Pakistani police recently raided an apartment near the capital Islamabad and released 24 people who were locked inside. Brought and held there through deception and threats, the terrified men and women were waiting to be taken to a clinic to have a kidney removed — unwilling participants in a global phenomenon known as organ trafficking. Here are some key facts and insights about this illicit activity and the efforts against it.

What is organ trafficking?

Organ trafficking — the sale and purchase of human organs for transplantation — is a widespread crime. Estimates put the worldwide number of commercial transplantations — transplantations that involve payment for the organ — at about 10,000 annually, roughly 10 percent of all transplantations. In most cases, the organ is a kidney, sold by a living person — illegally. Many countries have laws that prohibit the selling and buying of organs and ban physicians from transplanting organs obtained through payment. This practice is also banned by the World Health Organization, which requires organ donation to be altruistic.

What fuels the organ trade?

The shortage of organs for transplantation is a persistent worldwide problem: Demand for organs significantly outstrips supply. Consider the following statistics. As of early 2016, 100,791 people were waiting for lifesaving kidney transplants in the United States. Yet in 2014, only 17,107 kidney transplants took place there. That year, 4,761 Americans died while waiting for a kidney transplant.

Unable to obtain an organ at home, patients from rich countries might choose to travel to developing countries, where they can buy the organ and have it transplanted. In the developing countries, organ brokers lure poor, uneducated individuals into selling their kidney through the promise of financial gain and a better future. Economic need drives most organ sellers, but in some cases — as in the Pakistani case above — actual coercion is used. Such cross-border form of organ trafficking is known as “transplant tourism.”

Which countries are involved?

The organ trade typically takes place in developing countries whose hospitals are advanced enough to offer transplant services. It originated in India in the 1980s; in the following years, Pakistan, the Philippines, Egypt and China (where the organs were alleged to have come from executed prisoners) became hubs of commercial transplants. Such illegal transplants are also known to have been done in Turkey, Kosovo, South Africa and other sites. The patients typically come from the rich countries of East Asia (e.g., Japan and Taiwan), the rich countries of the Middle East (e.g., Saudi Arabia and Israel), as well as the United States and Western Europe.

But wait, why prohibit a trade that may save people’s lives?

This is indeed a question that libertarians raise. They argue that legal organ sales are an expression of individual liberty that would allow many patients to regain their health while financially benefiting low-income individuals.

Yet the existing medical consensus prohibits the organ trade, based on the ethical view that human organs are not a commodity to be bought and sold. It is also argued that the trade is inherently exploitative, since it is the poor and vulnerable members of society who sell their organs to the rich. Furthermore, kidney sellers receive only a small fraction of the $100,000-$200,000 typically paid by patients and rarely experience the hoped-for economic improvement. Many, in fact, suffer a deterioration of their health, which further worsens their financial problems, along with a sense of hopelessness and social isolation. And patients might also be disappointed. Given the often-inadequate pre-transplant evaluation and substandard medical treatment, commercial transplantations might yield poor health outcomes, and put patients at a higher risk of surgical complications, infections and organ rejection.

How difficult is it to curb organ trafficking?

Compared with other illicit trades, organ trafficking should be rather easy to curb. Governments are sometimes reluctant to suppress illicit activities that are economically important, such as the trade in drugs or counterfeit goods. But this is not the case with the organ trade that is of little economic significance, financially benefiting a small group of organ brokers and physicians.

Furthermore, fighting the organ trade entails limited law enforcement efforts, since it is less hidden and more detectable than many other criminal activities. The prohibited transplantations do not take place in back alleys, but in a few easily identifiable locations: hospitals. The physicians who perform these transplantations can be easily identified, as can the patients who receive the illegal transplants. Before the transplantation abroad, they are on the organ wait list in their own countries; after undergoing the procedure, they must receive continuing care, including immunosuppressive drugs.

Why, then, isn’t the organ trade eliminated?

The problem is a lack of willingness to enforce the law: While a legal prohibition may exist, governments often make little effort to stop the trade. My research identifies several reasons for that. One is that organ trafficking, at first blush, does not look harmful or morally repugnant. Transactions in organs may deceptively seem advantageous to both the organ buyer and seller, although in reality they are far from it. While the notion of buying sex — prostitution — meets widespread disapproval, many people accept the buying of kidneys as a legitimate solution for the shortage of organs for transplantation.

Governments also struggle to consider organ-trade participants as offenders, even when they break the law. Physicians, with an aura of respectability, hardly seem like shady criminals; and patients fighting for their lives have the authorities’ sympathy. Cracking down on the organ trade would condemn these patients to dialysis — an excruciating treatment that is also very costly for the health-care system — or, worse, to death.

What can be done?

While organ trafficking is a form of human trafficking, international initiatives against human trafficking have focused on the sex trade, paying little attention to the trade in organs. The medical community itself, however, mobilized to repudiate transplant commercialism. In 2008, two international medical associations jointly established the Declaration of Istanbul on Organ Trafficking and Transplant Tourism. This declaration aims to unify physicians in denouncing the organ trade and motivate governments to enhance ethical, altruistic organ donations.

My analysis shows that the medical community’s efforts indeed had an impact. Physicians’ advocacy, together with media criticism, brought Israel and Pakistan to pass laws against organ trafficking. The two countries’ involvement in the organ trade saw significant reduction, but not complete elimination — as the recent raid in Pakistan demonstrates. Legislative prohibitions ultimately mean little without vigorous enforcement, which requires sustained pressure on government authorities. Since the organ trade ranks low in the latter’s priorities, it is the job of the medical community, civil society and the media to raise public awareness and demand action. Tough enforcement, alongside policies to encourage altruistic organ donation, will go a long way toward abolishing the organ trade.

Asif Efrat is associate professor of government at the Interdisciplinary Center (IDC) Herzliya, Israel.