Related Experiment Video
Updated: May 31, 2025
13:39
Protocol for Production of a Genetic Cross of the Rodent Malaria Parasites
Published on: January 3, 2011
15.1K
Evolution of parasite transmission dispersion
Hannelore MacDonald1, Sebastian Bonhoeffer1, Roland Regoes1
1Institute for Integrative Biology, ETH Zürich, 8005 Zürich, Switzerland.
Royal Society Open Science
|January 23, 2025
Summary
Parasite adaptation to diverse host populations drives high transmission dispersion in epidemics. This adaptation can maintain high transmission even when infections become endemic, especially if virulence varies among hosts.
Area of Science:
- Epidemiology
- Evolutionary Biology
- Mathematical Modeling
Background:
- Transmission of infectious diseases is often overdispersed, with a small subset of infected individuals causing a majority of new infections.
- Host heterogeneity, such as variable viral loads (e.g., SARS-CoV-2), is a known driver of transmission overdispersion.
- The role of parasite adaptation in exacerbating transmission dispersion in heterogeneous host populations remains less understood.
Purpose of the Study:
- To investigate whether parasite adaptation to heterogeneous host populations can be an emergent property contributing to increased transmission dispersion.
- To explore the epidemiological and evolutionary dynamics of host-parasite systems under varying host heterogeneity.
- To provide a framework for understanding how parasite adaptation influences transmission patterns in emerging and re-emerging infectious diseases.
Main Methods:
- Development of a mathematical model based on the Price equation framework.
- The model integrates epidemiological dynamics (disease spread) with evolutionary dynamics (parasite adaptation).
- Analysis of a general host-parasite system to capture core principles applicable across various pathogens.
Main Results:
- Parasite adaptation to heterogeneous host populations significantly drives high transmission dispersion during the early stages of epidemics.
- Adaptation can sustain increased transmission dispersion at endemic equilibria, particularly when host virulence varies.
- The study demonstrates that adaptation can amplify dispersion by specializing on highly infectious hosts, reducing transmission from less infectious ones.
Conclusions:
- Parasite adaptation is a key factor that can emerge and drive substantial transmission overdispersion in heterogeneous host populations.
- This adaptive process can influence disease dynamics from initial outbreaks through to endemic states.
- The findings offer a predictive framework for understanding transmission patterns of novel and re-emerging infectious diseases.
Related Concept Videos
01:20Infection
7.6K
When a pathogen enters the body and reproduces, it can cause an infection, damage body cells, and cause illness symptoms that eventually lead to disease. Therefore, its prevention requires breaking the chain of infection.
The chain begins with pathogens: bacteria, viruses, fungi, prions, or parasites such as protozoa helminths. These can be present on the skin as transient or resident flora, or they can be acquired from the environment. Identifying and treating the type of infection and...
The chain begins with pathogens: bacteria, viruses, fungi, prions, or parasites such as protozoa helminths. These can be present on the skin as transient or resident flora, or they can be acquired from the environment. Identifying and treating the type of infection and...
7.6K
00:58Symbiosis
27.3K
Symbiotic relationships are long-term, close interactions between individuals of different species that affect the distribution and abundance of those species. When a relationship is beneficial to both species, this is called mutualism. When the relationship is beneficial to one species but neither beneficial nor harmful to the other species, this is called commensalism. When one organism is harmed to benefit another, the relationship is known as parasitism. These types of relationships often...
27.3K
01:09Mutation, Gene Flow, and Genetic Drift
57.9K
In a population that is not at Hardy-Weinberg equilibrium, the frequency of alleles changes over time. Therefore, any deviations from the five conditions of Hardy-Weinberg equilibrium can alter the genetic variation of a given population. Conditions that change the genetic variability of a population include mutations, natural selection, non-random mating, gene flow, and genetic drift (small population size).
57.9K
02:39Gene Flow
34.7K
Gene flow is the transfer of genes among populations, resulting from either the dispersal of gametes or from the migration of individuals.
34.7K
01:10Retrovirus Life Cycles
45.6K
Retroviruses have a single-stranded RNA genome that undergoes a special form of replication. Once the retrovirus has entered the host cell, an enzyme called reverse transcriptase synthesizes double-stranded DNA from the retroviral RNA genome. This DNA copy of the genome is then integrated into the host’s genome inside the nucleus via an enzyme called integrase. Consequently, the retroviral genome is transcribed into RNA whenever the host’s genome is transcribed, allowing the...
45.6K
00:54Distribution and Dispersion
21.6K
To understand intra-specific interactions in populations, scientists measure the spatial arrangement of species individuals. This geographic arrangement is known as the species distribution or dispersion. Highly territorial species exhibit a uniform distribution pattern, in which individuals are spaced at relatively equal distances from one another. Species that are highly tied to particular resources, such as food or shelter, tend to concentrate around those resources, and thus exhibit a...
21.6K