Risk of SARS-CoV-2 transmission upon return to work in RNA-positive healthcare workers.

BACKGROUND: Healthcare workers (HCWs) are at risk for coronavirus disease 2019 (COVID-19), and for spreading severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) amongst colleagues and patients. AIM: To study the presence of SARS-CoV-2 RNA and possible onward transmission by HCWs upon return to work after COVID-19, and association with disease severity and development of antibodies over time. METHODS: Unvaccinated HCWs with positive SARS-CoV-2 reverse transcriptase polymerase chain reaction (RT-PCR) were recruited prospectively. Data on symptoms were collected via telephone questionnaires on days 2, 7, 14 and 21 after a positive test. Upon return to work, repeat SARS-CoV-2 RT-PCR was performed and serum was collected. Repeat serum samples were collected at weeks 4, 8, 12 and 16 to determine antibody dynamics over time. Phylogenetic analysis was conducted to investigate possible transmission events originating from HCWs with a positive repeat RT-PCR. FINDINGS: Sixty-one (84.7%) participants with mild/moderate COVID-19 had a repeat SARS-CoV-2 RT-PCR performed upon return to work (median 13 days after symptom onset), of which 30 (49.1%) were positive with a median cycle threshold (Ct) value of 29.2 (IQR 26.9-29.9). All HCWs developed antibodies against SARS-CoV-2. No significant differences in symptomatology and presence of antibodies were found between repeat RT-PCR-positive and -negative HCWs. Eleven direct colleagues of six participants with a repeat RT-PCR Ct value <30 tested positive after the HCW returned to work. Phylogenetic and epidemiologic analysis did not indicate onward transmission through HCWs who were SARS-CoV-2 RNA positive upon return to work. CONCLUSIONS: HCWs regularly return to work with substantial SARS-CoV-2 RNA loads. However, this study found no evidence for subsequent in-hospital transmission.

Verb movement in acquisition and aphasia: same problem, different solutions-evidence from Dutch.

This paper focuses on verb movement in agrammatism and child language. We present data from a sentence completion experiment with 6 Dutch agrammatic aphasics and 21 Dutch-speaking children. The experiment compares completion of matrix clauses (which require verb movement) and embedded clauses (where such movement is not required) in these two populations. The results reveal a clear asymmetry: Both agrammatics and children do very well with embedded clauses but fail in 50% with the matrix clauses. It is concluded that the problem which both populations are facing is one of verb movement rather than verb inflection. An error analysis of the responses reveals that, although both agrammatics and children try to avoid movement, they apply different strategies to achieve this goal.

Case assignment in agrammatism.

Agrammatic speech is characterized by the omission and substitution of grammatical morphemes. Some recent papers suggest that certain patterns of omission and substitution are ruled by linguistic, that is, syntactic processes (e.g., Hagiwara, 1995; Friedmann & Grodzinsky, 1997; Bastiaanse & Van Zonneveld, 1998). In the present paper, the omission pattern of case markers in the spontaneous speech of Dutch and German speakers with agrammatic aphasia is analyzed within the framework of Chomsky's (1986) case theory, which says that every phonetically realized NP must receive (abstract) case. The inflected verb (I) assigns nominative case to the subject in the sentence, and the verb (V) assigns dative and accusative case to the indirect and direct object, respectively. This, in combination with the knowledge that verbs and verb inflections are notoriously difficult for speakers with agrammatism, served as the basis for this study. We hypothesize that, if no case assigner is produced, the noun will receive nominative case by default or the case marking morpheme (i.e., the determiner) will be omitted. This hypothesis has been tested and was supported by the data.

On the relation between verb inflection and verb position in Dutch agrammatic aphasics.

This study focuses on the relation between verb position and verb inflection in the speech production of Dutch agrammatic patients. In Dutch, the finite verb is moved to second position in the matrix clause (de jongen leest een boek: the boy reads a book), but remains in its base generated, that is final, position in the embedded clause (ik zie dat de jongen een boek leest: lit. I see that the boy a book reads). Nonfinite verbs (infinitives and participles) are always in clause final position. Spontaneous speech analysis shows that agrammatics are sensitive to this relation between finiteness and structural position, although they are reluctant to produce finite verbs. Experimental data shows that verb inflection as such is not the problem: these patients are perfectly able to produce a finite verb in final position in an embedded clause; this is not more difficult than producing a nonfinite verb in the same position. If the finite verb has to be produced in Verb Second position in the matrix clause, however, the patients' performance drops dramatically.

Comparison of analysis techniques for on-line detection of clinical mastitis.

Three techniques were compared for analysis of automatically collected data from the milking parlor. Mammary quarters showing signs of clinical mastitis were compared with randomly selected healthy quarters. Automatic data were analyzed from the milking on which the milkers observed clinical mastitis as well as data from the two prior milkings. Electrical conductivity of milk was not corrected for individual cows. Milking parlor data were preprocessed so that information on the electrical conductivity pattern during a milking was retained. Principal component analysis was used to verify whether variation in the data was caused by mastitis. Performance of logistic regression models for detection of clinical mastitis was compared with that of backpropagation neural networks. Variation in the quarter data was caused by mastitis. Automatic data from infected quarters did not always differ from data from healthy quarters, especially from the two prior milkings. The detection performance of the logistic regression model was similar to that of the neural networks. When both models were tested on the development data, sensitivity was approximately 75%, and specificity was approximately 90% at the milking of mastitis observation. Detection results were lower for the prior milkings. Therefore, not all incidences of clinical mastitis cases could be detected before clinical signs occurred.

The association between change in cognitive function and longevity in Dutch elderly.

The association between rate of change in cognitive function and longevity was investigated with data from the Dutch Longitudinal Study Among the Elderly. A group of 211 Dutch persons aged 65-84 years at baseline (1955-1957) was reexamined twice during an 8-year follow-up period, after which mortality was ascertained through 1983. Cognitive function was assessed based on an adaptation of the Wechsler Memory Scale. Rate of change in cognitive function during the 8 years of follow-up was determined by regression on time for each individual. Cognitive function declined significantly over the 8-year period (mean yearly change, -0.28 units; 95% confidence interval -0.34 to -0.22). The rate of decline in cognitive function was strongly associated with subsequent survival time in the ages 70 years and over, with those with a large decline having a short survival time. No association could be demonstrated in the age group 65-69 years. Adjustment for potential confounders did not affect the magnitude of the association. These findings suggest that the rate of decline of cognitive function is an independent predictor of longevity in older persons.

Weight change, survival time and cause of death in Dutch elderly.

Weight change, subsequent survival time and cause of death are reported from the Dutch Longitudinal Study among the Elderly. Data consist of a national sample of persons aged 65-99 years. Six hundred and fifty-eight subjects were examined in the baseline years 1955-1957 and were re-examined 5 years later. Vital status and cause of death were ascertained for 604 of these subjects through 1983. Those subjects who experienced a decline in body mass index (BMI, kg/m(2)) during the period of observation, were likely to be in poorer health and have a shorter survival time than those subjects with stable weight, regardless of initial BMI. Weight gain was associated with shorter survival time only in the age group 65-74 and in those with heart disease. Weight loss, on the other hand, was most likely to result in decreased survival time among those ultimately dying of stroke, pneumonia/influenza or heart disease. As such, weight loss may be an indicator of the severity of disease. The noted associations remained, even when those surviving less than two years were omitted from the analyses. Thus, in longer survivors, weight loss may be associated with decreased vitality and decreased ability to survive once a disease becomes apparent.

Medical and social predictors of longevity in the elderly: total predictive value and interdependence.

In the Dutch Longitudinal Study among the Elderly, a probability sample of 3149 persons from the population of the Netherlands, initial ages 65-99 years, was followed from 1955 for 28 years. Vital status was determined in 1983 for 84% of the original sample. Multivariate regression models were used to predict the realized probability of dying (RPD), a measure of longevity based on actual survival time, sex and age at baseline. Predictor variables included physical, mental and social indicators of health status. The total variance explained was 20.2%. Objective health (rated by the examining physician) showed the strongest relationship with the RPD. Upon removing objective health from the model, 19.5% of the variance remained explained. Separate analyses were performed for (1) bio-medical, physical and mental examination variables, (2) disability and health care use variables, and (3) social and psychological variables; in each case the variance explained was over 11%, demonstrating considerable interdependence among predictors. Across different regression models, bio-medical and disability variables proved to be the most stable predictors of longevity.

The role of longitudinal surveys among the elderly in predicting disability and longevity.

The burden of human suffering and the costs of money, manpower and material for the treatment and maintaining of disabled and/or chronically ill--particularly ageing and old--people are increasing immensely. Primary prevention--if possible--is therefore urgently needed in this field of health and social care. Prospective longitudinal epidemiological research may provide an important tool to learn more and better about the causes and development of many processes of malfunctioning and the incidence of disabling conditions at higher ages. For several reasons not many major extensive surveys of this kind have been undertaken so far, although a few are now underway. A very brief overview is presented of some main follow-up surveys, primarily where predictors of disability and longevity are involved. Comparability is difficult, results are sometimes conflicting. Good objective health, high scores on certain intelligence and memory tests seem to be good predictors for longevity, good subjective health more or less. In a Dutch survey disabilities with respect to activities of daily life were more strongly related to survival time in women than in men. Some variables indicating the use of health care services correlated all negatively with survival. The complexity of variables to predict better at high age the risks of disabilities, and survival time, requires a.o. sophisticated longitudinal studies, upon the results of which to base an adequate policy response.

[Drugs in old age--epidemiologic data on usage]. / Arzneimittel im Alter--Einige epidemiologische Daten über Verbrauch.

Surveys conducted in several countries corroborate the wellknown fact that a large proportion of old-age people take drugs (frequently different types at the same time). The situation in the Netherlands serves as an example in the article.