Background The degree of protective immunity conferred by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is currently unknown. As such, the possibility of reinfection with SARS-CoV-2 is not well understood. We describe an investigation of two instances of SARS-CoV-2 infection in the same individual.Methods A 25-year-old man who was a resident of Washoe County in the US state of Nevada presented to health authorities on two occasions with symptoms of viral infection, once at a community testing event in April, 2020, and a second time to primary care then hospital at the end of May and beginning of June, 2020. Nasopharyngeal swabs were obtained from the patient at each presentation and twice during follow-up. Nucleic acid amplification testing was done to confirm SARS-CoV-2 infection. We did next-generation sequencing of SARS-CoV-2 extracted from nasopharyngeal swabs. Sequence data were assessed by two different bioinformatic methodologies. A short tandem repeat marker was used for fragment analysis to confirm that samples from both infections came from the same individual.Findings The patient had two positive tests for SARS-CoV-2, the first on April 18, 2020, and the second on June 5, 2020, separated by two negative tests done during follow-up in May, 2020. Genomic analysis of SARS-CoV-2 showed genetically significant differences between each variant associated with each instance of infection. The second infection was symptomatically more severe than the first.Interpretation Genetic discordance of the two SARS-CoV-2 specimens was greater than could be accounted for by short-term in vivo evolution. These findings suggest that the patient was infected by SARS-CoV-2 on two separate occasions by a genetically distinct virus. Thus, previous exposure to SARS-CoV-2 might not guarantee total immunity in all cases. All individuals, whether previously diagnosed with COVID-19 or not, should take identical precautions to avoid infection with SARS-CoV-2. The implications of reinfections could be relevant for vaccine development and application.

Zygomycosis is an emerging infection worldwide. A study was conducted to understand its spectrum in the Indian scenario. All patients diagnosed for invasive zygomycosis at a tertiary care center in north India from 2000-2004, were retrospectively analyzed. A total of 178 cases (mean average of 35.6 cases/year) of zygomycosis were diagnosed. Rhino-orbito-cerebral type (54.5%) was the commonest presentation followed by cutaneous (14.6%), disseminated (9.0%), and gastrointestinal (8.4%) zygomycosis. Renal and pulmonary zygomycosis were seen in 6.7% patients each. Uncontrolled diabetes mellitus (in 73.6% of cases) was the significant risk factor in all types (Odds Ratio 1.5-8.0) except renal zygomycosis. Breach of skin was the risk factor in 46.2% patients with cutaneous zygomycosis. However, no risk factor could be detected in 11.8% patients. Antemortem diagnosis was possible in 83.7% cases. The commonest (61.5%) isolate was Rhizopus oryzae followed by Apophysomyces elegans in 27% patients. Combination of debridement surgery and amphotericin B therapy was significantly better in survival of the patients (P<0.005) than amphotericin B alone (79.6% vs. 51.7% survival). Thus, a rising trend of invasive zygomycosis was observed in patients with uncontrolled diabetes mellitus in India. Consistent diagnosis of renal zygomycosis in apparently healthy hosts and the emergence of A. elegans in India demand further study.

Like other herpesviruses, Kaposi's sarcoma-associated herpesvirus (KSHV, also designated human herpesvirus 8) can establish a latent infection in the infected host. During latency a small number of genes are expressed. One of those genes encodes latency-associated nuclear antigen (LANA), which is constitutively expressed in cells during latent as well as lytic infection. LANA has previously been shown to be important for the establishment of latent episome maintenance through tethering of the viral genome to the host chromosomes. Under specific conditions, KSHV can undergo lytic replication, with the production of viral progeny. The immediate-early Rta, encoded by open reading frame 50 of KSHV, has been shown to play a critical role in switching from viral latent replication to lytic replication. Overexpression of Rta from a heterologous promoter is sufficient for driving KSHV lytic replication and the production of viral progeny. In the present study, we show that LANA down-modulates Rta's promoter activity in transient reporter assays, thus repressing Rta-mediated transactivation. This results in a decrease in the production of KSHV progeny virions. We also found that LANA interacts physically with Rta both in vivo and in vitro. Taken together, our results demonstrate that LANA can inhibit viral lytic replication by inhibiting expression as well as antagonizing the function of Rta. This suggests that LANA may play a critical role in maintaining latency by controlling the switch between viral latency and lytic replication.

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Kaposi's sarcoma-associated herpesvirus (KSHV) is the cause of Kaposi's sarcoma and body cavity lymphoma. In cell culture, KSHV results in a latent infection, and lytic reactivation is usually induced with the expression of K-Rta or by treatment with phorbol 12-myristate 13-acetate (TPA) and/or n-butyrate. Lytic infection is marked by the activation of the entire viral genomic transcription cascade and the production of infectious virus. KSHV-infected cells express a highly abundant, long, noncoding transcript referred to as polyadenylated nuclear RNA (PAN RNA). PAN RNA interacts with specific demethylases and physically binds to the KSHV genome to mediate activation of viral gene expression. A recombinant BACmid lacking the PAN RNA locus fails to express K-Rta and does not produce virus. We now show that the lack of PAN RNA expression results in the failure of the initiation of the entire KSHV transcription program. In addition to previous findings of an interaction with demethylases, we show that PAN RNA binds to protein components of Polycomb repression complex 2 (PRC2). RNA-Seq analysis using cell lines that express PAN RNA shows that transcription involving the expression of proteins involved in cell cycle, immune response, and inflammation is dysregulated. Expression of PAN RNA in various cell types results in an enhanced growth phenotype, higher cell densities, and increased survival compared to control cells. Also, PAN RNA expression mediates a decrease in the production of inflammatory cytokines. These data support a role for PAN RNA as a major global regulator of viral and cellular gene expression.K aposi's sarcoma-associated herpesvirus (KSHV) is an oncogenic gamma herpesvirus that is the cause of Kaposi's sarcoma (1, 2). KSHV infection in cell culture manifests mainly as a latent infection; however, there is a percentage of spontaneous lytic reactivation. Lytic infection is marked by the production of infectious virus, whereas latency is characterized by the lack of infectious virus production and the expression of a limited number of viral transcripts and proteins. One of the most abundant transcripts present in KSHV-infected cells is a long noncoding RNA, referred to as polyadenylated nuclear RNA (PAN RNA) (3, 4).We previously showed that PAN RNA interacts with cell-and virus-encoded factors and mediates the regulation of immune response gene expression (5, 6). Data from our laboratory and others indicated that PAN RNA is a major regulator of viral gene expression through a mechanism that involves a direct interaction with the viral chromosome (5, 7). PAN RNA interacts with the demethylases UTX and JMJD3 to remove the suppressive H3K23me3 mark within the KSHV viral genome. In a recent study describing the transcriptome of KSHV-infected cell lines, PAN RNA was detected in the absence of lytic-phase induction, suggesting that PAN RNA is expressed during chronic latent infection in cell culture (8). This observation suggests that PAN RNA has the potential to influence viral and cellular gene expressio...