This is an important part of the equation, and it's unfortunate that the article doesn't go into sufficient detail about the actual mechanisms by which the infection can happen. If anything, the article's mentions of "people are simply eating more fresh produce these days" and "some contamination can still slip through" foster an attitude of helplessness, as if this is a new normal we need to get used to.
Poor living and working conditions for migrant farmworkers is a contributing factor to outbreaks like this. Workers who are present illegally or are otherwise marginalized and taken advantage of, even if they are part of legal guest-worker programs, suffer conditions where poor housing facilities or the need to work under great time pressures leads to inadequate sanitation.
A 2017 story [0] illustrates this:
>Kristina Espinoza, a labor department investigator who recently visited the farm, described a "makeshift labor camp" that was "dangerous" and "unsanitary," according to court documents. [...] Gonzalez had workers shower in nine stalls inside a cargo container; there was no functional sewage system, so wastewater accumulated underneath the container, Espinoza said. The electrical cord used to light the facility was exposed to standing water, posing a risk of electrocution, according to court documents. The workers shared one toilet in the trailer and had access to port-a-potties.
[0] http://www.latimes.com/business/la-fi-farmworker-abuse-20170...