Climate change is fuelling a global cholera outbreak, the World Health Organization said Friday, warning that vaccine shortages have worsened the situation, which will not be any better soon if measures are not taken.

The WHO is addressing cholera upsurges in 29 countries, including Haiti, where more than 1,200 cases are confirmed, more than 14,000 cases are suspected, and more than 280 are reported deaths.

Read: Haiti investigates suspected Cholera cases after one case confirmed

Haiti received this week almost 1.2 million doses of oral cholera vaccines, but according to the WHO, vaccine stockpiles were extremely low, and manufacturers were not happy about producing a vaccine mainly aimed at some of the poorest countries in the world.

"If we don't control the outbreak now, the situation will get worse and worse," the WHO's team lead on cholera, Philippe Barboza, told reporters in Geneva, adding that fatality rates are extremely high for most of the countries the UN health agency has data about.

Cholera is an acute bacterial infection that is transmitted via contaminated foods or water. 

If left untreated, the disease can be fatal, with the main symptom being severe diarrhea. Most people, however, recover after exhibiting mild symptoms with the help of oral rehydration.

"The factors which drive cholera are still the same: poverty, vulnerability and people who do not have access to clean water," Barboza said.

These are heightened by conflict, natural disasters, and humanitarian crises which reduce access to drinking water.

"But this year, we have a factor which is even more important: the direct impact of climate change, with a succession of major droughts, unprecedented floods in certain parts of the world, and cyclones which have amplified most of these epidemics," he said.

While there had been other epidemics in certain countries before, they had not happened all together, as is the case now, Barboza noted.

Cholera can kill within hours indeed, but it can also be treated with simple oral rehydration and antibiotics for cases that are more severe. However, the lack of timely access to the treatment is a problem.

Ensuring access to clean water and improving surveillance prevent outbreaks.

"It is not acceptable in the 21st century to have people dying of a disease which is very well-known and very easy to treat," said Barboza, adding that the "fight against cholera is not lost. We can win it."

This year, about 36 million cholera vaccine doses were produced.