In 2014, over 200 teen and tween girls fell sick with an unidentified illness in the small town of El Carmen de Bolivar, northern Colombia. The young girls ranged from 9 years old to 16 years old and one by one they began to experience the same odd symptoms.
They all experienced fainting, numbness in their hands and headaches. In isolated incidents, it could be any number of things, but after more than 200 young girls began to report the same symptoms within a matter of days, doctors grew concerned.
The strange outbreak appeared only to affect the teen girls and some suggested that it had been caused by their recent vaccinations against Human Papillomavirus (HPV). The sick girls had all received Gardasil vaccines. The immunization protects girls and women against four strains of the virus, some of which can cause cervical cancer.
In a single weekend 120 girls overwhelmed the hospitals in the small town, collapsing their limited medical facilities. All of the girls were released after their symptoms were deemed not to be life-threatening.
But worried parents still demanded answers. There was another possibility for the strange outbreak, but it has never been confirmed...
The strange outbreak appeared only to affect the teen girls, so for many it made sense to investigate the one thing they all had in common - the vaccine.
Colombian health and toxicology experts investigated the situation, but could find nothing to tie Gardasil to the girls' symptoms. The vaccine's manufacturer, Merck's head of communications in Latin America still maintains that all lots of the vaccine meet the quality and safety standards.
While fainting and headaches are listed as possible side effects, numbness is not listed.
Since nothing could definitely prove that the vaccine had caused the strange illness, some experts suggested that it was nothing more than a bizarre case of mass hysteria.
Although it hasn't been confirmed, they're probably not far from the truth. In fact, the human mind is strangely capable of producing symptoms - even when there is no disease or illness present.
Mass hysteria, or mass psychogenic disorder, results from the nocebo effect. It is the reverse of the placebo effect, where bad thoughts and associations produce bad results.
It is possible that whether by through their parents' aversion to the vaccine, or their own, these young girls already had in mind that they would experience side the negative side effects.
However the phenomenon got started, experts believe that young females under societal pressure became susceptible to the hysteria; as they were triggered by suggestibility, group mentality, and stress.
While a conclusion still hasn't been drawn, it appears that no lives were lost and the symptoms have all but disappeared.