 Good morning, Hank, it's Tuesday. So when I think about advances in the field of medicine, I usually think about, you know, like, medicines, antibiotics, anesthesia, chemotherapy. And if I think harder, maybe I'll consider medical devices like dialysis machines or artificial joints or refrigeration systems for vaccines, but I should be thinking about something else, too. So this is vibriocholary, the bacterium that causes cholera, a diarrheal disease that usually only lasts for a few days but can kill you very quickly via dehydration. It used to be one of the world's biggest health problems. About 160 years ago, a pandemic killed tens of millions of people, including over 150,000 Americans, one of whom was the U.S.'s 11th President, James K. Polk. Such was the fear of cholera, that Polk was initially buried not with a fancy ceremony befitting a president but in a public cemetery, as dictated by infectious disease regulations. Cholera was terrifying. You could lose 20 pounds of body weight via diarrhea in under a day, and depending on the strain, it killed up to half of the people it infected. And today, for most of the world, it's gone. Not because of antibiotics, although they can shorten the course of the disease, or because of vaccines, although there is a vaccine that provides up to six months of protection, but because of sewers and water purification systems. Cholera is caused by vibriocholary, but it's also caused by lack of access to clean water, which means that it's not just a health problem, it's also a social and political one, and we're seeing that now in Yemen. So around the world every year, more people have access to clean water and safe sanitation facilities, but even before the Yemeni Civil War that began in 2015, Yemen was one of the few countries on Earth where access to safe drinking water had actually declined since 1990. But since the war began, the situation has become truly dire. The war has displaced millions of people and killed more than 10,000, and thousands more have died from what is the worst outbreak of cholera since at least 1949, when good records started being kept. The outbreak began after the bombing of Yemen's capital, Sana'a, led to the failure of the city's sewer system, and cholera has now spread through most of the country. The World Health Organization estimates that over 500,000 people have been infected, about half of them children. Now cholera is treatable. The first line treatment is oral rehydration solution, which is super cheap. In fact, versions can be made at home with just a few ingredients, but it requires clean water, which is in short supply in some parts of Yemen. And the outbreak is complicated by the fact that most health workers in the hardest hit regions haven't been paid in over a year. Also, malnutrition is now common among Yemeni children, which lowers their resistance to infection. Despite these challenges, the cholera outbreak in Yemen has so far been less deadly than many previous outbreaks, partly due to the strains of cholera involved, but also because non-governmental organizations like Save the Children are working in extremely difficult conditions to provide oral rehydration solution. And many Yemeni health workers continue to provide care even as they go unpaid. But one of the hard truths about this epidemic is that fewer people would be dying if the world were paying more attention. I think there are a lot of reasons why we find this story difficult to pay attention to. The civil war in Yemen is complex, and there's no clear or simple path to peace. The political drama in the United States feels so astonishing and unprecedented that it's difficult to look at anything else. And also, most of us don't feel like we can do anything about cholera in Yemen, but that is simply not true. By donating to organizations working in Yemen, we can help pay for healthcare workers and the hydration solution that saves so many lives. And I'd also argue that we make a difference just by paying attention. For one thing, it encourages more news coverage about the crisis, but it also helps shrink the huge empathy gap between the rich and poor worlds. When there's a political or health crisis in Europe or Australia, I pay more attention than I do to crises elsewhere, even though Europe and Australia are distant from me because the people who live in those countries feel close to me. I watch them on YouTube. I read their posts on Reddit. I really believe that all human lives are equally valuable, but I can't live that belief if I can't empathize with the challenges faced by those who live in poverty or in fear of cholera. So I'm trying to pay attention because the cholera outbreak in Yemen is a health problem and a political problem, and also an empathy problem. Hank, I'll see you on Friday.