Assessing transmission risks and control strategy for monkeypox as an emerging zoonosis in a metropolitan area

Abstract

Objective: To model the spread of Monkeypox (MPX) in a metropolitan area for assessing the risk of possible outbreaks, and identifying essential public health measures to contain the virus spread. Methods: The animal reservoir is the key element in the modelling of a zoonotic disease. Using a one health approach, we model the spread of the MPX virus in humans considering animal hosts like rodents (e.g., rats, mice, squirrels, chipmunks, etc.) and emphasize their role and transmission of the virus in a high-risk group, including gay and bisexual men-who-have-sex-with-men (gbMSM). From model and sensitivity analysis, we identify key public health factors and present scenarios under different transmission assumptions. Findings: We find that the MPX virus may spill over from gbMSM high-risk groups to broader populations if efficiency of transmission increases in the higher-risk group. However, the risk of outbreak can be greatly reduced if at least 65% of symptomatic cases can be isolated and their contacts traced and quarantined. In addition, infections in an animal reservoir will exacerbate MPX transmission risk in the human population. Conclusion: Regions or communities with a higher proportion of gbMSM individuals need greater public health attention. Tracing and quarantine (or "effective quarantine" by post-exposure vaccination) of contacts with MPX cases in high-risk groups would have a significant effect on controlling the spreading. Also, surveillance for animal infections would be prudent.

Modelling vaccination and control strategies of outbreaks of monkeypox at gatherings

“…For simplicity, henceforth we use the subscript 1 for the LRG, and 2 for the HGR. Those two groups interact between and within groups as represented by a contact matrix ( c ij , i,j = 1,2), defined using the assumptions in Yuan et al 24 . We assume that there is no movement of population between the risk groups, unless there is a gathering event such that a proportion of LRG people may become part of the HRG.…”

“…We use the assumptions of Yuan et al 24 on the transmission of the monkeypox virus. The probability of transmission per contact was assumed to be 12.2% to 24.5%, and between 0.37% and 0.74%, respectively, among HRG and LRG, as calculated from the basic reproduction number R 0 derived from our simplified model without public health control measures (see Appendix A2 for details) all the other parameters being fixed ( Table 3 ).…”

“…Following Yuan et al 24 , the number of close contacts of newly confirmed cases in the LRG, who are in exposed state Z E 1 ( t ) and prodromal phase Z P 1 ( t ) at time t can be calculated as …”

Modeling vaccination and control strategies for outbreaks of monkeypox at gatherings

“…For simplicity, henceforth, we use subscript 1 for the LRG and subscript 2 for the HRG. Those two groups interact between and within groups as represented by a contact matrix (c ij , i, j = 1, 2), defined using the assumptions in Yuan et al (23). We assumed that there is no movement of population between the risk groups unless there is a gathering event such that a proportion of LRG people may become part of the HRG.…”

“…We used the assumptions of Yuan et al (23) on the transmission of the monkeypox virus. The probability of transmission per contact was assumed to vary between 12.2 and 24.5% among the HRG and between 0.37 and 0.74%, among LRG, as calculated from the basic reproduction number R 0 derived from our simplified model without public health control measures (see Supplementary material S2 for details) and all the other parameters being fixed (Tables 3, 4).…”