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On 27 May 2024, the Cuban Ministry of Health reported the first outbreak of Oropouche fever on the island. The etiologic agent, Oropouche virus (OROV), is a poorly understood arbovirus that has been known since the 1960s and represents a public health burden in Latin America. We report the whole-genome characterization of the first European OROV isolate from a returning traveler from Cuba with Oropouche fever-like symptoms. The isolate was obtained from the patient's serum; whole-genome sequencing was performed by next-generation sequencing, followed by phylogenetic analysis and genetic variability studies. The analysis showed that the most closely related sequence was from the French Guiana 2020 outbreak. Interestingly, our isolate is a reassortant virus, included in a highly supported monophyletic clade containing recent OROV cases (Brazil 2015-Colombia 2021), separated from the other four previously known genotypes. More deeply, it was found to be included in a distinct branch containing the sequences of the Brazil 2022-2024 outbreak. The reassortment event involved the S and L segments, which have high similarity with sequences belonging to a new cluster (here defined as OROV_SCDC_2024), while the M segment shows high similarity with older sequences. These results likely describe the viral strain responsible for the current outbreak in Cuba, which may also reflect the ongoing outbreak in Latin America. Further studies are needed to understand how OROV evolves towards traits that facilitate its spread and adaptation outside its original basin, and to track its spread and evolution in the European continent.

In 2022, an unprecedented outbreak of mpox raged in several nations. Sequences from the 2022 outbreak reveal a higher nucleotide substitution if compared with the estimated rate for orthopoxviruses. Recently, intra-lesion SNVs (single nucleotide variants) have been described, and these have been suggested as possible sources of genetic variation. Until now, it has not been clear if the presence of several SNVs could represents the result of local mutagenesis or a possible co-infection. We investigated the significance of SNVs through whole-genome sequencing analysis of four unrelated mpox cases. In addition to the known mutations harboured by the circulating strains of virus (MPXV), 7 novel mutations were identified, including SNVs located in genes that are involved in immune evasion mechanisms and/or viral fitness, six of these appeared to be APOBEC3-driven. Interestingly, three patients exhibited the coexistence of mutated and wild-type alleles for five non-synonymous variants. In addition, two patients, apparently unrelated, showed an analogous pattern for two novel mutations, albeit with divergent frequencies. The coexistence of mixed viral populations, harbouring non-synonymous mutations in patients, supports the hypothesis of possible co-infection. Additional investigations of larger clinical cohorts are essential to validating intra-patient viral genome heterogeneity and determining the possibility of co-presence events of slightly divergent MPXV strains.

Community-acquired pneumonias represent the first cause of mortality due to a infectious disease, and determine more than 500,000 hospitalizations per year in the USA: moreover, they are the terminal event in many geriatric patients. Although the etiological microbial agents responsible for the majority of such pneumonias, Haemophilus influenzae and Streptococcus pneumoniae, are still sensitive to traditional antibiotics, as ampicillin, many doctors treat community acquired pneumonias with more recent and expensive antibiotics, as the third generation cephalosporins or other beta-lactamines, so enhancing the cost of the treatments, without a known, real advantage with respect to the older therapies. In this study, to evaluate whether the use of the latter antibiotics improves the outcome of community acquired pneumonias of the elderly with respect to the traditional therapy with ampicillin, we studied 123 hospitalized patients older than 65 years, affected by community-acquired pneumonia, simple or complicated. We also evaluated the cost/benefit ratio of every single treatment. Our data demonstrate that the recent antibiotics do not influence the outcome of the disease of the elderly: in particular, they do not affect the duration of the hospitalization, do not have a lower incidence of side effects, do not show a better efficacy versus ampicillin. The cost of the treatment with ampicillin is about one third of the cost of a third-generation cephalosporin treatment. We conclude that the treatment of choice for community acquired pneumonias of the elderly is ampicillin; only in few cases, as in nosocomial or in nursing homes pneumonias, third-generation cephalosporins or other antibiotics are necessary.