How three girls started an epidemic that swept the nation

After Covid, we’re all familiar with the concept of ‘patient zero’, the unlucky person who is the first discovered to have a new disease.

But at the start of an epidemic in Tanganyika, now Tanzania, there were three patient zeroes. Three girls, all students at a boarding school in the village of Kashasha.

It wasn’t a disease they spread however, but laughter. That may sound funny, but as it made its way first around the school, then across the country, it quickly became no laughing matter.

On January 31, 1962, a group of students dissolved into a fit of giggles. But once they started, they couldn’t stop. They weren’t laughing for just a few minutes, as most of us have surely done, but for weeks.

Not entirely non-stop, but on and off, overcome with long bouts of debilitating laughter.

That would have been disruptive enough, but it got worse as the laughter spread to other students at the mission-run school. Eventually, 95 of the 159 pupils, aged between 12 and 18, were ‘infected’ with laughter.

After six weeks, it was more than the staff could handle, and eventually they were forced to close the school. Parents were summoned to come and collect their giggling girls – and promptly started laughing themselves.

While the teachers had appeared immune, clearly their families weren’t, and as the students went their separate ways and spread out across the region, so did their laughter.

Reports vary as to how many people were affected, from hundreds to thousands, but there is no doubt the contagious hilarity spread. How long it lasted is also up for debate, ranging from six to 18 months.

But the laughter was very real – and in some cases, very serious.

While no one died, laughing continuously for more than about 20 seconds can have serious side effects, including fainting and respiratory problems, due to disrupted breathing, rashes and flatulence.

Victims were also often left crying or screaming, unable to stop laughing but not finding it funny at all.

Thankfully, the epidemic eventually fizzled out. Fewer and fewer people suffered laughing fits, which became shorter and less frequent, until finally, the laughter stopped.

To this day, no one can be absolutely sure of the cause, but there is one leading theory as to why it started.

People laugh for many reasons, all studied by the wonderfully-named field of gelotology.

Often it is exactly why you might think – because something is funny, has tickled someone. It might be a joke, a video on Instagram or the sight of something unfortunate happening to someone else, maybe tripping over or falling off their chair.

Most of the time, laughing is good for us, releasing stress and boosting our mood. However, it can also be used as a defence mechanism when feeling nervous, or faked, to fit in with a group.

Pseudobulbar affect is a neurological condition in which people laugh or cry at inappropriate times, while some people with epilepsy have what are known as gelastic seizures, bouts of uncontrollable giggling, as seen in Tanganyika.

But in the case of the 1962 epidemic, it seems a more likely cause was anxiety.

Weeks earlier, Tanganyika had won its independence from Britain. This led to a time of uncertainty for adults and children alike. The country had also recently introduced a new school system, which resulted in extreme pressure on students to perform well. While laughter can help ease stress and anxiety, it can also be a symptom.

Reflecting on the case decades later, Dr Christian F Hempelmann explained the phenomenon.

‘Something did happen in Tanganyika,’ he said. ‘The bad news is, it had nothing to do with humour. There was no merriment. Laughter was one of many symptoms.

‘These people were showing anxiety-related symptoms, from pain, to fainting, to respiratory problems, and sometimes people got rashes. There were attacks of crying as well as laughing.’

Speaking to the Chicago Tribune, he continued: ‘It’s called mass hysteria. This is when a certain behaviour is observed in a group of people that is not related to a certain environmental stimulus. There is no specific cause.

‘Now we call it mass psychogenic illness (MPI). It’s psychogenic, meaning it is all in the minds of the people who showed the symptoms. It’s not caused by an element in the environment, like food poisoning or a toxin. 

‘There is an underlying shared stress factor in the population. It usually occurs in a group of people who don’t have a lot of power.’

This, unfortunately, means such an outbreak could happen again, anywhere in the world. 

‘It’s more common than you think,’ said Dr Hempelmann. ‘It usually starts in a school or in a workplace, when people are in a stressful situation and they don’t have the power to get out of that situation.

‘In 1962, Tanganyika had just won its independence. The young people involved reported that they were feeling stressed by the higher expectations of their teachers and parents.’

Now, more than 60 years on, no further laughing epidemics appear to have struck Tanzania – and many might argue that the world could use a bit more laughter.

But remember, there are many reasons people laugh, and in some cases, you don’t want to catch it.