Guinea, Liberia and Sierra Leone are struggling to contain the world’s deadliest recorded outbreak of the virus, which is transmitted by direct contact with the blood and body fluids of infected people as well as infected animals.
The West African epidemic is thought to have started when the virus crossed over from infected wildlife into the human population and subsequently began spreading between people.
Curbing human-to-human transmission is the most important focus for governments and international health agencies. However, FAO is working closely with the World Health Organization (WHO) to raise awareness of the transmission risks from wildlife among rural communities that hunt for bush meat – or meat obtained from the forests – to supplement their diets and income. These communities risk future spillover from species that can carry the virus, including fruit bats, some primates, and duikers.
FAO Chief Veterinary Officer, Juan Lubroth, said: “We are not suggesting that people stop hunting altogether, which isn’t realistic. But communities need clear advice on the need not to touch dead animals or to sell or eat the meat of any animal that they find already dead. They should also avoid hunting animals that are sick or behaving strangely, as this is another red flag.”
Fruit bats – usually eaten dried or in a spicy soup – are thought to be the most likely reservoir species for the virus, which they can carry without developing clinical signs of the disease, and should be avoided altogether, according to FAO.
“The virus is killed when meat is cooked at a high temperature or heavily smoked, but anyone who handles, skins or butchers an infected wild animal is at risk of contracting the virus,” Lubroth said.
According to Wikipedia, fruit bats, which belong to the family Pteropodidae, are flying mammals that live in dense forests in Africa, Europe, Australia, and Asia. There are about 166 species of fruit bats. Fruit bats are sometimes known as flying foxes. These bats live in huge colonies, known as “camps.” These nocturnal (most active at night) animals rest during the day while hanging upside down from their feet.
As fruit bats fly from plant to plant-getting food, they also pollinate the plants they visit. In addition, they disperse the plants’ seeds as they eat. Many plants, including some avocados, dates, mangos, and peaches, are dependent on these bats for either pollination or seed dispersal.
Fruit bats mostly eat fruit juice and flower nectar. They chew the fruit, then spit out the seeds, peel, and pulp. Fruit bats, like other Megachiropteran bats, use the sense of smell to find their food, fruit and/or nectar. Although they have large eyes and can see well, fruit bats do not use sight as their primary sense. Fruit bats eat other things too.
Link to Ebola virus
The first recorded human outbreak of Ebola virus was in 1976, but the source of the virus is still unknown. However, recent tests have shown that some species of fruit bats collected during Ebola outbreaks show the bats have the virus, but do not show any signs of it. Further studies also show that Ebola can reproduce in fruit bats and other bats in the Tadarida genus. This could mean that the bats are the source of the virus. The Marburg virus, which is related to Ebola, has also been found in fruit bats in Uganda.
Another explanation is that fruit bats could be an intermediate host because of the uncertainty that fruit bats are the index case for Ebola. It is also important to note that certain species of fruit bats in Africa are immune to the Ebola virus and that their DNA or RNA are similar to the Zaire Ebola virus. This could explain the spread to humans since people in that region tend to eat fruit bats.
High consumption of fruit bats by Nigerians
As early as 1978, researchers from the Department of Agricultural Biology, University of Ibadan, Ibadan, had reported that Nigerian people eat meat mainly from wild animals, and the straw-colored fruit bat is a popular meat in the south-west, where colonies may number a million animals. But the killing methods are inefficient and wasteful, and no management of the populations is attempted. The study was published in Oryx, the Internal Journal of Conservation. The author suggests there is need to improve the former and embark on the latter if this valuable resource is to be conserved.
The Guardian investigation reveals that bats are ubiquitous in Nigeria. In Lagos, they struggle with residents for ceilings on their rooftops and any available space in tall buildings.
Lagos bat virus
According to Wikipedia, Lagos bat virus is a lyssavirus of southern and central Africa that causes a rabies-like illness in mammals. It was first isolated from a fruit bat (Eidolon helvum) from Lagos Island, Nigeria in 1956. Brain samples from the bat showed poor cross-reactivity to rabies antibodies but the virus was found to be closely related to the rabies virus. This was the first discovery of a rabies-related virus. Until this time, rabies was thought to have a single causal agent. Four more lyssavirus species and numerous tentative species have since been identified.
Lagos bat virus has been isolated from wild and domestic mammals in southern Africa including bats, cats and one dog. One isolate was made in France in 1999 when a fruit bat (Rousettus egypticus), which had been displaying signs of aggression, died. The bat had been imported from Africa.
No human cases of Lagos bat virus infection have been documented.
Herbal preparation made predominantly with bitter leaf (Vernonia amygdalina), bitter cola (Garcinia kola), garlic (Allium sativum), neem tree (Azadiratcha indica), guava (Psidium guajava), lemon grass (Cymbopogum citratus), water yam (Dioscorea alata), corn/maize (Zea mays), sesame (Sesamum indicatum), Aloe vera (Aloe barbadensis), sugar cane, (Saccharum officinarum), and Green amaranth (Amaranthus caudatus, inine in Ibo, tete abalaye in Yoruba) may provide the elusive cure for Ebola virus disease.
Nigerian researchers claim they are a step closer to a universally accepted cure for Ebola virus.
Results of a study presented, in 1999, at the 16th International Botanic Congress in St Louis, Missouri, United States, indicate that bitter cola (Garcinia kola), a plant widely used in traditional African medicine may contain a compound that is effective against Ebola virus disease.
The plant has been found to halt the deadly Ebola virus in its tracks in laboratory tests, scientists have said. The extract can be eaten or rubbed into the skin.
They used a compound from Garcinia kola, a plant commonly eaten in West Africa. Compounds from the plant have also proved effective against some strains of flu.
Executive director of the Bio-resources Development and Conservation Programme, Prof. Maurice Iwu, explained that an extract derived from the seeds of Garcinia kola could inhibit this virus in cell culture at non-toxic concentrations.
Iwu and his colleagues identified Garcinia kola as a possible source of drugs using the method called Corbel (clinical observation-based ethno medical lead).
Extracts from Garcinia kola seeds were tested against many complex viral diseases. The active compound, now known to be a bioflavonoid, was found to be active against a wide range of viruses including the influenza virus.
Iwu told The Guardian last week: “The active substance is an extract from Garcinia kola (bitter kola) called Kolaviron, which contains bioflavonoids and prenylated xanthones and benzophenones.
“Work was done while a scientist at the Division of Experimental Therapeutics of Walter Reed Army Institute of Research Washington DC in collaboration with Southern Research Institute (SRI).
“But no follow up. Others at Ibadan and other Nigerian universities have done follow-up work on Kolaviron.”
He further explained: “The Garcinia kola compound has been shown to halt multiplication of the virus in the laboratory. If repeated in humans, this would give the body a chance to fight off the virus. The active compound is what is known as a dimeric flavonoid, which is two flavonoid molecules fused together.
“Flavonoids are non-toxic and can be found in orange and lemon rinds as well as the colourings of other plants.
“The discovery of these important properties in a simple compound – flavonoids – was very surprising. The structure of this compound lends itself to modification, so it provides a template for future work. Even if this particular drug does not succeed through the whole drug approval process, we can use it to construct a new drug for this deadly disease.”
Also, other researchers have identified asthma herb (Euphorbia hirta), pawpaw (Carica papaya), neem tree (Azadiratcha indica), lemon grass (Cymbopogum citratus), bitter melon (Momordica charantia) and Psidium guajava (guava) extracts as potential cures for dengue fever and other viral infections.
Euphorbia hirta (asthma herb) has been shown to not only to be effective in treating asthma but to possess antiviral activity against Human Immuno-deficiency Virus (HIV)/Acquired Immune Deficiency Syndrome (AIDS).
Euphorbia hirta belongs to the plant family Euphorbiaceae. It is called In Nigeria, asin uloko in Edo, endamyel in Fula-Fulfulde, ba ala in Igbo (Owerri), akun esan in Yoruba.
Euphorbia hirta is also locally known as ogwu ngwo (eczema drug) in some eastern parts of Nigeria is used locally to arrest bleeding in the event of an injury. Leaves of Euphorbia hirta are used in traditional medicine for the treatments of boils, wounds and control of diarrhea and dysentery.
Bush meat can be a viral feast
Monkeys and apes are considered edible game in many parts of Africa. As people from these regions have immigrated to other parts of the world, some have retained their love of this and other types of bush meat. A new study now finds that meat from nonhuman primates — from chimps to monkeys — can host potentially dangerous viruses.
Scientists in 2012 confiscated tested samples were confiscated at United States airports.
Veterinarian Kristine Smith of EcoHealth Alliance, a wildlife conservation and health group in New York City, led the new analysis, published in PLoS ONE. Her team analyzed primate and rodent bush meat that had been serendipitously caught at New York’s John F. Kennedy Airport and eventually at four others (in Philadelphia, Washington, Atlanta and Houston) over the past five years.
“These products ranged from raw and bloody to well smoked,” Smith says, “and we found virus even in the well-smoked pieces.” That’s a big concern, she and her coauthors maintain, since nearly 75 percent of emerging infectious diseases in humans comes from animals, mostly wildlife.
No one knows how much bush meat enters the United States, although the new study points to one European account that estimated Air France planes alone ferry more than 270 tons of bush meat into Charles de Gaulle Airport, in Paris, each year.
In the United States, most such contraband food is promptly incinerated, Smith notes. But in a few cases, some bush meat had been stored at between -20 and -80 °Celsius. This provided Smith’s group portions of 44 rats and primates to screen for germs. The researchers focused on wildlife pathogens with a known potential to infect people. And although the 35 rats hosted none of
the germs they scouted for (including anthrax, coronaviruses and more), the nine primates did show viral contamination — sometimes with multiple types of germs.
The good news:
This survey turned up none of the infectious agents that over the years have given rise to HIV/AIDS — simian immunodeficiency viruses — and to human T-lymphotropic viruses.
But Smith is not sanguine about this non-detects. Both types of viruses are so common in African primates that she had expected to see them in the bush meat. She now attributes her group’s failure to find them to the few samples available for testing.
The new analysis did turn up substantial contamination of the non-human primates with herpes viruses — ones known as cytomegalovirus and lymphocryptovirus. Cytomegalovirus normally causes few symptoms in people except when infection occurs during fetal development or among individuals with a compromised immune system. Lymphocryptoviruses includes a family of germs (the best-known being Epstein-Barr virus) that have been associated with serious infections and tumors in people.
Most people will find simian foamy virus the most curious germ identified in the bush meat samples. A retrovirus, it belongs to the same overarching family of disease-causing agents as HIV and human T-lymphotropic viruses (which has been linked with neurological impairments and blood cancers). Both HIV and HTLV appear to have arisen when infection with largely benign primate versions of the viruses didn’t prove so benign in our species.
Retroviruses tend to become lifelong infections that develop slowly and may be hard to spread. In the case of simian foamy virus, William Switzer of the Centers for Disease Control and Prevention has been following groups of people that picked up foamy virus infections in the United States and Africa from monkeys and apes that they had hunted, butchered, eaten or had frequent
contact with (such as vets, zookeepers or pet owners).
In more than a dozen years of follow-up, no one with simian foamy virus has yet exhibited disease symptoms — which could be taken as a sign that these bugs aren’t very dangerous, says Switzer, a coauthor of the new paper. But he cautions that this is only a suspicion as infected patients may not have been followed long enough yet to identify any slowly developing disease or immune impairment.
“Other retroviral diseases like HTLV can take decades to cause disease,” including leukemia, lymphoma, inflammatory diseases such as arthritis and potentially debilitating neurologic disorders affecting the spinal cord (such as tropical spastic paraparesis), Switzer points out.
Moreover, human foamy virus infections have only been followed in largely healthy individuals. That may downplay true risks if this virus does the most damage in people who are sick with other illnesses — or who were born with genes that can’t effectively manage effects of this virus.
Until simian foamy virus can be demonstrated to be benign, Switzer says it pays to work toward limiting its spread. And that includes screening blood donations. His team has already identified U.S. patients who had donated blood prior to being diagnosed with foamy virus. And in lab studies using infected macaque monkeys, he observes, “it’s been shown that this virus can be infective and spread from animal to animal via blood donation.”
“The pathogens we found in this study are not something I think everyone should be hugely alarmed about,” Smith says — “but they are very concerning.”
Before conducting the new pilot study, scientists had volunteered that confiscated bush meat will be so degraded that geneticists will never find evidence of viruses because the germs’ DNA will have been destroyed. In fact, Smith now points out, viruses and their genetic material survived just fine.
Her group, which was led by CDC scientists, now wants to test the infectiousness of such viruses and to broaden the search for disease contamination of bush meat arriving at ports throughout the United States.
Bush meat: a source of zoonotic disease
In the last decade, there has been an increase in the number of cases of zoonotic diseases in the United States. Zoonotic diseases are those, which can be transmitted from animals to humans.
They are caused by an array of bacteria, viruses, fungi, or parasites. Some examples include Bubonic Plague, Severe Acute Respiratory Syndrome (SARS), and Human Immunodeficiency Virus (HIV).
The worldwide increase in incidence of zoonotic disease is mainly due to human settlement in areas where animal populations and parasites were previously isolated from humans and from the increase in ownership of domesticated animals. In the past couple years, a new mode of transmission for zoonotic diseases has emerged. Human handling and consumption of bush meat, defined as “the use of wild animals for food, ranging from cane rats to gorillas,” has been cited as a source for several zoonotic diseases in Africa. Although not commonly consumed in the United States, increased illegal importation and consumption of bush meat could pose a serious threat to the health of the general population.
Worldwide market expansion of bush meat products and an increasing number of animal carriers for disease transmission are both factors that can have implications on emerging zoonotic diseases. Consumption of bush meat in Central Africa and South America has greatly increased over the past 20 years. An article published in Emerging Infectious Diseases estimates that 1-3.4 million tons of bush meat is consumed in Central Africa and 67-164 million kilograms of bush meat is consumed in South America annually.
Reasons cited for this increase include the expansion of commercial logging into isolated areas of Africa and disruption of control measures due to armed conflict in the area. Commercial logging creates an increased demand for bush meat due to the increased worker population in the area and few dietary options available to workers and residents. Armed conflict disrupts local law enforcement and allows for unregulated hunting and consumption of bush meat.
The worldwide bush meat market, estimated to be a multibillion-dollar business, not only allows for expanded consumption of infected bush meat but for increased frequency of human exposure to zoonotic diseases through direct contact with fresh bush meat. An article from Emerging Infectious Diseases claims “tracking, capturing, handling, butchering in the field, and transporting of carcasses involve risks of cross-species transmission.” Previous examples of cross-species transmission include simian foamy virus and human T-lymphotropic virus types 3 and 4. All have been found in people that hunt, butcher, or keep primates as pets.
The percentage of wild animals that are carriers for zoonotic diseases may be increasing, resulting in a growing concern for human safety. Handling and consumption of meat products from animal carriers poses great health concerns worldwide. Bush meat is regularly consumed in African communities and may make up approximately 80 per cent of all animal-based protein eaten in Central Africa.
A study conducted in Cameroon from 1999 to 2001 tested wild monkeys, bush meat animals, and pet monkeys for different strains of Simian Immunodeficiency Virus (SIV). SIV, the zoonotic form of HIV, is the virus responsible for the AIDS pandemic. Study results showed SIV infection in 16.6 per cent of all tested animals. The study’s limitations included not testing all primate species and under sampling of some species included in the study. For this reason, the percentage of primates infected with some strain of SIV could well be larger than 16.6 per cent.
The study also mentions that recombination between strains of HIV and SIV could pose a risk for a new zoonotic illness. The growing number of infected wildlife and this possibility for genetic recombination is of paramount importance in the development of new zoonotic diseases and their transmission to humans.
Zoonotic diseases from bush meat are not currently prevalent in the United States because the importation of bush meat into the United States is illegal. However, due to market expansion and illegal importation of bush meat, emerging zoonotic diseases can impact people in the United States as well.
The Washington Post reported that the Centers for Disease Control and Prevention (CDC) has stepped up its efforts of confiscating illegally imported bush meat after a two year pilot program in New York, Pennsylvania, Washington, Texas, and Atlanta. The pilot programme tested eight mail packages and 20 passenger-carried packages containing non-human primates and rodents. Rodents tested negative for viruses, but non-human primates tested positive for retroviruses including simian foamy virus and several herpes viruses.
Fortunately, none of these confiscated samples contained SIV. This increased attention to confiscating illegally imported bush meat may help prevent exposure to zoonotic diseases. Zoonotic diseases are among the fastest emerging infectious diseases and create an enormous health risk to the general population. Due to increase exposure to wild animals and high mutation rates of viruses, zoonotic diseases are spreading faster than ever.
The expanding bush meat market in Africa has the potential to cause global pandemic as it has done before with the AIDS pandemic. Although illegal in the United States, increased importation of bush meat has recently been brought to light under the CDC pilot program. Safeguards, such as increased surveillance and testing of confiscated bush meat, have been put in place to help prevent bush meat from entering the United States. The question is will this increased surveillance be enough to stop the spread and emergence of new zoonotic diseases from infected bush meat?
Myths and mistrust thwarting efforts
While several governments in the region have attempted to outlaw the sale and consumption of bush meat, bans have proved impossible to enforce and have met with suspicion from rural communities.
“There is a lot of mistrust, to the extent that people are hiding patients rather than getting medical help, and it’s very difficult to control the disease in the midst of many myths and rumours,” said Katinka de Balogh, FAO veterinary public health officer and Ebola focal point.
De Balogh said there were growing concerns about the effect the outbreak may have on food security in some parts of the region as some farmers are too afraid to work in their fields, while some markets have also closed down.
FAO action plan
FAO has already committed resources and is working with governments, WHO country offices and other partners in Guinea, Liberia and Sierra Leone to improve information about the virus at community-level, using existing networks such as rural radio and agricultural extension services.
“It is critical for rural communities to understand the risks, both of human-to-human transmission and from wildlife, so that they are in a position to make informed decisions themselves,” de Balogh said.
The Organization will work with governments to also set up wildlife surveillance systems to support early detection of the virus, collaborating with wildlife rangers, veterinarians and local universities.
“Rural communities have an important role to play in reporting unusual mortality in the animal population, which is another reason that their collaboration is so crucial,” de Balogh said.
In addition, FAO will help to assess the role of hunting in livelihoods with a view to finding healthier and more sustainable long-term livestock production alternatives to provide people with additional protein and income.
West Africa’s first human cases of Ebola virus disease were suspected to have occurred in December 2013, and according to WHO more than 600 people have died from the disease in the region.
Lethal in up to 90 percent of cases, Ebola virus disease causes multiple organ failure and, in some cases, severe haemorrhaging. There is currently no vaccine for the disease.