Technical article
Malaria, Altitude and Yellow Fever: Why the City Can Matter
Marcus wonders what thin air might do to his breathing.
Picture a couple named Helen and Marcus, both 66. They are comparing Nairobi with a town on the coast. Helen reads that one has a different malaria picture from the other. Marcus wonders what thin air might do to his breathing.
Those are two questions the official pages help with. They answer them unevenly, so I show what each one says.
Kenya: the clearest page
The NHS Fit for Travel page for Kenya says malaria risk is "high throughout the year in the whole country". It then gives exceptions: low risk in "Nairobi, the immediate surrounding areas" and in highlands above 2,500 metres. It adds, "there can be a high risk in valleys of the highlands." It also says "malaria tablets are not normally advised for Nairobi and the immediate surrounding areas."
On altitude, the same page says the country has areas of 2,400 metres or more. The UK government page says "Altitude sickness is a risk in parts of Kenya."
On yellow fever, the NHS page says a certificate is "required for travellers aged 1 year or over". The UK government health page does not mention yellow fever. I show both and do not pick.
One caution. The NHS page says updates "are paused until further notice" since 7 October 2025. The UK government page was updated on 9 October 2026.
The other four
| Country | Malaria | Yellow fever | Altitude |
|---|---|---|---|
| Rwanda | US CDC: transmission areas "All"; "CDC recommends that travelers going to Rwanda take prescription medicine to prevent malaria." (updated 23 April 2025) | US CDC: "Vaccine is generally not recommended"; not required on direct travel from the United States; required from countries with transmission risk | UK government: "Altitude sickness is a risk in parts of Rwanda." |
| Tanzania | Listed as a health risk by the UK government; no area detail read | Not mentioned on the UK page | UK government: "Altitude sickness is a risk in parts of Tanzania." |
| Senegal | NHS: "Malaria risk is high throughout the year in all areas"; less from January to June in central western regions | Listed as a health risk by the UK government; NHS vaccine section did not load | Not mentioned |
| Zambia | Listed as a health risk by the UK government; no detail | Listed, no detail | Not mentioned |
The UK government pages also describe care. Tanzania: "Medical facilities are limited, especially outside Dar es Salaam." Senegal: "Medical facilities in Dakar are reasonable, but are limited in the rest of Senegal." Zambia: lower standard than in the UK.
What is left open
- The US CDC pages for Kenya, Tanzania, Senegal and Zambia would not open for me, so them are not among the sources.
- City-by-city malaria for Tanzania, Rwanda and Zambia.
- Yellow fever entry rules for Tanzania, Senegal and Zambia.
- Exact elevations of the main cities. I left them out rather than guess.
You could…
- Ask a travel clinic which tablets suit your health and how long they are taken.
- Check each city's elevation on an official map, then ask your doctor about it.
- Look at the current page on the CDC or UK travel health sites for the exact date of travel.
- Ask a doctor about yellow fever vaccination before you book flights.
Would a lower malaria risk in one city, or a calmer altitude, change which city you look at first?
Figures are estimates for planning, based on public data. Date read: 10 October 2026.
Sources
- US CDC Rwanda:
- NHS Fit for Travel:
- and
- UK FCDO travel advice (health):
- /rwanda/health , /tanzania/health , /senegal/health , /zambia/health
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