More than 70 people have died since 2024 in an ongoing outbreak of yellow fever in Colombia. The country declared a national health emergency last year following an increase in cases of the potentially deadly mosquito-borne disease. Figures shared by the Colombian Government show 161 cases and 73 deaths were confirmed between 2024 and January 2026, including 13 cases and 10 deaths this year.
Symptoms of yellow fever — historically knwon as “yellow jack” for the yellow quarantine flag flown on ships — are similar to flu: a high temperature, headache, sickness, aches and pains, loss of appetite and feeling generally unwell. In serious cases it can cause severe infection leading to multi-organ failure and internal bleeding. Around 15% of patients develop severe symptoms and around half of those die, according to the World Health Organisation. The situation in Colombia is one of a number of global outbreaks being monitored by experts. Here’s a round-up of some of the latest disease reports around the world.
Mpox in Madagascar
Madagascar has reported almost 500 suspected (182) confirmed cases of mpox across 20 regions in recent weeks. Previously known as monkeypox, mpox is an infection that causes a rash and flu-like symptoms.
Symptoms of mpox can resemble other common childhood illnesses such as scabies and chickenpox,leading to late diagnosis and delayed treatment.
Nipah virus in India
An outbreak of deadly Nipah virus in India has sparked discussions about the potential for another pandemic, after two cases were confirmed among healthcare workers.
The virus can cause swelling of the brain in severe cases, with a death rate of between 40% and 75%.
The country is working to contain the outbreak, tracing and testing almost 200 contacts, while airport screening has been introduced in some major cities in Thailand to prevent the spread of infection.
Cholera in Mozambique
Mozambique is experiencing a cholera outbreak in central and northern areas of the country. Cholera is an infection that causes severe diarrhoea, spread through unclean drinking water or contaminated food.
It can lead to severe, rapid dehydration resulting in shock, organ failure and death if untreated.
More than 5,700 cases and 68 deaths were confirmed in Mozambique in 2025.
Measles in the USA
The USA is seeing the highest number of measles cases in decades, with more than 2,600 cases confirmed in 44 states since the start of 2025.
Measles starts as a respiratory illness with symptoms including fever, cough and a runny nose. In serious cases it can progress to pneumonia or brain swelling.
The biggest outbreak was in west Texas, where two unvaccinated schoolchildren died — the first measles deaths in the US in around a decade.
Experts have pointed to falling vaccination rates as a key cause. It is estimated that 95% of people must be vaccinated to protect a population through herd immunity, but vaccination rates among school-aged children fell to 92% in 2023.