Malaria Prevention Guideline

Download the Malaria Prevention Guideline

1 INTRODUCTION

1.1 Purpose of Guidelines

1.2 Pre-travel Health Risk Assessment Overview

2 MALARIA EPIDEMIOLOGY

2.1 Infectious agent

• Malaria is a life-threatening parasitic disease spread to humans through mosquito bites
• Malaria is caused by parasites from the genus Plasmodium (Table 1)
• Globally, most malaria cases and deaths are caused by P. falciparum and occur in Africa
• Most of the global P. vivax burden is found in the Asia-Pacific region

2.2 Global epidemiology of malaria

• Malaria remains a major global health challenge, with 85 countries and areas endemic for malaria in 2022 (Figure 1)
• In 2022, there were around 249 million malaria cases and 608,000 malaria deaths worldwide, with most occurring in the WHOWHO - World Health Organisation African Region²
• Despite progress, such as the WHO certifying new countries as malaria-free (including China in 2021 and Sri Lanka in 2016), progress against malaria has stalled since 2015, partly due to disruptions caused by the COVID-19 pandemic¹

2.3 Malaria epidemiology in Australia and New Zealand

• Australia has been malaria-free since 1981, but the risk of reintroduction remains in the tropical north due to the presence of Anopheles mosquito vectors³
• Malaria has never been endemic in New Zealand
• On average, Australia reports between 300 and 400 malaria cases per year, while New Zealand reports between 20 and 50 cases^4,5
• Travellers visiting friends and relatives (VFR) are at particular risk⁶
• Over half of all cases reported in Australia are caused by Plasmodium falciparum, and around one-third are due to Plasmodium vivax
• While almost half of the cases reported in Australia are acquired in sub-Saharan Africa, Papua New Guinea and India are among the most common acquisition countries (Figure 2)

2.4 Malaria transmission

• Malaria is transmitted to humans by the bite of infected female Anopheles mosquitoes
• Anopheles mosquitoes breed in freshwater environments in warm and humid climates and typically bite during the evening and night¹
• Though uncommon, malaria transmission can also occur through blood transfusion, organ transplantation or vertically from mother to foetus⁷
• Symptoms of malaria can appear as early as 7 days after being bitten by an infected mosquito and as late as several months or more after exposure (this is known as the incubation period)
• In infections caused by vivax and P. ovale, dormant parasites in the liver (hypnozoites) can cause relapses weeks to years later (Figure 3)

3 RISK ASSESSMENT

Malaria risk varies globally. Widespread transmission occurs in some countries, while in others it occurs in defined pockets. Factors influencing malaria transmission include:

• Human (and animal) host susceptibility
• Mosquito (vector) behaviour
• Intervention coverage (e.g. use of bed nets)
• Climate (e.g. temperature, humidity and rainfall) and season
• Altitude (malaria is rare above 2000m elevation)

Individual traveller risk depends on personal and itinerary-related factors (Table 2). When assessing risk, healthcare providers should consider:

• Where the traveller is going (destination)
• When the traveller is going (season of travel)
• Planned activities, accommodation and duration of travel
• Who the traveller is (reason for travel and health status)
• The traveller’s capacity and willingness to follow recommended strategies, taking into account their preferences and any logistical or practical constraints

4 MALARIA PREVENTION APPROACHES

Malaria prevention in travellers includes a range of preventive measures, often referred to as the ABCD of protection (Table 3).¹¹ The A (Awareness), B (Bite prevention) and D (early Diagnosis and treatment) components are universally recommended for travellers to malaria-endemic areas, whereas decisions around C (chemoprophylaxisUse of medication to prevent disease. In the context of malaria, it involves taking specific drugs to prevent the disease from developing after being bitten by an infected mosquito. These medications work by killing the malaria parasites during their early stages in the liver or blood) should be individualised based on risk and personal circumstances (Table 2). While the WHOWHO - World Health Organisation has approved two malaria vaccines for use in endemic settings, there is currently no vaccine available for travellers.¹²

4.1 Bite prevention

Travellers should be aware of personal protective measures to reduce the risk of malaria and other vector-borne diseases during their trip. These measures include:

• Covering up with protective clothing, such as long-sleeved shirts and long pants
• Applying insect repellent to any exposed skin
• Treating clothing and gear with an insecticide such as permethrin
• Staying in screened rooms or under an insecticide-treated bed net

The most effective insect repellents contain one of the following active ingredients:

• DEET (N,N-Diethyl-M-Toluamide)
• Picaridin (icaridin)
• PMD (p-Menthane-3,8-diol), also known as oil of lemon eucalyptus (OLE)

Repellents are available in the form of a lotion, spray or gel, and in different concentrations of the active ingredient. Higher concentrations providing longer-lasting protection. For travellers to malaria-endemic areas, it is recommended to use repellents with concentrations of at least 20% DEET, 20% picaridin, or 30% PMD.¹³ Insect repellents with up to 30% DEET are safe to use in children over two months of age. Australian travellers should use insect repellents approved by the Australian Pesticides and Veterinary Medicines Authority (APVMA). Approved products are scientifically assessed as safe and effective when used according to label instructions. The APVMA’s database lists approved products: https://portal.apvma.gov.au/pubcris

4.2 Chemoprophylaxis

Chemoprophylaxis involves taking medication to prevent disease. It is recommended for most travellers to high-risk areas such as Papua New Guinea and much of sub-Saharan Africa. Recommendations for other destinations depend on individual travel plans and personal factors. Groups at high risk of severe disease, such as pregnant women, should avoid malaria-endemic areas if possible. If travel is necessary, chemoprophylaxis is generally recommended. For further information about chemoprophylaxis recommendations, see the next section.  No antimalarial drug is 100% protective, so it’s important to combine medication with education and other preventive measures.

In Australia and New Zealand, several antimalarial drugs are available for chemoprophylaxis (Table 4). All recommended regimens involve taking medication before, during, and after travel to a malaria-affected area. The duration of the regimen depends on how the drug works. (14) Atovaquone-proguanil and tafenoquine act early in the parasite’s lifecycle (liver-stage schizonts) and require shorter courses. Atovaquone-proguanil also acts on the blood stage of the parasite’s lifecycle (by interrupting the formation of schizonts within red blood cells). Doxycycline and mefloquine are only effective on the blood stage form, so they need to be taken for four weeks after leaving the malaria area. Tafenoquine is the only drug available for chemoprophylaxis in Australia that kills the dormant form of the parasite (hypnozoites) and can prevent P. vivax and P. ovale relapses.

The choice of medication should be tailored to each individual, considering their itinerary, medical history, current medications, and personal preferences. Table 5 provides some factors to consider when choosing a drug for prophylaxis. Detailed dosing information can be found in the “Prophylaxis of Malaria” chapter of the Therapeutic Guidelines.¹⁵ Before prescribing tafenoquine, it is important to rule out G6PD deficiency (see “Testing for G6PD deficiency”).

4.3 Standby emergency self-treatment (SBET)

Standby emergency self-treatment (SBET) is a strategy recommended in some international malaria prevention guidelines, though not universally endorsed. It involves providing travellers with a reliable supply of antimalarial drugs to self-administer in an emergency when malaria is suspected but medical care is not readily available. The role of SBET in malaria prevention is controversial, with experts presenting arguments both for and against its use (Table 6).⁴ Studies suggest that travellers prescribed SBET rarely use it (<3%), and many do not follow usage guidelines.^17-19 SBET is generally considered most suitable for travellers going to remote areas where diagnosis and treatment is not accessible within 48 hours. In some cases, travellers are also supplied with a rapid diagnostic test (RDT) kits and instructions for self-testing. Travellers should be advised to seek medical attention in the event of a febrile illness, even if SBET is used.

4.4 Testing for G6PD deficiency

Tafenoquine and the related antimalarial drug primaquine can cause severe haemolysis in people with Glucose-6-phosphate dehydrogenase (G6PD) deficiency. Effects range from mild and self-limited to life-threatening.²⁰ G6PD deficiency is an X-liked genetic disorder with variable frequency in different populations and considerable geographical overlap with malaria-endemic areas.²¹ National and international guidelines recommend assessing all patients for G6PD deficiency before prescribing tafenoquine.^15,16 Patients with <70% of normal G6PD activity (based on local population standards) should not receive tafenoquine.²² Conventional qualitative tests, like the fluorescent spot test and rapid diagnostic tests (RDTs), can identify severe deficiency (<30% normal activity) but may not identify female heterozygotes with intermediate deficiency (30-70%).

Before prescribing tafenoquine, a quantitative G6PD test that provides a continuous measure of enzyme activity (e.g. spectrophotometry) should be used to rule out severe or intermediate G6PD enzyme activity.²⁰ Patients may be advised that only one test is necessary as the results do not change over a lifetime.

4.5 Global landscape of malaria prevention recommendations for travellers

Various global, national, and professional bodies provide guidance to assist healthcare providers in advising travellers on malaria prevention (Table 7). While these groups rely on similar data sources, such as the WHO’s annual World Malaria Report, they use different approaches. There is generally close alignment on guidance for higher-prevalence destinations like sub-Saharan Africa and Papua New Guinea, with chemoprophylaxis recommended for most travellers. However, for destinations with lower prevalence or limited data, recommendations vary, ranging from bite avoidance alone, to combinations of bite avoidance, standby emergency self-treatment (SBET), or chemoprophylaxis. These differences reflect variations in health systems, medicolegal climates and risk tolerance levels among countries.⁸ Other factors include differences in the availability and approved uses of antimalarial drugs, as well as the availability of malaria diagnostics and treatment for returning travellers.

4.6 Malaria prevention recommendations in Australia and New Zealand

In Australia and New Zealand, there are no official national guidelines for malaria prevention. The Australian Government’s Smartraveller website (https://www.smartraveller.gov.au/) offers information about malaria risk on individual country pages, but this is limited to basic details about whether malaria is present and a general overview of affected areas. For example, regarding Thailand, Smartraveller states that malaria is a risk throughout the year in rural areas, and the worst affected areas are near the borders with Cambodia, Laos and Myanmar. Additionally, the “prophylaxis of malaria” chapter in the Therapeutic Guidelines: Antibiotic provides an overview of general indications, dosing information and available antimalarial options. However, it directs readers to CDC and WHO resources for detailed information on malaria risk, drug resistance and chemoprophylaxis recommendations.¹⁵

Healthcare providers in Australia and New Zealand often refer to malaria prevention guidelines from the WHO, US or UK, due to their familiarity and availability in English. Destination-specific guidance is easily accessible through the related US Travelers’ Health (https://wwwnc.cdc.gov/travel/) and UK Travel Health Pro (https://travelhealthpro.org.uk/) websites. Some providers also subscribe to clinical decision support tools which provide more detailed regional information.

While recommendations for sub-Saharan Africa and Oceania are generally consistent across these guidelines, discrepancies arise for other regions, especially in Asia. The US and WHO guidance tends to be more conservative, recommending chemoprophylaxis for a broader range of destinations compared to the UK guidance. Regardless of the guidelines used, it is crucial that recommendations are based on an individual risk assessment, considering factors that affect a travellers’ likelihood of exposure to malaria or risk of severe disease.

5 RETURNING TO AUSTRALIA AND NEW ZEALAND

5.1 Seeking medical attention

When preparing for travel, ensure travellers understand that if they develop a fever lasting more than 24 hours during or after visiting a malaria-endemic area, malaria should be considered until proven otherwise. Advise them to seek immediate medical care and request malaria testing.

5.2 Diagnosis and treatment

Healthcare providers must consider malaria as a potential diagnosis in patients presenting with a febrile illness who have travelled to a malaria-endemic area, especially if the visit occurred within the preceding year.¹⁵  While malaria typically presents within weeks of infection, symptoms can occasionally be delayed for many months.²³

To diagnose malaria, a blood sample should be collected in an EDTA tube and sent to a qualified laboratory for microscopy (thick and thin blood films). Microscopy remains the gold standard for diagnosing malaria, as it allows for species identification and quantifies parasite density, an important marker of disease severity. However, a single negative blood film does not rule out malaria, particularly if the patient has recently taken antimalarial medication.

Rapid diagnostic tests (RDTs) can sometimes provide a quick diagnosis but are less sensitive and must be followed by microscopy. Some laboratories offer nucleic acid amplification tests (NAAT) such as polymerase chain reaction (PCR) as an alternative to microscopy. These tests are at least as sensitive as microscopy but may be less useful for diagnosing acutely ill patients due to longer turnaround times. NAAT can sometimes be used to confirm the species of the malaria parasite once a diagnosis has been made with microscopy or a RDT.

Treatment of malaria cases is beyond the scope of this document. Severe malaria is a medical emergency and requires intravenous antimalarial therapy in a hospital setting.

5.3 Public health management

Malaria is a nationally notifiable disease in Australia and New Zealand, and healthcare providers are required to report cases to the relevant health authorities.

Although Australia is considered malaria-free, Anopheles mosquitoes that can transmit the disease are still present in parts of northern Australia.³ If infected individuals travel to these areas, there is a risk of onward local transmission and potential re-establishment of the disease. Management of malaria cases in areas with Anopheles mosquitoes may require additional public health measures²⁴ beyond routine treatment, including:

• Administering a gametocidal drug (primaquine) to sterilise the sexual forms (gametocytes) of the parasite and prevent transmission to local mosquitoes
• Physically separating the patient from the mosquito environment until they are no longer able to transmit the parasite, to prevent transmission to local mosquitoes
• Implementing mosquito control measures around the patient’s residence and other places they visited at night, such as mosquito trapping, fogging and enhanced surveillance, along with community awareness activities in the local area

6 REFERENCES

1. Poespoprodjo JR, Douglas NM, Ansong D, Kho S, Anstey NM. Malaria. Lancet. 2023;402(10419):2328-45.
2. World Health Organization (WHO). World malaria report 2023. Geneva, Switzerland. Available from: https://www.who.int/teams/global-malaria-programme/reports/world-malaria-report-2023 (accessed 13 Feb 2024). 2023.
3. Beebe NW, Russell T, Burkot TR, Cooper RD. Anopheles punctulatus group: evolution, distribution, and control. Annu Rev Entomol. 2015;60:335-50. https://doi.org/10.1146/annurev-ento-010814-021206
4. Sohail A, Barry A, Auburn S, Cheng Q, Lau CL, Lee R, et al. Imported malaria into Australia: surveillance insights and opportunities. J Travel Med. 2024;31(3):taad164. https://doi.org/10.1093/jtm/taad164
5. The Institute of Environmental Science and Research Ltd. Notifiable Diseases in New Zealand: Annual Report 2021. Porirua, New Zealand. Available from: https://www.esr.cri.nz/digital-library/notifiable-diseases-annual-surveillance-summary-2021/ (Accessed 11 Feb 2025).
6. Heywood AE, Zwar N, Forssman BL, Seale H, Stephens N, Musto J, et al. The contribution of travellers visiting friends and relatives to notified infectious diseases in Australia: state-based enhanced surveillance. Epidemiol Infect. 2016;144(16):3554-63. https://doi.org/10.1017/S0950268816001734
7. Tan K, Abanyie F. Malaria. In: Centers for Disease Control and Prevention, editor. CDC Yellow Book 2024: Health Information for International Travel. New York: Oxford University Press; 2023. Available from: https://wwwnc.cdc.gov/travel/yellowbook/2024/infections-diseases/malaria (Accessed 10 Feb 2025)
8. McGuinness SL, Veit O, Angelin M, Antonini P, Boecken G, Boering M, et al. Streamlining malaria prevention recommendations for travellers: current and future approaches. J Travel Med. 2024; 31(8):taae113. https://doi.org/10.1093/jtm/taae113
9. Ashley EA, Pyae Phyo A, Woodrow CJ. Malaria. Lancet. 2018;391(10130):1608-21 https://doi.org/10.1016/S0140-6736(18)30324-6
10. Broderick C, Nadjm B, Smith V, Blaze M, Checkley A, Chiodini PL, et al. Clinical, geographical, and temporal risk factors associated with presentation and outcome of vivax malaria imported into the United Kingdom over 27 years: observational study. BMJ. 2015;350:h1703. https://doi.org/10.1136/bmj.h1703
11. Lalloo DG, Hill DR. Preventing malaria in travellers. BMJ. 2008;336(7657):1362-6. https://doi.org/10.1136/bmj.a153
12. The Lancet. Malaria vaccines: a test for global health. Lancet. 2024;403(10426):503. https://doi.org/10.1016/S0140-6736(24)00235-6
13. Stanczyk NM, Behrens RH, Chen-Hussey V, Stewart SA, Logan JG. Mosquito repellents for travellers. BMJ. 2015;350:h99. https://doi.org/10.1136/bmj.h99
14. Freedman DO. Clinical practice. Malaria prevention in short-term travelers. N Engl J Med. 2008;359(6):603-12. https://doi.org/10.1056/NEJMcp0803572
15. Antibiotic Expert Group. Malaria. In: Therapeutic Guidelines: Antibiotic (v16). Melbourne: Therapeutic Guidelines Limited. https://www.tg.org.au (Accessed 19 Apr 2024); 2019 (April).
16. Commons RJ, McCarthy JS, Price RN. Tafenoquine for the radical cure and prevention of malaria: the importance of testing for G6PD deficiency. Med J Aust. 2020;212(4):152-3.e1. https://doi.org/10.5694/mja2.50474
17. Ferrara P, Masuet-Aumatell C, Aguero F, Ramon-Torrell JM. The use of stand-by emergency treatment (SBET) for malaria in travellers: A systematic review and meta-analysis of observational studies. J Infect. 2018;77(6):455-62. https://doi.org/10.1016/j.jinf.2018.09.007
18. Tan R, Elmers J, Genton B. Malaria standby emergency treatment (SBET) for travellers visiting malaria endemic areas: a systematic review and meta-analysis. J Travel Med. 2019;26(4). https://doi.org/10.1093/jtm/taz027
19. Utzinger KS, Held U, Hanscheid T, Gultekin N, Fehr J, Grobusch MP, et al. Self-diagnosis and self-treatment of Plasmodium spp. infection by travellers (1989-2019): A systematic review and meta-analysis. Travel Med Infect Dis. 2020;38:101902. https://doi.org/10.1016/j.tmaid.2020.101902
20. Baird JK. Tafenoquine for travelers’ malaria: evidence, rationale and recommendations. J Travel Med. 2018;25(1). https://doi.org/10.1093/jtm/tay110
21. Howes RE, Piel FB, Patil AP, Nyangiri OA, Gething PW, Dewi M, et al. G6PD deficiency prevalence and estimates of affected populations in malaria endemic countries: a geostatistical model-based map. PLoS Med. 2012;9(11):e1001339. https://doi.org/10.1371/journal.pmed.1001339
22. Chu CS, Freedman DO. Tafenoquine and G6PD: a primer for clinicians. J Travel Med. 2019;26(4). https://doi.org/10.1093/jtm/taz023
23. Wilson ME, Weld LH, Boggild A, Keystone JS, Kain KC, von Sonnenburg F, et al. Fever in returned travelers: results from the GeoSentinel Surveillance Network. Clin Infect Dis. 2007;44(12):1560-8. https://doi.org/10.1086/518173
24. Northern Territory Department of Health Centre for Disease Control. Guidelines for Malaria 2012: Malaria guidelines for health professionals in the Northern Territory. Available from: https://hdl.handle.net/10137/555 (Accessed 20 Aug 2024).

7 FURTHER RESOURCES

• Australian Notifiable Diseases Dashboard (includes cases of malaria by year, age group, sex and jurisdiction): https://nindss.health.gov.au/pbi-dashboard/
• New Zealand Notifiable Diseases Dashboard (includes cases of malaria by year, sex and age group): https://www.esr.cri.nz/digital-library/notifiable-disease-dashboard/
• CDC’s Choosing a drug to prevent malaria: https://www.cdc.gov/malaria/hcp/drug-malaria/index.html (note that primaquine is not available in Australia for chemoprophylaxis)
• Guidance for safe use of insect repellents in children: https://www.rch.org.au/kidsinfo/fact_sheets/Insect_repellents_guidelines_for_safe_use/
• World Health Organization World Malaria Report: https://www.who.int/publications/i/item/9789240086173

Dated 28 February, 2025
Written by Sarah McGuinness and Colleen Lau.
Next update scheduled for 01 March 2026