Perennially popular Peru: It’s on the travel ‘bucket list’ of Australians of all ages. But, it can be one of the world’s most challenging destinations when it comes to avoiding illness.

A survey of 5000 Australian travellers last year found Peru had overtaken India as the place where they were more likely to get gastro-related illness. (More on so-called ‘Montezuma’s Revenge’ later, as well as the vaccinations recommended for Peru - including the mandatory yellow fever.)
Another challenge is altitude illness, the broad term for sickness due to high altitude exposure. It can range from Acute Mountain Sickness (AMS), to more severe High Altitude Cerebral Edema (HACE) and High Altitude Pulmonary Edema (HAPE).
Despite their immense attraction, relatively few of the international visitors who travel to Cusco (3400m above sea level) and then on to Machu Picchu (2430m), or other high-altitude destinations in the Andes understand the potentially fatal effects of altitude illness – even for fit, healthy people.

Altitude illness can be severe

Altitude illness generally occurs when ascent is rapid – usually short flights from low- to high-altitude airports. Suddenly, there is less oxygen in the air and our bodies find it harder to function normally.
In 2012, researchers surveyed almost 1000 travellers who took the 45-minute flight from Peru’s coastal capital, Lima to the ancient Inca city of Cusco (3400m) to learn how many had felt the effects of altitude illness and its severity.
Despite an average age of just 32, altitude illness had a surprisingly high impact on both the travellers’ health and their travel plans. The survey found:
• 48.5% experienced AMS. (Co-incidentally, about the same number who reported getting traveller’s diarrhoea.)
• 17% of these had severe AMS.
• 60% had headache, while 32% reported poor appetite, nausea, and/or vomiting. (Other mild symptoms included fatigue or weakness (71%), dizziness or light-headedness (38%), and poor sleep (46%).)
• 1-in-5 was forced to alter their travel plans. Most stayed in bed to recover (15%), but 4% cancelled tours, and 3% changed their itineraries.

Who gets altitude illness?

Few travellers experience altitude illness at 3000m or below. 
However, as the study revealed, 50% of travellers will feel unwell at 3500m, and virtually everyone has symptoms at 4300m or higher.
Studies have also shown that males are at higher risk than females, and children are just as susceptible as adults. (Children under two years should not sleep above 2000m, while those aged 2-10 should not sleep above 3000m.)
Fit people can experience symptoms, too. In fact, on Andes’ treks, fitter people climbed further and faster, and so were more prone to develop the symptoms of altitude illness.

When does altitude illness strike?

• Usually within a few hours of reaching a high altitude.
• It peaks at between 12 and 48 hours, but can last 3-4 days.
• Most people recover with no long-term ill-effects, but altitude illness can be fatal if not recognised and treated early.
Indeed, travellers who ignore the early symptoms of altitude illness could be risking life-threatening HAPE and/or HACE, which can be fatal within hours. Read more on the warning signs and impact of HAPE and HACE.

How do I prevent altitude illness?

While most people adjust well to a moderate reduction in available oxygen (hypoxia), the adjustment takes time. The degree of hypoxic stress will depend on the altitude reached, the rate of ascent, and the length of exposure.
For travellers, in particular mountain hikers and climbers, here’s some well-tested advice for acclimatising effectively and avoiding attitude illness:
• Ascend slowly. Above 3000m, ascend no more than 300m each day and take a rest day for every 1000m you climb.)
• When trekking, ‘climb high, sleep low’. (That is, sleep at a lower altitude than you’ve reached that day.)
• Stay hydrated (preferably 4-7 litres per day).
• Eat a high-carbohydrate diet.
• Avoid smoking and alcohol.
• Avoid sedatives at night.
Finally, be alert and attentive to yourself and your companions. Skipping meals, antisocial behaviour, stumbling, or poor co-ordination are all possible signs of altitude sickness.
(PS - There’s no evidence that drinking coca tea, which is often provided in Cusco’s hotels, is of any benefit in preventing or treating AMS.)

Book an AMS-friendly itinerary

Travelvax Australia’s Medical Director, Dr Eddy Bajrovic, experienced AMS first hand when he tackled Africa’s Mt Kilimanjaro (5895m) in 2011.
He had these tips for travellers visiting Cusco and Machu Picchu: “I would recommend booking an itinerary that helps reduce the risk of altitude illness.”
“Rather than booking a hotel room in Cusco and spending time there after flying up from Lima, consider staying at a lower altitude in the Valle Sagrado (Sacred Valley). Take the train from Cusco to the towns of Pisac (2972m) or Ollantaytambo (2792m), which are en route to Machu Picchu, and stay the night.
“Then make the journey back to Cusco after being acclimatised at their lower altitudes. There is much to see and do in Cusco, and it is better done when acclimatised and feeling free of AMS.”

Treating altitude illness

Diamox (acetazolamide) is the most effective medication for prevention and treatment of altitude sickness. It decreases the likelihood of illness and reduces its symptoms by speeding up acclimatisation.
The dosage most widely used is 125mg (1/2 tab) twice a day, but you should discuss whether Diamox is right for you and the most suitable dose with your travel medicine professional or GP.
For flights that involve rapid ascent, such as Lima to Cusco, discuss taking a preventative dose of Diamox – particularly if you have a past history of altitude sickness.
Diamox is also recommended for those who plan to hike the Inca Trail from Cusco to Machu Picchu. This trek takes you through some high mountain passes, the highest at 4215m.
Diamox is not recommended for travellers who are on aspirin therapy, for pregnant women, or nursing mothers. People allergic to sulphonamides should also discuss taking a test dose before departure.
It’s important to note that Diamox will NOT prevent either HAPE or HACE.
Treat AMS headache with ibuprofen or paracetamol. Ondansetron wafers are excellent for the treatment of nausea associated with AMS.
(Read more on how to recognise, prevent and treat altitude illness at, which includes accounts of deaths in Peru and other high-altitude destinations.)

Vaccines, malaria and more…

VACCINATIONS: Short stays (up to 2 weeks) – Hepatitis A and BTyphoid, and Yellow fever, plus boosters of relevant childhood immunisations – measles, tetanus, diphtheria, whooping cough, and mumps, if required. (Yellow fever is not an actual risk for travellers to Machu Picchu, Cusco or Lake Titicaca, unless their itinerary also includes jungle areas below 2300m east of the Andes Mountains.) However, due to the risk of introducing the disease to new areas, it is a mandatory requirement for travellers returning to Australia within six days of leaving Peru or transiting other countries in the region – including passengers on cruise vessels. They, too may be required to show proof of vaccination.) Longer stays (more than a month) – Add rabies to the above list, especially if travelling extensively in rural areas. In Peru, rabies is mainly transmitted by dogs and bats. Once symptoms appear, rabies is fatal. If bitten or scratched, treat the wound immediately and seek urgent medical assistance. Read more on rabies prevention and treatment.
MALARIA: Malaria is present below 2000m in all departments (states) of Peru except for Arequipa, Moquegua, Puno, and Tacna. However, the risk of malaria is generally low and anti-malarial medication is not recommended for short-stay travel to coastal areas, Nazca, Arequipa, Cusco, Machu Picchu, or Lake Titicaca. 
OTHER THINGS TO REMEMBER: Mosquito-borne dengue fever is present in coastal and low-altitude areas, including Lima, as is the sand fly-borne disease, Leishmaniasis. It’s important to avoid insect bites at all hours of the day by using an effective personal repellent containing DEET, Picaridin, IR3535, or oil of lemon eucalyptus. As mentioned, traveller's diarrhoea (TD) or Montezuma’s Revenge’ is common in Peru and travellers should take care to choose safe food and beverages and include TD self-treatment medication in a traveller’s first-aid kit (one that includes needles and syringes). Finally, don’t forget the sunblock – along with altitude sickness, there’s a greater risk of sunburn at higher altitudes, too.

Call Travelvax Australia’s free travel health advisory service on 1300 360 164 for obligation-free advice on altitude sickness, vaccinations and avoiding travel-related illness in Peru or other destinations.