Pinworm (Enterobius vermicularis)

Pinworm (Enterobius vermicularis). Pinworm is a parasite living in the caecum and it occurs in men. Female individuals are about 1 cm long and 0,4 mm wide. Their rears are transparent and sharpened. Male individuals are several mm long and they can barely be seen with a human eye. The female live for about 4 weeks then they leave the body through the anus. They crawl in the groin skin and dry a minute or so later. The pinworm migration generally takes place in the evening, when people are asleep. Every parasite leaves about 11000 eggs behing while moving. From the majority of eggs invasive larvas are hatched whithin 6 hours. It sometimes happens that the larvas leave their egg shells on the anus skin and come back to large bowel. Generally the invasive eggs get to the same or another host through the mouth or nose. Having left the egg shells, the larvas initially stay in the ileum and grow up in the small bowel.


Malaria (plasmodium vivax)

Malaria (plasmodiosis). Malaria coused by coccidia is the most serious parasite infestation on the world scale, taking into consideration its range and mortality. Malaria is caused by four species of Plasmodium: P. vivax, P. ovale, P. malariae i P. falciarum. They have a complicated life cycle consisting in asexual reproduction in human hepatocytes and erythrocytes, and gamogonic and sporogonic reproduction in gnats from the anopheles group. The incubation period lasts usually 8 – 15 days (28 – 37 in case of P.malariae infestation). The majority of P.falciparum infestations show symptoms a month after infection, however some strains, for instance P. vivax might show symptoms even after a year.

Massive fight against malaria, started by the UNO in 1953, led to its elimination in many countries, nevertheless 40% of the world population live in areas where it spreads easily. It is estimated that there are about 273 million cases of malaria infections all over the world, over a million of which end with death. Only in Africa 800 thousand children under 5 die because of this disease. Different environmental factors like: temperature, amplitude, humidity, access to water, people’s immunity, geneticlly fixed characters of erythrocytes determine the occurance of Anopheles and Plasmodium. In order to reduce the number of deaths caused by malaria it is significant to recognise infestation. The most serious complication of P.falciparum infection is brain malaria. It usually starts with anxiety, sanity disorders and convulsions. The infected usually fall into a coma within a couple of hours or days and 20 – 50 % of them die.

Nowadays, millions of genetically modified gnats are released in selected areas in order to fight this dangerous disease. For a long time, scientists have been working on producing a mosquito that will not be a malaria host or one that will not like the taste of human blood. The research will last for a long time yet but it proves how serious the problem is. Over time a malaria protozoon becomes resistant to drugs. Some medicines can be on the market only for a few years then they lose their efficiency compared with other drugs. The production of new ones takes years and costs millions of dollars. Every year, more people die of malaria than of tuberculosis, AIDS or meningitis altogether. These are 300 mln cases 1 mln of which will probably die.

Malaria protozoons attack liver cells, red blood cells and lead to death if not cured. There are many drugs on the market that effectively treat and prevent the disease but because of insufficient knowlege about their usage they might not be as helpful as they should. On average, one of four children dying Africa dies of malaria. Pregnant women are two or three times more prone to infection. It is also more likely for them die of malaria.

Malaria symptoms:

  • chills
  • increased body temperature – over 40˚C
  • headache
  • muscle pains
  • diarrhoea
  • ample sweats
  • anaemia


Infection sources

Malaria is transmitted by mosquitos and part of the protozoon life cycle takes place inside the insect. The protozoon before reaching its invasive form goes through many transformations inside the gnat. Their speed depends on temperature. The most immune protozoon to low temperature is Plasmodium vivax. During a gnat bite, malaria sporozoites, which are able to grow up only in a human body, get into the human organism along with the insect’s spit. They move with the circulation system to such organs like: the liver, the spleen, the pancreas and the brain capillary vessels. Inside the attacked cells, numerous divisions take place then the protozoons go to the blood cells, inside which they go through another transformations. When the infected person is bitten, the gnat will take in sporozoites along with the blood and the final development will take place in the insect’s body. The cycle will repeat when the gnat bites another person.


Complications might occur in the early and late stages of the disease

Early:

  • severe anaemia
  • hypoglycemia
  • haemorrhagic condition
  • kidney failure
  • spleen rhexis
  • shock
  • brain malaria
  • respiratory failure


Late:

  • nephrotic syndrome
  • hyperactive malaria syndrome with hypersplenism
  • pericardial fibrosis
  • Burkitt’s lymphoma


Leishmaniasis (leishmaniosis cutis)

Leishmaniasis (leishmaniosis cutis). It is a disease caused by chilomastix and transmitted by mosquitoes from the phlebotomus group. It may have two basic forms. One affects the skin and occurs inSouth America (“espundia”. The other one affects the intestines and is called “calazar’. The range of this disease covers: South Europe, Asia (mostly Pakistan and India), South America. The skin form is characterized by painless ulceration and upturned edges of the bite spots, which often heal themselves within a year. Nevertheless every noticeble skin change should be examined by a doctor and cured. The intestine form of the disease has the following symptoms: an enlarged spleen (sometimes also liver), black skin pigmentation, , vomiting and fever.

In Europe skin leishmaniasis is the most popular in Portugal, Spain, south France, Italy, Bulgaria, Greece, Crete and the territory of former Yugoslavia.
Chilomastix settles on the skin, in the cells of blood vessel walls centered around the infected area. They also occur in the absorbent gland, the mononuclear cells and in the immune system cells. They settle on animals, mostly on dogs, cats and certain rodents. They are transmitted from the source of infection to a human by mosquitoes. Next the parasites reproduce inside the cells or in the intercellular epithelium spaces.


There are 3 types of skin leichmaniasis

  • cutaneous leishmaniasis
    • wet necrosis-acute state (few weeks)
    • dry necrosis -chronic state (from half to 1,5 year)
  • disseminated leishmaniasis
  • mucocutaneous leishmaniasis


Cutaneous leishmaniasis is characterized by skin lesions limited only to areas vulnerable to bites: the face, the neck, the prearms, the lower parts of legs and the feet. This leishmaniasis is divided into Old World leishmaniasis (oriental) and a New World one. The incubation period lasts from several days to 6 months. Primary changes can be noticed around the bite spots. The lesions are about 2 – 10 mm wide. Then nodules appear that subsequently undergo necrosis and then ulceration. Inflammatory states appear near the ulceration. It heals after 2 -12 months but it leaves scars. Secondary bacterial infections also occur.

In disseminated leishmaniasis the first lesions are nodules, which spread. After closing the old nodules, new disseminated lesions appear on the face and limbs. This lesions might remain for years.

Mucocutaneous leishmaniasis occurs mostly in Brazil. In the infected mosquito bite spot a nidus appears, similar to that in cutaneous leishmaniasis. Promastigotes, transmitted by the insect spit form into a human body, they move into monocites and macrophages of the subcutaneous tissue and transform into another shapes. Secondary niduses develope in the mucosa areas. Skin lesions cover the mucosas of the anus, the vagina (women), the forskin (men). The incubation period lasts from 10 to 25 days, sometimes even a year!

The basic precautions that can be taken to prevent this disease are killing mosquitos, detecting and eliminating infection sources and curing infected people.


Lamblia (Giardia duodenalis)

Lamblia (Giardia duodenalis).

Lamblia (Giardia duodenalis) is a protozoom living mostly in the bowel (generally in the duodenum and the bile ducts).

Lamblia mostly inhabits the alimentary canal, the duodenum, the bile ducts, 1 cm of length contains 1000 lambia members. Lamblias sticks to the bowel. Its presence causes digestion problems, allergies, nutrient deficiency. Every tenth person infected with lamblia feels seek, the rest do not show any symptoms. The detection of lambia is a difficult task.

A single treatment is not sufficient, lamblia cysts can survive and another invasive forms can be created.

Lamblia occurs mostly in the alimentary canal.

Lamblia cysts spread through water systems or insects. Sometimes drinking water containing lamblia cysts can even start an epidemy.

Lamblia can produce toxins.

Lamblia existing in the bile ducts can threaten the liver or duodenum but it can also irritate the pancreas and infect it as a result.

Germs and parasites , which are inside of us, eat food that we consume and excrete as well, which is very toxic for our organism. It is very difficult to get rid of lamblia or staphylococcus so hygiene and your own body observation is essential.


Toxins excreted by this parasites cause:

  • hemoglobin level decrease
  • constipation
  • unfresh breath
  • oxidation disorders
  • toxic poisoning of the organism


Lamblia induces gall bladder stones, duodenum and pancrease problems.

Lamblia worms prefer sugar, refined products as they strengthen them the most. If somebody likes sweets then he is more prone to invasive infections caused by this protozoon.


Lamblia presence examination:

  • examining faeces is not effective enough therefore cell examinations are recommended

Immunoenzymatic tests are 89 – 95% accurate. They consist in examining faeces in search for specific enzymes produced by tropozoid.

Wild animals and pets are lamblia hosts.

Lambliasis is a parasite disease caused by a lamblia infection of the small bowel and liver. Human infections not always show clinical symptoms. Most people are healthy hosts.


Lambliosis symptoms:

  • pain resembling ulcers, liver colic or gall stones attack
  • diarrhoea or constipation
  • opulent strongly stinking stools
  • subfebrile body temperature
  • allergic rush
  • anaemia
  • bowel infection
  • liver infection
  • stomach rumble
  • heartburn


The bowel infection can cause a totally exhausting feeling. X-rays detect duodenal cup and gall bladder function disorders. Rarely, pain in the right part of the hip can occur. Lambliosis liver infection can be characterized by an inflammation of the gall bladder, the bile duct, the small bowel and colon or even cirrhosis of the liver. A gall bladder inflammation caused by lamblia is accompanied by strong pain like an acute colic in the liver or chronic pains increasing while eating. It can sometimes lead to vomiting, salivatin, diarrhoea, jaundice and high fever. A gall bladder inflammation caused by lamblia, without a secondary infection, can imitate bile stones. Sometimes a faster heart beat might suggest interference in the heart-vascular system. Symptoms such as nervous system disorders shown in tiredness, irritation, apathy, tearfulness, headache, temperature disturbances, kids’ slow growth, metabolism disorders, loss of weight, trembling fingers and increased sweating might be caused by toxins.


Infection sources

Parasites can get into our body with food and water or even during sexual anal intercourses. Persons with a weak immunity are more vulnerable to infections. They start a disease leading to absorption disorders of fat, carbohydrates, vitamin B12 and folic acid in the small intestine which leads to malnutrition and anaemia. In the bowels, lamblia creates oval cysts 10-14 cm long. Bad sanitary conditions stimulate lamblia extension.


Hydatid tapeworm (Echinococcus granulosus)

Hydatid tapeworm (Echinococcus granulosus). A clinical view of echinococcosis has the features of a cancer, which may lead to death in ten years.



Echinococcosis symptomssymptoms and consequences depend on larvas location, their size and the amount of blisters.

1. Liver echinococcosis symptoms:

  • blood vessels and bile ducts pressure can appear after several or dozen or so years after infection


2. Pressure on the blood vessels:

  • secondary hypertension


3. Pressure on the bile ducts leads to:

  • jaundice
  • bile duct inflammation


4. Lung echinococcosis in its initial state can be detected accidentally, during routine lungs x-rays. Big and numerous blisters, which lead to changes as a result of pressure on the lung tissue. The symptoms are:

  • dysponoea
  • cough
  • blood cough
  • shortening of breath
  • chest pains


5. If larvas are in the spleen the organ is enlarged and secondary infections occur.


6. When they are in the kidneys, the symptoms are:

  • organ enlargement
  • urinate problems
  • kidney area pains
  • blood and proteins in the urine


7. Larvas located in the bones may cause to the bone tissue to collapse


8. The earliest and the most acute clinical symptoms are in case of blisters located in the brain or eye ball suggesting tumor.

Larvas in such important organs, can lead to the death of the host, which happens when the diagnosis of echinococcosis is not always on time and the necessary treatment is not conducted.

Pharmacological treatment not always brings the result we expect. Moreover, it can’t be always surgically removed (taking its size into concideration, no surgical access or proximity to other tissues and the danger of injury), an accidental blister burst during an operation can lead to secondary echinococcosis. The blister burst and secondary echinococcosis can occur independently, when the blister grows so big that the organs or tissues in which the larva has embeded do not allow its further growth or as a result of mechanical injury. The secondary echinococcosis is a spreading of protoscolexes in the host organism, which can lead to an anaphylactic stroke and that generally causes death.


How the infection happens

Echinococcosis is caused by hydatid tapeworm larvas (Echinococcus granulosus lub Echinococcus multilocularis). The main sources are: infected dogs, cats, foxes and wolves. The infected animals excrete larva eggs and contaminate the environment. People can become infected by hydatid tapeworm by direct contact with an infected pet, it refers especially to kids who while playing with the pets take the tapeworm eggs into their mouth. An indirect source of infection can be dirty fruit and vegetables and other types of food prepared or kept in non-sanitary conditions. Rodens and small mammals, raw meat and the bowels of other animals can be the source of infection for pets, by eating the food with agressive forms of parasite. They become infected and excrete eggs in their environment. The infection of humans not always results in a disease, it depends on an individual immune system, and not every larva of a tapeworm will find suitable conditions for development in a human body. Additionally, only a few animals are infected with a tapeworm, so the echinococcosis is rarely found among people.

However you should not underestimate the disease as it is extremely dangerous. When it occurs, without the necessary treatment, it can lead to very acute, chronic and often irreversible complications and even to death.

Epidemiologists appeal not to eat forest berries, wild strawberries or raspberries without washing as these plants are often a “hotel” for a hydatid tapeworm. It causes echinococcossi which destroys our organism like a cancer. Specialists from The Military Hygiene Institute tested several jars of forest blackberries, every second jar contained hydatid tapeworm eggs.


Hydatid tapeworm development cycle

Hydatid is a very aggressive parasite. Its larvas after getting into an organism embed in the most important parts of the human body: the liver (over 90% cases), lungs and brain. Around the larva, a cyst is created which grows bigger and presses on the neighbouring tissues. The final hosts of the hytadis are carnivorous animals, mostly wild ones in which the parasite closes its development cycle. Echinococcisis does not have to show any symptoms for 10-15 years. The parasite reproduces itself and spreads on other organs creating metastasis like cancer. The burst of a cyst can be dangerous for life.


Human whipworm (Trichuris trichiura)

Human whipworm (Trichuris trichiura). A whipworm is 3 – 5cm long and has a frontal thread-like body. It penetrates the large bowel, especially in the caecum and around the anus. The female lay 2000 eggs a day which, similar to eelworm, develop in soil into an invasive form within a few weeks. It does not penetrate the liver or lungs but it settles in the large bowel. The parasite eggs appear in faeces in 3 months after infection. Whipworms live several years. Their infections are quite common, especially in hot and tropical countries. In Vietnam, 80% of the population is infected however these are not serious cases.


Human whipworm symptoms

  • bacterial infections and inflammatory states as a consequence of large bowel epithelium damage
  • itchy rushes
  • stomachache
  • nausea
  • diarrhoea
  • constipation
  • restlessness
  • insomnia
  • weakness
  • anaemia, eosinophilia


Human whipworm development cycle

Female individuals lay about 2000 eggs. The eggs together with faeces get into water and soil where they grow up in a couple of weeks. An infection takes place when the contaminated water or food are consumed. The eggs in the host’s alimentary system (the small bowel) release larvas, which become mature within a month and then move to the large bowel.


Human louse (Pediculus humanus)

Human louse (Pediculus humanus). Men are the main hosts of the species. It is divided into two subspecies: a body louse (Pediculus humanus corporis) and a head louse (Pediculus humanus capitis). The body louse’s eggs stick to human clothes mostly to underwear seams and clothes of natural textile. They seldom stick to hairy part of the chest or the armpit. The head flea embeds on the head, neck or back hair.

Lice are white-gray. Female individuals grow 2 – 4,7 mm long and males are smaller. The front of its head is narrow and its abdomen is oval without side spicules. They find appropriate conditions to grow in a humidity environment and temperature 28-31ºC. Their lifetime depends on the humidity level, temperature and nutritional status. Lice live only on men. The smell of human sweat attracts lice. The sweat composition and especially the lactic acid it contains determine the choice of the host. The head lice live mainly in the hair near ears or on the back of the head whereas the body lice live on theese parts of the body that are covered with clothes. Lice spread by a direct contact or an indirect one that is by the use everyday items like: combs and brushes or sleeping in the same bed. Children attending primary school are most likely to have the head lice because of weak hygene. The body lice occur mostly in regions with cold or moderate climate where people wear worm clothes for the most time of the year.
The bite spot is characterized by itchy inflammatory clods. Scratching them might cause secondary bacterial infection. Pus flows out of the ijuries and leaves scabs. Lymph nodes around the spot grow bigger and hurt when they are touched. The duration of the disease depends on their location in the hair. Their eggs stick to the hair at the bottom and move away from the skin as the hair grows. White eggs in the hair prove pediculosis.

Body pediculosis occurs mostly among soldiers, the homeless or prisoners. When lice are sucking blood their salivary glands put saliva into the body which makes the skin red and itchy. Scratching causes secondary bacterial infection. Some small scars might occur. The disease that is caused body louse activity is called “vagabond disease”. The disease might be recognized by a different colour of the sking and itching feeling.

Prevention

  • head examination among children
  • keep your clothes and body clean
  • keep public places like: hostels, hospitals, dormitories and hair dresser’s clean.

Human flea (Pulex irritans)

Human flea (Pulex irritans). Pulex irritans is a cosmopolitan species from the aphaniptera group occurring widely in the world. It attacks both people and animals (dogs, cats, pigs, foxes, hens, chickens, cows). It can grow 2 – 4 mm long. Its head is round. The development of this species lasts for 4 to 5 weeks in summer and 6 to 7 weeks in winter but in severe humid and cold conditions this period might last even a year.

The larvas and mature individuals are very demanding when it comes to temperature and humidity (humidity-70-90% and temp.-18-27 ºC). Fertilization might take place even after the female laid eggs. For 3 to 10 days after sucking blood from the host, the females lay eggs. The best place in the flat are cracks in the floor,carpets, old mattresses, the places where dogs or cats sleep and in public places like: cinemas, discos and gyms. It feeds with blood, sucking it directly from vessels, in short periods, several times a day.

A flea bite is not dangerous to most people but some individuals might suffer from skin lesions. The bite spot can be blue, swollen and covered with pimples. Scratching causes an inflammatory state. The lesion lasts for about 3 days. Frequent flea bites cause skin damages.


Hookworm (Ancylostoma duodenale)

Hookworm (Ancylostoma duodenale). Mature individuals are shorter than 2 cm and slightly pink. They live in the duodenum and causes a disease called ancylostomiasis. Ancylostomiasis is an invasive disease caused by nematodes of ancylostoma type. The main role in human pathogenesis is played by 2 species: hookworm and American hookworm. Ancylostomiasis is the most widespread parasite disease in a hot and worm climate e.i. Africa, South America, Asia, rarely in Europe. Larvas are hatched from eggs laid in the ground and can live there for a couple of weeks. In appropriate humidity they can get on the surface and attach to plants, stones, minning constructions, where they gather in large amounts. They are easily stimulated by human touch and are prone to chemical and thermal impulses so they can get into a human body through the skin and into the blood vessels. After passing the right side of the heart, larvas get into the bronchic cells, windpipe and throat. Swallowed larvas get into the small bowel where they grow up. Hookworms can live in a human organism for about 8 years. The penetration of invasive larvas through the skin causes itching and skin inflammations and its intensity depends on the larvas quantity and sensitivity of the man. A mature nematode sucks the blood while embedding in the mucosa. After its separation the bleeding doesn’t stop as a result of decrease in coagulability. The loss of blood can lead to serious anaemia. It can be accompanied by many symptoms regarding the alimentary and nervous system and physical deficiency in case of children.


Flukes (Paragonimus westermani)

Flukes (Paragonimus westermani). Paragonimus westermani is a fluke occurring also in humans. It causes the disease called paragonimiasis.


Symptoms

The fluke parasitizes in the lung tissue of a human causing cysts to be produced vulnerable to bacterial infections. During larvas’ migration to the lungs the following symptoms appear: fever, chest pains, cough and haemoptysis.


Epidemiology

The infection of the parasite and the related species(P. philippinensis, P. heterotremus, P. africanus, P. uterobilateralis, P. peruvianus, P. mexicanus)  is noticed in China, Taiwan, Laos, Korea, Japan, Thailand, Philippines, Malaysia, Indonesia and Cejlon.


Diagnosis

Diagnosis is based on detecting the presence of fluke eggs in the spit or stool. The typical size of a fluke egg is 85 – 53 µm (range 68-118 to 39-67 µm). The eggs are yellow and brown with a thin coating, often asymmetric with one end flattened. On the wider end there is en operculum and the opposite end is narrowed. Eggs are released unconverted.


Lifecycle

Humans are infected by eating raw fish or shellfish containing metacercariae of the parasite.