Clinical frailty scale as a predictor of disease severity in patients hospitalised with COVID-19 - an observational cohort study.

BACKGROUND: The coronavirus disease 2019 pandemic makes proper resource allocation and prioritisation important. Frailty increases the risk of adverse outcomes and can be quantified using the Clinical frailty scale. The aim of this study was to determine the role of the Clinical frailty scale, in patients ≥65 years of age with coronavirus disease 2019, as a risk factor either for critical coronavirus disease 2019 measured as intensive care unit admission or death or as a risk factor for death. METHODS: This was a retrospective observational study on patients ≥65 years hospitalised with coronavirus disease 2019 verified by polymerase chain reaction between 5 March 5 and 5 July 2020. The association between Clinical frailty scale and the composite primary outcome intensive care unit admission or death within 30 days post hospitalisation and the secondary outcome death within 30 days post hospitalisation was analysed using multivariable logistic regression models adjusting for gender, age, body mass index, hypertension, and diabetes. Clinical frailty scale was used as a categorical variable (fit score 1-4, frail score 5-6, and severely frail score 7-9). RESULTS: In total, 169 patients were included (47.3% women, mean age 79.2 ± 7.8 years). In the fully adjusted model, adjusted odds ratio for intensive care unit admission or death was 1.84 (95%-confidence interval 0.67-5.03, p = .234) for frail and 6.08 (1.70-21.81, p = .006) for severely frail compared to fit patients. For death, adjusted odds ratio was 2.81 (0.89-8.88, p = .079) for frail and 9.82 (2.53-38.10, p = .001) for severely frail compared to fit patients. CONCLUSIONS: A high Clinical frailty scale score was an independent risk factor for the composite outcome intensive care unit admission or death and for the secondary outcome death.

On the potential roles of ticks and migrating birds in the ecology of West Nile virus.

BACKGROUND: Mosquitoes are the primary vectors of West Nile virus (WNV). Ticks have, however, been suggested to be potential reservoirs of WNV. In order to investigate their role in the spread of the virus, ticks, which had been collected from birds migrating northwards from Africa to Europe, were analyzed for the potential presence of WNV-RNA. METHODS: On the Mediterranean islands Capri and Antikythira a total of 14,824 birds were captured and investigated from which 747 ticks were collected. RESULTS AND CONCLUSION: Most of the identified ticks (93%) were nymphs and larvae of Hyalomma marginatum sensu lato, most of which were or appear to be Hyalomma rufipes. Of these ticks 729 were individually screened for WNV-RNA. None of the ticks was found to be WNV positive. Thus, there was no evidence that Hyalomma marginatum s.l. ticks play a role in the spread of WNV from Africa to Europe.

Migratory birds, ticks, and Bartonella.

Bartonella spp. infections are considered to be vector-borne zoonoses; ticks are suspected vectors of bartonellae. Migratory birds can disperse ticks infected with zoonotic pathogens such as Rickettsia and tick-borne encephalitis virus and possibly also Bartonella. Thus, in the present study 386 tick specimens collected in spring 2009 from migratory birds on the Mediterranean islands Capri and Antikythera were screened for Bartonella spp. RNA. One or more ticks were found on 2.7% of the birds. Most ticks were Hyalomma rufipes nymphs and larvae with mean infestation rates of 1.7 nymphs and 0.6 larvae per infested bird. Bartonella spp. RNA was not detected in any of the tick specimens.

Genome dynamics of Bartonella grahamii in micro-populations of woodland rodents.

BACKGROUND: Rodents represent a high-risk reservoir for the emergence of new human pathogens. The recent completion of the 2.3 Mb genome of Bartonella grahamii, one of the most prevalent blood-borne bacteria in wild rodents, revealed a higher abundance of genes for host-cell interaction systems than in the genomes of closely related human pathogens. The sequence variability within the global B. grahamii population was recently investigated by multi locus sequence typing, but no study on the variability of putative host-cell interaction systems has been performed. RESULTS: To study the population dynamics of B. grahamii, we analyzed the genomic diversity on a whole-genome scale of 27 B. grahamii strains isolated from four different species of wild rodents in three geographic locations separated by less than 30 km. Even using highly variable spacer regions, only 3 sequence types were identified. This low sequence diversity contrasted with a high variability in genome content. Microarray comparative genome hybridizations identified genes for outer surface proteins, including a repeated region containing the fha gene for filamentous hemaggluttinin and a plasmid that encodes a type IV secretion system, as the most variable. The estimated generation times in liquid culture medium for a subset of strains ranged from 5 to 22 hours, but did not correlate with sequence type or presence/absence patterns of the fha gene or the plasmid. CONCLUSION: Our study has revealed a geographic microstructure of B. grahamii in wild rodents. Despite near-identity in nucleotide sequence, major differences were observed in gene presence/absence patterns that did not segregate with host species. This suggests that genetically similar strains can infect a range of different hosts.

First known case of Bartonella quintana endocarditis in Sweden.

In this report, we present the first known case of Bartonella endocarditis in Sweden. IgG antibody titres to Bartonella spp. were elevated but blood cultures remained negative. Sequencing of a gltA fragment from DNA extracted from heart valve tissue specimens revealed sequence homology with B. quintana.

High Bartonella spp. seroprevalence in a Swedish homeless population but no evidence of trench fever.

Blood samples and epidemiological data were collected from 50 homeless patients in central Stockholm, Sweden. Sera were analysed for antibodies to B. henselae, B. quintana, B. elizabethae and B. grahamii. Whole blood was cultured and used as substrate for a newly developed quantitative real time polymerase chain reaction (QPCR) specifically targeting Bartonella spp. DNA. 61 matched blood donor sera were used as controls. Homeless patients were significantly more often seropositive to Bartonella spp. than controls (OR 7.58 (3.30-17.39), p<0.05). Reactivity to the B. elizabethae antigen was dominating, although the difference between patients and controls was most significant in seroreactivity to the B. henselae antigen. There was no evidence of an ongoing B. quintana epidemic. The absence of louse infestation could explain the lack of B. quintana bacteraemia and the failure to amplify Bartonella DNA.