Characterization of an Emergent Chicken H3N8 Influenza Virus in Southern China: a Potential Threat to Public Health.

Although influenza A viruses of several subtypes have occasionally infected humans, to date only those of the H1, H2, and H3 subtypes have led to pandemics and become established in humans. The detection of two human infections by avian H3N8 viruses in April and May of 2022 raised pandemic concerns. Recent studies have shown the H3N8 viruses were introduced into humans from poultry, although their genesis, prevalence, and transmissibility in mammals have not been fully elucidated. Findings generated from our systematic influenza surveillance showed that this H3N8 influenza virus was first detected in chickens in July 2021 and then disseminated and became established in chickens over wider regions of China. Phylogenetic analyses revealed that the H3 HA and N8 NA were derived from avian viruses prevalent in domestic ducks in the Guangxi-Guangdong region, while all internal genes were from enzootic poultry H9N2 viruses. The novel H3N8 viruses form independent lineages in the glycoprotein gene trees, but their internal genes are mixed with those of H9N2 viruses, indicating continuous gene exchange among these viruses. Experimental infection of ferrets with three chicken H3N8 viruses showed transmission through direct contact and inefficient transmission by airborne exposure. Examination of contemporary human sera detected only very limited antibody cross-reaction to these viruses. The continuing evolution of these viruses in poultry could pose an ongoing pandemic threat. IMPORTANCE A novel H3N8 virus with demonstrated zoonotic potential has emerged and disseminated in chickens in China. It was generated by reassortment between avian H3 and N8 virus(es) and long-term enzootic H9N2 viruses present in southern China. This H3N8 virus has maintained independent H3 and N8 gene lineages but continues to exchange internal genes with other H9N2 viruses to form novel variants. Our experimental studies showed that these H3N8 viruses were transmissible in ferrets, and serological data suggest that the human population lacks effective immunological protection against it. With its wide geographical distribution and continuing evolution in chickens, other spillovers to humans can be expected and might lead to more efficient transmission in humans.

Influenza A virus transmission in swine farms and during transport in the swine supply chain.

The last influenza pandemic in 2009 emerged from swine and surveillance of swine influenza is important for pandemic preparedness. Movement of swine during husbandry, trade or marketing for slaughter provide opportunities for transfer and genetic reassortment of swine influenza viruses. Over 90% of the swine slaughtered at the central swine abattoir in Hong Kong are imported from farms located in multiple provinces in mainland China. There is opportunity for virus cross-infection during this transport and slaughter process. Of the 26,980 swabs collected in the slaughterhouse in Hong Kong from 5 January 2012 to 15 December 2016, we analysed sequence data on influenza A (H3N2) virus isolates (n = 174) in conjunction with date of sampling and originating farm. Molecular epidemiology provided evidence of virus cross-infection between swine originating from different farms during transport. The findings are also suggestive of a virus lineage persisting in a swine farm for over 2 years, although the lack of information on management practices at farm-level means that alternative explanations cannot be excluded. We used virus serology and isolation data from 4226 pairs of linked serum and swabs collected from the same pig at slaughter from swine originating from Guangdong Province to compare the force of infection (FOI) during transport and within farms. The mean weekly FOI during transport was λt  = 0.0286 (95% CI = 0.0211-0.0391) while the weekly FOI in farms was λf = 0.0089 (95% CI = 0.0084-0.0095), assuming a possible exposure duration in farm of 28 weeks, suggesting increased FOI during the transport process. Pigs sourced from farms with high seroprevalence were found to be a significant risk factor (adjusted OR = 2.24, p value = .015) for infection of imported pigs during transport by multivariable logistic regression analysis, whereas pigs with HAI titre of ≥1:40 were associated with a substantial reduction in infection risk by 67% (p value = 0.012). Transport may increase virus cross-infection rates and provide opportunities for virus reassortment potentially increasing zoonotic risk to those involved in the transportation and slaughtering processes.

The isolation of a DNA aptamer to develop a fluorescent aptasensor for the thiamethoxam pesticide.

Aptamers, which are called chemical antibodies for their high affinity and specificity to targets, have great potential as analytical tools to detect pesticides. In this work, a DNA aptamer for thiamethoxam was isolated by an improved SELEX (systematic evolution of ligands by exponential enrichment) strategy, in which the ssDNA library was fixed on streptavidin-agarose beads through a short biotin labeled complementary strand. After 13 rounds of selection, the random ssDNA pool was successfully enriched. Three sequences were chosen as aptamer candidates through sequencing and analysis and were transformed into fluorescent probes to evaluate their interactions with thiamethoxam. A fluorescent turn-on aptasensor for thiamethoxam based on the best aptamer (FAM-Thi13) and a short quenching strand were further designed and showed a quantitative linear range from 10 to 1000 nM with a detection limit of 1.23 nM for thiamethoxam. Molecular docking and molecular dynamics were used to investigate the binding site of the main probe of the aptasensor (FAM-Thi13) and thiamethoxam. Satisfactory results were also obtained in quantifying thiamethoxam in environmental water samples by the developed fluorescent aptasensor.

Recommendation about the perioperative prevention of infection to healthcare workers and the anesthesia management of children with SARS-CoV-2 infection.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread widely and persistently over 100 countries. New challenges have occurred in the perioperative management of airway and anesthesia in children diagnosed with SARS-CoV-2 infection. According to current publications and to our own experiences in anesthesia management for cases with SARS-CoV-2 suspected, we reviewed concerns about the perioperative prevention of SARS-CoV-2 to medical staff and the anesthesia strategy to the patient.

Residual airway foreign bodies in children who underwent rigid bronchoscopy.

OBJECTIVE: To analyze the causes of residual airway foreign bodies in children who underwent rigid bronchoscopy in order to improve the success rate of primary surgery. METHODS: Clinical data from 1130 children with airway foreign bodies, including 736 males and 394 females aged 0.42-14 years, who underwent rigid bronchoscopy in our hospital from January 2015 to May 2018 were retrospectively collected and analyzed by cluster sampling. Clinical characteristics including sex, age, time of onset, location of the foreign body, type of foreign body and experience of surgeon were gathered. All patients were classified into two groups as Group A (with residual airway foreign bodies) and Group B (without residual airway foreign bodies) according to chest CT scans and fiberoptic bronchoscope examinations after rigid bronchoscopy. The values were compared between the two groups. RESULTS: Thirty-one patients with residual foreign bodies were confirmed by fiberoptic bronchoscopy among 1130 children with airway foreign bodies who underwent rigid bronchoscopy under general anesthesia. The percentage of residual airway foreign body was 2.7%. The mean age was 1.55 ±â€¯0.46 years (range 1-3 years). There were 24 male patients (77.4%), and 7 female patients (22.6%), with a male/female ratio of 3.43:1. The time of onset was 1.0 (interquartile range: 1.0-8.0) day. There were no significant difference in age, sex and time of onset between the two groups. Most residual foreign bodies were food-related: nuts (n = 27, 87.1%), beans (n = 3, 9.7%), and one case was unclear in nature (3.2%). The residual incidence of fragile foreign bodies was higher than non-friable foreign bodies (P = 0.028). The most common residual foreign body locations were left superior lobar bronchi (32.3%), left inferior lobar bronchi (25.8%) and right inferior lobar bronchi (25.8%). The residual rate of foreign bodies for surgeons with more than 5 years of operative experience was 1.92%, and 4.25% for surgeons with less than 5 years of operation experience, showing a significant difference (P = 0.022). CONCLUSION: Friable foods, the complicated structure of the bronchus tree and the surgeon's experience are important causes of residual foreign bodies in the airway. Surgeons with sufficient experience are important for the success of the procedure, which is supported by chest CT and flexible bronchoscopy.

Application of end-tidal carbon dioxide monitoring via distal gas samples in ventilated neonates.

BACKGROUND: Previous research has suggested correlations between the end-tidal partial pressure of carbon dioxide (PETCO2) and the partial pressure of arterial carbon dioxide (PaCO2) in mechanically ventilated patients, but both the relationship between PETCO2 and PaCO2 and whether PETCO2 accurately reflects PaCO2 in neonates and infants are still controversial. This study evaluated remote sampling of PETCO2 via an epidural catheter within an endotracheal tube to determine the procedure's clinical safety and efficacy in the perioperative management of neonates. METHODS: Abdominal surgery was performed under general anesthesia in 86 full-term newborns (age 1-30 days, weight 2.55-4.0 kg, American Society of Anesthesiologists class I or II). The infants were divided into 2 groups (n = 43 each), and carbon dioxide (CO2) gas samples were collected either from the conventional position (the proximal end) or a modified position (the distal end) of the epidural catheter. RESULTS: The PETCO2 measured with the new method was significantly higher than that measured with the traditional method, and the difference between PETCO2 and PaCO2 was also reduced. The accuracy of PETCO2 measured increased from 78.7% to 91.5% when the modified sampling method was used. The moderate correlation between PETCO2 and PaCO2 by traditional measurement was 0.596, which significantly increased to 0.960 in the modified sampling group. Thus, the PETCO2 value was closer to that of PaCO2. CONCLUSION: PETCO2 detected via modified carbon dioxide monitoring had a better accuracy and correlation with PaCO2 in neonates.

Preventative effect of ondansetron on postanesthesia shivering in children undergoing caudal anesthesia: a randomized double-blinded clinical trial.

BACKGROUND: Ondansetron has been shown to decrease postanesthesia shivering in adults, but this effect has never been studied in children. This study aimed to determine whether ondansetron decreases postanesthesia shivering in children undergoing caudal anesthesia. METHODS: Fifty-nine 8- to 13-y-old children undergoing both intravenous and caudal anesthesia were included. As soon as anesthetization and caudal block were complete, children were given intravenous injections of 4 mg ondansetron or an equal volume of normal saline. Heart rate, blood pressure, oxygen saturation (SpO2), and body temperature were recorded just before application of general anesthesia to children and immediately upon entry into the recovery room after awakening from anesthesia. The shivering score was assessed, using a 4-point scale of severity, immediately upon entry into the recovery room after awakening from anesthesia, 15 min after entry into the recovery room, and 30 min after entry into the recovery room. RESULTS: Treatment with ondansetron was associated with decreased odds of postanesthesia shivering symptoms compared to the control group. There was also a significant decrease in shivering score with time after anesthesia. CONCLUSION: Ondansetron decreases postanesthesia shivering in children receiving caudal block after intravenous anesthesia.