The worst cholera epidemic in Nigeria in 19 years has killed nearly 800 people in two months and is spreading to Cameroon, Chad and Niger, where it has killed hundreds more.
At a maternity clinic and a nearby hospital in Ganjuwa, Nigeria, patients with blank eyes lay contorted on fouled mattresses from severe diarrhoea triggered by the cholera.
Small children laying under traditional brightly coloured cloth were hooked up to IV tubes as doctors tried to save them by rehydrating them intravenously.
As more and more patients arrived and occupied all the beds in the wards, doctors had to put them into storerooms and concrete hallways wet with human waste.
Throughout villages like Ganjuwa and cities across West Africa, lack of clean drinking water is allowing the waterborne bacterial disease to bloom. In Nigeria, 13,000 people have been sickened, according to the nation's Health Ministry.
Salisu Garba needs only to look at a communal trash pit outside his family's home in Ganjuwa to see how the cholera bacteria sickened and ultimately killed his 20-year-old brother.
Seasonal rains have turned the trash pit into a pond of raw sewage, which seeps into nearby wells, infecting Mr Garba's family and others in this rural village in northern Nigeria.
"That pond is a source of worry," Mr Garba said. "We don't have any hope."
"These areas become breeding ground for cholera," said Chris Cormency, a UNICEF official monitoring the epidemic.
Mr Cormency said the disease began in Nigeria and then spread to neighbouring Cameroon, where more than 300 people have died and 5,000 have fallen ill. In Chad, more than 40 have died and 600 are sickened, while the disease also has popped up in nearby Niger, he said. It was not immediately clear how many people were affected there.
After someone was found sick with cholera on a train in Cameroon, the other 1,500 people onboard panicked. Health officials gave out antibiotics and tried to decontaminate the train, media in Cameroon reported.
Cholera is a fast-developing, highly contagious infection that causes diarrhoea, leading to severe dehydration and possible death. The current outbreak is the worst in Nigeria since 1991, when 7,654 people died, according to the World Health Organisation.
Cholera is easily preventable with clean water and sanitation but in places like West Africa, sanitation often remains an afterthought in teeming city slums and mudwalled villages.
In Nigeria, almost half the country's 150 million people lack access to clean water and proper sanitation, according to the WHO, even though the government earns billions of dollars a year as one of Africa's top oil exporters.
Poor sanitation "is the backbone of this disease," said Adamu Abubakar, a Red Cross official in Bauchi state, a rural region of rolling mountains and pasturelands where Ganjuwa sits.
Doctors at the maternity clinic, which during this crisis has been transformed into a cholera hospital, try to keep the disease from spreading by waving off well-wishers and preventing ill mothers from holding their children.
The poorly funded clinics put patients on torn, yellow foam mattresses, with only a plastic bucket underneath to catch the waste that drains off.
The seriously ill receive drugs through an IV. Many can be treated simply by remaining well hydrated during the illness. Mr Abubakar and other Red Cross officials offered powdered mixes to families in Ganjuwa on a recent morning and gave advice.
In Bauchi, the state capital, the major state hospital has a clinic staffed by Doctors Without Borders, where more than 100 cholera patients are being treated. Officials say many more cholera sufferers are in local clinics or at home in other states throughout Nigeria's north.
Volunteers carrying large sprayers moved through the littered, narrow dirt streets of Ganjuwa and into family compounds, spraying a chlorine solution designed to kill the cholera bacteria. The teams also dumped chlorine tablets into wells.
Dr Musa Dambam Mohammed, a Bauchi state health official, said the local government has chlorinated every well in the region and informed the public about how to avoid contracting the illness.
However, the chlorine wears off over time, leaving the wells again susceptible to cholera.
The rains have not stopped, flushing sewage out of small holes at the base of mud walls along narrow dirt paths and into the trash-pit pond near Garba's family compound, where chickens peck at refuse and children learn to read the Koran from wooden tablets.
But now, everyone here knows the danger lurking in the algae-covered water.