Cape Verde has been certified malaria-free by the World Health Organization.

The archipelago to the west of Senegal consists of 10 islands, and has a population of over 500 000 people. It is the third country in Africa to be declared malaria-free, after Mauritius (in 1973) and Algeria (in 2019).

This brings the total of malaria-free countries to 43 worldwide.

Achieving malaria-free certification is no simple feat. As specialists in malaria prevention and control, we explain Cabo Verde’s long journey to eliminating the disease that killed over 600 000 people worldwide in 2022.

How Cape Verde achieved its goal

Malaria, endemic since settlement of the previously uninhabited islands in the 15th century, affected all 10 islands before 1950.

During the 1940s, malaria posed a serious health threat. Severe epidemics resulted in over 10 000 cases and 200 deaths annually until targeted interventions were implemented.

The country was close to eliminating malaria twice but these gains were not sustained.

Indoor residual spraying with DDT was done on each island until transmission ended nationwide in 1967. The residual effect of the insecticide helped kill mosquitoes over a longer period. Larviciding, the use of chemicals to target mosquito larvae at breeding sites, and active case detection were also undertaken.

The indoor residual spraying campaigns were stopped in 1969. The result was a recurrence of local transmission on Santiago island in 1973, followed by a large epidemic in 1977.

The second attempt to eliminate malaria started in 1978, and resulted in transmission interruption in 1983. Case numbers were maintained at low levels from 1989, confining malaria to Santiago and Boa Vista islands. But by 2006, rising cases threatened tourism.

A political decision was made to boost nationwide elimination efforts. This led to a change in the country’s national health policy in 2007.

The focus was on expanded diagnosis, early and effective treatment, and management of all cases.

The country also reoriented its elimination strategy with subnational elimination efforts. The WHO introduced this concept, providing guidance for particular areas within a country to attain and keep its malaria-free status.

Cabo Verde was on track to eliminate malaria, but in 2017 recorded its “worst malaria outbreak” since 1991 with 423 cases.

The outbreak prompted a strategy adjustment. A refocusing on vector control, targeting affected neighbourhoods and malaria infection-prone communities, prevented increases in cases. Transmission was successfully interrupted for four years.

Process to get certified malaria free

The WHO reported 249 million malaria cases and 619 000 malaria-related deaths globally in 2022.

The African region accounted for 94% of all cases and 96% of all deaths.

Achieving malaria-free status highlights a nation’s determination and commitment. Countries must meet the WHO’s stringent criteria to reach this goal. Firstly, there must be zero indigenous (locally) transmitted cases of malaria for at least three consecutive years.

Secondly, a country must show that it has the ability to prevent reintroduction of disease transmission.

Only then may countries request certification from the WHO, working with regional offices to develop a certification plan and timeline.

If a country fails, it can reapply after three years.

To maintain malaria-free status, countries must continue to prevent transmission and submit annual reports to the WHO.

Predictions for the next countries to take the leap

The WHO’s E-2025 initiative focuses on 25 countries targeting elimination by 2025.

Belize achieved elimination in 2023. Malaysia reported zero local transmission for the fifth consecutive year, while Timor-Leste and Saudi Arabia achieved two consecutive years without local transmission (2021 and 2022). If maintained, they may be declared malaria-free soon. For the first time, both Bhutan and Suriname reported zero indigenous cases in 2022.

In the Africa region, several countries reported significant reductions in indigenous transmission in 2022. These included Botswana (43.5%), Eswatini (57.6%) and South Africa (31.3%). The Comoros saw a doubling in cases in the same year. São Tomé and Principe noted a 46% increase.

Despite country efforts, extreme climate events and cross-border movement may have an impact on transmission or recurrence.

Attaining certification holds importance, and Cabo Verde’s success will drive positive development in the country.

Tourism plays an important role in the country’s economy. It accounted for a substantial share of the country’s GDP pre-COVID (24%), formal employment (10%), and the majority of foreign investment. Malaria-free status can potentially draw more visitors to the country.

The infrastructure established for malaria elimination has bolstered the country’s health system. This can be beneficial against other mosquito-borne diseases such as dengue fever, which also affects tourism.

A country’s “personal” milestone can help drive global malaria elimination efforts. Cabo Verde’s achievement is a call to action for the malaria community to not give up. We must push harder to end malaria for good!

Professor Tiaan de Jager is the Dean of the Faculty of Health Sciences at the University of Pretoria (UP) and Director at the UP Institute for Sustainable Malaria Control.

Dr Taneshka Kruger is Project Manager and Coordinator at the UP Institute for Sustainable Malaria Control.

This article first appeared in The Conversation on 2 February 2024.