Diving often takes us to some of the most remote and exotic corners of the world — but with adventure comes a dose of medical reality. From tropical diseases to underlying health conditions, divers face risks that can turn a dream trip into a medical emergency if not managed properly. In this edition of Ask DAN, the experts tackle two important questions: how divers can protect themselves from malaria when travelling to affected regions, and whether someone diagnosed with pulmonary hypertension should ever consider getting in the water.
Malaria Risks for Divers
Q: Can you explain the risks associated with malaria?
A: Malaria is a serious infectious disease threat that primarily exists in many of the world’s subtropical and tropical regions — areas popular with divers — where the environmental conditions support a stable, infected population of Anopheles mosquitoes. DAN urges all divers to assess their risk and take appropriate preventative measures — avoiding mosquito bites and using prophylactic medication — when travelling to these destinations.
How to Prevent Mosquito Bites While Travelling
To prevent mosquito bites that transmit malaria, stay in well-screened areas when possible. If outdoors, wear clothes that cover most of your body, including your feet and ankles. Use mosquito nets while sleeping, and treat your clothing, tents, and nets with insecticide and repellent.
Personal repellents should contain at least 30% DEET; concentrations above 30% do not significantly improve the protective effect or duration. Standard repellents last about four hours, but longer-acting versions are available. Picaridin is an effective alternative to DEET.
Medication and Prophylaxis: What Divers Need to Know
Ask your physician about prescription prophylactic drugs before travelling. Most medications are safe and well-tolerated, but some people may have severe side effects and toxic reactions, as with any drug. The antimalarial drug mefloquine (Lariam) occasionally causes side effects that mimic symptoms of decompression sickness. Some countries prohibit diving while taking mefloquine, so ask your physician about possible drug substitutions, such as a combination of atovaquone and proguanil (Malarone). If you cannot take a prophylactic antimalarial medication, do not travel to high-risk areas. It is still possible to contract malaria even with stringent preventive measures. The symptoms may not develop until long after your trip, so continue prophylaxis treatment for four weeks following your return home.
Immediately seek medical attention if you develop flu-like symptoms, such as chills, fever, headache, muscle aches, fatigue, or possibly nausea, during the trip or within several months after your last exposure. Be sure to share your travel history and possible malaria exposure with medical professionals. Malaria can become life-threatening if not quickly diagnosed and treated.
Pulmonary Hypertension and Diving: Why It’s a No-Go
Q: Can someone diagnosed with pulmonary hypertension become a diver?
A: Pulmonary hypertension is considered a severe risk condition, and diving is not recommended for anyone with this diagnosis. Endurance disciplines such as diving, which are likely to pose the highest haemodynamic demands and require a high physical fitness level, are challenging for people with pulmonary hypertension. The stress that diving puts on the lungs and the right side of the heart may be too much for such an individual.
Concerns of congestive heart failure or immersion-induced pulmonary oedema are just two significant risk factors. A person’s preexisting condition and exercise intolerance will affect the heart and lungs’ ability to perform underwater. Various factors while underwater lead to intravascular volume shifts to the central circulation involving the heart, coronary vessels, and lungs. In a healthy state, this increase in fluid usually causes no problem, but a person with pulmonary hypertension will struggle, sometimes even at rest, to keep up with the right ventricle’s increased workload as it tries to overcome the elevated pressure within the pulmonary vessels.
For an extensive range of diving health and safety information and downloadable resources, research studies, incident summaries, and free e-Learning courses, take the time to explore the DAN website.
Frequently Asked Questions
How can divers protect themselves from malaria while travelling?
Avoid mosquito bites by wearing protective clothing, using DEET-based repellent, and sleeping under treated nets. Consult a doctor about safe prophylactic medication before departure.
Which malaria drugs are not recommended for divers?
Mefloquine (Lariam) can mimic decompression sickness symptoms. Ask your physician about alternatives such as atovaquone and proguanil (Malarone).
Can someone with pulmonary hypertension dive safely?
No. Pulmonary hypertension places severe strain on the heart and lungs, and diving increases this load dramatically, raising the risk of heart failure or pulmonary oedema.
What should divers do if they develop malaria-like symptoms after travel?
Seek medical help immediately and inform doctors about your recent travel history. Malaria can appear weeks or months after exposure and requires prompt diagnosis and treatment.
This article was originally published in Scuba Diver Magazine
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