Algeria and Argentina have been declared malaria-free by the World Health Organization, in what has been described as a “historic achievement” for both countries.

The declaration follows warnings that the global fight against malaria has slipped off track in recent years, with cases rising in many of the countries worst affected by the disease.

Dr Tedros Adhanom Ghebreyesus, the WHO’s director general, said Algeria and Argentina’s achievement “serves as a model for other countries working to end this disease once and for all.”

Algeria and Argentina reported their last locally transmitted cases of malaria in 2013 and 2010 respectively, meaning 38 countries and territories are now free of the disease.

The countries’ success in tackling malaria was due to improved efforts to detect cases of the disease, as well as free diagnosis and treatment, the WHO said.

Algeria is the second country in the WHO African region to be officially recognised as malaria-free, after Mauritius, which was certified in 1973.

Argentina is the second country in the Americas to eliminate the disease in 45 years, following Paraguay in June 2018.

“As well as saving precious lives and strengthening health systems, malaria-free status provides external economic benefits for these countries, enabling them to free up resources to address other health and development priorities,” said Dr Abdourahmane Diallo, chief executive officer of RBM Partnership to End Malaria, an alliance of more than 500 partners.

“At a time when malaria cases are rising in the highest burden countries for the first time in more than a decade, celebrating and learning lessons from these victories is critical,” Diallo added.

Malaria remains one of the world’s leading killers. In 2017, there were roughly 219m cases of the disease and more than 400,000 malaria-related deaths. Approximately 60% of fatalities are among children aged under five years.

In November, the WHO said there had been “no significant progress” in reducing global malaria cases between 2015 and 2017.

In the 10 African countries where malaria is most prevalent – including Nigeria, Madagascar and the Democratic Republic of the Congo – there was a reported increase in cases of the disease in 2017 compared with the previous year.

A lack of funding, as well as the growing problem of drug and insecticide resistance, threaten to undermine efforts to tackle the disease, according to health experts.

“This is a historic achievement by Algeria and Argentina,” said Peter Sands, executive director of the Global Fund, a global aid partnership to help fight Aids, tuberculosis and malaria.

Ending malaria is an achievable goal, he added. “We need to step up the fight – achieving elimination wherever possible and breaking the transmission cycle and thus get on track towards elimination in the hardest-hit countries.”