Global cholera surge likely accelerated by climate change, warns WHO

Amid a global resurgence of cholera, a top World Health Organization (WHO) official on Friday said that climate change has driven an "unprecedented" number of larger and more deadly cholera outbreaks this year.

"The map is under threat (from cholera) everywhere," said Philippe Barboza, WHO Team Lead for Cholera and Epidemic Diarrhoeal Diseases. He was quoted as saying by UN News while speaking in Geneva.

Available data points to cases of infection in around 30 countries, whereas in the previous five years, fewer than 20 countries reported infections, on average.

"The situation is quite unprecedented, for not only we are seeing more outbreaks, but these outbreaks are larger and more deadly than the ones we have seen in past years," said Barboza. "This increasing number of cholera outbreaks is occurring after several years of regular reduction in the number of cases and deaths."

Barboza explained that all the "usual factors" had played their part in the global uptick of cholera in 2022, not least conflict and mass displacement.

Added to this was the "very visible impact" of climate change, he insisted. "Most of these larger outbreaks and the fact that they are simultaneously occurring - which makes the situation much more complex - is a direct impact of the increase in adverse climate troubles."

The cholera crisis has been playing out across the Horn of Africa and the Sahel accompanied by "major floods, unprecedented monsoons (and) a succession of cyclones", the WHO cholera expert said.

Many other countries have also been affected, including Haiti, Lebanon, Malawi and Syria, where there are large outbreaks, UN News reported.

In Pakistan, where previous years have seen only sporadic cases of cholera, there have been more than 500,000 reported cases of watery diarrhoea this year after devastating summer floods, but "less than a few thousand" laboratory-confirmed cases of cholera.

Equally worrying is the WHO assessment that the situation is "not going to change quickly" in 2023, because meteorologists have forecast that the La Nina climatic phenomenon is likely to persist for a third successive year.

Natural disasters associated with La Nina are prolonged droughts and rains and an increase in cyclones, "so we are very likely to see (a) similar situation that we saw at the beginning of 2022", Barboza said, indicating that the worst-hit areas were likely to be in Eastern and Southern Africa, the Caribbean and Asia.

According to WHO, every year, there are 1.3 to four million cases of cholera, and 21,000 to 143,000 deaths worldwide from the disease. The disease is an acute diarrhoeal infection caused by eating or drinking food or water that is contaminated with the bacterium Vibrio cholerae.