Book contents
- Frontmatter
- Contents
- Introduction
- Participants
- Non-Participant Contributors
- Part 1 Transmissible diseases with long development times and vaccination strategies
- Part 2 Dynamics of immunity (development of disease within individuals)
- Evolutionary dynamics of HIV infections
- Statistical models for analysis of longitudinal, CD4 data
- Some mathematical and statistical issues in assessing the evidence for acquired immunity to schistosomiasis
- Virulence and transmissibility in P. falciparum malaria
- Invited Discussion
- Invited Discussion
- Invited Discussion
- Lifespan of human T lymphocytes
- Diversity and virulence thresholds in AIDS
- Statistical analysis of AZT effect on CD4 cell counts in HIV disease
- Modeling progression of HIV infection: staging and the Chicago MACS cohort
- The interpretation of immunoepidemiological data for helminth infections
- The distribution of malaria parasites in the mosquito vector: consequences for assessing infection intensity in the field
- When susceptible and infective human hosts are not equally attractive to mosquitoes: a generalisation of the Ross malaria model
- The dynamics of blood stage malaria: modelling strain specific and strain transcending immunity
- Part 3 Population heterogeneity (mixing)
- Part 4 Consequences of treatment interventions
- Part 5 Prediction
The interpretation of immunoepidemiological data for helminth infections
Published online by Cambridge University Press: 04 August 2010
- Frontmatter
- Contents
- Introduction
- Participants
- Non-Participant Contributors
- Part 1 Transmissible diseases with long development times and vaccination strategies
- Part 2 Dynamics of immunity (development of disease within individuals)
- Evolutionary dynamics of HIV infections
- Statistical models for analysis of longitudinal, CD4 data
- Some mathematical and statistical issues in assessing the evidence for acquired immunity to schistosomiasis
- Virulence and transmissibility in P. falciparum malaria
- Invited Discussion
- Invited Discussion
- Invited Discussion
- Lifespan of human T lymphocytes
- Diversity and virulence thresholds in AIDS
- Statistical analysis of AZT effect on CD4 cell counts in HIV disease
- Modeling progression of HIV infection: staging and the Chicago MACS cohort
- The interpretation of immunoepidemiological data for helminth infections
- The distribution of malaria parasites in the mosquito vector: consequences for assessing infection intensity in the field
- When susceptible and infective human hosts are not equally attractive to mosquitoes: a generalisation of the Ross malaria model
- The dynamics of blood stage malaria: modelling strain specific and strain transcending immunity
- Part 3 Population heterogeneity (mixing)
- Part 4 Consequences of treatment interventions
- Part 5 Prediction
Summary
Introduction
Acquired immunity is a particular type of density-dependent process that may affect the establishment, mortality or fecundity of parasitic helminths, as functions both of current infection and of past infection; that is, a densitydependent process with ‘memory’. This type of process is likely to have complicated impacts on parasite population dynamics because of this memory component (Woolhouse 1992a). The epidemiological impact of acquired immunity will also depend on which parasite life-cycle stage provides the antigen stimulating a protective response and on which stage is the target of the response. For human schistosomes (the main example used here), the relevant life cycle stages are larvae (cercariae and schistosomulae) (L), adult worms (A), and eggs (E). The evidence for different forms of immunity to schistosomes has been elegantly reviewed in Hagan and Wilkins (1993); possible combinations of target and response are: larval antigen/anti-larval response (an LL process); adult antigen/anti-larval response (an AL process); and adult antigen/antiadult response (an AA process).
Mathematical models
The models used here are described in detail elsewhere (Woolhouse 1992b, 1993, 1994) and are based on earlier elaborations of a simple immigrationdeath process (Anderson and May 1985, Roberts and Grenfell 1991). The models describe the dynamics of the worm burden, experience of infection, and level of resistance for a set of individuals in a population. Worm burden is self explanatory. Experience of infection corresponds to the (discounted) cumulative exposure to parasite antigens and can be interpreted as related to the numbers of specific memory cells.
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- Models for Infectious Human DiseasesTheir Structure and Relation to Data, pp. 200 - 203Publisher: Cambridge University PressPrint publication year: 1996