RESUMEN
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein (S) plays critical roles in host cell entry. Non-synonymous substitutions affecting S are not uncommon and have become fixed in a number of SARS-CoV-2 lineages. A subset of such mutations enable escape from neutralizing antibodies or are thought to enhance transmission through mechanisms such as increased affinity for the cell entry receptor, angiotensin-converting enzyme 2 (ACE2). Independent genomic surveillance programs based in New Mexico and Louisiana contemporaneously detected the rapid rise of numerous clade 20G (lineage B.1.2) infections carrying a Q677P substitution in S. The variant was first detected in the US on October 23, yet between 01 Dec 2020 and 19 Jan 2021 it rose to represent 27.8% and 11.3% of all SARS-CoV-2 genomes sequenced from Louisiana and New Mexico, respectively. Q677P cases have been detected predominantly in the south central and southwest United States; as of 03 Feb 2021, GISAID data show 499 viral sequences of this variant from the USA. Phylogenetic analyses revealed the independent evolution and spread of at least six distinct Q677H sub-lineages, with first collection dates ranging from mid-August to late November 2020. Four 677H clades from clade 20G (B.1.2), 20A (B.1.234), and 20B (B.1.1.220, and B.1.1.222) each contain roughly 100 or fewer sequenced cases, while a distinct pair of clade 20G clusters are represented by 754 and 298 cases, respectively. Although sampling bias and founder effects may have contributed to the rise of S:677 polymorphic variants, the proximity of this position to the polybasic cleavage site at the S1/S2 boundary are consistent with its potential functional relevance during cell entry, suggesting parallel evolution of a trait that may confer an advantage in spread or transmission. Taken together, our findings demonstrate simultaneous convergent evolution, thus providing an impetus to further evaluate S:677 polymorphisms for effects on proteolytic processing, cell tropism, and transmissibility.
RESUMEN
Brucellosis is the world's most widespread zoonosis, but also ranks as one of the seven most neglected diseases, according to the World Health Organization. Additionally, it is recognized as the world's most common laboratory-acquired infection. There are a reported 500,000 incident cases of human brucellosis per year. However, true incidence is estimated to be 5,000,000 to 12,500,000 cases annually. Once diagnosed, focus is directed at treating individual patients with antibiotic regimes, yet overall neglecting the animal reservoir of disease. Countries with the highest incidence of human brucellosis are Syria (1,603.4 cases per 1,000,000 individuals), Mongolia (391.0), and Tajikistan (211.9). Surveillance on animal populations is lacking in many developed and developing countries. According to the World Animal Health Information Database, Mexico had the largest number of reported outbreaks, 5,514 in 2014. Mexico is followed by China (2,138), Greece (1,268), and Brazil (1,142). The majority of these outbreaks is Brucella abortus, the etiologic agent of bovine brucellosis. Brucellosis is an ancient disease that still plagues the world. There are still knowledge gaps and a need for better diagnostics and vaccines to make inroads towards control and eradication.
RESUMEN
Canine dysautonomia is a sporadic, generally fatal disease that rarely affects groups of related animals. Four 10-week-old Havanese puppies from a litter of 5 developed clinical signs of canine dysautonomia. The 4 affected dogs were exposed to an outdoor environment, whereas the fifth littermate was not exposed to the outdoors and remained clinically healthy. Clinical signs of dysautonomia developed 10-16 days after going outside the house. An unrelated dog also developed dysautonomia after exposure to 1 of the affected Havanese littermates. All 5 dogs had morphological changes consistent with dysautonomia (widespread neuronal degeneration in autonomic ganglia, select brainstem nuclei, and ventral horn motor neurons). Differential diagnoses were excluded through negative toxicological evaluation, fecal parasite screening, negative Canine distemper virus reverse transcription polymerase chain reaction, fluorescent antibody testing, attempted virus isolation, and electron microscopy. The 5 affected dogs were in the Kansas City, Missouri area, where there is a high incidence of dysautonomia.
Asunto(s)
Crianza de Animales Domésticos , Virus del Moquillo Canino/aislamiento & purificación , Moquillo/diagnóstico , Disautonomías Primarias/veterinaria , Animales , Animales Recién Nacidos , Diagnóstico Diferencial , Moquillo/epidemiología , Virus del Moquillo Canino/genética , Perros , Ambiente , Missouri/epidemiología , Reacción en Cadena de la Polimerasa/veterinaria , Disautonomías Primarias/diagnóstico , Disautonomías Primarias/epidemiologíaRESUMEN
INTRODUCTION: E-cigarette use has surged during the past few years while the debate about the product's safety and efficacy for smoking cessation continues. Little is known about the characteristics that distinguish users from nonusers; in this study, we aimed to elucidate these characteristics among hospitalized smokers, a heretofore unstudied population. METHODS: Cross-sectional data were collected from cigarette smokers via hospital bedside interviews. Participants reported e-cigarette use status, reasons for use (if used), e-cigarette advertising exposure, expected likelihood of future e-cigarette use, desire to quit smoking, and demographic characteristics. RESULTS: Of the 657 English-speaking hospitalized smokers who provided data, 97% reported awareness of e-cigarettes and 46.4% reported e-cigarette use, with 20% reporting use in the previous 30 days. Previous e-cigarette use was significantly more likely among those who were White (odds ratio [OR] = 4.7; confidence interval [CI] = 3.2-6.7), were married/had a domestic partner (OR = 1.5; CI = 1.0-2.2), had more than a high school education (OR = 1.7; CI = 1.1-2.7), had e-cigarette advertising exposure (OR = 1.6; CI = 1.1-2.4), and were younger (OR = 1.3; CI = 1.1-1.5). Expected likelihood of future e-cigarette use was high and positively correlated with desire to quit smoking (Spearman's ρ = .18, p < .0001). CONCLUSIONS: Rates of awareness and use of e-cigarettes may be elevated among hospitalized smokers, with more use reported among those who were White, younger, more educated, in a relationship, and exposed to e-cigarette advertising. The association between desire to quit smoking and expected likelihood of future e-cigarette use suggests that cigarette smokers may perceive e-cigarettes as a useful cessation aid.