The extent of the crisis was clear during a recent trip through some of Yemen’s hardest hit areas, where clinics are overburdened and short on supplies, and families struggle to reach them and pay for treatment. Some watch their relatives suffer and die.

Before the war, Yemen was already the Arab world’s poorest nation, and its people never enjoyed high-quality infrastructure. But travel by car, the only means available, has become far more difficult because the Saudi-led bombing campaign has shattered bridges and left huge bomb craters in the main roads.

A simple 20-mile ride that would have taken an hour before the war is now a maze of complex routes that can take many more hours and cost more than what many families live on for an entire month.

To pay for rides to the hospital, many families borrow money or sell heirloom gold — the equivalent of an American family liquidating retirement accounts. Some who cannot pay carry their loved ones through the rugged terrain on trips that can aggravate dehydration.

Cholera medications are supposed to be freely provided by Yemen’s two competing administrations, but both have favored their military efforts over public health, forcing many families to buy medications from private pharmacies. Acute cases also require families to buy diapers or carry their infected relatives to the toilet several times an hour.

Mr. Siraa, the farm laborer, spoke of his family’s tragedy at a school that a local philanthropist had turned into a clinic in Haja Province, which has been hit hard by the cholera epidemic and the war.

The bridge connecting it to the rest of Yemen was destroyed in an airstrike last year. The clinic has 35 beds, but only a couple of IV fluid bags, two fans and four nurses.