An experiment in debunking misinformation about typhoid could provide lessons for fighting false claims about other diseases. It also cuts against some common recommendations on tackling falsehoods on any topic.
Typhoid, a bacterial infection that was once a major killer worldwide, is now typically rare – but infects around 15,000 people a year in Sierra Leone, with common myths hindering efforts to eradicate the disease. Dr Maike Winters of the Karolinska Institute led a team testing different approaches to creating a more accurate picture of how typhoid spreads. The results are reported in the British Medical Journal, with the opening line; “Misinformation can be as contagious as a virus – sometimes more.”
“Misinformation, amplified by social media, is a growing public health challenge,” Winters said in a statement. “It can potentially reduce protective actions, encourage risky behavior and with that, promote the spread of infectious diseases.”
The researchers identified two myths widespread in Sierra Leonne that undermine typhoid-fighting efforts. One is that it is spread by mosquitoes, and the other is that typhoid is connected to malaria. The two diseases have such similar symptoms that, outside the country's one hospital able to test blood culture, “typhoid-malaria” is often diagnosed. However, their causes are very different. Malaria is mosquito-borne. Typhoid's cause is the bacteria species Salmonella enterica, often spread by poor hygiene as illustrated by the case of Typhoid Mary, one folk memory that has persisted in places long freed of the disease.
The team divided 736 Freetown residents into three groups, paid in data credit to download audio dramas. A control group received unrelated health information, while another included detailed refutations of typhoid myths, plus an explanation of how typhoid is a bacterial disease spread mostly through food and water. The last group got the facts without references to the myths.
Two important lessons arose from the study that may apply to the spread of falsehoods about COVID-19 and future pandemics. The first is that providing factual information can work. In the face of frequent failures to debunk false information, a cynical conclusion is sometimes articulated that once misinformation takes hold it cannot be defeated.
Initially, 51 percent of participants believed mosquitoes spread typhoid, while 59 percent thought it always co-occurs with malaria. Being presented with facts alone without mention of the myths reduced these to 36 and 39 percent respectively.
Perhaps more importantly, however, myth-busting worked even better, with 33 and 29 percent support for the two myths post-intervention. The difference between the two approaches was not statistically significant on the first question but was on the second.
Communication courses often teach not to rebut false information directly, because repeating a falsehood just reinforces it, and may even spread it to people who hadn't heard it before. Most studies reaching these conclusions were done on university students in laboratories, however.
The interventions didn't just change people's minds, they altered their actions, with those in both groups becoming more likely to seek treated water compared to the controls.
Although any discovery about combating health misinformation may have some relevance to COVID-19, Winters noted one important difference: there is no politicized campaign to spread false information about typhoid. “If the same strategies would work to reduce beliefs in heavily polarized misinformation surrounding COVID-19 remains unknown, but is definitely worth exploring.” she said. COVID-19 myths are often propagated by people aware their claims conflict with scientific consensus, and may hold onto them as a sign of tribal loyalty. Consequently, it is feared direct contradiction may inspire an oppositional response, causing them to work harder to mislead others.