Comment by vablings
6 hours ago
"If you spent over 4 weeks in primitive or rural accommodation you have to wait for 4 months after your return before giving blood. However, if you were travelling and staying in places which are modern and clean, such as typical tourist areas, please wait 4 weeks from your return due to Tropical Virus risk which includes Chik V, Dengue or Zika risk providing you do not have symptoms of these."
Not quite the four years.
The first paragraph is
“ If you visited the rural areas of the states - Chiapas, Chihuahua, Durango, Sinaloa districts, Quintana Roo, you need to wait for 4 months after your return to the UK before giving blood. ”
The US rules also aren’t 4 years (not sure why someone told the OP that). It’s 3 years after undergoing malaria treatment. And 3 months after visiting a malaria prone area.
https://www.redcrossblood.org/faq.html#eligibility-travel