Dengue figures with their dates, the chikungunya risk that guidance lists, where malaria and yellow fever occur, which mosquitoes bite by day and which by night, and when a bed net matters.
What the newest dengue figures show, and when they were published
Start with dates, because dengue counts move every week. The Pan American Health Organization updated its regional dengue report on 23 October 2026, with data to epidemiological week 39 of 2026. It records 1,813,577 suspected dengue cases across the Americas, 55% below the same period in 2025 and 62% below the five-year average. The report lists 614 deaths, a case fatality rate of 0.034%, and 565,945 laboratory-confirmed cases. In week 39 alone it counts 28,008 new suspected cases, including 76 classified as severe dengue and 10 deaths. For Colombia, its table gives 85,824 cumulative suspected cases through week 39 and 2,268 cases in that week. The regional curve is falling, but the virus has not gone away, and a winter visitor still meets it.
Colombia in the regional picture
An earlier PAHO update, published on 20 October 2026, gives a slightly different snapshot because its dengue data run to week 37. It reports 1,692,937 suspected and 523,102 confirmed dengue cases regionally in 2026, with 3,413 severe cases and 571 deaths. For Colombia it records 83,905 suspected dengue cases between weeks 1 and 38, including 51 deaths. Of those, 28,677 were confirmed, an incidence of 157.12 per 100,000 population and a case fatality rate of 0.177%. All four dengue serotypes circulated in Colombia from 2023 to 2026, and PAHO says DENV-3 has dominated since the fourth quarter of 2025. PAHO also frames the outlook around the expected intensification of El Niño and the approaching South American peak season, so the present decline is not a promise about your travel dates.
Chikungunya: what the guidance lists for Colombia
The chikungunya picture is thinner, and travellers should read that gap honestly. The same PAHO update of 20 October 2026 records 213,919 suspected and 78,481 confirmed chikungunya cases in the Americas in 2026, with 88 deaths in 20 countries and territories. Its country section does not include Colombia and gives no Colombian chikungunya figure. UK guidance does list the risk: TravelHealthPro's Colombia page states that there is a risk of chikungunya in the country, alongside dengue and Zika. That is a risk statement, not a count, so treat it as a reason to take bite prevention seriously rather than as a measure of how many people are affected. Where a national figure is absent, the sensible response is the same precautions you would take for dengue.
Malaria: below the altitude line
Malaria in Colombia is tied to altitude, and the two main authorities draw the line in slightly different places. TravelHealthPro puts malaria at low risk in rural areas below 1,600 m, and at very low risk above 1,600 m and in Cartagena. It says antimalarials may be considered in exceptional circumstances for higher-risk travellers to low-risk rural areas, and would not be advised in very-low-risk areas. CDC places malaria in all areas below 1,700 m, states that there is no transmission in Bogotá, Cartagena or Medellín, and recommends that travellers going below 1,700 m take prescription medicine to prevent malaria. Note the difference: 1,600 m against 1,700 m. If your itinerary sits between those heights, ask a travel health professional which advice applies to you.
Yellow fever: real cases, and a certificate rule that differs
Yellow fever is the most serious item on this list, and PAHO's alert of 13 March 2026 gives the recent Colombian record. In 2025 Colombia reported 125 confirmed human cases, plus three originating abroad, including 46 deaths. Cases were reported in Caldas, Cauca, Guaviare, Meta, Putumayo and Tolima, with 115 cases and 43 deaths in Tolima. Between weeks 1 and 7 of 2026, Colombia reported 25 confirmed cases including 13 deaths, a case fatality rate of 52%, all in Tolima. PAHO rates the regional risk as high and advises that travellers to areas with reported cases be informed and protected. On vaccination, TravelHealthPro recommends it below 2,300 m but generally not for travel only to Barranquilla, Cali, Cartagena, Medellín, Bogotá or San Andrés y Providencia. The two authorities also differ on certificate rules, so check before booking.
Day biters and night biters
Which mosquito bites you depends on the hour and the species, and the two groups need different habits. TravelHealthPro's factsheet 38, updated on 13 August 2026, states that some mosquitoes bite during daylight, including Aedes species, while others are more active from dusk to dawn, including Anopheles species. It adds that Aedes aegypti can bite at night in well-lit areas, and that Anopheles can be active by day, at dawn and dusk, and through the night depending on species and place. The World Health Organization's chikungunya fact sheet, updated on 14 April 2025, says the mosquitoes that spread chikungunya bite primarily during daylight and that Aedes aegypti feeds both indoors and outdoors. So daytime cover matters as much as an evening routine.
Repellents, screens and when a bed net matters
Repellent choice is settled enough to state plainly. TravelHealthPro recommends repellent containing DEET at 50% concentration for all travellers over two months who can tolerate it, says protection does not increase beyond 50%, and notes that icaridin has similar properties at 20%. Apply DEET after sunscreen, and use a 30 to 50 SPF sunscreen. DEET is not recommended under two months; protect babies with clothing and insecticide-treated nets draped over cots and prams, secured around the edges. WHO recommends DEET, IR3535 or icaridin according to the product label, and advises insecticide-treated nets for people who sleep during the day, such as young children, sick patients and older people. For malaria areas, TravelHealthPro says all travellers should sleep under a net unless the room is well screened or has working, switched-on air conditioning where mosquitoes cannot enter. Fine mesh on doors and windows matters too.
Sources
- Report on the epidemiological situation of dengue in endemic countries of the Americas, as of epidemiological week 39, 2026: Pan American Health Organization / World Health Organization
- Epidemiological Update: Dengue and Chikungunya in the Americas Region, 20 October 2026: Pan American Health Organization / World Health Organization
- Colombia country information: TravelHealthPro (UK National Travel Health Network and Centre)
- Colombia, CDC Travelers' Health: US Centers for Disease Control and Prevention
- Insect and tick bite avoidance: TravelHealthPro (UK National Travel Health Network and Centre)
- Chikungunya (fact sheet): World Health Organization
- Epidemiological Alert: Yellow fever in the Americas Region, 13 March 2026: Pan American Health Organization / World Health Organization
This article is general information, not medical advice. Ask a doctor or pharmacist about your own health.