Pho and mosquitoes…
Travel advice about mosquitoes often sounds straightforward, but the evidence behind individual protections is uneven. Repellents, long clothing and screened or air-conditioned rooms are all reasonable layers of protection, yet none is perfect on its own. Consumer products such as bracelets may feel reassuring, but their real-world effectiveness can be variable, so they are best treated as add-ons rather than substitutes for proven measures.
The broader public-health issue is less about a single bite and more about where mosquitoes can survive. Climate, rainfall and standing water shape mosquito range and abundance, so warming temperatures can create longer seasons or new pockets of risk. That does not mean every warmer place will suddenly become a malaria zone, but it does help explain why experts watch for changes in mosquito species and locally acquired infections outside traditionally endemic regions.
For travellers, the main decision is usually practical rather than dramatic. Risk depends on destination, season, itinerary and accommodation, so official travel advice matters more than general rules of thumb. A person staying in a city hotel has a different exposure profile from someone spending evenings near flooded ground, rural waterways or open windows without screens. Small behaviour changes can meaningfully reduce exposure, even when they do not eliminate it.
One more complication is symptom interpretation. Red bumps after travel may reflect bites, allergy or another skin reaction, and that uncertainty can make people overread or underread what happened. The takeaway is not to self-diagnose from a rash alone, but to think in terms of exposure, timing and whether fever, severe headache or other systemic symptoms appear.
Pho and mosquitoes
I recently went travelling around Vietnam, where I indulged in bowls of pho and sugarcane juice. I inevitably got bitten even though I slapped on bug spray and wore mosquito repellant bracelets. Still,ย none of the bites were life-threatening. Others arenโt so lucky: the World Health Organization estimates malaria infectedย 249 million people last year, killing more than 600,000. The US Centers for Disease Control and Prevention has called mosquitoes the worldโs deadliest animal.
I suffer from long Covid, which made me especiallyย worried about any kind of infection and its potential impact on my immune system. I developed hivesย earlier this year after getting sick with a common cold and was prescribedย antihistamines to keep the itchy welts under control.ย
So in preparation for my trip, I chatted with the nurse at my local NHS surgery about what kind of vaccinations I might want to get and other health precautions to take.ย Mosquito-borne diseases such as Zika virus, dengue fever, malaria and Japanese encephalitis are health risks in Vietnam, according to the UK governmentโs foreign travel advice. Thereโs low risk of malaria in most of the country, and no risk in big cities like Hanoi and Ho Chi Minh City, but itโs still recommended to avoid getting bitten.
As the world gets warmer and flooding becomes more frequent because of climate change, experts are wondering whether diseases that are commonly associated with tropical areas will start causing havoc elsewhere. Already, the European Centre for Disease Prevention and Control has warned about the risk of increased infections and potentially deaths because of the establishment of new mosquito species across the continent.
Climate change could also directly affect the transmission of malaria, leading to new cases in areas that were previously malaria-free, according to the WHOโs latest report on the disease. Locally acquired malaria infections were registered in Florida, Texas and Maryland earlier this year, the US CDC said, the first such incidences in the US in about two decades.
While I avoided getting bitten during the first few days of my Vietnam trip, I became itchy during an unexpected stop-off atย a so-called monkey bridge, where the water belowย was a breeding ground for mosquitoes. I hadnโt put onย bug spray that morning and wasnโt wearing my insect repellent bracelet around my ankle, but became more diligent after that. One of the braceletโs active ingredients isย eucalyptus citriodoroย oil, which some people consider a natural bug repellent. Keeping the air conditioning on at night and windows closed also helpedย to deter mosquitoes. I still ended up with a few red bumps as I travelled through the countryside, but itโs difficult to know whether they were because of insect bites, allergic reactions or something else.
Iโm back in London now where the chilly weather means Iโm relatively shielded from the cold-blooded pests. But for those of you planning to escape the northern hemisphere winter by going somewhere warm, donโt forget to read up on how to avoid mosquito bites. โย Lisa Pham
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