What Does it Take to Track and Tame Measles Outbreaks?

by Jumana Farouky

An unvaccinated toddler whose mild case of measles turned deadly after his family waited too long to take him to a doctor. A 12-year-old girl who died from intracranial hemorrhage after developing a rarely seen complication of the disease that causes a person to bleed underneath the skin, turning it black.

These are just two of the children Dr Sabrina Kitaka has witnessed succumbing to measles in her years as a pediatrician at Uganda’s Makerere University College of Health Sciences (MakCHS) and the Mulago National Referral Hospital, which works closely with MakCHS to treat measles cases in the country. “For me, the pain is real. The anguish and the fear are real,” Kitaka said.

Measles is so contagious that if there is even one child with the virus in a room that can hold 100 children there is already the threat of an epidemic.

“Across Uganda we have pockets of unvaccinated children, which means more and more children coming into the hospital with measles complications.”

Once thought to be on the brink of elimination, measles is making an alarming comeback around the world. In 2024, there were 475,036 reported measles cases globally, according to the World Health Organization (WHO). That represents a drop in annual cases since 2023, when nearly 300 people were dying every day from the disease, mostly children under the age of 5. But it is still more than double the number of cases the world saw in 2022. Countries across Africa, South-East Asia, Europe, and, recently, parts of North America, are experiencing outbreaks that threaten to reverse decades of progress against the highly contagious disease.

Behind the scenes, however, a quiet but powerful surveillance system is working to contain measles outbreaks before they spiral into nationwide – or worldwide – emergencies. The Global Measles and Rubella Laboratory Network (GMRLN), coordinated by WHO, connects more than 750 laboratories in 164 countries to ensure rapid, accurate testing for measles and rubella – a typically milder form of the virus – and feed crucial data into national, regional, and global elimination strategies so that health organizations and authorities can make evidence-based decisions on the best course of action.

“Measles is a cross-cutting, highly infectious disease, it can affect all people, across any borders,” said Dr Charles Byabamazima, Vaccine-Preventable Diseases Laboratory Coordinator of the WHO Intercountry Support Office for the East and Southern Africa Measles and Rubella Laboratory Networks. “Coordination between WHO, the Global Measles and Rubella Partnership, NGOs, government bodies, public hospitals, private clinics, and community healthcare workers is essential.”

Three Confirmed Cases Makes an Outbreak

Measles can cause severe complications such as pneumonia, blindness, encephalitis – an infection causing brain swelling – and death, particularly among those who have a weakened immune system or are malnourished.

Health officials warn that falling immunization rates, fueled by disruptions caused by the COVID-19 pandemic, vaccine hesitancy, and fragile health systems, are leaving millions of children vulnerable to infection. Kitaka said the Mulago National Referral Hospital in Kampala, Uganda’s capital, saw six or seven children admitted with serious measles cases every day in June and July 2025. While that figure is concerning, she noted that in the two months prior the hospital was admitting closer to 20 young measles patients every day. Those numbers were brought down by a reactive vaccination campaign that the Ugandan Ministry of Health launched in response to the testing, tracing, and tracking that the national lab constantly conducts to help keep the country and wider region safe as part of the GMRLN.

The surveillance process starts when a suspected measles case comes into a hospital or is reported in the community. During a suspected outbreak, doctors, nurses, and community health workers who encounter anyone with symptoms of the disease – high fever, cough, runny nose and a rash all over the body – are asked to collect blood samples from up to five affected patients. The samples are then sent to the Expanded Program on Immunization (EPI) Laboratory at the Uganda Virus Research Institute (UVRI). As part of its crucial role in Uganda’s immunization efforts, the UVRI in Entebbe works with the Ministry of Health to train health workers in how to spot measles and properly obtain blood samples.

“We teach everything about how to detect and investigate a potential outbreak, how to take a sample – such as what part of the body they take it from – how to package it properly and how to transport it to the lab,” explained Dr Josephine Bwogi, Principal Research Officer and Head of the EPI Laboratory.

Once the lab confirms three positive measles samples from the same area in a given month, it declares an outbreak. “Three cases means there are already other cases in that area we don’t know about. That means it’s going to spread; it’s going to get ugly, Bwogi added.”

So far this year the EPI Laboratory has tested more than 1,100 samples from Uganda, as the country deals with about 30 outbreaks across several districts.

Digging Deeper for a Targeted Response

After an outbreak is declared, the EPI lab initiates the process of finding out which strain of measles it is dealing with. A team is sent into the affected community to take oral swabs from reported cases, within five days of the onset of a rash, for molecular testing.
This helps identify whether that particular strain originated within Uganda or was imported from a neighboring country. As a WHO Measles and Rubella Regional Reference Laboratory, the EPI Laboratory is responsible for training, quality-assurance testing and genotyping, and tracking for eight other countries – Burundi, Comoros, Eritrea, Ethiopia, Kenya, Rwanda, South Sudan and Tanzania – that lack or only have partial capacity for some of the necessary activities and roles.

Once the origin country has been determined, the EPI Laboratory and health ministry will send out a district task force to dig deeper and find out the underlying factors that allowed the outbreak to happen in the first place. The main question is: Was it vaccine failure or a failure to vaccinate? “If we know that many people in that community have already been vaccinated, maybe there is a problem with the way the vaccine is being stored or administered,” explained Dr Annet Kisakye, Immunization Officer for WHO in Uganda. The combined measles and rubella vaccine needs to be stored at between 2 °C and 8 °C (35 °F and 46 °F), which is difficult in remote areas with unreliable or no electricity.

“If instead we discover that not enough children have been vaccinated in that area, we know we have to plan for a reactive immunization response,” Kisakye continued.

The data collected by the task force helps the health ministry and WHO ensure that response is as efficient and effective as possible. “We need to figure out which age bracket we are going to target. And in which areas – the entire district or a few subcounties? And how are we going to do it with the limited resources that we have?” said Kisakye.

Funding Constraints and Equipment Shortfalls

As Uganda works to get back on track toward measles elimination, Dr Kitaka said the current goal is to vaccinate over 95% of Uganda’s population to establish herd immunity, when enough people are immune to a disease that it is difficult for the infection to spread. According to WHO, in 2024 about 90% of Ugandans had received the first dose of measles vaccine, which is usually given around 9 months, but only 50% got the crucial second dose at about 18 months.

“Parents are very excited to vaccinate their children in the early days, when mom is home with her newborn,” said Kitaka. “But when mom becomes busy and maybe the vaccination service is a bit far or distrust of vaccinations sets in, she deprioritizes the second dose.”

At the same time, the scientists at UVRI said funding constraints are leading to shortfalls in essential personnel, reagents, kits, consumables and equipment, as well as in meeting key operational costs at the labs that make up the global measles network.

For Kitaka, advocacy and education are the keys to ensuring that the measles surveillance and response systems in Uganda and around the world are strong enough to stop the next pandemic.

“We need communities to understand that measles is not just like a flu, it’s a very serious disease,” she said. “And vaccination training should be better supported by academia,” she added, explaining that vaccinology is not seen as a priority topic for undergraduates in Uganda’s medical schools.

The reasons for doing so are clear – WHO data shows that between 2000 and 2023, measles vaccination averted more than 60 million deaths.

“If we have a large population of healthcare workers who are all thinking the same way about vaccines and speaking up with one voice, it becomes easier to motivate everyone to take vaccinations more seriously,” Kitaka said.