Mass psychogenic illness following HPV immunization in Carmen de Bolivar, Colombia (2014): more uncertainty is required

ABSTRACT

The interesting article by Simas et. al. describes an outbreak case with over 600 individuals who exhibited neurological symptoms and which occurred in a town located at the northern region of Colombia in 2014. The community associated this event to the second-dose vaccination campaign against the Human Papillomavirus (HPV) and scientists defined it as a mass psychogenic illness. Unfortunately, the authors did not include in their article important findings related to a case-control study (with n = 137 and n = 437, respectively), conducted by the Colombian government. After inquiring “have you ever received vaccination against human papillomavirus?”, a significant association with the vaccine was identified (adjusted OR: 10.8, 95% CI: 1.4–80.2).

Dear editor:

The interesting article by Simas et al. describes an outbreak case with over 600 individuals who exhibited neurological symptoms and which occurred in a town located at the northern region of Colombia in 2014. The community associated this event to the second-dose vaccination campaign against the Human Papillomavirus (HPV) and scientists defined it as a mass psychogenic illness.^1,2 Unfortunately, the authors did not include in their article important findings related to a case-control study (with n = 137 and n = 437, respectively), conducted by the Colombian government. After inquiring “have you ever received vaccination against human papillomavirus?”, a significant association with the vaccine was identified (adjusted OR: 10.8, 95% CI: 1.4-80.2). A similar situation occurred when questioning “how many doses of the vaccine have you had applied?”, which was answered with “just one dose” (as the reference category) and “more than one dose” (adjusted OR: 1.95, 95% CI: 1.02-3.74). Similar results were achieved throughout several questions which investigated about psychosocial factors, leading to the diagnosis of mass psychogenic illness. Data related to the vaccine and the bizarre signs and symptoms were available online at the Colombian National Institute of Health website, but they are no longer easily accessible through public records.

While the intention is not to argue against the case correspondence to a clear example of mass psychogenic illness, it is interesting that the possible role of vaccination was not comprehensively discussed when facts did indicate that it influenced the event. A possible hypothesis that comes from situations like these, is the current partial understanding of the adverse effects that vaccination against HPV could potentially display in a population with a specific set of sociocultural traits. From one point of view, the hegemonic approximation towards the analysis of adverse effects of medicines prioritizes chemical or pharmacological explanations,³ putting aside all adverse effects that have psychosocial or sociocultural mechanisms of action. On the other hand, mass psychogenic illnesses are by definition group events, not individual, requiring an ecological or multilevel approach.⁴ Therefore, mass psychogenic illnesses represent more than a group of individuals with conversion disorder,⁵ and it is necessary to understand the social, cultural and maybe even economic determinants associated with their occurrence,⁶ which do not necessarily correspond to risk factors⁷ for the aforementioned disease (see Figure 1).

Figure 1.

Suggested multilevel approach for exploring conversion disorder and mass psychogenic illness related with vaccines.

In conclusion, given that vaccines against HPV are still under rigorous scientific research, and more accurate data regarding their effectiveness and safety is expected within the next few years, the best position from a strictly scientific standpoint, is to maintain uncertainty: the ability to be astonished by new discoveries. There is still much to learn from cases such as mass psychogenic illnesses; the biggest mistake to be made is to ignore its association to vaccines,⁸ even if we do not understand yet how and why they happen. In these cases, both psychological traits and sociocultural environments seem to have important effects that need to be studied with much more detail.

Disclosure of potential conflicts of interest

No potential conflicts of interest were disclosed.