Overview
The goals for malaria programs today are to reduce the burden of malaria, and to set the stage for malaria elimination. Our exploration of mathematical models is designed to cover both topics, even though they emphasize very different features of these systems: understanding burden puts an emphasis on exposure and disease, particularly severe disease, and it may require delving into interactions between malaria and other health conditions; understanding malaria elimination would keep us focused on transmission dynamics.
If we want to develop a box of quantitative tools that are up to addressing malaria burden and elimination, we will need to start with the basics and expand. An outline of the material is found on the sidebar. The following is a brief narrative:
We start with Simple Models and an introduction to Malaria Metrics.
In Realism, we discuss some of the reasons why simple models fail, and we introduce the challenges of learning how to build models to answer questions.
Next, we five major domains:
Malaria epidemiology, defined in the narrow sense to cover issues related to human malaria: exposure, infection, disease, immunity, infectiousness, diagnostics and detection and associated issues;
Transmission dynamics by adult mosquitoes, including mosquito blood feeding and demography, heterogeneous transmission, seasonality, and spatial dynamics;
Mosquito ecology, including exogenous forcing by weather and aquatic dynamics;
Malaria Control is covered in two parts:
Health systems and interventions use antimalarial drugs, vaccines, and monoclonal antibodies
Vector control
In Analysis, we focus on the standard methods available to analyze models.
In Advanced, we delve into some topics at the leading edge of research, including some models and topics that might be of interested to many malaria analysts.
In Models and Data, we look at some core questions about malaria transmission dynamics and control, including the data describing the relationship between the EIR, the FoI, and the PR.
NOTE: This material is concerned mainly with Plasmodium falciparum. When we say malaria, we generally mean human disease caused by infection with P. falciparum. While all the species of human malaria share some features in common, the main difference is that the non-falciparum human malaria parasites have another stage, called hypnotozoites that remain dormant in the liver. When other malaria parasite species are discussed, we will be very explicit about it.
Simple Models
To understand malaria in populations, we start by introducing simple models of malaria in populations and supporting concepts: parasite transmission through blood feeding and malaria transmission dynamics. Next, we introduce the metrics used to measure malaria.
Malaria Epidemiology
Malaria epidemiology, in the narrow sense, describes a set of concepts including exposure, infection, disease, immunity, infectiousness, care seeking, drug taking, diagnostics, and detection. Within malaria epidemiology, we recognize two important, closely related themes:
Exposure, infection, and malaria transmission.
Exposure, infection, and disease.
Transmission Dynamics
Parasite transmission through blood feeding by adult mosquitoes and parasite infection dynamics in adult mosquitoes. We understand blood feeding as an interaction between adult female mosquitoes and humans. These are the core processes that sustain malaria in populations, and we would like to understand parasite dispersal, the structure of malaria transmission, the spatial scales that characterize transmission, malaria connectivity, and other concepts that will help us to understand malaria transmission well enough to plan for malaria control;
Mosquito Ecology
Vector Ecology includes blood feeding by adult mosquitoes and all the other processes that regulate mosquito population dynamics, and the factors that determine the distribution and abundance of mosquitoes. Under vector ecology, we study adult mosquito behavior, exogenous forcing by weather, mosquito dispersal, mating, habitat dynamics, and all the factors that could become an important factor in the management of malaria;
Health Systems
The management of malaria, through health systems and vector control, has played a major role in shaping the epidemiology of malaria in the world today, and it is critical to understand those effects before we try to modify existing systems. Under malaria control, we recognize two major domains:
- Medical interventions and malaria therapeutics applied through routine health care and used for public health measures including mass treatment, mass distribution of vaccines, and mass distribution of monoclonal antiboddies. These interventions play a direct role in reducing disease, and they can also play some role in reducing transmission.
Vector Control
- Vector control to reduce exposure, suppress mosquito populations, and suppress malaria transmission.