Deadly Disease: Mycobacterium Marinum

Mycobacterium marinum (also known as freshwater infection, saltwater infection, marine bacteria and water-borne bacteria) is a bacterium that is able to infect humans and cause significant harm. It is now thought that all fish species are susceptible to mycobacterium marinum, this means that people working or handling fish are at the greatest risk. The bacterium can only get into the body if there is a cut at the skin, if someone handles fish with cuts on their hands this gives the bacterium the window of opportunity it needs.

The people at the highest risk of contracting such a pathogen are as follows:

1) Fishermen and people working saltwater fish

2) Marine biologists

3) Divers who stay under water for extended periods of time

4) People who swim in the sea on a regular basis

5) People who have an aquarium at home

6) People who clean aquariums and other water bodies where fish inhabit

7) People who have a suppressed immune system

A common sign that someone has contracted mycobacterium marinum is a nodule (a prominent bump) on the hands, fingers, wrists, toes, feet or ankles. The nodules will get larger as time goes on forming ulcers on the skin which will cause agonising pain. The temperature of 37 degrees Celsius hinders the growth and population expansion of mycobacterium marinum significantly; this means the pathogen can only inhabit the cooler regions of the body such as the hands and feet. To combat the infection the body produces white blood cells which attempt to engulf (ingest) the invading bacteria, however they are able to withstand the attack and thus kill the white blood cells in the process.

Mycobacterium marinum

The bacteria will then slowly, but surely creep their way to the bone, if treatment does not take place quickly amputation maybe the only way to get rid of such of pathogen. In some cases the hands or feet are not amputated, instead the infected tissue and bone are cut out, however this leaves the person with permanent neurological damage for life). The bacterium is highly resistant to microbial drugs so powerful antibiotics must be taken in order to kill it swiftly and effectively. The antibiotics should be taken for 10 weeks possibly longer depending on how long it took to diagnose the disease.

The antibiotics that could be taken include:

1) Clarithromycin

2) Fluoroquinolones

3) Tetracyclines

4) Trimethoprim-sulfamethoxazole

Precautions need to be taken in order to insure that people do not contract mycobacterium marinum, these include:

1) Avoid getting in contact with fresh or saltwater if there are cuts on the hands.

2) Do not handle fish if you skin scratches.

3) When cleaning an aquarium make sure that you wear gloves if there are any cuts.

4) Make sure that swimming pools have an adequate amount of chlorine.

Although reports of this disease are rare across the planet, it is nonetheless a very serious disease if you contract it. It is easy to prevent this disease by taking a few simple precautions (as mentioned above).

Thank you for reading.


Deadly Diseases: Leishmaniasis

Leishmaniasis is a disease caused by the parasite Leishmania (which happens to be a protozoon). The Leishmania parasite lives naturally in the gut or the digestive track of a female sand fly which happens to be one third the size of your average mosquito. When a female sand fly feeds on a host (in this case a human) it will inject the parasite into the bloodstream, there the parasite multiplies rapidly and spreads like wildfire. When an unaffected female sand fly (a sand fly that does not carry the parasite) bites an affected human host (a person who has the parasite) the Leishmania parasite travels back into the digestive track of the ‘unaffected’ sand fly. Once this has occurred the life cycle is complete.

To combat the infection the body send in your first line of defence neutrophils (a type of white blood cell) more commonly known as phagocytes. Phagocytes get their name because they perform ‘phagocytosis’ where these white blood cells engulf or ingest pathogens (disease causing organisms). However the Leishmania parasite is able fight back and will hijack the nucleus of the white blood cell which most of the time kills it. After killing the white blood cell the parasite will feed on it. The Leishmania parasite will feed on red blood cells, platelets, nutrients in the blood, organ cells and particularly white blood cells. Many people who suffer from Leishmaniasis will often have a ‘comprised immune system’.

When someone contracts Leishmaniasis the parasite can live undetected in the body for several years before springing into action when the immune system becomes weakened. However, usually the symptoms of Leishmaniasis appear with couple of weeks to a couple of months after being bitten by the sand fly.

The most common signs of contracting Leishmaniasis are the following:

1) Low white blood cell count.

2) Enlargement of vital and non-vital organs such as the liver and the spleen.

3) Rapid weight loss in a short amount of time.

4) A terrible fever where the body can reach up to 40 degrees Celsius.

5) The skin may also turn slightly darker in colour hence the name “Kala-zar” which translates into ‘black fever’ or ‘black sickness’.

There are 2 main types of Leishmaniasis which are ‘Cutaneous Leishmaniasis’ (being the most common) and ‘Visceral Leishmaniasis’. A clear sign if someone has contracted ‘Cutaneous Leishmaniasis is lesions on the skin. People can have many lesions to very few, the lesions are yellowish in colour and often a deep yellow liquid which is believed to smell as bad as rotten flesh will ooze out of the lesions persistently. These lesions will form permanent scars on the skin. If the disease remains untreated it could spread to the face and neck causing suffocation thus killing the patient. However if the disease reaches to the chest area it can cause paralysis to the lungs and even cause myocardial infarction (a heart attack).

‘Visceral Leishmaniasis’ is where the Leishmania parasite attacks and invades the tissues of important organs especially the bone morrow, the liver and more commonly the spleen. In many cases the spleen enlarges up to 5 times its original size (this is known as splenomegaly). The spleen is classified as a non-vital organ and is located in the ‘upper left quadrat’ of the human body.

The functions of the spleen are:

1) Playing a part in the immune system by filtering the blood to remove and destroy any foreign object found in the blood stream.

2) Aid the production of certain types of red and white blood cells.

3) Hold an emergency supply of blood in the event of sudden blood loss.

If the size of the spleen increases to such a high extent then it will rupture thus killing the patient in a very short space of time. There are over 20 different species of the Leishmania parasite that can infect humans as well as other animals particularly mammals and birds.

Facts about Leishmaniasis include the following:

1) Leishmaniasis affects people in around 88 different countries.

2) A staggering 12 million people die each year because of the disease and an additional 2 million people contract the disease of which 1.5 million have ‘Cutaneous Leishmaniasis’ and 0.5 million have ‘Visceral Leishmaniasis’.

3) Interestingly people who have been cured of ‘Cutaneous Leishmaniasis’ can still develop lesions on the skin years after parasite has been killed. Such infections are very rare and are known as ‘Mucocutaneous Leishmaniasis’.

Leishmaniasis can be prevented by getting an insect repellent and sleeping under a mosquito net which is covered with insecticides such as deltamethrin. Also people should avoid travelling during dusk in affected areas as this is when the sand flies are most active. People most always wear protective clothing such as long sleeves and trousers.

I hope you enjoyed reading this and please feel free to comment below.