The fight against tropical diseases has had major successes in the last few years, and goals to control or eradicate them by 2020 are right on track, the World Health Organization (WHO) said in Geneva.

Alongside WHO, the Melinda and Bill Gates Foundation also hailed several record-breaking achievements that ramp up efforts to fight these neglected tropical diseases.

However, the health organization believes drug companies need to step up donations of medicines, as millions of people still require cures and treatments.

Major Progress In Fighting Tropical Diseases

Statistics from the Centers for Disease Control and Prevention (CDC) reveal that neglected tropical diseases such as dengue, chikungunya, leprosy, rabies, and trachoma affect 1 billion people and kill about 534,000 every year.

In 1999, the Melinda and Bill Gates Foundation began a campaign to fight these illnesses, and these investments have improved millions of lives, said Gates.

"None of these diseases are getting worse," the philanthropist said. "We're behind on some of the very ambitious goals which were set in London for 2020, but the burden from all these diseases is getting better."

Indeed, Gates told BBC News several major achievements in recent years in ensuring that these tropical diseases are eliminated.

For illnesses such as lymphatic filariasis, which is a mosquito-borne worm that causes swelling in the limbs, there has been a reduction in the patient population. From 1.5 billion people, the number of cases has gone down to 1 billion, he said.

One illness that was close to being fully eradicated is the Guinea worm, which had 25 cases in 2016, although Gates said the unrest in Sudan is making the work more difficult.

Meanwhile, the WHO has cited progress in the treatment of river blindness, which is a parasitic disease transmitted by black flies. Data showed that more than 60 percent of patients or 114 million people with river blindness have received treatment.

Challenges Remain

These major successes are the result of partnership between governments, non-government organizations, and companies, said Gates, but several issues remain.

Before the Geneva conference, Gates met up with CEOs of big pharmaceutical companies to discuss efforts to fight against these tropical diseases.

"Good progress, some of these diseases are on track to be done (eliminated) by 2020, some by 2025," said Gates. "Some will take longer than that."

In 2012, the Gates Foundation, the UK Department for International Development (DFID), and the U.S. Agency for International Development (USAID) signed an agreement known as the London Declaration on Neglected Tropical Diseases to eradicate these illnesses by 2020.

Drug companies have been donating drugs for these diseases for years, but the lack of effective distribution systems has prevented people from securing treatments.

The USAID has attempted to fix this issue by funding NGOs that make sure workers in remote towns use the proper tools they need. More than 1.6 billion treatments have now reached 31 countries.

Dr. Dirk Engels, director of WHO's Department of Control of Neglected Tropical Diseases, said he hopes neglected tropical diseases could be part of history by 2030.

"There are still gaps," said Engels. "I hope in the next few years, we will be able to fill in those gaps."