Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases
-
Infect. Genet. Evol. · Jan 2017
Migration, recombination, and reassortment are involved in the evolution of severe fever with thrombocytopenia syndrome bunyavirus.
Severe fever with thrombocytopenia syndrome bunyavirus (SFTSV) has been identified as the etiological agent causing severe fever with thrombocytopenia syndrome (SFTS). SFTSV was reported in recent years as a newly emerging tick-borne virus in China, Japan and South Korea and is a novel member of the genus Phlebovirus, family Bunyaviridae, which is suspected to be transmitted by the tick Haemaphysalis longicornis. The genetic diversity and evolutionary relationships between geographically distributed SFTSV strains are currently unclear. ⋯ Further, potential correlations between the geographic distribution and migration pathways of SFTSV were subject to in-depth analysis. The potential of birds migration related to SFTSV migration were also discussed. The results of this study will facilitate better understanding of the mechanisms of evolution of SFTSV, which will be important in developing public-health interventions and strategies for SFTS disease control and prevention in endemic areas.
-
Infect. Genet. Evol. · Oct 2016
Historical ArticleComparative genomic analysis of two isolates of Vibrio cholerae O1 Ogawa El Tor isolated during outbreak in Mariupol in 2011.
Cholera is a water-borne, severe enteric infection essentially caused by toxigenic strains of Vibrio cholera O1 and O139 serogroups. An outbreak of cholera was registered during May-July 2011 in Mariupol, Ukraine, with 33 cholera cases and 25 carriers of cholera. Following this outbreak, the toxigenic strain of V. cholerae 2011EL-301 was isolated from seawater in the recreation area of Taganrog city on the territory of Russia. ⋯ Mariupol isolates shared a common ancestor with Haiti\Nepal-4\India clade indicating that outbreak progenitor strain most likely originated in the South Asia region and later was introduced to Ukraine. Moreover, genomic data both based on hqSNPs and similarity of virulence-associated mobile genomic elements of Mariupol isolates suggests that environmental and clinical isolates are a part of joint outbreak which confirms the role of contaminated domestic sewage, as an element of the complex chain of infection spread during cholera outbreak. In general, the genome-wide comparative analysis of both genes and genomic regions of epidemiological importance indicates accessory of this isolates to 'new' clone of toxigenic multiple drug resistance atypical variant of V. cholerae O1 El Tor.
-
Infect. Genet. Evol. · Jul 2016
Vitamin D level and vitamin D receptor genetic variations contribute to HCV infection susceptibility and chronicity in a Chinese population.
Vitamin D and vitamin D receptor (VDR) are involved in multiple immune-mediated disorders including chronic hepatitis C virus (HCV) infection. The aim of this study was to determine the association between plasma vitamin D level, VDR genetic polymorphisms and risk of HCV infection susceptibility and chronicity. Seven single nucleotide polymorphisms (SNPs) in VDR gene were genotyped and plasma 25-hydroxyvitamin D [25(OH)D] levels were measured in a Han Chinese population of 898 HCV persistent infection cases, 558 spontaneous clearance subjects and 1136 uninfected controls with high risk of HCV infection. ⋯ The protective effects of three favorable alleles were more evident among males, females and subjects aged ≤50years (all P<0.05). Haplotype analyses suggested that compared with the most frequent haplotype Ars7975232Trs731236Crs11574129, CTT was correlated with a reduced risk of HCV infection susceptibility (P=2.200×10(-3)). These findings implied that low vitamin D levels might be associated with an increased risk for HCV infection and chronicity, and favorable VDR variants (rs7975232-C, rs2239185-T and rs11574129-T) might contribute to a decreased susceptibility to HCV infection in a high-risk Chinese population.
-
Infect. Genet. Evol. · Jul 2016
ReviewMolecular epidemiology, evolution and phylogeny of Chikungunya virus: An updating review.
Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus belonging to the Togaviridae family, causing a febrile illness associated with severe arthralgia and rash. In this review, we summarized a series of articles published from 2013 to 2016 concerning CHIKV epidemiology, phylogeny, vaccine and therapies, to give an update of our most recent article written in 2014 (Lo Presti et al.,2014). CHIKV infection was first reported in 1952 from Makonde plateaus and since this time caused many outbreaks worldwide, involving the Indian Ocean region, African countries, American continent and Italy. ⋯ Phylogenetic and phylodinamic analysis are useful tools to investigate how the genealogy of a pathogen population is influenced by pathogen's demographic history, host immunological milieu and environmental/ecological factors. Phylogenetic tools were revealed important to reconstruct the geographic spread of CHIKV during the epidemics wave and to have information on the circulating strains of the virus, that are important for the prediction and control of the epidemics, as well as for vaccines and antiviral drugs development. In conclusion, this updating review can give a critical appraisal of the epidemiology, therapeutic and phylogenesis of CHIKV, reinforcing the need to monitor the geographic spread of virus and vectors.
-
Infect. Genet. Evol. · Oct 2015
High rates of co-infection of Dengue and Chikungunya virus in Odisha and Maharashtra, India during 2013.
Dengue viral (DENV) infection is endemic in different parts of India and because of similar primary signs and symptoms, Chikungunya virus (CHIKV) is mostly undiagnosed. Hence, we investigated 204 suspected Dengue cases in a hospital based cross-sectional study in Odisha, India in 2013. It was observed that 50 samples were positive for DENV only, 28 were positive for CHIKV only and interestingly, 28 patients were co-infected with both DENV and CHIKV. ⋯ Together, it appears that a significantly high number of dengue patients (43, 44.8%) were co-infected with DENV and CHIKV during this study. This emphasizes the need of a routine diagnosis of CHIKV along with DENV for febrile patients. This will be useful in early and proper recognition of infecting pathogen to study the correlation of clinical symptoms with single or co-infection which will ultimately help to implement proper patient care in future.