Namibia, how much malaria?

Background 

What do we know from official and scientific sources about the malaria risk in Namibia?

I am not a malaria researcher, but I have had a look on the malaria data from Namibia based on my background as a Medical Doctor, Infectious Diseases Specialist and Professor of Infectious Diseases Epidemiology in Denmark. For the last 28 years, I have worked in a Travel Clinic at the National Hospital in Copenhagen.

Please note that you can find some information and inspiration below, but you should always consult your general practitioner, travel clinic, or travel doctor for specific advice. Such specific advice will also depend on any comorbidities (conditions you may have) and potential interactions with the medication you take. Additionally, although there is general agreement among experienced travel doctors, there may be differences in national recommendations.

Anopheles stephensi, female
Photo by Jim Gathany

Global malaria burden according to WHO (WHO malaria report 2022)

According to the WHO World Malaria Report 2022, there were an estimated 247 million malaria cases in 2021 across 84 malaria-endemic countries in the world, an increase from 245 million in 2020. Most cases occurred within the WHO African Region, with an estimated 234 million cases in 2021 (96% global malaria cases). Twenty-nine countries accounted for about 95% of global cases, with four countries: Nigeria (27%), the Democratic Republic of the Congo (12%), Uganda (5%), and Mozambique (4%), accounting for almost half of all cases worldwide.

Malaria in Namibia

WHO, World malaria report 2022.
Confirmed malaria cases per 1000 pop., 2021

Article

In Namibia, the overall risk of malaria is low, as indicated on the two maps above, except in the northernmost parts of the country bordering Angola and the Caprivi Strip

As indicated in the table below, there were estimated between 17,000 and 26,000 cases of malaria in Namibia in 2021 (latest WHO data) with 23-92 deaths. The vast majority of cases were observed in the constituencies; Omusati, Oshana, Changwena, Oshikoto, Kavango, and Caprivi. This corresponds to the older map above (2009 data)

WHO, World malaria report 2022,
Incidence and mortality rate Namibia 2000-2021.

The influence of climate / rain on malaria risk

The rainy season enhances the conditions favorable for mosquito breeding and survival, thereby considerably increasing the risk of malaria transmission. Rain leads to the accumulation of water, creating ideal breeding grounds for Anopheles mosquitoes, which are responsible for transmitting malaria. For example, a scientific article from Namibia found that rain was strongly associated with malaria risk, with each millimeter of rainfall linked to a 2% increase in the adjusted odds of malaria. Similarly, higher levels of vegetation were associated with increased odds of malaria.

Malaria pills in Namibia from a practical point of view?

Personally, and based on the data above, I consider the area north of Windhoek to be a malaria zone, except for the Skeleton Coast (e.g., if you only drive along the Skeleton Coast to Terrace Bay, you are not in a malaria area). Depending on the medication you take, you may need to start it days to weeks before entering the malaria area and remember to continue taking it after leaving the area for as long as recommended, usually 1-4 weeks depending on the choice of medication.

An alternative option could be to take anti-malarial medication south of Etosha only during the rainy season and then seek medical attention if fever occurs. Personally, I would not do this, but I think it might be an option. If so, be extra careful to follow the mosquito avoidance advice below.

Which malaria profylaxis?

• Antimalarial Medication

Prescription Drugs: Take antimalarial drugs as prescribed by your healthcare provider. The type of medication, dosage, and duration depend on your health status and any existing medications. Some of the most fewquently used drugs are

1. Atovaquone/proguanil, sold under the brand name Malarone among others. It must be taken with a fatty meal, or at least some milk, for the body to absorb it adequately - and to avoid painful stomach irritation, which proguanil frequently causes if taken without food. Note that there are important interactions with other medications. 
2. Doxycycline is a broad-spectrum antibiotic of the tetracycline class that can also be used to prevent malaria. Note that an erythematous rash in sun-exposed parts of the body is not unusual for persons taking doxycycline for malaria prophylaxis. The rash resolves upon discontinuation of the drug. Good sun protection reduces the risk. 
3. Mefloquine, sold under the brand name Lariam among others, is a medication used to prevent or treat malaria. Because of potentially severe side effects, it´s not used so often. Severe side effects requiring hospitalization are rare, but include mental health problems such as depression, hallucinations, anxiety, and neurological side effects such as poor balance, seizures, and ringing in the ears. Mefloquine is therefore not recommended in people with a history of psychiatric disorders or epilepsy.

• Mosquito Avoidance

1. Use Insect Repellent: Apply insect repellent, e.g. with DEET (>20% (>40% preferred)) on exposed skin.
2. Wear Protective Clothing: Wear long sleeves, long pants, and socks, especially during dusk
3. Insecticide-Treated Bed Nets: While sleeping, especially in high-risk areas, to prevent mosquito bites. These nets are treated with insecticide, which kills or repels mosquitoes.

Again, always! Consult your general practitioner, travel clinic, or travel doctor for specific advice. Such specific advice will also depend on any comorbidities (conditions you may have) and potential interactions with the medication you take. Additionally, although there is general agreement among experienced travel doctors, there may be differences in national recommendations.