Malaria: How to Recognise It, How to Prevent It and What to Do When You Suspect It

What is malaria and how does it spread?

Malaria is a parasitic disease caused by Plasmodium species, transmitted to humans through the bite of an infected female Anopheles mosquito when it feeds on blood, predominantly at night. The mosquito injects parasites into the bloodstream through its saliva. Malaria cannot spread from person to person through direct contact, coughing, shaking hands or shared meals.

There are four Plasmodium species that infect humans: Plasmodium falciparum, the most dangerous and the dominant species in sub-Saharan Africa, Sudan and Yemen; Plasmodium vivax, more common in temperate climates and parts of the Middle East; and Plasmodium malariae and Plasmodium ovale, which cause milder disease. Knowing the species is not just academic: treatment choices differ between them.

In the Arab world, Sudan and Yemen carry the heaviest malaria burden. A 2023 study in Malaria Journal documented the expansion of Anopheles stephensi, an urban-adapted mosquito that breeds in water storage containers and urban water infrastructure, across Yemen and several other countries in the region. This species raises the risk of malaria in cities that have not traditionally been considered high-risk, including urban centres with dense populations who have little immunity.

What are the symptoms and how do they develop?

Malaria symptoms typically appear one to two weeks after the infective bite, though P. vivax can remain dormant in the liver for months before causing illness. The classic attack passes through three phases: a cold stage with intense shaking chills even in hot weather, a hot stage with a sudden sharp fever rise, and a sweating stage as temperature falls back toward normal. In P. vivax infection this cycle repeats every 48 hours. In P. falciparum the fever pattern is often irregular and less predictable.

Accompanying symptoms include severe headache, muscle and joint pains, nausea, vomiting and sometimes diarrhoea. The resemblance to influenza, typhoid and other febrile illnesses makes laboratory confirmation essential. Clinical impression alone is not sufficient to diagnose or exclude malaria, and a 2021 study of malaria patients in the White Nile State of Sudan found haematological abnormalities even in uncomplicated falciparum cases, underlining why laboratory testing guides management decisions.

Cerebral malaria is the most feared complication of P. falciparum, occurring when parasites obstruct the cerebral microvasculature. Signs include clouding of consciousness, seizures and coma. This is a medical emergency where hours matter. A Cochrane review published in 2019 confirmed that intravenous artesunate reduces mortality in severe malaria compared to quinine, making access to this drug at referral hospitals a critical priority.

How is malaria diagnosed?

Laboratory diagnosis is mandatory before starting any treatment. Three methods are available: blood film microscopy, which is the gold standard but requires a skilled microscopist; rapid diagnostic test (RDT), which gives a result in fifteen minutes from a fingerprick blood drop; and PCR, the most sensitive method but available only in reference laboratories. In endemic areas with limited resources, RDT is the workhorse of malaria diagnosis.

A comprehensive review published in the American Journal of Tropical Medicine and Hygiene confirmed that high-quality RDTs achieve good sensitivity and specificity for P. falciparum, making them a reliable first-line tool in field settings. Most modern RDTs also distinguish falciparum from non-falciparum species, which directly influences the treatment chosen. They are widely stocked by WHO and national malaria programmes across the region.

A negative RDT does not completely exclude malaria when suspicion is high, particularly if parasitaemia is low in the early days of illness. If symptoms strongly suggest malaria and the RDT is negative, the test should be repeated after 24 to 48 hours, or blood film microscopy should be requested. This point is especially important because falciparum malaria can deteriorate rapidly and a false negative can delay life-saving treatment.

How is malaria treated?

Treatment depends on the Plasmodium species, the severity of disease, the patient's age and weight, pregnancy status, and the local drug resistance pattern. Uncomplicated P. falciparum malaria is treated with an artemisinin-based combination therapy (ACT), typically artemether-lumefantrine or artesunate-amodiaquine depending on regional guidelines. The full course must be completed even when the patient feels better after the first dose, because stopping early leaves residual parasites and accelerates resistance.

Severe P. falciparum malaria requires emergency treatment with intravenous artesunate in a hospital setting. Delay of even a few hours in initiating treatment for cerebral malaria significantly worsens survival outcomes. The 2023 study of antimalarial drug efficacy across Eastern Mediterranean region countries confirmed that resistance patterns vary by country, reinforcing the need for current local guidance rather than generic protocols.

P. vivax malaria requires an additional drug, primaquine, to clear the dormant liver forms (hypnozoites) that cause relapses months later. Before giving primaquine, G6PD enzyme status must be checked because people with G6PD deficiency can develop severe haemolytic anaemia from this drug. G6PD deficiency is common across the region, particularly in populations from the Arabian Peninsula and Mediterranean countries, making this test essential before prescribing.

Drug resistance: why you must not self-medicate for malaria

Antimalarial drug resistance is a growing global threat. Chloroquine, once the universal first-line drug for falciparum malaria, is now ineffective against P. falciparum in virtually all endemic regions. The 2023 drug efficacy study across Eastern Mediterranean countries found variable resistance profiles by country, meaning that a drug regimen that works in one country may fail in a neighbouring one.

Taking antimalarial drugs without a confirmed diagnosis or from a market stall without prescription creates two compounding problems. First, an incorrect drug or incorrect dose for the specific organism involved will fail to clear the infection while giving it time to progress to severe disease. Second, sub-therapeutic dosing, meaning taking less than the full course or using a drug with substandard drug content, drives the selection of resistant parasites. Counterfeit and substandard antimalarials are a documented problem in parts of the region.

Correct prescribing depends on knowing the species from laboratory testing, calculating the dose from the patient's weight particularly in children, and checking for contraindications including pregnancy and G6PD deficiency. Do not use leftover antimalarials that were prescribed for someone else. A partial course left after a previous illness is both insufficient for a new infection and a contributor to resistance.

How to protect yourself and your family from malaria

Sleeping every night under an insecticide-treated bed net (ITN) is the most effective individual protection available. The Anopheles mosquito bites predominantly between dusk and dawn, so the net provides protection during the highest-risk period. The net must be intact with no holes and should be retreated with insecticide every six months to a year if it is not a long-lasting insecticidal net (LLIN). Hanging the net before the child goes to bed rather than after dark is a practical habit that matters.

Insect repellents containing DEET at twenty to fifty percent concentration provide several hours of protection when applied to exposed skin. Wearing long-sleeved clothing and covering ankles particularly around dusk and dawn reduces the skin surface available for biting. Fitting window screens, eliminating standing water near the home (including water stored in containers without lids), and using indoor residual spraying where programmes offer it all reduce local mosquito density.

Chemoprophylaxis, meaning taking antimalarial medication before, during and after travel to an endemic area, is recommended for visitors from non-endemic areas. The appropriate drug depends on the destination and its resistance profile: chloroquine for sensitive areas, doxycycline or atovaquone-proguanil for chloroquine-resistant areas. Prophylaxis must start before arrival, not on arrival, and continue for the recommended period after leaving. A travel health clinic or informed physician can advise on the right choice before any trip to an endemic region.

Malaria and pregnancy

Pregnancy substantially increases susceptibility to malaria and the risk of severe disease. Malaria in pregnancy is associated with severe anaemia in the mother, low birth weight, preterm delivery and intrauterine death. The WHO recommends intermittent preventive treatment in pregnancy (IPTp) with sulfadoxine-pyrimethamine for pregnant women in high-transmission areas, given at each antenatal visit from the second trimester.

Treatment choices in pregnancy are restricted by safety concerns. Quinine is used for severe disease in the first trimester under close monitoring. ACT regimens are generally used from the second trimester onward. Primaquine is contraindicated throughout pregnancy. Never self-medicate for malaria during pregnancy: the stakes for both mother and fetus are too high and drug choice must be made by a clinician.

Breastfeeding is generally compatible with most antimalarial treatment, but some drugs transfer to breast milk in small amounts. A clinician will choose the most appropriate drug accounting for both the infection and breastfeeding status. Do not stop breastfeeding simply because antimalarial treatment is needed unless specifically advised to do so.

Fever after travel: do not ignore it

Malaria must be on the list of possibilities for any person who develops fever within one to two months of returning from an endemic area, even if they took prophylaxis. Chemoprophylaxis is highly effective but not one hundred percent protective, and adherence is often imperfect. Tell your doctor precisely where you travelled, naming specific countries and regions, before describing your symptoms, because this information directly changes what diagnoses are considered.

P. vivax can remain dormant in the liver for months to years and cause relapse long after the initial infection and return from a malaria-endemic area. If you were treated for P. vivax malaria, ask your doctor whether you received a full course of primaquine to eliminate the liver reservoir, because many treatment protocols omit this step, particularly outside specialist settings.

In Arab countries that are themselves non-endemic, such as Jordan, the Gulf states and large parts of Egypt, local clinicians may not initially consider malaria when a patient presents with fever because they do not see it regularly. If you have recently been in Sudan, Yemen, or any other endemic area, state this clearly and early in any clinical encounter and request that malaria testing be done before any other explanation is accepted.

Sources

• Elkhalifa AME, Abdul-Ghani R, Tamomh AG et al: Hematological indices and abnormalities among patients with uncomplicated falciparum malaria in Kosti city of the White Nile state, Sudan: a comparative study, BMC infectious diseases, 2021
• Al-Eryani SM, Irish SR, Carter TE et al: Public health impact of the spread of Anopheles stephensi in the WHO Eastern Mediterranean Region countries in Horn of Africa and Yemen: need for integrated vector surveillance and control, Malaria journal, 2023
• Assada M, Al-Hadi M, Esmail MA et al: Molecular Confirmation of Anopheles stephensi Mosquitoes in the Al Hudaydah Governorate, Yemen, 2021 and 2022, Emerging infectious diseases, 2024
• Wongsrichanalai C, Barcus MJ, Muth S et al: A review of malaria diagnostic tools: microscopy and rapid diagnostic test (RDT), The American journal of tropical medicine and hygiene, 2007
• Esu EB, Effa EE, Opie ON et al: Artemether for severe malaria, The Cochrane database of systematic reviews, 2019
• Adam M, Nahzat S, Kakar Q et al: Antimalarial drug efficacy and resistance in malaria-endemic countries in HANMAT-PIAM_net countries of the Eastern Mediterranean Region 2016-2020, Tropical medicine and international health, 2023
• World Health Organization: World Malaria Report 2023. WHO, Geneva, 2023