Notation

Author
Affiliation

University of Washington

Conventions:

Structural Parameters

  • \(N_p\) — the number of patches in a model

  • \(N_q\) — the number of habitats in a model

  • \(N_h\) — the number of population strata in a model

Bionomic Parameters

  • \(f\) — the overall blood feeding rate, per mosquito, per day

  • \(q\) — the human fraction

  • \(\tau\) — the EIP (see the EIP vignette)

  • \(g\) — mosquito mortality rate

  • \(\sigma\) — the patch emigration rate

  • \(\mu\) — emigration-related loss, including mortality and emigration

  • \(K\) — a mosquito dispersal matrix \[K = \left[ \begin{array}{ccccc} -1 & k_{1,2} & k_{1,3} & \cdots & k_{1, n} \\ k_{2,1} & -1 & k_{2,3} & \cdots & k_{2, n} \\ k_{3,1} & k_{3,2} & -1 & \cdots & k_{3, n} \\ \vdots & \vdots & \vdots & \ddots & \vdots \\ k_{n,1} & k_{n,2} & k_{n,3} & \cdots & -1 \\ \end{array} \right]\] with the constraint that \(\sum_j k_{i,j} = 1.\)

  • \(\Omega\) — the mosquito demographic matrix:

\[\Omega = \left[\left< g + \sigma \mu \right> \right] - K \cdot \left[\left<\sigma(1-\mu)\right>\right]\]

  • \(B\) — the total human blood feeding rate, per patch

\[B = fqM\]

Transmission

  • \(w\) — The Blood Feeding Search Weights a vector of length \(N_h\) that is used to compute relative biting.

  • \(\Psi\) — The Time at Risk matrix is an \(N_p \times N_h\) matrix that describes the fraction of time in each habitat spent by each population stratum.

  • \(W\)Availability, a vector of length \(N_p,\) is a weighted measure of ambient human population density in each patch:

\[W = \Psi \cdot \left(w H\right) \]

  • \(\beta\) — the Biting Distribution Matrix is an \(N_h \times N_p\) matrix that describes the expected number of bites on a human in each stratum from a single bite in each patch. \[\beta = \left[ \left< w \right>\right]\cdot \Psi^T \cdot \mbox{diag}\left[\left< \frac{1}{W}\right>\right]\]

  • \(E\) — the daily entomological inoculation rate (dEIR) and the dEIR Matrix. The expected number of infective bites, per person, per day is: \[E = \beta \cdot fqZ\]

  • \([E]\) — the dEIR Matrix. A matrix describing the number of infective bites, per person in each stratum, per day, from exposure to infective biting in every patch: \[[E] = \beta \cdot \left[ \left< fqZ \right> \right]\]

  • \(\beta^T\) — the Blood Meal Distribution Matrix is an \(N_p \times N_h\) matrix that describes the probability a human blood meal taken by a mosquito came from a human in each stratum: \[\beta^T = \left[\left< \frac{1}{W}\right>\right] \cdot \Psi \cdot \left[ \left< w \right>\right] \]

  • \(\Xi\) — the The Availability Matrix \[\Xi = \left[\left<W\right>\right] \cdot \beta^T \cdot \left[\left<H \right>\right] = \Psi \cdot \left[ \left< w H\right>\right] \]

  • \(\kappa\)Net Infectiousness (NI), a vector of length \(\kappa,\) is the probability a mosquito becomes infected after blood feeding on a human in each patch. If \(X\) is the infective density of hosts, then: \[\kappa = \beta^T \cdot X\]

  • \([D]\) — the Human Transmitting Capacity Matrix is the expected number of fully infectious days in each patch caused by an infectious bite in each patch:

\[[D] = \Psi \cdot \left[\left<wH \right>\right] \cdot \left[\left<bD \right>\right] \cdot \beta = \Xi \cdot \left[\left<bD \right>\right] \cdot \beta \]


Fig. 1 — This figure provides context for the terms describing the elements of HTC and their use in computing transmission dynamics, connectivity, and parasite generations.