How to improve adherence with quarantine: rapid review of the evidence.

OBJECTIVES: The December 2019 outbreak of coronavirus has once again thrown the vexed issue of quarantine into the spotlight, with many countries asking their citizens to 'self-isolate' if they have potentially come into contact with the infection. However, adhering to quarantine is difficult. Decisions on how to apply quarantine should be based on the best available evidence to increase the likelihood of people adhering to protocols. We conducted a rapid review to identify factors associated with adherence to quarantine during infectious disease outbreaks. STUDY DESIGN: The study design is a rapid evidence review. METHODS: We searched Medline, PsycINFO and Web of Science for published literature on the reasons for and factors associated with adherence to quarantine during an infectious disease outbreak. RESULTS: We found 3163 articles and included 14 in the review. Adherence to quarantine ranged from as little as 0 up to 92.8%. The main factors which influenced or were associated with adherence decisions were the knowledge people had about the disease and quarantine procedure, social norms, perceived benefits of quarantine and perceived risk of the disease, as well as practical issues such as running out of supplies or the financial consequences of being out of work. CONCLUSIONS: People vary in their adherence to quarantine during infectious disease outbreaks. To improve this, public health officials should provide a timely, clear rationale for quarantine and information about protocols; emphasise social norms to encourage this altruistic behaviour; increase the perceived benefit that engaging in quarantine will have on public health; and ensure that sufficient supplies of food, medication and other essentials are provided.

A systematic review of infectious illness Presenteeism: prevalence, reasons and risk factors.

BACKGROUND: Workplace presenteeism is common and leads to the spread of infectious diseases. Previous reviews have focused on presenteeism in relation to general physical or mental ill health. In this systematic review we identified the prevalence of, and reasons and risk factors for, presenteeism in relation to an infectious illness. METHOD: We searched Medline, Scopus, Web of Science, PsycINFO and PsycARTICLES with terms relating to infectious illnesses and presenteeism at the work place or school; reference lists of relevant articles were also hand-searched. RESULT: Our search yielded 3580 papers after deduplication. After title, abstract and full text screening, 23 papers reporting on 24 studies were included. Twenty-three studies were cross-sectional studies and one was prospective. The quality of included studies was relatively poor due to problems such as sampling and non-response bias. Presenteeism prevalence ranged from 35 to 97%. Self-reported reasons for presenteeism fell into three main themes: 1. Organisational factors (organisational policy, presenteeism culture, disciplinary action), 2. Job characteristics (lack of cover, professionalism, job demand), and 3. Personal reasons (burden on colleagues, colleague perceptions, threshold of sickness absence and financial concerns). Statistical risk factors fell into four themes: 1. Sociodemographic, 2. Health, 3. Influenza-related behaviour, and 4. Employment characteristics. Most of the risk factors had insufficient evidence to allow us to draw any firm conclusions, and evidence regarding gender and age was inconsistent. The risk factor with the most consistent findings concerned occupation type, suggesting that those who worked in the healthcare sector, and specifically physicians, were at a higher risk of infectious illness presenteeism. CONCLUSION: Infectious illness presenteeism is common. To address the public health consequences, organisations should focus on promoting a positive working culture and developing sickness absence policies that reduce presenteeism. Further research is needed in non-health sector organisations and schools to identify risk factors related to different organisations, which can then be used to tailor interventions at the organisational and individual level.

Explaining all without causing unnecessary harm: Is there scope for positively framing medical risk information?

Clinicians in the United Kingdom are now legally obliged to tell patients about every risk involved in prescribed medical treatments. Although important for informed consent, warning patients of risks such as side-effects can increase the incidence of these very side-effects, through the nocebo effect. Positively framing risk information could be a potential solution to this dilemma, and preliminary data has shown it is effective in healthy volunteers receiving a sham drug. Future research is needed to test its effectiveness in a clinical population.

Population structure of Fusarium fujikuroi from California rice and water grass.

The recent observance of Fusarium fujikuroi, the causal agent of Bakanae disease of rice, in California provides a unique opportunity to assess the population diversity of an introduced pathogen in a new environment. We collected 172 isolates of this pathogen between 2000 and 2003 from California rice and two from water grass (Echinochloa spp.). Pathogenicity of F. fujikuroi was demonstrated on early water grass (E. oryzoides) and barnyard grass (E. crus-galli) indicating that weed control should be part of Bakanae management programs. Both mating types and six unique amplified fragment length polymorphism haplotypes corresponding to six identified vegetative compatibility groups were detected. The two most frequently isolated haplotypes encompassed 94% of the collected isolates, suggesting that clonal reproduction dominates. Coefficients of similarity between the unique haplotypes ranged from 0.94 to 0.98, and indicate that there is very little genotypic variation in the F. fujikuroi population in California. The near fixation of the MAT-1 idiomorph (observed ratio 170 MAT-1:4 MAT-2), is consistent with a hypothesis of predominant or exclusive asexual reproduction. The low level of introduced genotypic diversity, in conjunction with the asexual reproductive strategy of this population will slow evolutionary processes, including adaptation to the California environment.

Effects of Rice Straw Management on Sclerotium oryzae Inoculum, Stem Rot Severity, and Yield of Rice in California.

Under continuous rice cropping, open field burning has been the primary means of rice residue disposal and of minimizing the carryover inoculum of Sclerotium oryzae, the cause of stem rot of rice. The phase down of open field burning in California has necessitated the development of alternatives to burning. In 1993, a continuous-year experiment was initiated in Colusa County to evaluate the effects of alternative residue management strategies on overwintering sclerotia of S. oryzae, stem rot incidence and severity, and yield. Treatments were arranged in a split-plot design with winter flooding and winter nonflooding as the main plots, and fall incorporation of the straw residue, rolling of the straw to enhance soil contact, baling and removal of residue, and fall burning as the subplots. S. oryzae inoculum and disease severity were significantly lower and yield was significantly higher in 5 out of 6 years in the winter-flooded main plots compared with the winter nonflooded plots. Over the duration of the trial, S. oryzae inoculum was consistently lower in burn subplots when compared with all other subplots. No consistent differences in disease incidence and severity or yield occurred in the subplots, although average yield over the 6 years was highest in burn subplots when compared with all other subplots. The results suggest that winter flooding is the best alternative to burning for stem rot management.

Occurrence, Distribution, Epidemiology, Cultivar Reaction, and Management of Rice Blast Disease in California.

Rice blast, caused by Pyricularia grisea, was first found in California in 1996. Disease surveys have shown the blast disease is spreading at a moderate rate in California rice fields. Although no effective major resistance genes are known to occur in widely grown commercial California cultivars, there appear to be differences among the cultivars with respect to field susceptibility to the pathogen. P. grisea was recovered from rice crop residue and commercial seedlots which are suggested as possible sources of initial P. grisea inoculum in California rice fields. Examination of weather data indicates that environmental conditions in California rice-producing areas are permissive for rice blast but generally not optimal for epidemic development. Spore trapping determined that the majority of P. grisea conidia are generally not released until approximately 6:00 A.M. and would not have sufficient time for infection before leaf wetness periods end. Azoxystrobin showed positive results with respect to reduction of neck blast incidence and yield increases in small-plot and large-scale fungicide trials.

Identification of Molecular Genetic Markers in Pyrenophora teres f. teres Associated with Low Virulence on 'Harbin' Barley.

ABSTRACT Two isolates of the barley net blotch pathogen (Pyrenophora teres f. teres), one possessing high virulence (0-1) and the other possessing low virulence (15A) on the barley cultivar Harbin, were crossed and the progeny of the mating were isolated. Conidia from cultures of the parent and progeny isolates were used as inoculum to determine the inheritance of virulence in the pathogen. Of the 82 progeny tested, 42 exhibited high virulence and 40 exhibited low virulence on 'Harbin' barley. The data support a model in which a single, major gene controls virulence in P. teres f. teres on this barley cultivar (1:1 ratio; chi(2) = 0.05, P = 0.83). Preparations of DNA were made from parental and progeny isolates, and the DNA was subjected to the random amplified polymorphic DNA (RAPD) technique in a search for molecular genetic markers associated with the virulence phenotype. Five RAPD markers were obtained that were associated in coupling with low virulence. The data indicate that the RAPD technique can be used to tag genetic determinants for virulence in P. teres f. teres.

First Report of Rice Blast Caused by Pyricularia grisea in California.

Rice blast, caused by Pyricularia grisea (Cooke) Sacc., generally recognized as the most important disease of rice (Oryzae sativa L.) worldwide, was first found in the Sacramento Valley of California in 1996. Symptoms observed in commercial fields during September and October consisted mainly of darkened lesions at the panicle neck node and flag leaf collar. Many of the panicles with neck rot were partially filled or blank. Disease foci were irregular within fields and the most severely affected areas had approximately 50% of the panicle necks with symptoms. Initial identification of P. grisea was made by isolating the fungus from panicle neck nodes and leaf collars on potato dextrose agar. Subsequent identifications were made by placing symptomatic panicle neck nodes or leaf collars on moist filter paper in petri dishes to allow sporulation of the fungus. P. grisea was consistently recovered from these tissues and was identified by conidial morphology. A survey of over 500 rice fields in five Sacramento Valley counties was conducted in September and October 1996. Rice blast was confirmed in 33 commercial fields, which are spread over an area of approximately 460 km2 in Glenn County (27 fields) and northern Colusa County (6 fields). No blast was found in Butte, Sutter, or Yolo counties. P. grisea was recovered from cvs. M-201, M-202, M-204, M-103, M-401, S-102, L-204, and Calmochi-101 and several proprietary lines. To confirm pathogenicity of P. grisea, cv. M-201 was inoculated in the greenhouse 28 days after seeding with a suspension of 20,000 conidia per ml of sterile deionized water, covered with plastic bags for 2 days, and evaluated 7 days later. P. grisea isolates from cvs. M-201, M-202, and M-204 produced typical leaf and collar blast symptoms on inoculated plants, whereas control plants remained asymptomatic. P. grisea was consistently recovered from lesions on inoculated plants. No rice cultivars currently grown in California are known to have resistance to blast.

Genetic variability for pathogenicity, isozyme, ribosomal DNA and colony color variants in populations of Rhynchosporium secalis.

Samples of Rhynchosporium secalis were collected from two experimental barley populations known to carry a diverse array of alleles for resistance to this fungal pathogen. Classification of 163 isolates for four putative isozyme systems, a colony color dimorphism and 20 ribosomal DNA restriction fragment length variants revealed 49 different multilocus phenotypes (haplotypes). The six most common haplotypes differed significantly in pathogenicity. Genetic analyses of the data indicated that effective population sizes of the fungus were very large, that the effects of genetic drift were small, and that negligible recombination occurred in the populations studied. Frequency dependent selection was suggested as an explanation for the maintenance of variation in pathogenicity in the fungus.

Coevolution of host and pathogen populations in the Hordeum vulgare-Rhynchosporium secalis pathosystem.

Isolates of Rhynchosporium secalis collected from two experimental barley populations were scored for putative isozyme, colony color, and virulence loci. Allelic frequencies, multilocus haplotype frequencies, and multilocus genetic structure differed in the two populations of R. secalis; haplotypes also differed widely from each other in virulence. The average virulence of isolates collected from the more resistant host population was greater than the average virulence of the isolates collected from the less resistant host population; also the least virulent haplotype, which made up 19% of the pathogen population collected from the less resistant host population, accounted for only 0.3% of the isolates collected from the more resistant host population. It was concluded that the genetic systems of the barley host and fungal pathogen interacted in a complementary fashion and that the genetic structures of both the host and pathogen populations were shaped by coevolutionary processes featuring interactions among loci affecting many different traits, including interactions among host resistance genes and pathogen virulence genes.

Evolution of resistance to scald, powdery mildew, and net blotch in barley composite cross II populations.

Progenies of barley plants taken at random from generations F8, F13, F23, and F45 of Composite Cross II were tested for reaction to three barley pathogens, Helminthosporium teres, Erysiphe graminis, and Rhynchosporium secalis (four races). The frequency of families resistant to each of the three pathogens (excepting one race of R. secalis) increased from early to later generations. Many families carrying combinations of multiple resistance not observed among the parents were found in the later generations; one-half of the parents were susceptible to all three diseases but only 4% of the families in generation F45 were of this phenotype. The frequency of multiply resistant families also increased sharply over generations. Among the parents the greatest concentration of resistant reactions observed was triple resistance: 14% were triply resistant; none were quadruply resistant; nor were any resistant to all three pathogens. In generation F43 36% of the families were triply resistant, 32% were quadruply resistant and 6% were resistant in five of the six disease reactions. The value of later generations of Composite Cross II for breeding against pathogens thus appears to have been increased by recombination and natural selection. Significant positive correlations were found for resistance to races 40, 61, and 74 of R. secalis whereas correlations between resistance to R. secalis, E. graminis, and H. teres were generally nonsignificant. Use of these multiply resistant genotypes in breeding is thus unlikely to be hindered by negative associations between resistance to the three diseases.

Evolution of resistance to Rhynchosporium secalis (Oud.) Davis in barley composite cross II.

Changes in resistance to scald disease which occurred in barley composite Cross II over 45 generations were analyzed genetically. This population, which was synthesized in 1929 by pooling equal numbers of f1 seeds from 378 pair wise crosses among 28 barley varieties, has subsequently been grown at Davis, California under standard agricultural conditions without conscious selection. Progenies derived from self-pollinated seeds from random plants taken from four generations (F8, F13, F23, and F45) were tested against four different races of scald (40, 61, 72, and 74), and rated as resistant, susceptible or segregating. Striking increases in the frequency of families resistant to races 40, 61, and 74 occurred in CC II. A test for randomness showed that quadruply susceptible and triply resistant families were more common than expected under the assumption that resistance to different races is independent. Positive correlations were found between resistance to races 40, 61, and 74, but resistance to race 72 was independent of resistance to all other races. Possible reasons for these correlations are discussed.

Elemental composition of lunar surface material.

Elemental abundances, so far obtained, derived from the analysis of Apollo 11 lunar material are reported. Similarities and differences exist between lunar material, the eucritic achondrites, and the augite achondrite Angra dos Reis, the analysis of which is also reported.

Separation scheme for the determination of alkali metals (K, Rb, Cs), alkaline earths (Sr, Ba) and rare earths (Ce, Nd, Sm, Eu) in silicate materials by isotopic dilution analysis.

A scheme is outlined for the separation of Li, K, Rb, Cs, Sr, Ba, Ce, Nd, Sm and Eu from silicate materials. The elements are separated by cation-exchange to provide groups suitable for mass spectrometric analysis, and are then further purified by anion-exchange. Results obtained by isotopic dilution analysis are reported for G-1, W-1, and the Harwell meteorite-in these measurements the alkali metals were determined separately from the other elements. Requirements are discussed for combining the procedures to form a more comprehensive method for use with a single sample.