Honest about the risks, and specific about what prevents each one.
Water and food
CDC states that tap water is not drinkable in China, even in major cities, and that bottled water is easily available. The Government of Canada calls travellers’ diarrhoea the most common illness affecting travellers, with young children, older people and anyone with existing health problems more at risk.
Prevention Bottled or boiled water including for brushing teeth, ice only where you would trust the kitchen, food cooked fresh and hot. Rehydration salts weigh nothing and we can send you with a standby antibiotic where appropriate.
Air pollution
The Government of Canada says air pollution can be severe across much of China, that levels change quickly, and that during severe episodes you should expect school closures, cancelled outdoor events, limits on car use and transport disruption. CDC’s China page does not cover this at all — it is the clearest example on this page of one source carrying something the other does not.
Prevention If you have asthma, COPD or heart disease, plan around it: extra reliever inhaler in your day bag rather than the suitcase, a well-fitted N95, and check the air quality index the way you would check the weather. Move sightseeing to the better part of the day and follow local instructions when an alert is in force.
High altitude
The Government of Canada names Tibet, Qinghai, western Sichuan and parts of Xinjiang as sitting above 3,000 metres, says high-altitude illnesses may occur there and that they can be fatal. Its trekking advice asks you to know the symptoms and to insure for helicopter rescue and medical evacuation. Much of that country is reached by air or fast train, so you arrive at altitude rather than climbing to it.
Prevention Build a slow first day into the itinerary and argue for it before the tour is booked, since Tibet must be visited on an organised tour. Know the symptoms: headache, nausea, breathlessness at rest, confusion. Descending is the treatment that always works. Altitude medication is prescribable by a pharmacist in Alberta — bring your route.
Rabies and animals
CDC says dogs infected with rabies are commonly found in China, with rabies also in some wildlife; the Government of Canada adds bats. Both note that treatment is generally available in the country, which is the reassuring half of the fact.
Prevention Do not touch or feed animals you do not know, supervise children closely around them, and stay out of caves where animal waste builds up. Any bite, scratch or lick on broken skin: wash for about fifteen minutes with soap and clean water, then medical care the same day, vaccinated or not.
Avian influenza
The Government of Canada reports human cases of avian influenza in China and carries a travel health notice about it, while saying the risk is low for most travellers. Higher risk goes with visiting live bird or animal markets and poultry farms, working with poultry, or handling wild birds and wild mammals. CDC’s China page does not raise it.
Prevention Avoid contact with live, farmed or dead birds and with surfaces that may carry droppings — a live-animal market is a photograph, not a walk-through. Make sure poultry, eggs and wild game are properly cooked. The seasonal flu shot does not prevent avian influenza, but the Government of Canada notes it reduces the chance of catching a human and an avian flu at once.
Dengue and other mosquito-borne illness
The Government of Canada says dengue is a risk to travellers in China, that risk varies by season, year, region and elevation, that it can become severe dengue which is sometimes fatal, and that no vaccine or medication to prevent it is available in Canada. The mosquitoes bite in daylight, particularly around sunrise and sunset. CDC also lists dengue and leishmaniasis, which is spread by sand flies, mostly between sunset and sunrise.
Prevention Repellent with 20% or more DEET, or picaridin, applied through the day rather than only in the evening. Long sleeves at dawn and dusk, air-conditioned or screened rooms, permethrin-treated clothing for rural stays.
Fresh water
CDC says schistosomiasis, a parasitic infection spread in fresh water, is found in China, and also lists leptospirosis, which is picked up from water or mud contaminated with animal urine and from floodwater. The Government of Canada is on the same page in general terms, advising you to keep water out of your eyes, mouth and nose when swimming in fresh water, especially after heavy rain or flooding.
Prevention No swimming, wading or washing in lakes, ponds, canals or rivers. Chlorinated pools and the sea are a different question. Avoid floodwater entirely — the typhoon and monsoon season runs April to October.
Tuberculosis
Both sources name TB. The Government of Canada says the risk is low for most travellers but lists travellers visiting friends and relatives among the high-risk group, alongside people visiting or working in hospitals, prisons, shelters and refugee camps, and asks higher-risk travellers to discuss pre- and post-travel options with a healthcare provider. CDC lists it as spread by breathing in the bacteria from someone contagious and advises avoiding people who are unwell.
Prevention For a short hotel-based trip this changes nothing. For a long stay in a household, or work in a healthcare setting, tell us at the appointment — it is a before-and-after conversation, not a vaccine you can pick up on the way out.
Getting treated
The Government of Canada says medical care is widely available in urban areas but not in remote ones, that clinics offering international-standard care to foreigners are much more expensive, that payment is expected at the time of service, and that medical evacuation can be very expensive. It asks you to have doctors and dentists use sterilised equipment. CDC advises carrying a card in the local language listing your blood type, chronic conditions, serious allergies and the generic names of your medicines.
Prevention Travel insurance including medical evacuation and hospital stays, with the policy number saved offline. Emergency numbers: 120 for an ambulance, 110 police, 119 fire. A card in Chinese characters listing your conditions and medicines is worth more than a phrasebook.
Roads
CDC names motor vehicle crashes the number one killer of healthy travellers abroad and advises avoiding driving at night where street lighting is poor. The Government of Canada says road conditions and safety vary greatly, drivers often do not respect the rules, and drivers do not always give pedestrians and cyclists the right of way. Canadian and international driving licences are not recognised in China.
Prevention Trains and licensed taxis or a reputable ride-hailing app rather than driving yourself. Have your hotel’s name and address written in Chinese characters — the Government of Canada notes most drivers speak neither English nor French. Seatbelts, back seat, and care crossing the road.