I've worked for Rentokil Initial for quite a long time now, and I've learned all sorts of things about cockroaches that - quite possibly - I might rather not have known.
I know that if you see one, big cockroach on the bathroom wall you (probably!) don't have too much to worry about, but that if you see lots of small ones when you turn on the kitchen light, you're in trouble.
What I haven't learned yet is how not to freak out whenever I see a cockroach, big or small. Screaming, running away and jumping on a chair all seem like valid responses to the situation. They really are my absolute worst - provoking a visceral reaction like no other pest. In September we posted a blog which looked at the fear of cockroaches and whether we are predisposed to be scared of them, but I started to wonder whether our fear of them may be related to just how many diseases they can carry.
Because that's another thing I've learned working for Rentokil: that cockroaches can make you very, very sick. This is primarily due to the fact that cockroaches are synonymous with dirt and filth, and can often be found inhabiting sewers and other unhygienic areas. Added to which their diet consists of pretty much anything, including animal faeces and other cockroaches. All of the above factors mean that cockroaches can spread a range of really unpleasant and harmful diseases. In short, answering the question "will cockroaches in my home make me sick?" with a resounding yes.
How do cockroaches spread disease?
The most common way of contracting a disease carried by cockroaches is by eating or drinking anything a cockroach has contaminated directly, or by eating or drinking something that has been made using contaminated cooking utensils, cutlery or crockery, or by eating or drinking something that has touched a contaminated surface. Contamination can occur from infectious particles the cockroach has picked up on the outside of its body (mechanical transmission), or from its saliva or faeces.
Cockroaches spread the following diseasesIn case you don't want to take my word for it, in a paper on sanitation the World Health Organisation says cockroaches are "proven or suspected carriers of the organisms causing:
- typhoid fever
- viral diseases such as poliomyelitis (polio).
I'll confess to being surprised by the addition of leprosy to this list, having never associated this particular disease with insects, but along with other insects, cockroaches are suspected of being carriers of the bacillus Mycobacterium leprae which causes leprosy. Cockroaches are believed to spread the disease through their faeces.
Whilst Mycobacterium leprae is not highly infectious, if left untreated, it can cause permanent damage to the skin, nerves, eyes and skin which can lead to disfigurement and deformities. Leprosy has an incubation period of around five years but symptoms may take as long as 20 years to appear. Since the 1980's the preferred treatment method has been multidrug therapy.
The plague was another disease that I wasn't expecting to see on this list. It's thought that the bubonic plague was responsible for around 50 million deaths in the fourteenth century. According to the WHO, from 2010 to 2015 there were 3248 plague cases reported worldwide, including 584 deaths. Although plague is usually regarded as a rodent-borne disease (it's actually a flea-borne disease, but rodents transport the fleas which transport the plague) cockroaches are also suspected of spreading the Yersinia pestis bacterium which causes plague. Common symptoms of plague include, but are not limited to:
- Swollen and painful lymph nodes
- Muscle cramps
- High fever
People infected by the plague need to receive urgent treatment and should be given antibiotics 24 hours after infection to avoid severe consequences.
Dysentery, cholera and typhoid
And please don't think that just because I jumped straight to plague and leprosy, that the other diseases on this list above aren't serious. Dysentery, cholera and typhoid fever are definitely not illnesses you'd like to contract, with the Mayo clinic describing the symptoms of typhoid fever as including a high fever, headache, abdominal pain, and either constipation or diarrhoea; the symptoms of cholera as including diarrhoea, nausea, vomiting and dehydration; and the symptoms of dysentery as including frequent near-liquid diarrhea flecked with blood, mucus, or pus.
Cockroaches are also known to transmit the Salmonella bacterium which can cause salmonellosis, a disease with symptoms similar to food poisoning. Cockroaches accumulate the bacteria by crawling in filth and feeding on contaminated food materials. The Salmonella remains in their digestive system for a month or more and is deposited onto food and surfaces through their vomit and faeces. Human symptoms, which typically show 12 to 72 hours after infection, include diarrhoea, fever, and vomiting. None of those sound like a fun way to spend a weekend.
And as if all of the horrible illnesses above aren't enough, the WHOÂ goes on to say that "In addition, (cockroaches) carry the eggs of parasitic worms and may cause allergic reactions, including dermatitis, itching, swelling of the eyelids and more serious respiratory conditions".
Cockroach allergy was first reported in 1943 and was discovered when patients developed a rash after cockroaches crawled on their skin. Cockroaches can also trigger respiratory conditions such as asthma because certain proteins in their bodies are an allergen for some people. Tiny airborne particles from cockroaches bodies are inhaled and can trigger an asthma attack people sensitive to this particular allergen. It is estimated by the WHO that 300 million people worldwide suffer from asthma and that around 23-60% of people with asthma are sensitive to cockroach allergens.
So I think it's safe to say that having cockroaches in your house will indeed make you sick, possibly even very sick. So if you have a cockroach problem at home, visit the Rentokil website for more information on how to keep your family safe from the health risks posed by a cockroach infestation.