Weekly Digest: Climate and SARS-CoV-2 outbreaks; The COVID-19 conversation is about language; Genomic-informed pathogen surveillance in Africa; Economic evaluations of new antibiotics.  

Weekly Digest: Climate and SARS-CoV-2 outbreaks; The COVID-19 conversation is about language; Genomic-informed pathogen surveillance in Africa; Economic evaluations of new antibiotics.   


Assessing the influence of climate on wintertime SARS-CoV-2 outbreaks. Several common viral infections, such as varicella, influenza, and respiratory syncytial virus, exhibit seasonal cycles related to specific humidity. Although evidence suggests the SARS-CoV-2 virus is sensitive to the climate in laboratory settings, the role of climate on the global spread of the virus has not been determined. A recent study in Nature Communications evaluated the spread of COVID-19 and the relative efficacy of non-pharmaceutical interventions (NPIs) such as social distancing and mask-wearing compared to climatic factors. The authors estimated the reproductive number (R0) of the virus and used SIRS models to evaluate the contributions of climate and NPIs to R0. They found that although climate sensitivity and weather affected COVID-19 cases, particularly in areas far from the tropics, the efficacy of NPIs had a much larger effect on peak values of the epidemic. The authors conclude that more stringent NPIs may be required in the winter months than summer to reduce COVID-19 cases in a highly susceptible population, though large outbreaks were estimated to occur regardless of climatic conditions in the absence of NPIs. [Nature]

Changing the COVID-19 conversation: it’s about language. Language gives meaning to messages that are conveyed and, when used effectively, has the potential to influence behavior. In a letter to JAMA, authors elaborated on how the COVID-19 pandemic has exposed the challenges with communicating public health messages in the US. The authors cited the findings from a nationwide poll of 1100 registered voters in the US, where 47% of the respondents had a more favorable reaction to a “stay-at-home order” than to a “lockdown” (15%) or “aggressive restrictions” (19%). Furthermore, concerning policies to combat the pandemic, the term “fact-based” (46%) or “based on science” (43%) had more significant influence than saying they are based on “evidence,” “data,” or “medicine.” The authors concluded by emphasizing that warlike imagery of language is not optimal and that while many people are exhausted by the pandemic, messages should convey that public health measures are not the enemy but the road map for a faster and more sustainable recovery. [JAMA Health Forum

Urban-rural differences in COVID-19 exposures and outcomes in the South: A preliminary analysis of South Carolina. The COVID-19 pandemic initially hit urban areas in the Northeast United States the hardest. However, in South Caroline, the transmission was initially concentrated in small towns and metro counties then spread to urban and rural areas. This study investigates county-level spatial and temporal patterns of COVID-19 cases in South Carolina from March 1 – September 5, 2020. Researchers report cases drastically increased after Memorial Day when state mitigation measures were relaxed, peaking in mid-July and then slowly declining. Results indicate mortality rates were positively correlated with pre-existing social vulnerability (rs = 0.403, p<0.01) and negatively correlated with county resilience patterns (rs = -0.313, p<0.05). Significant differences were observed between urban and rural counties with rural cases rates higher than urban cases rates (2757.40 vs. 2373.14 per 100,000) over the study period. Findings support the hypothesis that higher rates in rural areas are driven by disparities in pre-existing conditions and healthcare access. These findings are consistent with urban-rural trends visualized on CDDEP’s ResistanceMap. [PLOS ONE]

SARS-CoV-2 infection is effectively treated and prevented by EIDD-2801. Researchers at UNC have developed a murine model to investigate the pathogenesis and replication of SARS-CoV-2 and other human coronaviruses in human lung tissue. The model, called a lung-only mouse (LoM) model, allows for the in vivo study of human coronaviruses without modifying the virus or the host cells by implanting authentic lung tissue in immune-compromised mice. This model was applied to study the in vivo effect of EIDD-2801, an orally administered broad-spectrum antiviral, on inhibiting SARS-CoV-2. The study revealed that EIDD-2801 efficiently inhibited SARS-CoV-2 replication in human lung tissue and prevented SARS-CoV-2 infection when administered as a preventative measure. EIDD-2801 is currently in phase II-III trials. [Nature]


Drug Resistance and Global Health

Genomic-informed pathogen surveillance in Africa: opportunities and challenges  Endemic infectious diseases, antimicrobial resistance, and outbreaks account for at least 35% of the 10 million deaths in Africa. However, gaps in surveillance data due to lack of infrastructure and expertise hamper prevention, control, and elimination efforts. The COVID-19 pandemic has demonstrated that genomic surveillance can be instrumental in managing outbreaks. WHO has already recommended using next-generation sequencing (NGS) as an additional surveillance tool for drug resistance to HIV, TB, malaria, and foodborne pathogens, among others. However, sequencing capacity in Africa is scarce, is disproportionately concentrated in 5 countries (71%) and in the private sector (70%), underscoring the importance of national public health capacity building. Incorporating pathogen genomics into public health requires substantial investments; the initial capital for establishing sequencing capacity can range from US$100 000 to 700 000. However, these costs can be minimised using functional networks of multi pathogen genomics facilities, sequencing through high-level multiplexing, centralised bulk purchasing, and price negotiations. Whereas capacity building could include leveraging established African institutions. [The Lancet Infectious Disease]

Associations between private vaccines and antimicrobial consumption across Indian states, 2009–2017. A study by CDDEP researchers found that private-sector vaccine use was negatively associated with antibiotic consumption in 22 Indian states and territories from January 2009 to December 2017. India had the greatest total antibiotic consumption of any country in 2015, and increasing antibiotic consumption in the country has been associated with increased antibiotic resistance rates. The authors used monthly consumption data from IQVIA, representing private-sector sales, and the Government of India’s Health Management Information System to evaluate the association between vaccination and antibiotic consumption in Indian states. Because vaccines in India are primarily targeted to children and used to avert diseases over the long-term, the authors evaluated this association at various time intervals and found a reduction in antibiotic consumption beginning 32 months after vaccination. The analysis adds to evidence suggesting that vaccination can reduce antibiotic consumption and, consequently, antibiotic resistance in low- and middle-income countries. [Annals of the New York Academy of Science]

Economic evaluations of new antibiotics: the high potential value of reducing healthcare transmission through decolonization. Antibiotics that decolonize carriers of drug-resistant pathogens benefit population health by preventing outbreaks. However, determining their cost-effectiveness is difficult as antibiotics are typically evaluated only by benefits to individual recipients. Researchers developed a model to estimate the effects of two hypothetical antibiotics targeting carbapenem-resistant Enterobacteriaceae (CRE) in long-term care hospital inpatients: one that reduced the death rate among individuals with CRE bloodstream infections (BSIs), and another that decolonized detected CRE infected individuals. A cost-effectiveness analysis investigated direct (among patients receiving the drug) and indirect (among all patients) effects of both drugs compared to usual care and compared to each other. Outcomes included life-years gained and costs for antibiotic doses and for CRE BSI. When both direct and indirect effects were included, the decolonizing antibiotic was less costly and more effective (dominant) than both the BSI treatment antibiotic and usual care. Researchers concluded that incentivizing the development of decolonizing antibiotics could have significant public health benefits, especially among populations vulnerable to outbreaks. [Clinical Infectious Diseases]

Evidence for selection of multi-resistant E. coli by hospital effluent. An investigation of the wastewater produced by a large Swedish hospital found it highly selective for antibiotic-resistant E. coli. The theory behind this being that unfiltered wastewater from hospitals is rich in antimicrobials that kill off susceptible bacterial strains at an accelerated rate. The researchers found that several antibacterial agents in the wastewater were above the minimal inhibitory concentration; however, they could not conclude which antibiotic contributed directly to the selection pressure. This research’s implications may have an outsized impact in the low- and middle-income countries with more inadequate water treatment infrastructure and greater antimicrobial prescribing. [Environment International]

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