The Epidemiology and Iatrogenic Transmission of Hepatitis C Virus in Egypt: A Bayesian Coalescent Approach

Pybus, Oliver G.; Drummond, Alexei J.; Nakano, Tatsunori; Robertson, Betty H.; Rambaut, Andrew

doi:10.1093/molbev/msg043

Cited by 223 publications

(229 citation statements)

References 37 publications

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“…Changes in genetic diversity through time are also sometimes determined by transmission mechanism. For example, rates of population growth for hepatitis C virus transmitted by blood products or injecting drug use are significantly higher than those in Asian and African populations with endemic hepatitis C virus infection (37). It is also possible that differences in mosquito susceptibility affect growth rates (3), although our finding that the two serotypes reached equivalent population sizes in the Caribbean argues against this.…”

Section: Discussionmentioning

confidence: 80%

“…First, if we assume that population subdivision has had only a minor effect on our coalescent estimates of demographic history, then the estimated growth rate for DENV-4 was approximately 16-fold higher than that for DENV-2; the population size of DENV-2 was estimated to have doubled every 32 weeks, with DENV-4 having a doubling time of only 2 weeks. The latter is the highest viral population growth rate measured by coalescent methods to date (37,44). The growth rate for DENV-2 subtype III is also much higher than those estimated for other viruses, with the exception of DENV-2 in Venezuela between 1997 and 2000, which had an estimated doubling time of 25 weeks (44).…”

Section: Discussionmentioning

confidence: 98%

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Invasion and Maintenance of Dengue Virus Type 2 and Type 4 in the Americas

Carrington

Foster

Pybus

et al. 2005

J Virol

121

106

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Dengue virus type 4 (DENV-4) was first reported in the Americas in 1981, where it caused epidemics of dengue fever throughout the region. In the same year, the region's first epidemic of dengue hemorrhagic fever was reported, caused by an Asian strain of dengue virus type 2 (DENV-2) that was distinct from the American subtype circulating previously. Despite the importance of these epidemics, little is known about the rates or determinants of viral spread among island and mainland populations or their directions of movement. We employed a Bayesian coalescent approach to investigate the transmission histories of DENV-2 and DENV-4 since their introduction in 1981 and a parsimony method to assess patterns of strain migration. For both viruses there was an initial invasion phase characterized by an exponential increase in the number of DENV lineages, after which levels of genetic diversity remained constant despite reported fluctuations in DENV-2 and DENV-4 activity. Strikingly, viral lineage numbers increased far more rapidly for DENV-4 than DENV-2, indicative of a more rapid rate of exponential population growth in DENV-4 or a higher rate of geographic dispersal, allowing this virus to move more effectively among localities. We propose that these contrasting dynamics may reflect underlying differences in patterns of host immunity. Despite continued gene flow along particular transmission routes, the overall extent of viral traffic was less than expected under panmixis. Hence, DENV in the Americas has a clear geographic structure that maintains viral diversity between outbreaks.Dengue viruses (DENVs) are single-stranded, positive-sense RNA viruses (family Flaviviridae) that exist as four antigenically distinct serotypes (DENV type 1 [DENV-1] to DENV-4

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Section: Discussionmentioning

confidence: 80%

Section: Discussionmentioning

confidence: 98%

Invasion and Maintenance of Dengue Virus Type 2 and Type 4 in the Americas

Carrington

Foster

Pybus

et al. 2005

J Virol

121

106

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“…This model assumes a continuous epidemic process in which the viral transmission parameters remain constant through time. Model fitting was evaluated by likelihood ratio tests of the parametric ML estimates [Lemey et al, 2003;Pybus et al, 2003]. Approximate 95% confidence intervals for the parameters were estimated using the likelihood ratio test statistics.…”

Section: Demographic Modelmentioning

confidence: 99%

“…Time t was then transformed to year using the same rate, assuming the collecting time to be the present. Figure 3 shows the skyline plots and population growth for the HBV patients in Ehime, according to a specific demographic model in Genie v3.0 with three parameters, a piecewise expansion growth model, which was evaluated by likelihood ratio testing [Lemey et al, 2003;Pybus et al, 2003]. Based on this molecular evolution, it was estimated that the divergence time of the most recent common ancestor of HBV/D in Ehime was also estimated to be approximately 1,900.…”

Section: Rates and Demographic History Of Hbv Evolutionmentioning

confidence: 99%

Tracing the history of hepatitis B virus genotype D in western Japan

Michitaka

Tanaka

Horiike

et al. 2005

Journal of Medical Virology

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The major hepatitis B virus (HBV) genotypes in Japan are B and C. HBV genotype D (HBV/D), however, is widespread in a small area of Western Japan, where the Gianotti-Crosti syndrome caused by HBV subtype ayw, which is suspected to be HBV/D, was endemic in the 1970s. The aim of the study was to elucidate its origin, time of transmission, and spread in this area. Genotyping of HBV-DNA was done in 363 patients with HBV infection. The year of birth was checked in patients with HBV/D. The full genome sequences of 20 HBV/D strains, 2 of which were obtained from a single carrier with a 19-yearinterval, were analyzed. An evolutionary rate, the date of the most recent common ancestor, and the effective number of HBV/D infections were calculated. Fifty-two of 363 patients were infected with HBV/D, and 39 were born in 1970s. In a phylogenetic tree, the 20 HBV/D strains produced a definite cluster, and the evolutionary rate was calculated to be 5.4 Â 10 À5 nucleotide substitutions/site/year. The root of the tree was estimated to be in approximately 1,900 and began to spread from the 1940s, leading to a rapid increase of infected patients in the 1970s. From these results, it is suspected that HBV/D was likely transmitted to the area investigated approximately 100 years ago and then spread widely in the 1970s. From the history of the area and the genetic analysis, HBV/ D in this area was speculated to be of Russian origin.

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“…The highest prevelance was among Egyptians; 10 -20% of the population were chronically infected, some with HCC and others were cirrhotic (13,14).…”

Section: Introductionmentioning

confidence: 99%

NF. Evaluating Anti β-2 Glycoprotein as Rapid Thromboembolic Marker Among HCV Patients in Egypt

Eh¹

2013

AJLS

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Abstract:Although antiphospholipid (APL) antibodies are still not clearly known, yet they have association with thromboembolic events associated with hepatitis C virus (HCV) infection. Moreover, high percent of HCV infections and thromboembolic risk was associated among thalassemic patients. So our aim was to screen and evaluate the significance of ACL and anti β-2 glycoprotein seroprevelance among patients receiving repeated blood transfusions, in patients with infectious diseases as chronic HCV disorders, and in healthy subjects resident in Egypt, a tropical country endemic for hepatitis and to evaluate these tests as rapid markers for early detection of thrombotic HCV infection among chronic liver disorders and cases receiving repeated blood transfusion aiming at early anticoagulant therapy.The study was carried out on 70 patients attending Tropical, Hepatology and Hematology departments in Alexandria Main University Hospital, Egypt as well as 30 healthy subjects served as controls. Group I; 35 chronic liver disorders as chronic HCV, cirrhosis and Hepatocellular carcinoma(HCC) diagnosed by clinical, ultrasound and histopathology. Group II ; 35 receiving repeated blood transfusion as thalassemia. Group III; healthy relatives -ve for HCV antibody of matched age and sex. Both markers were screened by commercial enzyme immunosorbant assays (ELISA) (Calbiotech,USA). Our results revealed that patients with chronic HCV infection had higher anticardiolipin (ACL) IgG and antibeta2GP1 IgG compared to healthy controls. (26.6%) 8 patients from group I had high ACL IgG compared to 6 patients (20%) of group II .The study also revealed that anti β-2 glycoprotein IgG was higher among Group I and II compared to controls group III. Group I was higher than group II. Three patients (10%) of group I had high antiβ2 glycoprotein1 IgG compared to 2 patients (6.6%) among group II . We can conclude that anticardiolipin (ACL)alone is not diagnostic for thrombosis & it should be accompanied with antibeta(β )2glycoprotein-1 in serum of the same patient to be considered a cause of thrombosis in chronic HCV patients. So, ACL alone can not be considered rapid marker of thrombosis in HCV positive patients. We recommend anti β2 glycoprotein as a biomarker predicting thrombotic HCV infection.

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The Epidemiology and Iatrogenic Transmission of Hepatitis C Virus in Egypt: A Bayesian Coalescent Approach

Cited by 223 publications

References 37 publications

Invasion and Maintenance of Dengue Virus Type 2 and Type 4 in the Americas

Invasion and Maintenance of Dengue Virus Type 2 and Type 4 in the Americas

Tracing the history of hepatitis B virus genotype D in western Japan

NF. Evaluating Anti β-2 Glycoprotein as Rapid Thromboembolic Marker Among HCV Patients in Egypt

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