As life expectancy grows and the majority of people in the developed world die of chronic disease, the study of viruses that can fell people young and old within days or weeks has lost prominence.
Only a small fraction the size of the average bacterium and too small to be seen directly with an ordinary microscope, these parasitic particles of genetic material contained in a protein coat have the power of destruction in the world of plants, animals, humans and even bacteria.
As they constantly mutate, these tiny infectious agents are a moving target that challenge a small band of virologists in a constant battle against them. Millions of different viruses are believed to exist and some 5,000 have been described in detail since the first was identified in 1892 as an infecting agent against tobacco plants.
Long after chicken pox, the common cold and influenza challenged man, new viral diseases such as avian flu, SARS, West Nile virus, AIDS and Ebola fever have emerged.
While apparently not a threat to the rest of the world, at least in the foreseeable future, the deadly Ebolavirus, which is hypothesized to have a reservoir in bats and spread to monkeys in West Africa, has in the latest round killed nearly 900 people in Liberia, Guinea, Sierra Leone and other countries. More than half of those infected died within a few weeks of showing symptoms.
The World Health Organization (WHO) in Geneva has warned of catastrophic consequences if the disease was not controlled.
The current outbreak began in the forests of Guinea, but the first documented outbreak of Ebolavirus took place in 1976, just before the HIV virus that causes AIDS was formally identified by scientists. Two American aid workers who worked in Liberia and contracted Ebola fever there were transferrred in very serious condition last week to Emory University Hospital in Georgia; federal health officials said they pose no threat to the general public.
DR. LESLIE Lobel, a New York-born virologist and physician in the department of microbiology, immunology and genetics in Ben-Gurion University of the Negev’s Faculty of Health Sciences is one of the small band of soldiers in the battle against Ebolavirus and other hemorrhagic fever viruses.
Working for the last 12 years out of his Beersheba lab but traveling to Uganda about four times a year to examine and test survivors, Lobel is supported by US and other foreign financial grants to find a cure.
“I received my MD and doctorate in virology at The College of Physicians and Surgeons of Columbia University in New York,” Lobel told The Jerusalem Post in an interview, “but from the outset I wanted to do research rather than treat patients. As virology was not a very big field, I decided to shift to oncology and studied the human immune response to cancer. My team and I isolated and produced in the lab human monoclonal antibodies, which are molecules that are naturally produced by the immune system. But then, my good friend in the US military asked whether our technology can be used for viral diseases. It was an instant awakening and changed the course of my research. I took the technology that we developed for cancer studies to isolate and produce human monoclonal antibodies against viral diseases.”
Coming on aliya in 2002, he accepted a faculty position at BGU and went directly to work at the medical school. Although the Second Intifada was raging, Lobel had no reservations about coming with his family and has not looked back since. “I figured that I should first focus on a serious virus – and Ebola is a very serious disease, lacking a cure and fatal in the majority of cases. It is also a biodefense threat. I thought human antibodies could be very useful for treating this viral disease.”
The first symptoms of Ebola are flu-like – headache, muscle pains and fever – but they can quickly develop into diarrhea, vomiting and bleeding from the mucous membranes and then under the skin, which can rapidly result in death, he said.
While there is no specific approved treatment for Ebola hemorrhagic fever and only supportive care such as intravenous fluids are given to help the victim fight for survival, there are several good specific diagnostic tests to help identify those in the field who have been infected. “I even developed such a test myself.” Lobel noted.
However, the Ebola virus poses a very small danger to Israel. “There is general hysteria in the West about it, but it is overblown.
The risks to Israel are very minimal.
Currently, the only way for it to spread here is through an infected traveler on a passenger plane. Infected individuals, before they appear sick, could possibly board a plane and come here. However, sick individuals would be effectively quarantined in Israel, and the infection would be rapidly controlled,” Lobel explained. “Israel has a security and medical system that is second to none.”
Lobel’s collaborators are those that developed the lifesaving experimental drug cocktail used recently in the current Ebolavirus outbreak. Lobel’s lab is working on different cocktails of the same type for other strains of the virus and with broad reactivity so that it might cover an outbreak of a new strain.
ARMED WITH anti-malaria pills and antibiotics, Lobel is one of the few who follow the condition of Ebola hemorrhagic fever survivors, and he is well familiar with their immune system. He was later joined by US military researchers and together they work with “wonderful collaborators in Uganda. We have drivers, and everything is well organized. We don’t cover our faces or hands when talk to survivors, because we must gain their trust. I go in as a proud Israeli, very respectful of the Ugandans. It took many years to develop relationships with them. I didn’t want to just run into the country, take biological samples and leave,” he said. He in partnership with the US military and the Uganda Virus Research Institute are one of the very few in the world to be developing human monoclonal antibodies against Ebola in the way they are.
The WHO “is a global body that does a lot of outreach. But they are involved in controlling outbreaks, not in developing therapeutics. They don’t fund research.”
“We have been studying survivors, not victims of outbreaks, to find out what gives them protection to live despite the viral infection, We believe that it is likely the specific molecules that their immune systems produce, however it might be related to genetic background or perhaps epigenetics -- environmental effects on genes -- from food or other influences. There are even children as young as two years old who have survived.”
By defining who among survivors in Uganda has best protection against Ebola, Lobel and his colleagues have been able to isolate immunity in the form of human monoclonal antibodies. They have already published their studies on the virus in The New England Journal of Medicine and other prominent journals. They hope their research will be turned into clinical studies in the near future, with the monoclonal antibodies used to neutralize the virus in patients. “It would be a great scenario if Ebola were to be wiped out, but Nature has way of propagating itself. There is always another strain. I know from my studies that viruses will always be ahead of us.”
THERE HAS been much speculation that African fruit bats might be the original sources of the Ebola virus, as these large bats leave their secretions on fruit that is then eaten by monkeys or humans. But Lobel said that thus far there is no definitive evidence for this. “A lot of existing evidence has been only circumstantial and epidemiological, but while I think it is very likely that Ebola originated in some species of bats, it is not clear what kind or where they are. Fruit bats have been implicated as reservoirs of Marburg virus infections going back to 1967, but they have not been proven to cause Ebola.”
Lobel recalls that on his scientific visits to Uganda (where HIV and West Nile virus originated as well), he saw thousands of fruit bats huddling together and many flying overhead as he ate dinner outdoors.
Israeli bats, which roost upside down mostly in caves, are much smaller than fruit bats and subsist typically on insects.
Human consumption of equatorial animals in Africa in the form of bushmeat has been linked to the transmission of diseases to people, including Ebola. But in Africa, most viruses that infect humans are insect borne or Arboviruses. The BGU virologist notes that despite its afflictions of infectious and parasitic diseases such as malaria, Uganda is a beautiful, lush country. “It has a rich ecosystem and plenty of water, which leads to swarms of mosquitoes and other insects.”
While Israel has not been blessed with abundant supplies of water, it is on the migratory path of millions of birds, which carry parasitic insects. “West Nile virus is thus endemic to this country, but most of our population have serological titers to the virus; this means there is herd immunity, so generally it is nothing to worry about,” Lobel said.
“Many infectious diseases come in cycles around the world. Ebola in Africa is just the tip of the iceberg. The world in general has been complacent about these deadly disorders during the past few decades. Ironically, scientists thought in the 1960s that they had conquered most viral diseases like polio and yellow fever, but they have been proven wrong. Research into chronic diseases like heart disease and cancer is important, but we’ve ignored the fact that infectious diseases keep evolving. This trend will only get worse with globalization and global warming, which will bring about extremes in climate, both hot and cold.”
Medical care, said Lobel, “is unintentionally weakening the human genome. Many people are alive who would have been killed in the past by viral diseases. HIV is one such example; patients take anti-retroviral “cocktails” of medications and can live with it as a chronic disease. There are many HIV-positive people walking around. Of course, doctors should keep people alive, but in the old days, viruses weeded out weak genomes. This means there will be a lot more viral diseases in the future as the pathogens evolve in our bodies.”
He strongly advocates that parents take their infants and toddlers for all available vaccinations. “If fewer children are protected, old diseases that killed in the past could come back.”
IN ADDITION to viruses, there are prions (which cause Creutzfeldt-Jakob or “Mad Cow disease” and others but they are not as contagious as viral disorders). Fungi can also cause infections, but they are so far under control. “Overuse of antibiotics around the world causes bacteria to become resistant to them, and as they offer much lower profits than medications for chronic diseases, pharmaceutical companies have little incentive to develop new ones, and some factories have been closed down,” the BGU scientist concluded.
“Many serious infectious diseases are our own doing. It is up to us to reinvigorate the fields of Virology, Bacteriology and Parasitology so that we will be prepared for the infectious challenges of the future and the clear and present dangers of today. As the Nobel Laureate Joshua Lederberg said “The single biggest threat to man’s continued dominance on this planet is the virus.”