It seems amazing to think of it now. But rats and fleas were so common in the filthy cities of medieval Europe that people saw no connection between them and the deadly plague that was coming on them. Rats carried fleas from one country to another, usually on board ships as stowaways in search of the "free" food transported between ports. And sometimes the fleas carried the bubonic plague, passing it on to the people in the homes they visited. Rodent Millions of people died. Between one third and one half of all the people in the affected areas died. In some places, it's estimated that as many as 90 percent of the people perished. The plague was to last over 300 years, repeatedly coming back in waves to kill more people. People didn't realize that simple changes to their lifestyles would have saved them. They were living in filth and squalor--in cities that were overcrowded. Their houses were close together. They threw their garbage out of the window and left it to rot in the narrow streets below. The same narrow paths between houses were used as latrines, and the stench was so familiar that city dwellers had no idea what fresh air smelled like. Then the rats came with the infected fleas on their backs. They only stayed long enough to eat all that was available, before moving on to the next town and further victims of the plague. People had no idea what hit them. It came suddenly and ended just as quickly, leaving perhaps half the members of each family to die gruesome, agonizing deaths. Those left alive were too frightened to bury their relatives, afraid to go near them in case they might catch whatever they had. The "black death," they called it. When it arrived in England in 1348 the population was six million. By 1500 the population of the country was only 1.6 million. Other countries suffered even more. The continent of Europe was ravaged by the plague. People's lives were dominated by death, the thought of death and the fear of death. They thought the disease was carried through the air. They had no idea that rats and fleas were responsible and that they could have eradicated the problem by improving their standard of hygiene. The black death was a disease of filth, the physical filth that people lived in during the Middle Ages. They were ignorant of some of the basic laws of hygiene that we understand today. They needn't have been so ignorant—those hygiene laws that would have saved them were written down in the pages of the Bible thousands of years ago. In the book of Deuteronomy we see God's instruction to the Israelites regarding their toilet habits, a rudimentary law of hygiene that is still ignored in many areas of the world (Deuteronomy 23:12-13). Additionally, Isaiah 5:8 instructed the Israelites not to build their houses close together. Today's disease Today there's another plague killing millions of people. And, again, ignorance is a significant problem. Most of the victims of this plague do not know why they have it. Many think they know the solution, but only make matters worse. It's another plague of filth—not the same physical filth that affected people in the Middle Ages, but the moral filth that is so much a part of our world today. This plague is called AIDS (for acquired immunodeficiency syndrome). It's a virus that gets into your blood, the HIV virus that is similar to a virus carried by the African green monkey. Somehow the HIV virus entered into the bloodstreams of some human beings. They passed it on to others, mainly through sexual contact. Sick child AIDS has spread rapidly but not as rapidly as the black death. That's because AIDS takes time. From the time a person gets infected until the time he dies can be many years. It was only a couple of days with the black death. The HIV virus can be in people's blood for many years before they come down with AIDS. When AIDS takes over, it's often only a few months until they die. Because AIDS attacks the immune system, it is easy to die from just about anything. Africa's plight In the United States and other western countries, the AIDS plague has not yet resulted in the deaths of millions. But in Africa, it is killing so many people that entire nations may not even exist by the time today's teens reach the age of 30. So many parents have died, there are over 10 million AIDS orphans in sub-Saharan Africa. Mortuaries and graveyards work round the clock to keep up the horrific task of burying the millions who have fallen victim to AIDS. Sadly, most of these people are so uneducated they do not even know how they got the disease. In their ignorance, they have passed it on to others, even their own children. The fact is, though some in their ignorance and superstition may dispute it, AIDS is passed from one person to another solely through bodily fluids. In most cases, that means sexual relations (or sharing needles in illegal drug use). It also means that somebody at some time has broken God's law relating to sex. The truth is that a husband and wife who are not infected cannot get AIDS from each other during marital relations. As long as they are faithful to each other, they have nothing to fear from AIDS. A simple but effective solution AIDS is truly a disease of moral filth, just as the black death was a disease of physical filth. The solution to the black death was improved hygiene. The solution to AIDS is improved morals. The Bible teaches that each person should only have one sexual partner, the person he or she has committed to in marriage. This is so important that God made it the subject of one of the Ten Commandments. "You shall not commit adultery," says God in Exodus 20:14. Only within marriage are a man and woman to become "one flesh" (Genesis 2:24) in a union that is to last a lifetime. Even among educated people there is a refusal to accept this simple solution to the seemingly complex problem of AIDS. The reason is that people don't want to change. People living an immoral lifestyle want to continue that way, being sexually active with multiple partners. Society has become so accepting of immorality that "high risk" sexual activity is now considered to be more than six partners a year. In contrast, the Bible clearly defines "high risk" as having any partners outside of marriage, even one. If we are to stop AIDS, there must be a return to the laws of God governing marriage and morality. If this does not take place, then hundreds of millions will die of AIDS needlessly. Make sure you're not one of them.