A Glasgow doctor is among those currently responding to a major measles epidemic in Malawi.
Dr Neil Stone, who is working with international aid agency, Medecins Sans Frontieres (MSF), tells BBC Scotland about his role in the battle against the deadly outbreak.
"Come forward those patients with measles," shouts the medical assistant in Lirangwe Health Central, close to the city of Blantyre.
There is a near stampede as 25 mothers with babies on their backs push to the front of the crowd.
All of the babies are feverish, with runny noses, red eyes, and a telltale rash over their bodies - visible proof of the largest measles epidemic to hit Malawi in more than a decade.
This particular health centre has been seeing more than 100 cases of measles every week, and the outbreak has led to more than 9,000 cases across Malawi so far.
Measles is caused by a virus, and is highly contagious. It spreads easily by coughing or sneezing.
A disease which many people in the West dismiss as a minor childhood ailment can be a killer here.
Whilst most sufferers will recover uneventfully, some will go on to have potentially fatal complications such as pneumonia and diarrhoea.
Children with a vitamin A deficiency can sometimes lose their sight, while others can end up with an incurable form of meningitis.
Medecins Sans Frontieres has been working in Malawi for over 20 years now and was therefore well placed to respond to the measles outbreak.
My role has been to support Malawi's health workers and to help them record the true scale of the epidemic.
Malawi has a chronic shortage of medical staff - there are just two doctors per 100,000 people.
Health centres are usually staffed by medical assistants who have just two years training and see up to 200 patients per day.
I have been visiting health centres in Blantyre district, helping staff identify measles cases, deal with complications, and spot those who need a hospital referral.
Essential drugs are often in short supply, or completely unavailable, so MSF has made regular donations of whatever is necessary, including vitamin A supplements, antibiotics for secondary infections, and paracetamol for fever - all of them simple drugs, but lifesaving.
At the main hospital in Blantyre - Queen Elizabeth Central Hospital - two extra wards have been opened just for measles cases, one for adults and one for children.
Both have been full to bursting point during the epidemic.
Treatment is one thing, but the only really effective way to halt a measles epidemic is vaccination.
In collaboration with the Ministry of Health, MSF has been carrying out a mass vaccination programme, the biggest of its kind ever seen in Malawi.
About 200 local staff have been trained in vaccination techniques, and how to maintain the 'cold chain' - so called because the measles vaccine must be kept at between two and eight degrees Celsius at all times, a major logistical challenge in a tropical climate.
We have constructed hundreds of vaccination sites to provide shade for staff from the burning sun, as well as to ensure an orderly flow of patients.
All children between the ages of six months and 15 years - the age group worst affected by the epidemic - are being offered vaccination free of charge.
At times the crowds are overwhelming. Under the beating African sun, the queues snake around the vaccination site several times.
The town criers spread the campaign message using megaphones and radio and newspaper publicity is also used.
Parents are desperate to have their children vaccinated. Almost every family has been affected by measles in one way or another.
On a single day during this campaign, more than 80,000 children were vaccinated.
My role in this has been to ensure that everything is running smoothly, and to deal with any accidental needle injuries which occur - an important consideration given the appallingly high prevalence of HIV in Malawi.
As I make my health centre visits in the weeks following the vaccination campaign, beaming staff delight in telling me that they are seeing fewer and fewer cases of measles every day.
An intervention which cost 1 euro per person is clearly going to save hundreds of lives.
But we are not finished yet. MSF is currently vaccinating children in the capital, Lilongwe, and is preparing to move on to other districts around the country.
By the end of our campaign, we aim to have vaccinated more than 2.5m of Malawi's children.