Molecular Characterization of the First Ebola Virus Isolated in Italy, from a Health Care Worker Repatriated from Sierra Leone.

Here, we report the complete genome sequence of an Ebola virus (EBOV) isolated from a health worker repatriated from Sierra Leone to Italy in November 2014. The sequence, clustering in clade 3 of the Sierra Leone sequences, was analyzed with respect to mutations possibly affecting diagnostic and therapeutic targets as well as virulence.

Seroprevalence of dengue infection: a cross-sectional survey in mainland Tanzania and on Pemba Island, Zanzibar.

OBJECTIVE: Evidence available to date indicates that dengue viruses 1, 2, and 3 could be among the causes of acute fever in eastern Africa. Recently, four reports on dengue infection in travelers and residents have raised concerns over the occurrence of dengue fever in mainland Tanzania and in Zanzibar. The objective of this study was to provide seroprevalence data on dengue infection in Tanzania. METHODS: This study was conducted in 2007 at two peripheral hospitals, one on Pemba Island, Zanzibar and one in Tosamaganga, Iringa Region, mainland Tanzania. Two hundred and two consecutive febrile outpatients were studied for antibodies and viral RNA to assess the circulation of dengue virus in Tanzania. RESULTS: A seroprevalence of 7.7% was found on Pemba Island and of 1.8% was found in Tosamaganga. No acute cases and no previous infections among patients under 11 years of age were detected. CONCLUSION: These findings provide the first baseline data on dengue seroprevalence in the country. No recent dengue virus circulation in Tanzania and in the Zanzibar archipelago up until the early 1990s is reported.

Chikungunya virus isolates with/without A226V mutation show different sensitivity to IFN-a, but similar replication kinetics in non human primate cells.

Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus responsible for the first autochthonous Italian outbreak in 2007. A226V mutation in E1 has been associated with enhanced replication in A. albopictus vector. Possible involvement of this mutation in enhanced infection capability in primate cells and sensitivity to exogenous interferon (IFN)-a was investigated. No significant differences were observed between the two isolates in terms of replication kinetic, virus yield and cytopathic effect (CPE). Interestingly, the A226V-carrying strain was more susceptible to the antiviral action of recombinant IFN-a. The interplay between A226V mutation and innate defence mechanisms needs further investigation.

Cross-subtype immunity against avian influenza in persons recently vaccinated for influenza.

Avian influenza virus (H5N1) can be transmitted to humans, resulting in a severe or fatal disease. The aim of this study was to evaluate the immune cross-reactivity between human and avian influenza (H5N1) strains in healthy donors vaccinated for seasonal influenza A (H1N1)/(H3N2). A small frequency of CD4 T cells specific for subtype H5N1 was detected in several persons at baseline, and seasonal vaccine administration enhanced the frequency of such reactive CD4 T cells. We also observed that seasonal vaccination is able to raise neutralizing immunity against influenza (H5N1) in a large number of donors. No correlation between influenza-specific CD4 T cells and humoral responses was observed. N1 may possibly be a target for both cellular and humoral cross-type immunity, but additional experiments are needed to clarify this point. These findings highlight the possibility of boosting cross-type cellular and humoral immunity against highly pathogenic avian influenza A virus subtype H5N1 by seasonal influenza vaccination.

Rapid detection and quantification of Chikungunya virus by a one-step reverse transcription polymerase chain reaction real-time assay.

Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus. A large outbreak of CHIKV disease occurred in 2005 in the Indian Ocean Islands. Many cases have been imported in European countries. Laboratory confirmation of suspected cases is mandatory for control measures during an outbreak. We report a novel, real-time, reverse transcription-polymerase chain reaction (RT-PCR) for the nonstructural protein 1 region that can quantify a wide range of viral RNA concentrations. This assay was validated by in vitro experiments in which interferon-alpha, a well-known virus inhibitor, showed a dose-dependent inhibition of virus replication on Vero cells that was assessed by viral infectivity and viral RNA production. This new real-time RT-PCR was used to measure viral load in serum samples from cases recently imported to Italy, and may be a useful tool in rapid detection of CHIKV and monitoring the extent of viral replication in patients.

[Rapid differential diagnosis of Orthopoxviruses and Herpesviruses based upon multiplex real-time PCR]. / Un nuovo metodo rapido, basato su real-time PCR multiplex, per la diagnosi differenziale di infezioni da Orthopoxvirus e Herpesvirus.

OBJECTIVE: Variola virus, belonging to Orthopoxviridae family, is one of the most dangerous human pathogens that could be used as biological weapon. We have developed a new rapid assay, based upon Real-time PCR and melting temperatures analysis of amplicons, for the contemporary detection of Orthopoxvirus, VZV and HSV1-2, that are the most important infectious agents to be considered for differential diagnosis. METHODS: The target for detection of orthopoxvirus DNA has been a region of the crmB gene which is common to Variola virus and to other old world orthopoxviruses pathogenic for humans. The targets for VZV and HSV1-2 have been ORF 29 and DNA polymerase, respectively. Suitability of the amplified fragments to RFLP or sequencing analysis, to recognize the involved viral species, has been also tested. RESULT: The selected primers have showed high sensitivity, specificity and compatibility with common amplification conditions. A mean melting temperature difference of 8.7 degree C was observed between the amplicons from the two virus types. Further identification of individual pathogens was made using RFLP analysis. CONCLUSION: The PCR-based protocol set up in this study for presumptive differential diagnosis of variola and herpesviral infections is rapid and specific and it can be used also to detect other orthopoxviral infections, like monkeypox.