Fig 1.
Agents are always in one of five mutually exclusive states: susceptible (S), presymptomatic (P), infected with symptoms (I), asymptomatically infected (A), or recovered (R).
Fig 2.
The bar charts show the shedding level of an infected individual whose presymptomatic period and symptomatic period are 6 and 7 days, respectively. The percentage in the parenthesis of each model corresponds to the percentage of shedding during the presymptomatic state (P) relative to the total shedding volume. The peak shedding level differs in the two models, but the total shedding volume remains the same.
Fig 3.
HCP nodes, MWF patient nodes, and TThS patient nodes are depicted in blue, chocolate, and burlywood colors, respectively. Contacts within the same type of nodes are represented as edges colored according to node type. Grey colored edges represent HCP-patient contacts. The thickness of the edge corresponds to the contact duration. Patients mostly have contact with other patients at the same dialysis session unless there is an overlap between sessions, hence we observe 6 patient clusters (3 sessions per day on MWF and TThS) of 6 or 7 patients each. For any session, a patient will be in contact with at most 2 neighboring patients, thanks to how neighboring dialysis chairs are positioned. Over several sessions, depending on which chair they occupy, a patient may come in contact with several other patients.
Table 1.
Calibrated values of the parameters for the shedding model.
Table 2.
Network statistics of static graph G.
Table 3.
Network statistics of temporal graph Gd,t.
The statistics shown here are obtained by averaging over all (approximately) 177K temporal graphs (177K ≈ 26 days × 6822 timesteps per day).
Fig 4.
Cumulative distributions of transmission events over 30 days in Baseline simulation.
(A) Scenario 1: dialysis patient is the infection source and (B) Scenario 2: HCP is the infection source. In both scenarios, the most frequent transmission route is from HCP → patient (52.7% in Scenario 1 and 56.8% in Scenario 2), followed by patient → patient (22.1% in Scenario 1 and 22.5% in Scenario 2), HCP → HCP (16.6% in Scenario 1 and 18.5% in Scenario 2), and a small fraction of patient → HCP transmission (6.7% in Scenario 1 and 2.6% in Scenario 2).
Fig 5.
Attack rates for individual NPIs and selected NPIs in combination in Scenario 1 (infection source: Dialysis patient), R0 = 3, exp/exp (60%).
(A) Voluntary self-isolation vs. active syndromic surveillance and compulsory isolation. (B) Use of masks and respirators. (C) Improved social distancing among HCPs. (D) Increased physical separation of dialysis stations. (E) Patient isolation and preemptive isolation of exposed HCPs. (F) Combinations of inexpensive NPIs denoted Baseline+, Baseline++, and Baseline+++. Each figure displays cumulative attack rates as a function of simulation days. Each plot includes the Baseline curve for comparison; lower curves correspond to fewer infected agents. See text for descriptions of the individual NPIs.
Fig 6.
Attack rates for individual NPIs and selected NPIs in combination in Scenario 2 (infection source: HCP), R0 = 3, exp/exp (60%).
These are the same plots as in Fig 5, except that these are for Scenario 2.
Fig 7.
Frequency of replicates as a function of attack rates for different NPIs: (A) Scenario 1 and (B) Scenario 2.
Each histogram displays the number of replicates (y axis; out of 500) with the specified overall attack rate. In Scenario 1, two peaks are commonly observed for each histogram; one where no transmission events occur (the infection is immediately quashed) and one indicating the fuller extent of an eventual outbreak. When no intervention is imposed (Baseline), only 31 simulations (6.2%) have no transmission events, while 83.6% (418) resulted in attack rates larger than 90%. In contrast, Baseline+++ and Baseline++ significantly increases the likelihood of observing no transmission events (162 and 175 simulations, 32.4% and 35.0%, respectively). In Scenario 2, even with interventions, infection is never quashed in any replicate. However, even in this scenario, there are no replicates with Baseline+++ interventions that have a near-100% attack rate. Furthermore, the frequency mass of the Baseline+++ intervention is substantially shifted to the left (towards lower attack rates) relative to the Baseline simulations.
Table 4.
Attack rates for combinations of NPIs under different modeling assumptions.
“SM” is short for “shedding models”, “B” is short for “Baseline,” in Scenario 1 the infection source is a dialysis patient and in Scenario 2 the infection source is a HCP.