Incubation Period Of Hepatitis Research Articles

Detection of Serum Markers of Hepatitis B Virus and Its Application in Clinical Diagnosis

Due to the rapid global population mobility and close interaction among populations, as well as the different medical and health conditions around the world, the prevention and control of hepatitis B face great challenges. In addition, the incubation period of hepatitis B is relatively long and easily overlooked, so the demand for early diagnosis is becoming increasingly prominent. This article focuses on the detection of serum markers of hepatitis B virus and their application in clinical diagnosis. By systematically exploring the detection methods of different biomarkers and their clinical applications, the aim is to deepen our understanding of the diagnosis and treatment of hepatitis B.

The incubation period of hepatitis E genotype 1: insights from pooled analyses of travellers.

Hepatitis E virus genotype 1 (HEV G1) is an important cause of morbidity and mortality in Africa and Asia. HEV G1's natural history, including the incubation period, remains poorly understood, hindering surveillance efforts and effective control. Using individual-level data from 85 travel-related HEV G1 cases in England and Wales, we estimate the incubation period distribution using survival analysis methods, which allow for appropriate inference when only time ranges, rather than exact times are known for the exposure to HEV and symptom onset. We estimated a 29.8-day (95% confidence interval (CI) 24.1-36.0) median incubation period with 5% of people expected to develop symptoms within 14.3 days (95% CI 10.1-21.7) and 95% within 61.9 days (95% CI 47.4-74.4) of exposure. These estimates can help refine clinical case definitions and inform the design of disease burden and intervention studies.

Estimating Incubation Period and Predicting Risk of Developing Hepatocellular Carcinoma in Patients with HCV Infection from the Clinic of a County-Level City in China

Background: To estimate incubation period in patients infected with hepatitis C virus (HCV) and to predict patients’ risk of developing hepatocellular carcinoma (HCC) for indicating health policymaking. Methods: An outbreak of HCV infection from a clinic was occurred due to the injection treatment of varicose veins called minimally invasive thrombolysis and meridian activating therapy (MITMT) in a county-level city of China. Conventional method and bootstrapping approach were used to estimate HCV incubation period. Risk assessment model generated from the previous study was applied to predict the risk of developing HCC in the coming 5-, 10-, and 15-year for HCV infected patients from the above outbreak. Results: A total of 120 subjects were underwent MITMT between October 22, 2012 and January 28, 2013; of those, 99 subjects were diagnosed with HCV infection. Mean age of the subjects was 54.42 years old, and females were accounted for 51.5% in contracted subjects. Mean incubation period of hepatitis C (HC) was 45.76 days using first MITMT as infected date and 30.68 days using bootstrapping approach, their standard deviations were 23.01 and 15.05 days, respectively. A total of 1.3, 4.7, and 10.6 persons will be developed into HCC in the coming 5, 10, and 15 years in infected subjects based on a risk prediction model. Conclusion: Some patients with HCV infection from a nosocomial clinic in a county-level city will be suffered from more severe HCC in the coming decade; effective measures and controls were urgently needed to manage these patients with high risk of developing into end-stage liver disease.

Hepatitis B virus traceback and lookback: factors to consider

Hepatitis B virus traceback and lookback: factors to consider

Autoantibody response to microsomal epoxide hydrolase in hepatitis C and A

Autoimmune responses were observed in a large proportion of hepatitis C cases and are suspected to be part of viral pathogenesis. The AN6520 antigen (AN-Ag) is a normal cellular protein mainly expressed in liver that was found associated with non-A, non-B hepatitis. To elucidate its pathogenic role in hepatitis C, we developed an IgM capture assay using purified AN-Ag and confirmed that the antibody response to AN-Ag is associated almost exclusively with hepatitis C cases (29%). Screening of a human liver expression library revealed that AN-Ag is mainly the microsomal epoxide hydrolase (mEH), a drug-metabolizing enzyme that plays an important role in the metabolism of some mutagenic and carcinogenic epoxides. Using the purified recombinant human mEH as an antigen, we now found that antibodies against this protein are associated with nearly 82% of hepatitis C virus infections and surprisingly with 46% of patients with hepatitis A. The appearance of AN-Ag/mEH in the incubation period of hepatitis C as previously reported and the antibody responses shown here indicate that this enzyme may be a marker for or even a cause of some of the pathology associated with hepatitis C and A.

NEONATAL CHOLESTASIS RESULTING FROM VERTICAL TRANSMISSION OF HEPATITIS A INFECTION

NEONATAL CHOLESTASIS RESULTING FROM VERTICAL TRANSMISSION OF HEPATITIS A INFECTION

Epidemiology of hepatitis B in Europe and worldwide.

Hepatitis B virus (HBV) infection is a major public health problem and cause of infectious disease mortality worldwide. Approximately 2 billion people one third of the world’s population have serologic evidence of past or present HBV infection, and 350 million people are chronically infected. Each year over 1 million people die from HBV-related chronic liver disease, including cirrhosis and hepatocellular carcinoma (HCC) (1). HCC is one of the most common cancers worldwide, and HBV is responsible for at least 75% of these cancers (2).

Foodborne viruses and fresh produce.

Raw and minimally processed fruits and vegetables are typically sold to the consumer in a ready-to-use or ready-to-eat form. These products do not generally contain preservatives or antimicrobial agents and rarely undergo any heat processing prior to consumption. For many years raw fruits and vegetables have been implicated as vehicles for transmission of infectious micro-organisms. Although fresh produce can support the growth and/or survival of many pathogenic bacteria there is little published information on the stability of human pathogenic viruses on these food products. Viruses cannot grow in or on foods but may sometimes be present on fresh produce as a result of faecal contamination. This contamination can arise at source in the growth and harvesting area from contact with polluted water and inadequately or untreated sewage sludge used for irrigation and fertilization. Alternatively, fruits or vegetables handled by an infected person might become contaminated with virus and transmit infection. The most frequently reported foodborne viral infections are viral gastroenteritis and hepatitis A: both have been associated with the consumption of fresh fruit or vegetables.

Medical advice for international travelers.

Each year, approximately 30 to 40 million Americans travel outside the United States. Although the most popular destinations are Europe, Central America, and the Caribbean, travel to Africa and Asia is increasing substantially. International travel, particularly to developing countries, can be associated with the risk of infectious and noninfectious diseases. These risks can be decreased, eliminated, or modified with vaccinations, prophylactic medications, and education. Optimally, pretravel advice must be individualized to a person's medical history, itinerary, and risk behavior. In addition to risk assessment-based immunizations, issues such as traveler's diarrhea, malaria prophylaxis, sexually transmitted diseases, and management of underlying medical problems must form a part of pretravel management. Adventure or prolonged travel or persons with underlying medical diseases such as insulin-dependent diabetes mellitus, transplantation, immunodeficiencies, and dialysis warrant additional preventive measures. This review primarily updates pretravel management of adults.

Hepatitis E virus DNA vaccine elicits immunologic memory in mice

Injection of an expression vector pJHEV containing hepatitis E virus (HEV) structural protein open reading frame 2 gene generates a strong antibody response in BALB/c mice that can bind to and agglutinate HEV. In this study, we tested for immunologic memory in immunized mice whose current levels of IgG to HEV were low or undetectable despite 3 doses of HEV DNA vaccine 18 months earlier. Mice previously vaccinated with vector alone were controls. All mice were administered a dose of HEV DNA vaccine to simulate an infectious challenge with HEV. The endpoint was IgG to HEV determined by ELISA. Ten days after the vaccine dose, 5 of 9 mice previously immunized with HEV DNA vaccine had a slight increase in IgG to HEV. By 40 days after the vaccine dose, the level of IgG to HEV had increased dramatically in all 9 mice (108-fold increase in geometric mean titer). In contrast, no control mice became seropositive. These results indicate that mice vaccinated with 3 doses of HEV DNA vaccine retain immunologic memory. In response to a small antigenic challenge delivered as DNA, possibly less than delivered by a human infective dose of virus, mice with memory were able to generate high levels of antibody in less time than the usual incubation period of hepatitis E. We speculate that this type of response could protect a human from overt disease.

Immunologic events during the incubation period of hepatitis C virus infection: the role of antibodies to E2 glycoprotein. Multicentre Hemodialysis Cohort Study on Viral Hepatitis.

The study of the sensitivity of screening assays is greatly facilitated by testing the sequential changes in seroconverting individuals. The aim of this study was to investigate the early immunologic response after hepatitis C virus (HCV) infection and to evaluate whether HCV envelope (E2) recombinant antigen would provide a significant increase in sensitivity for detection of anti-HCV. Twenty hemodialysis patients who were seroconverting to anti-HCV were included in this study. They were followed up for a mean period (+/- SD) of 10.5 +/- 3.3 months, in which 13 to 46 serum samples per case were collected. Each sample was tested for anti-HCV by second- and third-generation enzyme immunoassay (EIA-2 and EIA-3) and recombinant immunoblot assay (RIBA-3). E2 antibodies were tested by a prototype EIA in which E2 was expressed as a recombinant antigen in Chinese hamster ovary cells. Alanine aminotransferase elevation was observed in 18 of 20 cases. Reactivity against c100, c33c, c22, NS5, and E2 was detected in 15 (75%), 19 (95%), 15 (75%), 2 (10%), and 17 (85%) patients, respectively; c33c was the most immunogenic antigen, followed in descending order by E2, c22, c100, and NS5. E2 antibody reactivity resolved the two RIBA-3-indeterminate cases. However, there was no case in which E2 reactivity preceded all other HCV antigens. Anti-E2 was found to react in all patients of genotypes 1a, 1b, and 3a but in only 2 of 4 patients of genotype 4a. In this group of seroconverting individuals, E2 antigen was shown to be highly immunoreactive and did resolve some RIBA-3-indeterminate samples as being positive, on the basis of reactivity to multiple antigens, but it did not improve early detection of seroconversion.

Immunological events during the incubation period of hepatitis C virus infection in immunocompromised individuals: [formula omitted]. ∗Athens University Medical School, ∗∗Ortho Diagnostic Systems Inc. Raritan, NJ

Immunological events during the incubation period of hepatitis C virus infection in immunocompromised individuals: [formula omitted]. ∗Athens University Medical School, ∗∗Ortho Diagnostic Systems Inc. Raritan, NJ

Passive immunization against hepatitis A

Administration of human serum immune globulin (Ig) is an effective means of protecting individuals against hepatitis A virus (HAV) infection and disease. Several large field studies have demonstrated that if given before exposure, Ig will prevent infection with HAV. Furthermore, if Ig is given during the incubation period of hepatitis A, the severity of infection may be reduced and potentially clinical infections may be converted into subclinical ones. Although uncommon, infection which occurs in the presence of circulating antibody may occasionally lead to passive-active immunity. Unfortunately, the duration of Ig protection is dose dependent, and high dose administration provides less than six months protection. Ig preparations contain HAV antibodies at levels detectable by commercial immunoassays; however, recipients of Ig do not have detectable levels of HAV antibodies when tested by the same method. Using more sensitive immunoassays and neutralization assays, low titres of HAV antibody can be detected in Ig recipients. Since Ig provides ≈ 90% efficacy in preventing hepatitis A, it would appear that very low levels of HAV antibody are needed to prevent infection. Consequently, measurement of HAV antibodies elicited by HAV vaccines should provide a reasonable method to evaluate their immunogenicity and predict their efficacy.

Two Superb Vaccines Against Hepatitis B in Mexican Standoff-Reply

In Reply. —To clarify and extend major points in our previous letter, 1 both Heptavax-B and Recombivax-HB (the only hepatitis B vaccines licensed in the United States) have been well tolerated, highly immunogenic, and equally effective in preventing hepatitis B when used at their respective recommended doses (Heptavax-B, 20 μg for adults and 10 μg for children; Recombivax-HB, 10μg for adults and 5 μg for children). Although antibody titers after three-dose regimens of Heptavax-B generally have been somewhat higher than after administration of Recombivax-HB, there are no significant differences between them with respect to seroconversion rates in healthy adults or children. Similarly, while persistence of vaccine-induced antibodies seems to be directly related to peak titer after vaccination, decline in titer over time is of no concern in terms of protection against clinically significant infections. 2 The long incubation period of hepatitis B provides sufficient time for anamnestic antibody responses in

BLOOD TRANSFUSION HEPATITIS IN OPEN-HEART SURGERY.

One of the major problems confronting blood banks is the occurrence of hepatitis following blood transfusions. It has always been difficult to obtain valid statistics because the incubation period of hepatitis may be relatively long. Hence some cases are unrelated and unreported. With the use of many blood transfusions for open-heart surgery to prime the pump oxygenator and to replace blood loss, and because of the close contact established with these patients by our Regional Blood Center, we felt that this group of surgical cases presented an ideal opportunity for the investigation of hepatitis possibly due to massive blood transfusions. By the end of 1962, the Los Angeles-Orange Counties Red Cross Regional Blood Center had collected 2,173,156 units of blood since its inception as a civilian blood program in 1946. Table 1 depicts the yearly blood collections at the Regional Blood Center since 1954 and the number of cases of