Bat Guano - Is it really safe to use?

[Nuggz]

I know many folks here at AFN regularly sing the praises of using bat guano when growing the noble herb. There is no doubt that bat poop has a very high nutrient value, but did you know that scientists consider bat feces to be one of the greatest spreaders of disease on the face of the earth?


I first became aware of the subject of bats as carriers of disease last year when the Ebola virus scare struck an unsuspecting public in the USA. Most scientists believe that the deadly disease that has killed so many people in Africa is spread by fruit bats. Ebola spreads across the land when humans, animals or birds have contact with bat feces. However, the bats themselves appear to be merely carriers of the disease and are thought to be generally asymptomatic.


In America, insect-eating bats are thought to be one of the primary carriers of the rabies virus, but several other infectious diseases, SARS for instance, can also be transmitted by bats. Whatever the disease is, if a bat eats an insect that has bitten a diseased human or animal the bat generally becomes the asymptomatic carrier of that disease and the disease organism is usually spread by their poop.


Composted bat guano that has been subjected to high heat composting for at least 40 days would likely be safe, but unfortunately, most bagged bat guano doesn't seem to be composted. IMO, if you are using bagged, uncomposted bat guano you may be exposing yourself to substantial health risks and infecting your soil as well.


Here's an introductory article on the subject:


"Why Do Bats Transmit So Many Diseases?

"Bats have a pretty bad reputation, which is not surprising considering the number of pathogens they carry that can infect humans. Rabies, Nipah, Hendra, Ebola and Marburg are all viruses carried by bats that can cause serious disease in humans. Marburg virus and some strains of Ebola virus can kill up to 80-90% of humans infected. Furthermore, most of these are emerging diseases that have rudely burst onto the scene over the past 50 years (although some arguethey have been around a lot longer, but weren't diagnosed). But what is causing this rise in viral disease? It turns out that it is just as much their fault as it is ours.

Humans have started creeping into bat territory, especially in the tropics, which has led to an increased risk of contact with these animals. For example, in Malaysia, commercial pig farms were installed in bat inhabited forests which consequently led to the first human outbreak of Nipah, via pigs.

However, it seems that bats also carry more human pathogens than other animals. Why is this? Bats like to live close to one another, snuggling up as they roost, giving plenty of opportunity for pathogens to spread between the bats.

So why don’t these nasty viruses kill off the bats? Scientists think it’s actually thanks to their ability to fly. Flight is hugely costly energy wise, and when a lot of energy is used a lot of waste is consequently produced. To prevent this reactive waste from damaging the bats’ DNA, bats have evolved sophisticated defence mechanisms that conveniently also help to prevent the bats from succumbing to disease.

Now you may be thinking- how do the viruses survive in the bats, then? Once again it’s back to flight. Viruses are totally dependent on the host to replicate, unlike bacteria, and consequently they require quite specific conditions. When bats fly, their internal temperatures are ramped up to around 40oC (104oF), which is too hot for many viruses. This will kill off a lot of the viruses in the bats, leaving only those hardy viruses that have evolved tolerance mechanisms. Unfortunately for us, this also means they can tolerate a burning human fever.

But don’t go hating on bats because of this- they’re incredibly important pollinators and they also eat mosquitoes. You win some, you lose some."

(Source: http://www.iflscience.com/plants-and-animals/why-do-bats-transmit-so-many-diseases )


Additionally, here are two more articles that delve more deeply into the subject of bats as one of the world's most prolific carriers of disease which can and does infect human beings with deadly pathogens via their feces.

http://www.wired.com/2014/10/bats-ebola-disease-reservoir-hosts/


http://www.eht-journal.net/index.php/ehtj/article/view/7159/8775

 

[TimeTraveler]

Typically, when you buy any kind of manure it's been composted so that it's safe for use in the garden, as the composting process kills off harmful and dangerous pathogens.

 

[Nuggz]

Hmmm. I've looked at several well-known brands of bat guano on Amazon, and so far not a single one of them says a dang thing about the product being heat composted. I'm assuming that if the guano was composted, it'd say so on the label as that would be an additional selling point. If you know of a brand that actually states it's been composted, please clue me in so I can take a look at it.

 

[Nuggz]

As far as I can tell, even "certified organic" manures wouldn't necessarily have to be heat composted:


"Heat-treated, dried, and other processed manures, and manure that has not been composted according to NOP specifications, may still be used in organic crop production. However, it must be applied as if it were raw manure.

• According to the NOP's rules (9), raw manure: can be applied at will to crops not intended for human consumption
• cannot be applied to a crop within 120 days of harvest if the edible portion has direct soil contact
• cannot be applied to a crop within 90 days of harvest when the edible portion does not have soil contact. "

(source: http://www.carolinafarmstewards.org...ng-Mixes-for-Certified-Organic-Production.pdf)


To be on the safe side, I'm thinking that any and all manures need to state on the package that they've been heat composted, or that's a product I'm not going to buy.

 

[TimeTraveler]

Some brands refer to "aging" their bat guano, not sure if that's the same as heat composting. A few of the more common brands I've seen do warn with their products to avoid inhalation because it can lead to Histoplasmosis (a fungal infection from spores dormant in the guano), but then again pretty much every fertilizer, organic or no, warns against inhaling the dust/particles that can be kicked up when using them.

Honestly, a much bigger concern with bat guano is how it's harvested; Jamaican bat guano mining has been linked to decreasing numbers of bats on the island, and reckless practices can scare off the bats from their roost, leading to dead young or starved adults. I haven't heard of people getting sick from using bat guano, but there's clear research that shows that bat guano needs to be harvested carefully to avoid destroying bat populations.

 

[Nuggz]

Generally speaking, an "aged" manure means it's at least 6 mos. old. But aged manures and composted manures are two entirely different things. Aged manure means that it isn't "hot" any more, so it's far less likely to burn the roots of your plants. While aging does indeed make manure more usable as far as its nutrient value is concerned, aging doesn't do a heck of a lot in terms of safety. Salmonella, for instance, can live for a very long time. Studies show that even very cold freezes don't kill salmonella; freezes just slow it down. As soon as the weather warms up again, the dormant salmonella spores wake up and become active all over again.


Yes, there are a lot of very real environmental issues surrounding the collection of bat guanos. That said, I've also read several articles over the years stating that the people who collect the guano do so at serious risk to their health. People have gotten very ill from collecting, which goes hand in hand with breathing in the fresh guano spores. Generally, only the very poorest of natives take that risk and when they fall ill, it's often just swept under the table. Guano is big business and those companies that deal in it don't want any bad press hurting their profit margins. You know how it goes…


Any manure or guano that has not been heat composted first is really not safe to use. But bat guano, in particular, can carry some very exotic and death dealing diseases. In my book, if it hasn't been composted, you're playing Russian roulette with your health.


Just look at the map in this article of the serious diseases being spread by bats. Marburg Virus and Ebola are Hemorrhagic fevers! That's some very scary bat crap!


http://www.eht-journal.net/index.php/ehtj/article/view/7159/8775

 

[TimeTraveler]

Are these pathogens present in the guano, though? It is true that bats themselves are host to a variety of dangerous diseases, but I've not heard anything about those being present in their droppings. The article in your last post, for example, didn't contain any references to bat guano as a disease vector, and only mentioned that viral RNA was found in their guano, not even viruses themselves.

Bats are certainly a potentially dangerous animal in the wild, and I wouldn't recommend getting near a roost without the proper precautions and safety equipment, if at all. However, I think you're overstating the risks associated with the guano itself. Guano collection is hazardous primarily because of conditions you won't find in your bag at the store (abnormally high, toxic levels of airborne ammonia, the presence of wild bats carrying live pathogens, and a frankly skin-crawling number of insects that live and thrive in their guano).

 

[Nuggz]

Time Traveler, I repeat! Scientists have determined that the spread of Ebola through Africa is directly linked to animal and human contact with bat feces! It is now, of course, being spread from human to human, but the original spread from Central Africa to Sierra Leone (etc.) was from migrating bats leaving behind contaminated droppings! Even the endangered gorillas are now dying off from Ebola! Look at that map! I have no clue how in the hell Ebola spread from Africa to the South China Sea, but it did! Dead bats in shipping crates? I don't know...

That map is specific to diseases being spread by bats, and the way they spread it is through their droppings.

Even the CDC is warning people to stay away from bats and their droppings because of disease! Here. Read this...

"Bats and Diseases around the World
Even though rabies and histoplasmosis can be found all over the world, some diseases associated with bats are found exclusively in certain regions of the world. Notably, research suggests that bats might be the source of several hemorrhagic fevers, which affect multiple organ systems in the body and often lead to life-threatening diseases.

One of these diseases is Marburg hemorrhagic fever, which is found exclusively in Africa. Past outbreaks have shown that Marburg Hemorrhagic Fever kills up to 90% of those infected.

While the natural host had for years been unknown, new research suggests that fruit bats are a natural source of this virus, and the virus has been isolated repetitively from fruit bats in Uganda.

The same may be true for Ebola hemorraghic fever. The virus that causes this disease is often referred to as the "cousin" of Marburg virus, since they are the only distinct viruses that belong to a group of viruses known as filoviruses. Like Marburg, Ebola is highly fatal and is found mostly in Africa. Recent studies indicate that, as with Marburg, bats are likely to be a natural source of this virus, although no Ebola virus has been isolated from bats.

Two other viruses - Nipah (which causes Nipah virus encephalitis) and Hendra (which causes Hendra virus disease) - are also associated with bats. Research suggests that Hendra virus is associated with fruit bats (commonly called flying foxes) in Australia. Nipah and related viruses are also associated with the same group of bats in Southeast Asia and parts of Africa, although outbreaks of disease in humans have so far been limited to Malaysia, Singapore, India, and Bangladesh. Both viruses can cause severe respiratory and neurologic disease in humans.

Another group of viruses known as coronaviruses have been detected in multiple species of bats. Coronavirus infection can sometimes cause mild respiratory illness in humans, but these viruses were also implicated in the outbreak of Severe Acute Respiratory Syndrome (SARS) in Southeast Asia. While bats do not carry or transmit SARS, research has linked coronaviruses to bats in countries all over the world.

In addition, Lyssaviruses have been discovered on every inhabited continent. This group of viruses causes rabies, in addition to other diseases that can be fatal to humans. While current rabies vaccines are effective against many of the viruses in this group, several Lyssaviruses identified in Africa and Asia primarily associated with bats cannot be prevented with current rabies vaccines.

Further studies may shed light on the role of bats as the source of these viruses and their ability to transmit diseases caused by these viruses to humans....

....Histoplasmosis is another disease associated with bats. Its symptoms vary greatly, but the disease primarily affects the lungs. Occasionally, other organs are affected. When this happens it can be fatal if untreated.

In addition, Histoplasmosis is caused by a fungus that grows in soil and material contaminated with droppings from animals, including bats. Droppings, also known as bat guano, can contaminate the soil and cause infectious spores to be released when the soil is disturbed.

(Source: http://www.cdc.gov/Features/Bats/index.html)

I don't think I'm overstating things. I think I am saying some things that most marijuana growers don't want to hear, because we growers of the noble herb are the biggest buyers of bat guano.

You can ignore the CDC and what the scientists say in the other articles if you want to. That's your choice.

 

[TimeTraveler]

I'm not ignoring, I'm just pointing out that, even in this latest post, nothing indicates the guano itself is responsible. Bats are carriers, of diseases, but your bolded section only mentions Histoplasmosis. I -DO- want to hear or read or whatever your sources that say those viruses and bacteria are found in feces, not just "bats carry diseases, oh and you'll find spores in their guano too". I'm not ignoring anything, I'm reading through what you provided and looking for references to back up that assertion, and not finding it.

There's plenty to suggest they're a much bigger concern as a disease vector than people think, but again we're talking about the bats themselves, not the guano we harvest.

 

[Nuggz]

Most of the bat guano that is for sale seems to be coming from Jamaica. To date, Jamaican bats, like most of the bats in the USA are known carriers of both Rabies and Histoplasmosis. Unfortunately, Histoplasmosis is indeed spread by bat droppings.


According to this article:


"Bat and chicken droppings are the most common carriers of the fungus Histoplasma Capsulatum. Pigeons, starlings, and some other species of birds can carry the fungus as well. The high body temperatures of birds prevent them from actually having an infection of histoplasmosis from bats, but they can carry it on their bodies, and it can be present in their droppings. People who work with live poultry are very likely to come in contact with Histoplasma Capsulatum, and they should take precautions to prevent inhalation of the spores. Bats produce large amounts of guano, or waste, and the fungus is commonly found in bat guano.

While many bats are found in caves, bats can also infest a house. If not removed, the guano of the bats can cause corrosion to building materials, a terrible odor, and the risk of infection with Histoplasmosis. If a colony of bats invades a home, the size of the colony will quickly increase and more guano will be produced. Live exclusion of the bats is the only way to remove the bats permanently. After the bats are removed, the area where the colony lived must be thoroughly cleansed to remove all traces of the guano, eliminating the risk of infection from the fungus."



(Source: http://batsintheattic.org/histoplasmosis.html)


As I understand the symptoms of histoplasmosis, most people who have contracted it usually assume they have come down with a cold or flu. Undiagnosed, histoplasmosis can result in chronic lung disease and serious breathing problems which are especially dangerous to the elderly and the young as well as people who have compromised immune systems, (like a good number of AFN people growing marijuana for its medical benefits.)


To date, the Jamaican bats show no evidence of carrying the more exotic diseases that have been traced to bats and their droppings, particularly in Africa and East Asia. BUT Jamaica exists in the tropical zone where many diseases, once they get a foothold, unquestionably flourish.


I guess we can all hope, pray and cross our fingers that Jamaican bats will not further contract and spread the rather alarming host of other diseases carried by bats and their feces that are found across the globe.


However, in the meantime it may be very prudent of Guano users to contact the companies that bag up the guano for sale, state your concerns over the disease vectors known to be found in bat guano and nicely ask them if they would please, please, please heat compost bat guano (a good rule of thumb is 40 days) in order to make sure that it is safe for growers to use.


I'm certain that guano has to be somehow processed before it is bagged up for sale. Some outfits may put the guano in ovens and subject it to mechanical heat processing, while others may simply lay the guano out in thin layers on a tarp and allow it to dry in the sun.


Considering the number of serious diseases that have been traced back to bats and their droppings, it would be very prudent for companies that bag and sell guano to state on their bags how the guano is processed. They aren't going to spend the money to do that until a substantial number of people contact them stating their concerns over disease.