Yes yes, bed nets and deworming initiatives are the go-to . But what about directly helping someone out of poverty or at least an unwanted living circumstance to come live in a Western country? They could also get a job and potentially provide a huge ROI; here is a story from an anonymous Quora user:
The one who became my wife wanted me to pay for college in the USA. I was like no problem; I felt putting her through college was a great way for her to make her own circle of friends and integrate into my country. I stashed away 50% of my senior engineer paycheck in preparation. Then I fly in and visited her twice. First trip was 2 weeks and we kind of went of vacation together.
That was to learn about each other. Second time was to get married after she had taken the college entrance exam and gotten accepted to a university in my city and the fiancée visa was issued. I showed my wife her budget (around $20K) and let her choose how much to apply to the wedding and how much to her schooling. She put most of it towards schooling (had to pay foreign student tuition the first year….ouch).
Anyways, 4 years later she graduated Summa Cum Laude and eventually lands a great job that pays six figures. Did I mention she graduated with no student debt?