Cases of the deadly airborne plague in Madagascar are still spreading and have spiraled by eight per cent in just a week, official figures have revealed.
The outbreak, which has been described as the 'worst in 50 years' and deemed to be at 'crisis' point, has now infected 1,947 people in the country off the coast of Africa.
New figures from the World Health Organization also show the 'medieval disease' has now claimed the lives of 143 people.
It comes amid warnings that cases could reach mainland Africa, with nine countries placed on high alert and told to brace for potential outbreaks.
Experts are concerned as the outbreak of plague in Madagascar this year is being fueled by a strain more lethal than the one which usually strikes the country.
Two thirds of cases have been caused by the airborne pneumonic plague, which can be spread through coughing, sneezing or spitting and kill within 24 hours.
It is strikingly different to the traditional bubonic form that strikes the country each year. This year's outbreak has another six months to run, the WHO warns.
Paul Hunter, professor of health protection at the world-renowned University of East Anglia, was the first expert to predict it could reach mainland Africa.
He told MailOnline last week: 'The big anxiety is it could spread to mainland Africa, it's not probable, but certainly possible, that might then be difficult to control.
'If we don't carry on doing stuff here, at one point something will happen and it will get out of hand control cause huge devastation all around the world.'
Professor Hunter's concerns echoed that of dozens of leading scientists, many of whom have predicted the 'truly unprecedented' outbreak will continue to spiral.
Professor Jimmy Whitworth, an international public health scientist at the London School of Hygiene & Tropical Medicine, told MailOnline earlier this week that this outbreak 'is the worst for 50 years or more'.
And Professor Johnjoe McFadden, a molecular geneticist at Surrey University, said that the plague is 'scary' and is predominantly a 'disease of the poor'.
Speaking exclusively to MailOnline, he also said: 'It's a crisis at the moment and we don't know how bad it's going to get.'
Their comments came after official figures released by the WHO showed last week cases of the plague had rocketed by 40 per cent.
Amid concerns the plague had reached crisis point, the World Bank decided to last week release an extra $5 million (£3.8m) to control the rocketing cases.
The money will allow for the deployment of personnel to battle the outbreak in the affected regions, the disinfection of buildings and fuel for ambulances.
Professor McFadden added: 'It's a terrible disease. It's broadly caused more deaths of humans than anything else, it's a very deadly pathogen.
'It is a disease of poverty where humans are being forced to live very close to rats and usually means poor sewage and poor living conditions.
'That's the root cause of why it's still a problem in the world. If we got rid of rats living close enough to mankind then we wouldn't have the disease.'
Professor McFadden warned in countries such as Madagascar 'people often need to walk more than a day to receive proper medical treatment'.
He also stressed the pneumonic strain of plague which is currently blighting the island off the coast of Africa can still be deadly even with treatment.
Last week MailOnline revealed the 'Godzilla' El Niño of 2016 has also been blamed for the severity of this year's outbreak by causing freak weather conditions.
And aid workers warned the scale of the outbreak could be made worse by crowds who gathered for an annual celebration to honour the dead last Wednesday.
All Saints Day, otherwise known as the 'Day of the Dead', is a public holiday which takes place on November 1 each year. Families often gather at local cemeteries.
'In that type of situation, it may be easy to forget about respiratory etiquettes,' Panu Saaristo, the International Federation of Red Cross' team leader for health in Madagascar, told MailOnline.
Plague season hits Madagascar each year, and experts warn there is still six months to run – despite already seeing triple the amount of cases than expected.
It has started earlier as forest fires have driven rats into rural communities, which has then spread into cities for the first time, local reports state.
The most recent WHO figures dispute claims by Dr Manitra Rakotoarivony, Madagascar's director of health promotion, that the epidemic is on a downward spiral.
He told local radio last week: 'There is an improvement in the fight against the spread of the plague, which means that there are fewer patients in hospitals.'
The WHO, which issues a new report into the outbreak every few days, also remains adamant that cases are on the 'decline in all active areas' across the country.
It said on its website: 'In the past two weeks, 12 previously affected districts reported no new confirmed or probable cases of pulmonary (pneumonic) plague.'
Bubonic plague, which is transmitted by rat flea bites, was responsible for the 'Black Death' in the 14th century, which killed 100 million people.
If left untreated, the Yersinia pestis bacteria can reach the lungs. This is where it turns pneumonic – described as the 'deadliest and most rapid form of plague'
Health officials are unsure how this year's outbreak began, but local media report that forest fires have driven rats towards rural communities.
This is believed to have been the start of the bubonic outbreak, which then develops into the more virulent pneumonic form which spreads rapidly without treatment.
Concerned health officials have also warned an ancient ritual, called Famadihana, where relatives dig up the corpses of their loved ones, may be fueling the spread.
To limit the danger of Famadihana, rules enforced at the beginning of the outbreak dictate plague victims cannot be buried in a tomb that can be reopened.
Instead, their remains must be held in an anonymous mausoleum. But the local media has reported several cases of bodies being exhumed covertly.
Despite the serious risks publicised by the authorities, few in Madagascar question the turning ceremonies and dismiss the advice.
Willy Randriamarotia, the Madagascan health ministry's chief of staff, said: 'If a person dies of pneumonic plague and is then interred in a tomb that is subsequently opened for a Famadihana, the bacteria can still be transmitted and contaminate whoever handles the body.'
Experts have long observed that plague season coincides with the period when Famadihana ceremonies are held from July to October.
The plague outbreak in Madagascar tends to begin in September and ends in April. Tarik Jašarević of the World Health Organization confirmed it would be no different this year.
He said: 'After concerted efforts of the Ministry of Health and partners, we are beginning to see a decline in reported cases but there are still people being admitted to hospital.
'At this time we cannot say with certainty that the epidemic has subsided. We are about three months into the epidemic season, which goes on until April 2018.
'Even if the recent declining trend is confirmed, we cannot rule out the possibility of further spikes in transmission between now and April 2018.'
However, this year's worrying outbreak has seen it reach the Indian Ocean island's two biggest cities, Antananarivo and Toamasina.
Experts warn the disease spreads quicker in heavily populated areas. It is estimated that around 1.6 million people live in either city.
The first death this year occurred on August 28 when a passenger died in a public taxi en route to a town on the east coast. Two others who came into contact with the passenger also died.
This year's outbreak is expected to dwarf previous ones as it has struck early, and British aid workers believe it will continue on its rampage.
Olivier Le Guillou, of Action Against Hunger, previously said: 'The epidemic is ahead of us, we have not yet reached the peak.'
A WHO official added: 'The risk of the disease spreading is high at national level… because it is present in several towns and this is just the start of the outbreak.'
International agencies have so far sent more than one million doses of antibiotics to Madagascar. Nearly 20,000 respiratory masks have also been donated.
However, the WHO advises against travel or trade restrictions. It previously asked for $5.5 million (£4.2m) to support the plague response, which has now been issued.
Despite its guidance, Air Seychelles, one of Madagascar's biggest airlines, stopped flying temporarily earlier in the month to try and curb the spread.
Schools and universities have been shut in a desperate attempt to contain the respiratory disease, with children known to come into contact with each other more than adults. The buildings have been sprayed to eradicate any fleas that may carry the plague.
Madagascan press reported that the finances and budget minister, Vonintsalama Andriambololona was pleased with the decision to grant an extra $5 million in the fight against plague.
'We are pleased that the Bank has listened to our call. The ministry promises to closely supervise the good management of such resources in order to quickly tame the epidemic,' she said.