Semiquantitative Risk Evaluation Reveals Drivers of African Swine Fever Virus Transmission in Smallholder Pig Farms and Gaps in Biosecurity, Tanzania

Table 4

Expert opinion ranking of susceptibility to hazard among the group of pigs in the farm in premises as identified by the stakeholders.

Pig group	Ranking
Shared adult boars	1
Pregnant and lactating sows (in pigs)	2
Nonpregnant sows	3
Nonshared adult boars	4
Growers	5
Weaners	6
Piglets	6
Porkers	8

Note. 1 = the most affected and 8 = the least affected. Stakeholders observed and provided anecdotal evidence that at the farm level, the subgroupings of pigs listed above have been affected to different degrees. It is hypothesized that different degrees of immunities in different pigs and the dose of infection may influence the degree of affection. Experts’ opinions were provided based on years of experience and empirical evaluation of ASF in farms. Piglets die typically due to starvation because of the death of sow. It should be noted that most dead piglets are not examined pathologically for causes of death. There was no significant difference between the rankings; hence, all subgroupings of pigs were classified as high in terms of susceptibility to the hazard. Full details of the reasoning behind the ranking are available in the Supplementary Table 4c.