Much of the world’s border control responses to COVID-19 trace back to the 19th century. A cholera pandemic in the 1800s led to greater surveillance of Indians by the British Raj. Pilgrims, especially at the Kumbh Mela and the Hajj, were subjected to greater scrutiny and restrictions.Episode 4 of Scrolls & Leaves, a world history podcast that tells stories from the margins, tells the story of cholera and how it has made travel for people from poorer nations more difficult.Many of those historic events find an echo in the present day. When COVID-19 began spreading, countries, states, cities and neighbourhoods locked down quickly. People couldn’t cross borders to help out families; parents were separated from their children abroad; poor labourers had to walk hundreds of kilometres home.Travel bans are based on the International Health Regulations, which is a legal agreement adopted by all 194 member nations of the World Health Organisation (WHO). The IHR originates from responses to the 19th century cholera pandemic, and it allows countries to take action to prevent the spread of disease, while balancing the impact on international traffic and trade.But there is limited evidence to show that travel bans work – and a lot of evidence to show that they have undesirable side effects, according to a 2020 study.Historically, travel bans can stigmatise people who are identified with disease, even if they are not actual carriers. It can restrict the movement of healthcare supplies and other goods into the affected regions. And it can discourage people from disclosing their illness, for fear of repercussions.Investments in surveillance, which goes together with the restriction of movement, may be better spent on public health needs, says Martin French, a surveillance expert at Concordia University in Montreal.For example, in 1987, the United States prohibited people with HIV/AIDS from travelling into the country. The result was that illegal immigrants in the US who had the disease did not seek treatment, increasing the chance of transmission.Previously, travel bans have been used to deal with the spread of Zika, Ebola, MERS and SARS. But there isn’t strong data showing they work, the study states.Listen to the story using the audio player to find out, and subscribe here. This episode is presented in immersive sound, and you can place yourself in the scene if you listen with headphones.