Liz Szabo

USA TODAY

Sierra Leone is reporting an increase in the number of new Ebola cases, with 435 confirmed in the past week.

About 24% of the Ebola cases in Sierra Leone have been reported in the past three weeks, although the outbreak began in March, according to the World Health Organization.

Those stark figures contrast with the hopeful news last week from Liberia, where the number of new cases has been falling. Officials at the WHO have said the drop in Liberia could be partly due to an increase in safe burials.

Ebola transmission in Guinea, where the outbreak started, "remains intense," according to the WHO.

Health officials from the WHO have cautioned, however, that the Ebola virus is unpredictable. Cases may appear to fall or level off only to come raging back a short time later.

Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, says people shouldn't overreact to the latest numbers. He notes that the number of Ebola cases can vary widely from day to day and week to week, much like daily fluctuations in temperatures.

Case reports may not be completely reliable, Osterholm says. Some families are clearly keeping their loved ones at home, rather than taking them to the hospital or calling an official burial team, because families want to avoid being forced to cremate their loved ones, he says. Traditional burial practices, in which family members and mourners touch the bodies of the deceased, have been blamed for spreading the virus. Cremating bodies is safer, but unpopular with many residents.

Because of these problems, case counts that rise and fall from week to week are "really hard to interpret," Osterholm says.

Regardless of what the numbers show, most agree there's no doubt that the situation in Sierra Leone is serious, Ebola has spread to every district in Sierra Leone, said Tim Shenk, a spokesman for Doctors Without Borders.

"The government has put five of the worst affected districts under quarantine, setting up checkpoints on roads to prevent people leaving the area -- measures which affect between 1 and 2 million people," Shenk said.

But the government's response has been uncoordinated at both the local and national level, Shenk said. Up to 85% of calls to Sierra Leone's Ebola hotline get no response. There is a shortage of ambulances and labs, so that test results are often delayed. The country also lacks a strong surveillance system to detect new cases and trace contacts.

"Transit centers" used to house people with suspected Ebola cases are overcrowded, leading staff to send many patients on to treatment centers, where people without Ebola could be exposed to patients with the disease, Shenk said.

"As there are few treatment centers, and these are often far away, people often die on the long journey there," Shenk said. "Dead bodies have the highest viral load possible, putting other passengers (in cars and vans) at risk."

Although "the international response is beginning to get underway, but it is slow and uncoordinated," Shenk said. Although several countries have pledged to build new treatment cetners, "getting these new centers up and running is a matter of urgency."

The United States is opening a clinic this weekend to treat infected health care workers outside Monrovia.

A British-built Ebola treatment clinic in Sierra Leone, equipped to treat 80 people, opened this week.

A total of 13,268 people have been infected with Ebola and 4,960 have died, mostly in the hard-hit West African nations of Guinea, Liberia and Sierra Leone.

Even with the additional facilities, the WHO reports that West Africa has only 22% of the hospital beds it need to treat patients with Ebola. Only about half of Ebola patients are being isolated appropriately to prevent the spread of the virus. Just 27% of all the burial teams needed to halt the spread of Ebola are trained and in place.

Ebola has caused the West African countries' already fragile health systems to collapse, said Lina Moses, an epidemiologist with Tulane University's Ebola task force who has worked in Sierra Leone.

According to the WHO, there have been 549 infections and 311 deaths of health care workers in the three hardest hit countries. The WHO has moved more than 1 million sets of personal protective equipment to West Africa to protect workers.

With many hospitals now devoted entirely to Ebola patients, there is no place for patients to receive treatment for malaria or medical emergencies, said Armand Sprecher, a physician and epidemiologist with Doctors Without Borders.

"The number of people dying of non-Ebola causes is unknown, but it may be larger than the number of people dying of Ebola," Sprecher said.

Women in Sierra Leone are now at high risk of dying in childbirth because of the lack of doctors willing to perform C-sections, Moses said. Many doctors are afraid of contracting Ebola during the procedure because it involves a lot of blood.

Some health care workers from West Africa are unwilling to report to work for fear of contracting the virus, Moses said. Government agencies are often unable to meet their payrolls, making workers even less willing to report to work, Moses said. Burial teams went on strike earlier this fall because they hadn't been paid.

Osterholm says that the USA and other countries should try to help make sure that sanitary and health workers get their paychecks on time, and also make sure that they are guaranteed health care if they fall ill. Both measures could encourage more workers to help fight Ebola, he said.

"Most of them are the primary breadwinners for their families," said Moses, who is returning to Sierra Leone this weekend. "If they die of Ebola, their families are going to starve. That is a really good incentive not to show up for work."