Molecular epidemiology of hepatitis B viral serotypes and genotypes in taiwan

Subtypes of hepatitis B virus (HBV) have specific geographic distributions and can serve as epidemiological markers. The relationship of HBV serotypes and genotypes in Taiwan and their correlation with the domiciles of origin in 122 patients with chronic HBV infection were investigated. The serotype of HBV was determined by comparing the surface gene encoding amino acids 22-148 of the major surface protein with published sequences. Genotyping of HBV was performed by polymerase chain reaction-restriction fragment length polymorphism. Serotype adw accounted for 70% (85/122) of all HBVs, with the remaining belonging to serotype adr. All adr HBVs were genotype C, regardless of the patient's domicile. Of the 85 adw HBVs, 69 (81%) were genotype B, 10 (12%) were genotype C, 5 (6%) were genotype F and only 1 (1%) was genotype A. In the 31 patients originating from mainland China, the prevalence of adr/genotype C was higher than in the 91 Taiwanese patients (15/31 vs. 22/91; p < 0.05). The distribution of the HBV serotypes and genotypes was not significantly different between 17 patients born in Taiwan (6 adw/genotype B, 2 adw/genotype C, 1 adw/genotype F and 8 adr/genotype C) and 14 patients born in mainland China (5 adw/genotype B, 2 adw/genotype C and 7 adr/genotype C). Our results indicate that in Taiwan, most HBVs of serotype adw are genotype B, and all HBVs of serotype adr are genotype C. Patients with origins in mainland China have a higher proportion of serotype adr/genotype C infection.     

The current problems in the epidemiology and prevention of viral hepatitis B and C in the Russian Federation

The data on the epidemiological situation with hepatitides B and C in the Russian Federation in 1991-1998 are presented. Morbidity rates in hepatitis B, registered during the recent 3 years, were 35.8 (1996), 36.3 (1997) and 35.7 (1998) per 100,000 of the population. Morbidity rates in acute hepatitis C were 3.2 (1996), 9.1 (1997) and 11.6 (1998) per 100,000 of the population. Different regions of the Russian Federation were noted to have pronounced differences in the activity of the epidemic processes of hepatitides B and C.     

Etiological structure of viral hepatitis in the area about one of the cities in Gorki Province

The etiological structure of viral hepatitides (VH) in one of the towns of the Gorky region was studied with the use of specific methods for diagnosing hepatitis A (detection of IgM to hepatitis A virus) and hepatitis B (detection of HBsAg in the passive hemagglutination test). The study revealed that hepatitis A was the major nosological from in the structure of VH among children and adults in the area under survey, which was documented by the detection of IgM to hepatitis A virus. The form, second in importance among VH cases, was hepatitis B. The ratio of these two forms of VH was determined by the epidemiological situation in the area. The proportion of hepatitis B cases increased at the period between epidemics. Nondifferentiated hepatitis constituted 6.8% of all cases of sporadic hepatitis among adults. In 90% of cases clinical diagnosis coincided with the serological one.     

Pathogenesis of viral hepatitis

The aim of our research is to use animal models to elucidate the molecular basis for viral clearance and liver disease in the pathogenesis of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections. The results herein discussed provide insight into immunological and virological processes that may lead to the development of new therapeutic strategies to terminate chronic HBV and HCV infections.     

Tendencies in the epidemic process of dysentery in Ryazan

In shigellosis caused by Sh. sonnei and Sh. flexneri the epidemic process was found to have considerable difference in the tendencies and pace of its development. Shigellosis which dominated in the etiological structure at the period following 1966 was dysentery caused by Sh. sonnei; it showed the tendency towards a decrease in morbidity rate. Dysentery caused by Sh. flexneri was second in respect to the frequency of its occurrence after 1966 and showed the tendency towards increase. The simultaneous circulation of Sh. sonnei and Sh. flexneri, the differences in the epidemiology of these types of shigellosis make it imperative that they be studied separately, taking into ccount their etiological selectivity to the main routes of transmitting the infection.     

Modelling the epidemiology of hepatitis B in New Zealand

Hepatitis B is a vaccine preventable disease caused by the hepatitis B virus (HBV) that can induce potentially fatal liver damage. It has the second highest mortality rate of all vaccine preventable diseases in New Zealand. Vaccination against HBV was introduced in New Zealand in 1988, and the country is now categorised with overall low endemicity but with areas of both high and medium endemic levels. We present an SECIR compartmental mathematical model, with the population divided into age classes, for the transmission of HBV using local data on incidence of infection and vaccination coverage. We estimate the basic reproduction number, R₀, to be 1.53, and show that the vaccination campaign has substantially reduced this below one. However, a large number of carriers remain in the population acting as a source of infection.     

Trace elements in viral hepatitis

In this study, serum trace elements, including selenium (Se), zinc (Zn), copper (Cu), were determined by using Atomic Absorption Spectrophotometer (SpectrAA 250 Plus Zeeman, Varian, Australia) in sera of patients with viral hepatitis (A, B, C, D, E) cases (n = 102), and statistically compared with the controls (n = 52). In viral hepatitis, Cu levels were found as 3.23 ± 1.02 mg/L, and this value was significantly higher than the control group (1.13 ± 0.21) (p < 0.01). Both, Se and Zn levels found to be significantly low in viral hepatitis cases (p < 0.01). While Se level was 81.4 ± 26.01 μg/L in viral hepatitis (n = 101), it was found to be 166.15 ± 4.58 μg/L in healthy individuals. Meanwhile, Zn levels were 0.230 ± 0.081 mg/L and 0.748 ± 0.392 mg/L in hepatitis cases (n = 101) and the control group, respectively. There was no difference amongst viral hepatitis groups classified in regard with agents and clinical manifestation, such as A, acute hepatitis B, chronic hepatitis B, C, D and E. Previously, it was indicated that absorption disorders in gastrointestinal system, especially in chronic cases, were not main causes of decrease of trace elements by iron and several other parameters in sera of the cases. Therefore, we suggest that decrease in Zn and Se levels and elevation in Cu levels are probably resulted from defence strategies of organism and induced by the hormone-like substances.