Geneva - The Ebola epidemic tearing through western Africa is by far the deadliest known outbreak of the disease, yet the magnitude of the spread is believed to be severely underestimated.
The World Health Organization on Friday provided an overview of how the outbreak, which has killed 1,350 people since March and has been declared a global health emergency, has been downplayed.
Here are some of the main reasons.
Many families hide infected loved ones in their homes in the belief they will be more comfortable dying at home from the disease, for which there is no available cure or vaccine.
Others deny that a patient has Ebola and balk at allowing them to enter an isolation ward, seen as incubators for the disease, out of fear they will be infected and die.
Many deny Ebola has affected someone in their family out of fear of stigma and social rejection.
In rural villages, corpses are buried without notifying health officials and with no investigation into the cause of death - epidemiologists have in some cases travelled to villages and counted the number of fresh graves as a crude indicator of suspected cases.
There are numerous so-called “shadow zones”, or villages where there are strong suspicions of cases and deaths from Ebola, but that cannot be investigated due to community resistance or lack of adequate staff and vehicles.
Many treatment centres and general clinics have closed, as fear of the virus keeps patients out and prompts caregivers to flee.
In parts of Liberia, which has seen the biggest toll with 576 deaths, many previously unregistered patients are flooding into new treatment centres as soon as they open, strongly suggesting the existence of an invisible caseload of patients going undetected by the surveillance system.
In the capital Monrovia for instance, a new Ebola treatment centre with 20 beds opened last week only to be swamped immediately with more than 70 patients.
In Monrovia and some other areas, many health services have shut down, leading to scenes like the mobbing incident last Saturday in the West Point township, Liberia's most disease-prone slum.
Rumours spread that the holding facility set up by local authorities in an abandoned schoolhouse was actually a general health care clinic, leading many people suffering from other ailments to crowd in with suspected Ebola patients.
People from West Point resented the presence of patients from other communities, leading to rioting and looting, and possibly the removal of contaminated materials.
WHO said on Friday it was working with other agencies, including the charity Doctors Without Borders and the US centres for Disease Control and Prevention, “to produce more realistic estimates and thus communicate the true magnitude of needs.”