Experts outline methods to eradicate malaria in Tanzania

Dar es Salaam. As the world observes Malaria Day today, it has been revealed that approximately 86.2 percent of Tanzania’s population (around 58 million people) is at risk of contracting malaria, with children under five and pregnant women being the most vulnerable.

The malaria infection rate in Tanzania averages 8.1 percent, but this figure varies significantly by region, ranging from under one percent to more than 24 percent.

In response to this challenge, scientists and health experts are proposing various strategies to combat and potentially eliminate the disease.

A senior researcher at the Ifakara Health Institute (IHI), Dr Nico Govella, asserts that malaria can be completely eradicated with concerted efforts.

He explains that the current approach to combating malaria includes the use of insecticide-treated nets and seeking treatment at hospitals.

However, he points out that certain mosquitoes bite in the evening, outside the home, and that many infections occur before people return indoors.

"Therefore, in addition to using bed nets, alternative methods are needed, such as targeting mosquitoes at their breeding sites," says Dr Govella.

He further explains that while Tanzania has a factory producing insecticides to target mosquito breeding grounds, relying solely on insecticides is insufficient.

Efforts must also focus on eliminating breeding sites by draining stagnant water, cleaning drains, and filling holes.

"The fight against malaria should not be left solely to the health ministry; every sector must play its part. Urban planners, for example, must contribute by improving infrastructure," he adds.

Dr Govella stresses that communities need to actively engage in eliminating environments conducive to mosquito breeding.

He also highlights the importance of maintaining clean surroundings, such as trimming grass, removing cans and tyres, and improving household conditions.

"In Dar es Salaam, research conducted a few years ago found that improving surroundings, even by simply installing roofs and sealing homes, reduced malaria by 60 percent," he says.

Investment in new approaches

Researchers are calling for greater investment in strategies to eradicate mosquito breeding sites as a key measure in controlling malaria in the country.

Despite its proven effectiveness, the strategy of targeting mosquito breeding sites is often underfunded and overlooked, mainly due to difficulties in identifying and treating these areas.

Lead researcher on mosquito breeding site eradication, Dr Fredros Okumu, says their efforts have resulted in seven key recommendations for controlling malaria and other mosquito-borne diseases across Africa.

"These include increasing financial investment in public health systems, with recognition from the World Health Organization (WHO) as a critical step; identifying breeding sites and applying larvicides; and managing environments, such as drying up stagnant water, which serve as breeding grounds for mosquitoes," says Dr Okumu.

He explains that this approach differs from using insecticide-treated nets or indoor insecticide spraying, which target adult mosquitoes.

Eliminating breeding sites offers a long-term solution by disrupting the mosquito lifecycle earlier.

Dr Okumu advocates for prioritising the eradication of breeding sites in malaria control policies, suggesting that global health leaders can make significant strides in reducing malaria and ultimately eliminating it.

Another researcher, Issa Mshani, emphasises the need for improved diagnostic tools to strengthen the fight.

"The current diagnostic tools are not always sufficient to detect malaria accurately. Some patients remain undiagnosed, and certain areas may not receive the resources they need. More effective diagnostic tools can help health professionals create better malaria maps and accurately target control measures," explains Mr Mshani.

Mr Mshani shares findings from research conducted in 35 villages in the Ulanga and Kilombero districts of southeastern Tanzania between 2022 and 2023, where he compared three diagnostic methods: Rapid Diagnostic Tests (RDTs), microscopy, and quantitative PCR (qPCR).

The results highlighted significant differences in effectiveness. While RDTs and microscopy are inexpensive and widely used, they often fail to detect malaria in areas with low transmission rates.

In some villages, the positive predictive value of these tests fell below 20 percent.

"These results underscore the need for easy-to-use, affordable, and highly effective diagnostic tools in malaria-prone areas," he adds.

Malaria in Tanzania

Malaria is caused by the plasmodium parasite, transmitted through bites from female Anopheles mosquitoes carrying the parasite.

Regions such as Songwe, Njombe, Arusha, Manyara, and Kilimanjaro have malaria infection rates below one percent, while areas in the south and northwest report infection rates above 20 percent.

The head of the Malaria Program at the Ministry of Health, Dr Samwel Lazaro, comments on the current malaria situation, stating that, according to the 2022 malaria indicator survey, the infection rate has dropped by 45 percent, from 14.8 percent in 2015 to 8.1 percent in 2022.

He highlights the five regions with the highest infection rates in percentage as: Tabora (23.4), Mtwara (19.7), Kagera (17.5), Shinyanga (15.6), and Mara (15.1).

However, Dr Lazaro notes that the number of regions with high malaria infection rates has decreased from 14 in 2015 to eight in 2023.

He also reports that regions with the lowest infection rates (below one percent) have increased from six in 2017 to nine in 2022, including Arusha, Manyara, Kilimanjaro, Dodoma, Songwe, Mwanza, Dar es Salaam, Iringa, and Singida.

"Confirmed malaria cases have fallen by 45 percent, from six million in 2020 to 3.3 million in 2024," says Dr Lazaro.

He also points out that the most vulnerable groups include pregnant women, children under five, the elderly, and people living with HIV.