Related Experiment Video
Updated: Feb 3, 2026
06:18
Frequency and Distribution of Crossovers in Caenorhabditis elegans Meiosis by SNP Genotyping using Real-time PCR
Published on: July 11, 2025
884
The Global Hepatitis B Virus Genotype Distribution Approximated from Available Genotyping Data
Stoyan Velkov1, Jördis J Ott2, Ulrike Protzer3,4
1Institute of Virology, Technische Universität München/Helmholtz Zentrum München, Trogerstrasse 30, D-81675 München, Germany. stoyan.velkov@tum.de.
Genes
|October 18, 2018
Summary
Hepatitis B virus (HBV) genotypes C, D, E, A, and B cause 96% of the 250 million chronic HBV infections globally. Research highlights the need for models representing these common genotypes to develop new treatments.
Area of Science:
- Hepatology
- Virology
- Epidemiology
Background:
- Hepatitis B virus (HBV) infection affects an estimated 250 million people worldwide.
- Nine distinct HBV genotypes (A-I) exist, but their global distribution and contribution to chronic infections are not fully understood.
Purpose of the Study:
- To analyze global HBV genotyping data and estimate the proportion of chronic infections attributed to each genotype.
- To identify the most prevalent HBV genotypes contributing to the global disease burden.
Main Methods:
- A comprehensive literature search was conducted, assessing over 900 publications.
- Data from 213 studies across 125 countries were extracted.
- HBV prevalence and population data were used to approximate genotype-specific infection numbers globally.
Main Results:
- Five genotypes (C, D, E, A, B) account for 96% of all chronic HBV infections.
- Genotype C is the most prevalent (26%), followed by D (22%), E (18%), A (17%), and B (14%).
- Genotypes F through I collectively cause less than 2% of global chronic HBV infections.
Conclusions:
- This study provides an updated analysis of global HBV genotype distribution and their contribution to the chronic infection burden.
- Developing HBV cell culture and animal models for genotypes A-E is crucial for testing novel therapeutic strategies against prevalent strains.
Related Concept Videos
01:19Data: Types and Distribution
1.8K
In biostatistics, data are the observations collected for analysis. There are two main types: parametric and non-parametric. Parametric data, which include continuous (e.g., weight) and discrete numerical data (e.g., number of tablets), assume a particular distribution pattern, often the normal distribution. Non-parametric data do not adhere to a specific distribution and typically comprise nominal (e.g., gender) and ordinal categorical data (e.g., pain scale ratings).
Distributions in...
Distributions in...
1.8K
01:50Global Climate Change
28.9K
Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global temperatures is well outside of the Earth’s cyclic norms, and evidence for human-caused global climate change is compelling. Paleoclimatology, the study of ancient climate conditions, provides ample evidence for human-caused global climate change by comparing recent conditions with those in the past.
28.9K
01:24Approximate Integration
51
In many practical and theoretical contexts, the exact value of a definite integral may be inaccessible. This limitation typically arises when the antiderivative of a function is either unknown or cannot be expressed in a closed mathematical form. Alternatively, it can occur when a function is defined not by a formula but by a finite set of empirical data points, such as those collected during experiments. In these cases, approximate integration techniques provide a valuable solution.One of the...
51
01:26Linearization and Approximation
60
Linearization is a mathematical technique used to approximate complex, nonlinear functions with simpler linear models in the vicinity of a chosen reference point. The method is based on the idea that, although a function may be difficult to evaluate exactly, its behavior near a specific input value can often be closely approximated by the tangent line at that point. This approach is particularly useful when small deviations from a known value are involved.Consider the square root function, for...
60
01:28Accuracy, limits, and approximation
1.3K
Accuracy, limits, and approximations are common in many fields, especially in engineering calculations. These concepts are imperative for ensuring that a given value is as close as possible to its true value.
Accuracy is defined as the closeness of the measured value to the true or actual value. In engineering mechanics, repeated measurements are taken during theoretical or experimental analyses to ensure that the result is precise and accurate.
The accuracy of any solution is based on the...
Accuracy is defined as the closeness of the measured value to the true or actual value. In engineering mechanics, repeated measurements are taken during theoretical or experimental analyses to ensure that the result is precise and accurate.
The accuracy of any solution is based on the...
1.3K
01:29Application of Linearization and Approximation
92
A drone flying through complex terrain often relies on more than one sensing method to estimate small changes in altitude. Along with direct measurements, air pressure provides a useful indirect indicator of vertical movement. Atmospheric pressure decreases as altitude increases, and this relationship is commonly described using an exponential model. Although accurate, converting pressure measurements into altitude values requires calculations that are too complex to perform repeatedly during...
92