In Africa, a Glimpse of Hope for Beating H.I.V.

The health problems of millions of Americans are directly related to patients' failure to follow doctors’ orders. Community health workers are increasingly successful in New York and other American cities – not to substitute for doctors, but to help patients stick to their treatment plans.

Two columns on how Iran averted a major AIDS epidemic through needle exchange programs; a conservative theocracy is successfully treating drug abuse as if it were Amsterdam.

Tuberculosis is still a rampant problem in the developing world. Doctors are looking for even more advanced ways to test for TB beyond the GeneXpert tests.

One-pill-a-day generic AIDS drugs for poor countries are hard to make because each ingredient is patented by a different pharmaceutical company. The Patent Pool provides a way for companies to donate their intellectual property safely.

Colorado causes a large decline in teen pregnancy and abortions by implementing free, long-term birth control to prevent pregnancy. While demonstrating massive success, its continuity is in the air considering the ongoing fight over health insurance at the federal level.

Slow test results make it difficult to stop the spread of tuberculosis. Using faster diagnostic technology and driving vans to rural areas in Tanzania, GeneXpert is making progress in treating this curable disease.

Although patients go to hospitals to receive medical care, many Americans will acquire infections that did not already have them. The United States as a whole has made modest progress at reducing the rates of hospital-acquired infections. Spearheading the efforts, the Veterans Affairs Medical Centers have devised anti-MRSA strategies to keep patients safe.

For decades, AIDS has taken the lives of millions of people and infected millions more worldwide. The key to reducing the effect of AIDS, and even potentially curing it, involves treating patients as early as possible after being diagnosed with HIV, before the disease damages organs. San Francisco General Hospital developed the RAPID program for this purpose, with the goal of “Getting to Zero” the number of new infections and deaths.

Two columns on how Iran is treating its massive epidemic of injecting drug use by tackling it as a health problem, effectively lowering H.I.V. rates among drug users using an approach to drugs known as harm reduction.

In a mountainous region of Lesotho, a man named Tsepo Kotelo visits 20 villages every week on his new motorcycle to provide health care to local villagers. The Elton John AIDS Foundation gifted the motorcycles to Kotelo and his colleagues, allowing them to increase the number of patients they visit by 600 percent. An organization called Riders for Health helps maintain the bikes, ensuring that remote villages will continue to receive medical care.