Genome sequencing reveals Zika virus diversity and spread in the Americas

Although the recent Zika virus (ZIKV) epidemic in the Americas and its link to birth defects have attracted a great deal of attention, much remains unknown about ZIKV disease epidemiology and ZIKV evolution, in part owing to a lack of genomic data. Here we address this gap in knowledge by using multiple sequencing approaches to generate 110 ZIKV genomes from clinical and mosquito samples from 10 countries and territories, greatly expanding the observed viral genetic diversity from this outbreak. We analysed the timing and patterns of introductions into distinct geographic regions; our phylogenetic evidence suggests rapid expansion of the outbreak in Brazil and multiple introductions of outbreak strains into Puerto Rico, Honduras, Colombia, other Caribbean islands, and the continental United States. We find that ZIKV circulated undetected in multiple regions for many months before the first locally transmitted cases were confirmed, highlighting the importance of surveillance of viral infections. We identify mutations with possible functional implications for ZIKV biology and pathogenesis, as well as those that might be relevant to the effectiveness of diagnostic tests

Distinct Zika virus lineage in Salvador, Bahia, Brazil.

Sequencing of isolates from patients in Bahia, Brazil, where most Zika virus cases in Brazil have been reported, resulted in 11 whole and partial Zika virus genomes. Phylogenetic analyses revealed a well-supported Bahia-specific Zika virus lineage, which indicates sustained Zika virus circulation in Salvador, Bahia's capital city, since mid-2014

Recurrent COVID-19 including evidence of reinfection and enhanced severity in thirty Brazilian healthcare workers

BACKGROUND: There is growing concern about individuals reported to suffer repeat COVID-19 disease episodes, these in a small number of cases characterised as de novo infections with distinct sequences, indicative of insufficient protective immunity even in the short term. METHODS: Observational case series and case-control studies reporting 33 cases of recurrent, symptomatic, qRT-PCR positive COVID-19. Recurrent disease was defined as symptomatic recurrence after symptom-free clinical recovery, with release from isolation >14 days from the beginning of symptoms confirmed by qRT-PCR. The case control study-design compared this group of patients with a control group of 62 patients randomly selected from the same COVID-19 database. RESULTS: Of 33 recurrent COVID-19 patients, 26 were female and 30 were HCW. Mean time to recurrence was 50.5 days which was associated with being a HCW (OR 36.4 (p <0.0001)), and blood type A (OR 4.8 (p = 0.002)). SARS-CoV-2 antibodies were signifcantly lower in recurrent patients after initial COVID-19  (2.4 ± 0.610; p<0.0001) and after recurrence (6.4 ± 11.34; p = 0.007).  Virus genome sequencing identified reinfection by a different isolate in one patient. CONCLUSIONS: This is the first detailed case series showing COVID-19 recurrence with qRT-PCR positivity. For one individual detection of phylogenetically distinct genomic sequences in the first and second episodes confirmed bona fide renfection, but in most cases the data do not formally distinguish between reinfection and re-emergence of a chronic infection reservoir. These episodes were significantly associated with reduced Ab response during initial disease and argue the need for ongoing vigilance without an assumption of protection after a first episode

Prior fragility fracture and risk of incident ischaemic cardiovascular events: results from UK Biobank

Summary: In the large UK Biobank population-based cohort, we found that amongst men, but not women, prior fragility fracture was associated with increased risk of admission with ischaemic heart disease. Introduction: We aimed to investigate the relationship between prior fracture and risk of incident ischaemic cardiovascular events in a UK population-based cohort. Methods: UK Biobank is a large prospective cohort comprising 502,637 men and women aged 40–69 years, with detailed baseline assessment. History of fracture was self-reported, and details of hospital admissions for ischaemic heart disease (IHD) (ICD-10:I20-I25) were obtained through linkage to UK Hospital Episode Statistics. Cox proportional hazards models were used to investigate the prospective relationships between prior fracture and hospital admission for men and women, controlling for age, BMI, smoking, alcohol, educational level, physical activity, systolic blood pressure, calcium and vitamin D use, ankle spacing-width, heel BUA and HRT use (women). Results: Amongst men, a fragility fracture (hip, spine, wrist or arm fracture resulting from a simple fall) within the previous 5 years was associated with a 35% increased risk of IHD admission (fully adjusted HR 1.35; 95%CI 1.00, 1.82; p = 0.047), with the relationship predominantly driven by wrist fractures. Associations with hospitalisation for angina in men were similar in age-adjusted models [HR1.54; 95%CI: 1.03, 2.30), p = 0.037], but did not remain statistical significant after full adjustment [HR 1.64; 95%CI: 0.88, 3.07); p = 0.121]. HRs for admission with angina were lower in women, and neither age- nor fully adjusted relationships attained statistical significance. Conclusions: Prior fragility fracture is an independent risk factor for incident ischaemic cardiovascular events in men. Further work may clarify whether this association is causal or represents shared risk factors, but these findings are likely to be of value in risk assessment of both osteoporosis and cardiovascular disease.</p