Consultant veterinary surgeon, Dr Bala Muhammed, tells EMMANUEL OJO how anthrax, a deadly infectious disease, can be prevented and management
What is anthrax?
Anthrax is an infectious disease of ruminant animals and ruminant animals are those herbivores that always graze. Basically, they are divided into two classes: those that graze and those that browse. The first group that we know very well and animals that cause the issue or that become an issue for veterinary medicine or animal health are cattle, sheep and goats because those animals graze and browse anywhere there is grass. They can just survive on grass without any other thing. Camels also graze. I keep talking about grazing and browsing because that’s where the risk factor lies.
Mostly, the bacteria are usually in the grass and they can easily get washed even by rain, as it is now, into the vegetation. They are spore-forming, they have gotten some adaptation to the environment and then they can survive weeks, months and even years. So, those animals that strictly graze or browse, like cattle, sheep and goats, are highly susceptible. Camels and horses will be susceptible too because they also graze but camels are animals that survive in the arid desert. They virtually don’t have anything to graze on. So, they browse at shrubs, raise their necks and eat from the trees and shrubs around them. However, in Lagos, we tested some animals and they were positive for anthrax, meaning, not far from there, they will have a lot in the South. The animals will likely have a lot of grass they could graze and browse on, unlike in the North where they will not find anything on the ground. In other words, if you also find horses that have very good land and this virus is in the soil, likely, the horses, camels or grass-eating grazers will come down with anthrax infection.
How does an anthrax infection occur?
Anthrax is an infection caused by spore-forming bacteria and they are bacteria that are very rare and when we see them, we become very worried because of the dangers they pose to public health. In grazing animals, we don’t have a very good husbandry system for raising animals. Animals are always going to roam around. You rarely would even notice that they are sick until the disease has taken a toll on the animal and within eight hours of showing signs, you are likely going to lose the animal. Most times, in those types of grazers, you rarely don’t pick it, all you see is sudden death. You just wake up and see that you have lost some of the animals. They are bloated with discharges which means an infection that we consider peracute, meaning you are very unlikely to see an animal manifest the sign until the point of slaughter and that is where it portends a lot of danger and concerns for public health, because if it wasn’t detected by the meat inspectors, very likely it will be passed for human consumption.
What are the signs to look out for in animals?
For animals, the signs you actually see, if you are lucky, is that animals that should be going around to graze will just be very reserved – they wouldn’t want to go along grazing – and then you would see them having drooling salivation or nostril discharge. They pant as though they had just had a race and if you test them, they would have very high body temperature.
Those are the signs that, if you are lucky, you will find. These are issues you will see in an organised ruminant farm, not like the traditional practice. More than 80 to 90 per cent of our cattle, sheep and goats are in the hands of traditional production people. This is where the problem lies and no matter the situation, an average farmer allows his animal to die without slaughtering it and they pass to the market for human consumption and that’s where the danger lies.
What is the origin of this disease?
So, the name is again in history. We learnt as microbiology students that the name, anthrax, is a terminology gotten from Egypt. It means charcoal. So, the sign of this infection in humans is the presence of black spots all over the skin. It was the cutaneous form that was prevalent when it was discovered, so, anthrax means charcoal and in Latin, like a charcoal spot.
How does anthrax spread to humans?
So, humans generally are known to contract it from two major sources. The first will be via ingestion; if you don’t cook your meat very well, and here, it is very important to look at culture. You will say that our people cook their meat very well but I come from the North and I have been around for a while and up till recently, I saw someone eating raw liver. I also saw someone in an abattoir when we went for public enlightenment, cutting the larger part of the stomach called the rumen and then just cleaning it up with their knife even without washing it and just eating it raw. That is where the danger lies for human health.
On the other hand, a lot of people say that nutrients would be destroyed after cooking meat very well, and that is where we learnt in history that the infection hit the human population in a part of America called Haiti because they ate these things raw. Our butchers in abattoirs need a re-orientation. I saw a young person eating raw meat. I went closer and he was just smiling; they don’t even understand what you are talking about, so, oral ingestion is the first one that will cause disaster.
The second one is the respiratory form, which is common during the dry season. That is, when there is wind, the environment is dusty, the anthrax spore is still there in the environment and those working in this weather could just inhale and have respiratory form.
Which among the types you have mentioned is the major one?
Now, these are two major ones that we have talked so much about but the most important type is the cutaneous form. In the cutaneous form, you can get to observe and treat. Both the intestinal form through ingestion and the respiratory form will always come in very late. Many of them don’t go to the hospital, hence, you may not know what exactly led to their deaths. But for the cutaneous form, you are likely going to see and it’s very common and it could basically come as a result of the inhalation or contact with the fresh anthrax spore in the blood, in the body discharge because one critical thing with anthrax in the deaths of animals after slaughter is that you are likely going to have leakage of un-coagulated blood from the natural openings of the animal: the nose, eye, mouth, ears, vulva, and anus. The blood will just ooze through those parts, and it (the blood) will not clot. It’s very common for anthrax in animals.
How can butchers get infected with the disease?
In the process of killing animals, butchers may have cuts or broken skin and very likely, they are going to inoculate themselves with these smears of blood or body discharges and infections could also happen. So, if you look at certain groups of people that are at risk, that will be animal health workers like me but also those working in slaughterhouses, abattoirs, slaughter slabs and meat sellers.
In Nigeria and some other developing economies, we operate the hot meat market system, where as soon as an animal is slaughtered, it goes straight to the table and the butchers are just there with freshly processed meat and again, it will go to our mothers who will now do the preparations. Now, those categories of people that I have just mentioned, including our mothers that prepare the beef because it has to be washed before it gets into the cooking process, are at risk of contracting anthrax.
Anthrax has implications for growing economies because if it is not well handled, in terms of decontamination, it could destroy a country’s economy and public health system because it is very easy to culture in any laboratory and within 24 hours, you could have a spore.
What are the early symptoms to look out for in humans?
What we have learnt from our one health initiative, is that it’s basically fever and again, in the case of intestinal, where one gets infected through ingestion, there could be an involvement of the gastro-intestinal tract. For instance, there can be diarrhoea with blood, but what you are likely going to see is cough and shortness of breath and you are also likely going to have a very high body temperature.
Basically, the signs are similar to what you have in cattle, where you have shortness of breath, respiratory involvement, also, gastro-intestinal tract involvement with diarrhoea but in all cases, there is fever. So, the moment you have that, you should report at a clinic, especially in areas where you know that something has happened with animals. The moment you get some of these signs, please report yourself to the doctors and due diligence should be followed.
Is it also a communicable disease which can be transmitted from human to human?
The moment there is contamination as is said, it’s like a three-step kind of infection. The environment is involved, human health is involved but also, animal health care is involved. Humans and animals will also have discharges. If one goes to the toilet and there is an infection and then there is a discharge because the toilet is not too clean, the next user gets contamination and you know the role hygiene plays and then if the spore is ingested, the next person can pick it up and ingest it and here, I must add that the blueprint is hand-washing. There should be a high level of hygiene, particularly when you visit public places. Hygiene should be thorough hand-washing before eating, hand washing after work, hand washing when one gets home before embracing family members and total disinfection of one’s garments in terms of the use of personal protective equipment. These must now be adopted for those in the risk group working with animals or working in the laboratories or the abattoir. They must have a way to keep changing and washing themselves before joining their families.
How is it diagnosed?
When you talk about confirmatory diagnosis it will have to be the laboratories. It involves taking blood or discharges from the nostrils, eyes or anus to the lab. Laboratory testing will include culturing whatever smears that one has which is part of microscopy but basically, they will culture and do the identification of whatever growth they have been able to see. There is an aspect of it both in humans and animals where you do specific detection of antibodies against these infections but the common diagnostic test in both animal health and human health include microscopic examination, culture and the use of advanced technology like the use of the PCR assay.
Those are the three ways of having a confirmatory, definitive diagnosis of the disease. Also, let me stress at this point that an area where it is likely going to likely affect humans is the laboratory. Many of our laboratories haven’t gotten very good protocols when it comes to biosafety and biosecurity because when you deal with this kind of suspicion or samples coming from suspected animals, there has to be some level of bio-safety and security dealing with these issues and that is why it must be stressed because in the lab and not just any lab if you want to do this, you have to culture it and find a way of containing it within the lab if not, it will become a major source of infection for humans.
Is it treatable?
It is treatable even in humans. Once you catch it early, it is treatable with antibiotics and some other medications.
How can it be prevented?
This is one disease that works in such a way that early detection requires early reaction and here, I have always said that for even the animals that picked it up easily, it is important that we go ahead of the infection and then we have gotten three tools; the first one is vaccination. We have very effective vaccines against anthrax in animals in Nigeria. In fact, the National Reference Laboratory has even gotten very good capacity in producing these vaccines just like they have done already but we have also gotten some cost-effective vaccines and it is very affordable. It is affordable but my only concern here for vaccination is that the government will stress procuring the vaccine but they don’t always look at the aspect of delivering the vaccines to the animals and when you do this, it is important that you take note of some budgets. There has to be a budget line for every vaccination for both humans and animals, to be sure that these vaccines are delivered into the body of either the animals or humans. You don’t spend billions of naira producing the vaccine and then they end up expiring because there isn’t an arrangement for syringes or ambulatory vehicles to take the people to the hospital. Remember that animals that stay in the bush are not like humans that you can tell to go to a particular hospital and to take it. You have to visit them right inside the bushes and therefore, a budget will have to be made to drive the administering of vaccines or inoculating these animals so that they can be protected.
How important is surveillance in the management of the disease?
The aspect of surveillance is very important in our lives if we want to stay ahead of highly infectious diseases in both animals and humans. We need to actively make surveillance. Here in the case of anthrax, you need to mount very good surveillance at the abattoir but there is a need to also do constant sampling of animals around the country, then you check if it is the antibody or the real infection that is going on in the heart, to stay ahead of an outbreak. The third aspect is to create public enlightenment because resources have dwindled, and we don’t have the capacity to carry out vaccination. It does not mean that the disease will not meet us while we are asleep. It is likely not going to be a problem with us if we cook our meat very well.
