scholarly journals Chemical disinfection of human rotaviruses: efficacy of commercially-available products in suspension tests

1986 ◽  
Vol 97 (1) ◽  
pp. 139-161 ◽  
Author(s):  
V. Susan Springthorpe ◽  
Jodi L. Grenier ◽  
Nellie Lloyd-Evans ◽  
Syed A. Sattar
Keyword(s):  
Organic Matter ◽  
Infectious Virus ◽  
Plaque Assay ◽  
Inorganic Salts ◽  
Fecal Matter ◽  
Human Rotavirus ◽  
Tryptose Phosphate Broth ◽  
Control And Prevention ◽  
Selection Of ◽  
Chemical Disinfection

SUMMARYSuspension tests were conducted on 69 commercial and 7 non-commercial disinfectant formulations to determine which classes of chemicals were most active against human rotavirus (HRV). Virus samples, in the presence of varying levels of organic matter, were exposed to the disinfectants for 1 min. The levels of remaining infectious virus were determined by plaque assay. Products were rated by their ability to reduce the levels of infectious virus by more than 3 log10in the presence or absence of tryptose phosphate broth (peptides and inorganic salts) or fecal matter.Of the commercially-available products tested, only 25% were rated as highly and 7% as moderately effective. The remaining 68% were either effective only in the absence of any additional organic matter (48%) or were completely ineffective (20%). The majority (64%) of the moderately and highly effective products were further examined for their ability to inactivate > 6 log10of infectious HRV in the presence of fecal matter or tryptose phosphate broth. With one exception, all these products were still effective. Products potentially suitable as topical antiseptics, hard surface disinfectants and instrument soaks were identified. The results emphasize the care that should be exercised in the selection of disinfectants for the control and prevention of rotaviral infections.

scholarly journals Chemical disinfection of human rotavirus-contaminated inanimate surfaces

1986 ◽  
Vol 97 (1) ◽  
pp. 163-173 ◽  
Author(s):  
Nellie Lloyd-Evans ◽  
V. Susan Springthorpe ◽  
Syed A. Sattar
Keyword(s):  
Stainless Steel ◽  
Infectious Virus ◽  
Plaque Assay ◽  
Virus Titre ◽  
Relative Resistance ◽  
Hard Surface ◽  
Human Rotavirus ◽  
And Control ◽  
Rotavirus Infections ◽  
Chemical Disinfection

SUMMARYFomites may play a role in the transmission of rotavirus infections, and in view of this, 27 disinfectants were evaluated for their ability to inactivate human rotavirus (HRV) on contaminated non-porous inanimate surfaces. Disks of stainless steel, glass and two types of plastics were contaminated with about 107 plaque-forming units of HRV suspended in faecal matter. The inoculum was allowed todry and an equal volume of the product under test was applied to the contaminated surface. After contact for 1 min, the action of the disinfectant was stopped by dilution. Surviving infectious virus on the disks was determined by plaque assay in MA-104 cells. A product was considered to be effective if itcould reduce the virus titre by at least 3 log10. Only 33·3% (9/27) of the formulations tested proved to be effective. Further testing of the effective products, which included antiseptics, instrument soaks and hard-surface disinfectants, showed that all of them could, in fact, reduce the virus titre on contaminated surfaces by at least 6 log10. These findings show the relative resistance of HRV to a widerange of chemical disinfectants in common use, and also emphasize the need for a more thorough evaluation of the virucidal potential of formulations regularly employed in attempts to prevent and control outbreaks of rotaviral diarrhoea.

scholarly journals Antiviral Activity of the PropylamylatinTM Formula against the Novel Coronavirus SARS-CoV-2 In Vitro Using Direct Injection and Gas Assays in Virus Suspensions

Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 415
Author(s):  
Ashley N. Brown ◽  
Gary Strobel ◽  
Kaley C. Hanrahan ◽  
Joe Sears
Keyword(s):  
Propionic Acid ◽  
Infectious Virus ◽  
Direct Injection ◽  
Plaque Assay ◽  
Antiviral Effect ◽  
Dependent Manner ◽  
Global Public Health ◽  
Novel Coronavirus ◽  
The Individual

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of novel coronavirus disease 2019 (COVID-19), has become a severe threat to global public health. There are currently no antiviral therapies approved for the treatment or prevention of mild to moderate COVID-19 as remdesivir is only approved for severe COVID-19 cases. Here, we evaluated the antiviral potential of a Propylamylatin formula, which is a mixture of propionic acid and isoamyl hexanoates. The Propylamylatin formula was investigated in gaseous and liquid phases against 1 mL viral suspensions containing 105 PFU of SARS-CoV-2. Viral suspensions were sampled at various times post-exposure and infectious virus was quantified by plaque assay on Vero E6 cells. Propylamylatin formula vapors were effective at inactivating infectious SARS-CoV-2 to undetectable levels at room temperature and body temperature, but the decline in virus was substantially faster at the higher temperature (15 min versus 24 h). The direct injection of liquid Propylamylatin formula into viral suspensions also completely inactivated SARS-CoV-2 and the rapidity of inactivation occurred in an exposure dependent manner. The overall volume that resulted in 90% viral inactivation over the course of the direct injection experiment (EC90) was 4.28 µls. Further investigation revealed that the majority of the antiviral effect was attributed to the propionic acid which yielded an overall EC90 value of 11.50 µls whereas the isoamyl hexanoates provided at most a 10-fold reduction in infectious virus. The combination of propionic acid and isoamyl hexanoates was much more potent than the individual components alone, suggesting synergy between these components. These findings illustrate the therapeutic promise of the Propylamylatin formula as a potential treatment strategy for COVID-19 and future studies are warranted.

scholarly journals Two-Way Contact Network Modeling for Identifying the Route of COVID-19 Community Transmission

Informatics ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 22
Author(s):  
Sung Jin Lee ◽  
Sang Eun Lee ◽  
Ji-On Kim ◽  
Gi Bum Kim
Keyword(s):  
Simulated Data ◽  
Contact Network ◽  
Transmission Route ◽  
Time Step ◽  
Source Of Infection ◽  
Health Authorities ◽  
Control And Prevention ◽  
Community Transmission ◽  
Centrality Analysis ◽  
Selection Of

In this study, we address the problem originated from the fact that “The Corona 19 Epidemiological Research Support System,” developed by the Korea Centers for Disease Control and Prevention, is limited to analyzing the Global Positioning System (GPS) information of the confirmed COVID-19 cases alone. Consequently, we study a method that the authority predicts the transmission route of COVID-19 between visitors in the community from a spatiotemporal perspective. This method models a contact network around the first confirmed case, allowing the health authorities to conduct tests on visitors after an outbreak of COVID-19 in the community. After securing the GPS data of community visitors, it traces back to the past from the time the first confirmed case occurred and creates contact clusters at each time step. This is different from other researches that focus on identifying the movement paths of confirmed patients by forward tracing. The proposed method creates the contact network by assigning weights to each contact cluster based on the degree of proximity between contacts. Identifying the source of infection in the contact network can make us predict the transmission route between the first confirmed case and the source of infection and classify the contacts on the transmission route. In this experiment, we used 64,073 simulated data for 100 people and extracted the transmission route and a top 10 list for centrality analysis. The contacts on the route path can be quickly designated as a priority for COVID-19 testing. In addition, it is possible for the authority to extract the subjects with high influence from the centrality theory and use them for additional COVID-19 epidemic investigation that requires urgency. This model is expected to be used in the epidemic investigation requiring the quick selection of close contacts.

Estimation of fermentable energy by the automatic in vitro gas production technique for a selection of feedstuffs incubated alone and in combination

1998 ◽  
Vol 1998 ◽  
pp. 69-69
Author(s):  
S. Fakhri ◽  
A. R. Moss ◽  
D.I. Givens ◽  
E. Owen
Keyword(s):  
Organic Matter ◽  
Incubation Period ◽  
Gas Production ◽  
Production Technique ◽  
In Vitro Gas Production ◽  
Fe Content ◽  
The Individual ◽  
Gas Volume ◽  
Selection Of

The gas production (GP) technique has previously been used to estimate the gas volume (fermentable energy (FE)) of compound feed ingredients for ruminants (Newbold et al., 1996). It was shown that the FE content of feed mixtures was represented by the combination of the total gas from the incubation of the individual feeds. However this additivity might not be consistent throughout the incubation period. The objectives were to test whether 1. other GP parameters give better estimates of FE for simple mixtures and are they additive; 2. whether organic matter apparently degraded in the rumen (OMADR) explain differences in GP; and 3. to find out if there are any other better measures than OMADR for estimating FE.

scholarly journals Pulmonary Versus Extrapulmonary Tuberculosis Associated Factors: A Case-Case Study

2019 ◽  
Vol 12 ◽  
pp. 117863611984036 ◽  
Author(s):  
Alberto Arnedo-Pena ◽  
Maria Angeles Romeu-Garcia ◽  
Noemi Meseguer-Ferrer ◽  
Iraya Vivas-Fornas ◽  
Ana Vizcaino-Batllés ◽  
...  
Keyword(s):  
Associated Factors ◽  
Extrapulmonary Tuberculosis ◽  
Incidence Rates ◽  
Epidemiological Surveillance ◽  
Logistic Regression Models ◽  
Control And Prevention ◽  
Epidemiological Characteristics ◽  
Microbiological Confirmation ◽  
Selection Of

Background: Tuberculosis (TB) incidence remains low in health departments of Castellon and La Plana-Vila-real, but TB elimination is challenging. The objective of this study was to estimate associated factors of pulmonary tuberculosis (PTB) compared with extrapulmonary tuberculosis (ETB) and investigate epidemiological characteristics of these pathologies to orient control and prevention actions. Materials and Methods: A prospective case-case study was implemented by comparing PTB and ETB incidences during 2013-2016 from notification reports, epidemiological surveillance, and microbiological results of hospitals’ laboratories Hospital General Castellon and La Plana-Vila-Real in the province of Castellon of Valencia region in Spain. In this design, cases were patients with PTB and controls were patients with ETB. Directed acyclic graph approach was used for selection of potential risk and confounding factors. Adjusted odds ratios (AORs) were estimated by logistic regression models. Results: The study included 136 patients with PTB and 57 patients with ETB, with microbiological confirmation of 93.4% and 52.6%, and the annual median of incidence rates were 7.5 and 3.1 per 100 000 inhabitants, respectively. In general, patients with PTB were younger with higher male proportion than patients with ETB. Risk factors of PTB were smoking tobacco (AOR = 3.98; 95% confidence interval [CI] = 1.66-9.56), social problems (social marginalization, homeless, residence in shelters for the poor, or stay in prison) (AOR = 3.39; 95% CI = 1.05-10.94), and contact with patients with TB (AOR = 2.51; 95% CI = 1.06-5.95). No-smoking tobacco and no-drug abuse interaction decrease PTB risk (AOR = 0.27; 95% CI = 0.12-0.64). From these results, specific measures of health promotion and prevention can be addressed. Conclusions: The estimated associated factors of PTB may be prevented, and it was demonstrated that the case-case design is useful in the study of TB.

Rotavirus inactivation by chemical disinfectants and antiseptics used in hospitals

1983 ◽  
Vol 29 (10) ◽  
pp. 1464-1469 ◽  
Author(s):  
S. A. Sattar ◽  
R. A. Raphael ◽  
H. Lochnan ◽  
V. S. Springthorpe
Keyword(s):  
Organic Matter ◽  
Contact Time ◽  
Prevention And Control ◽  
Povidone Iodine ◽  
Hospital Environment ◽  
Organic Load ◽  
Common Occurrence ◽  
Test Conditions ◽  
Tryptose Phosphate Broth ◽  
And Control

Nosocomial outbreaks of rotaviral gastroenteritis are a common occurrence. Although proper disinfection practices in the hospital environment are considered to be important in the prevention and control of such outbreaks, very little information has been available on the rotavirus-inactivating capacity of chemical disinfectants and antiseptics commonly used in hospitals. In view of this, 11 such products were selected and screened for their capacity to bring about at least a 3 log10 reduction in the plaque titre of rotavirus SA-11 after a contact time of 1–30 min. Consept "D" (1:100), D.R.X. (1:80), Dustbane Germicidal (1:80), Hibitane, and Wescodyne (1:200) were found to be ineffective under these test conditions even in the absence of an added organic load. The virucidal capacity of Savlon (1:200) and Zephiran was completely neutralized when single-strength tryptose phosphate broth was added to the virus–disinfectant mixture to simulate an organic load. Cidex (2% acid glutaraldehyde), Proviodine (10% solution of povidone-iodine), Septisol (0.75% hexachlorophene), and Sana Rinse (70% isopropylalcohol, 0.1% hexachlorophene) were able to produce at least a 3 log10 (99.9%) reduction in the virus plaque titre even in the presence of added organic matter. These findings should be of help in the prevention and control of outbreaks of rotaviral diarrhea in the hospital environment.

scholarly journals Lyme Neuroborreliosis: Preliminary Results from an Urban Referral Center Employing Strict CDC Criteria for Case Selection

2010 ◽  
Vol 2010 ◽  
pp. 1-3 ◽  
Author(s):  
David S. Younger ◽  
Stuart Orsher
Keyword(s):  
Lyme Disease ◽  
Sensory Neuropathy ◽  
Lyme Neuroborreliosis ◽  
Late Infection ◽  
Serological Evidence ◽  
Single Institution ◽  
Case Selection ◽  
Control And Prevention ◽  
Immunological Effects ◽  
Selection Of

Lyme neuroborreliosis or “neurological Lyme disease” was evidenced in 2 of 23 patients submitted to strict criteria for case selection of the Centers for Disease Control and Prevention employing a two-tier test to detect antibodies toBorrelia burgdorferiat a single institution. One patient had symptomatic polyradiculoneuritis, dysautonomia, and serological evidence of early infection; and another had symptomatic small fiber sensory neuropathy, distal polyneuropathy, dysautonomia, and serological evidence of late infection. In the remaining patients symptoms initially ascribed to Lyme disease were probably unrelated toB. burgdorferiinfection. Our findings suggest early susceptibility and protracted involvement of the nervous system most likely due to the immunological effects ofB. burgdorferiinfection, although the exact mechanisms remain uncertain.

Efficiency of conversion of food to wool at two nutritional levels by three merino strains

1966 ◽  
Vol 17 (1) ◽  
pp. 81 ◽  
Author(s):  
AA Dunlop ◽  
CHS Dolling ◽  
MT Carpenter
Keyword(s):  
Organic Matter ◽  
Energy Level ◽  
Strain Differences ◽  
The Other ◽  
Net Energy ◽  
Wool Production ◽  
Nutritional Level ◽  
Maintenance Ration ◽  
Selection Of ◽  
Digestion Experiment

Efficiency of conversion of fodder to wool in a fine-wool (F), a medium-wool (B), and a strong-wool (S) strain of Merino was estimated by measuring individual fodder consumption and wool production of nine wethers of each strain in two periods, each of 16 weeks. In the first period lucerne chaff and wheat were fed in a 7.2/1 ratio (dry basis) at a maintenance level. In the second, lucerne chaff and wheat were fed in a 2.8/1 ratio at approximately 1.4 times maintenance level. The efficiencies of the strains in the two periods in terms of pounds of oven-dry wool produced per 100 therms of net energy consumed were: Strain Maintenance Maintenance x 1.4 F 1.76 1.52 B 2.03 1.82 S 2.19 1.90 The overall strain differences F v. B and F v. S were significant (P < 0.001) but the remaining difference was not significant. Interactions of strains and nutritional levels were not significant. Individual sheep within strains tended to remain in a similar order of efficiency from one nutritional level to the other, the within-strain correlation between levels being estimated as 0.89. The results suggest that selection of strains and to a lesser extent of individuals on the basis of efficiency will not be seriously affected by the energy level at which efficiency is measured. In a digestion experiment involving all 27 animals of the efficiency experiments, each fed at its maintenance ration, differences between strains in digestibility of organic matter and of protein were extremely small and were non-significant. It is concluded that strain differences in efficiency depend largely on differences in utilization.

STUDIES OF INFECTIOUS BOVINE RHINOTRACHEITIS VIRUS: 1. PLAQUE ASSAY AND SOME CHARACTERISTICS IN BOVINE KIDNEY CELLS

1963 ◽  
Vol 9 (4) ◽  
pp. 567-576 ◽  
Author(s):  
Leslie R. Sabina ◽  
Raymond C. Parker
Keyword(s):  
Infectious Virus ◽  
Plaque Assay ◽  
Growth Curves ◽  
Kidney Cells ◽  
Infectious Bovine Rhinotracheitis ◽  
High Input ◽  
Bovine Kidney ◽  
One Step ◽  
Step Growth ◽  
Infectious Bovine Rhinotracheitis Virus

A reproducible plaquing procedure for infectious bovine rhinotracheitis virus (IBRV) in an established bovine kidney cell line is reported. The validity of this system for quantitative analysis has been established by conventional methods.After infection at different multiplicities, one-step growth curves have shown that the eclipse period for IBRV lasts approximately 4 hours and that the infectious virus increases at a logarithmic rate for 12 to 14 hours. The virus yield with the low and high input is 30 PFU and 210 PFU per cell, respectively. Only 1 to 9% of the total virus is released at 24 hours postinfection. The data presented indicate the half-life of IBRV at 37 °C and 42 °C to be 16 and 3.5 hours, respectively. A comparison of hyperimmune bovine and rabbit sera has shown that 92% of the infective particles are neutralized within 30 minutes.

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