Paper Work On Human Protozoan And Helminthes Infections

MADONNA UNIVERSITY, ELELE CAMPUS

DEPARTMENT OF OPTOMETRY

COURSE TITLE: GENERAL PATHOLOGY

TOPIC: HUMAN PROTOZOAN AND HELMINTHES INFECTIONS

LECTURER: PROF DR. ######

PROTOZOAN INFECTIONS

WHAT IS A PROTOZOAN?

Protozoa are one of the three main classes of parasites that cause diseases in humans. They are single-celled organism, and can only be seen under a microscope. When they invade a human, they are able to multiply easily, which causes them to be at a great advantage and put humans at a disadvantage. This helps them survive in the human body and causes a serious infection even with the arrival of a single protozoan.

Infections caused by protozoa are contagious. Those protozoans that have inhabited the human intestine can be transmitted from one human to another via the fecal-oral route, such as through sharing food the infected person has touched and through direct person to person contact. Protozoa living in the blood or tissue can be transmitted through a third source such as mosquitoes. Infections are easily transmitted and persons carrying this parasite should avoid interactions with others, especially those with compromised and weakened immune system.

There are four main groups of protozoa that cause infections in humans. They have been grouped according to how they move: the sarcodina (ameba), mastigophora (flagellates), cilliophora (ciliates) and sporozoa.

PROTOZOAN DISEASES OF HUMAN BEINGS

1) AMOEBIASIS. 

This disease is caused by the sarcodina group of protozoa. They secrete enzymes that are then absorbed by the tissue of the host. This disease is transmitted through contact with infected feces. Food and water contaminated by feces is the common route of transmission, however, oral contact with fecal matter can also cause infection. Sometimes, there are no visible symptoms but the common ones include loose stools with varying amounts of blood and an inflamed colon.

SIGNS AND SYMPTOMS. Some signs and symptoms of this disease may include;

•  Visible blood in stool
• Abdominal pain and discomfort
• Inflamed colon
• Restlessness.

TREATMENT. The following drugs can be used to treat this disease;

•  Mebendazole
•  Albenzdazole.

2) AFRICAN SLEEPING SICKNESS.

This disease also called trypanosomiasis is caused by a protozoa, which are carried by the tsetse fly and are transmitted to human tsetse fly bite. This disease is fairly damaging to the human body and can cause serious illness. Symptoms of this disease include; confusion, seizures, insomnia, personality changes, weight loss, slurred speech and trouble talking and walking.

SIGNS AND SYMPTOMS. This disease can manifest as certain signs and symptoms which might include;

•  Insomnia
• Patient finds it difficult to speak or walk well
• Mood swings
• Confusion and sometimes, forgetfulness.

3) LEISHMANIASIS.

This disease is caused by the leishmania parasite. These parasites are found mainly in southern Europe, the tropic and subtropics. The most common form of this disease being spread is through the bite of a sand fly, which carries the parasite. External leishmaniasis affects the inner organs such as spleen and liver. Those parasites that affects the skin cause sores, which will enlarge and become deeper as the disease progresses without treatment. Internal infection will cause weight loss, organ enlargement, fever and extremely high or low blood levels.

SIGNS AND SYMPTOMS. Possible signs and symptoms of this disease may include;

•  Weight loss
• Low blood level
• Sometimes, blood increases in level too
• Weakness, coupled with high fever.

4) TOXOPLASMOSIS.

Toxoplasmosis is caused by one of the most common parasites in the world, according to the Mayo Clinic. Many of the people infected by this disease do not have any symptoms. However, for those who have weak immune systems such as infants and people suffering from chronic illness, this parasite can cause serious illness. Infants who are born to mothers who carry the infection can experience complications at birth. Other symptoms include body aches, fatigue, fever, sore throat and swollen lymph nodes. Symptoms are very similar to flu like symptoms and this disease can sometimes be mistaken for the flu.

SIGNS AND SYMPTOMS. This disease may show itself in some ways like;

• Weakness or fatigue
• Headaches
• High fever which may lead to nausic feelings
• Inflammation of the lymph none.

5) MALARIA.

Malaria is a very common disease in some countries and is spread through mosquito bite of mosquitoes that have been infected by one of the many different malaria-causing parasites. Some malaria symptoms may include headache, chills, tremor, aches and shaking. The female anophelex mosquito is the vector which carries the parasite responsible for this disease.

SIGNS AND SYMPTOMS. Malaria can manifest in the following symptoms or signs;

• Fever
• Chills
• Headache
• Body ache and weakness
• Vomiting
• Nausea

TREATMENT. Primarily, antimalarial drugs coupled with some antibiotics are used in treating malaria.

6) TRICHOMONIASIS.

This disease is caused by protozoan parasite, Trichomonas vaginalis. This disease is mostly transmitted sexually. It is a dangerous parasite as it can also help along HIV transmission. The symptoms of this disease differ from gender to gender. In woman, vaginitis may occur which will white discharge. Men may experience a burning while urinating. This disease is treatable with an antibiotic such as metronidazole.

SIGNS AND SYMPTOMS. Some of which are;

• Swelling of the genitals
• Smelly discharge
• Discomfort or painful experience during sexual activities.

7) BABESIOSIS.

This disease is caused by Babesia parasite that is transmitted through ticks. It can also be transmitted through blood transfusion of donors who carry the Babesia parasite. Individuals infected with the Babesia parasite may not be presented with any symptoms. However, common signs and symptoms include, nausea, body aches, fatigue, fever, chills, weight loss, and decreased appetite. For those who are already suffering from health problems and those who have compromised immune system, this disease can be life threatening and cause serious health problems.

SIGNS AND SYMPTOMS. This disease presents itself as;

• Body weakness and aches
• Severe fever
• Cold and chills
• Vomiting
• Headache

8) GIARDIASIS.

This disease is also transmitted through oral contact of feces as the parasite is found in fecal matter. If hands are not properly washed after using bathroom or changing diapers, it is easy to come into contact with this parasite. Drinking water which have been contaminated by this parasite or even ingesting contaminated swimming water can cause giardiasis. Some symptom may include; mucusy stools, diarrhea, nausea, abdominal pain and stomach upset.

SIGNS AND SYMPTOMS. This disease manifests itself in one of the following signs and symptoms;

• Abdominal pain
• Restlessness
• Stomach pain or upset
• Blood or mucus is present in stool
• Body pain and weakness.

9) ASCARIASIS.

This is caused by microbial activities of a worm called ascarid. This worm lives in the small intestine of the human. Adult female worm can grow over 12inches in length, while adult males are much smaller. The worm larvae present in the bowel attaches itself to the bowel walls. It then migrates into the lungs, and finally into the small intestines and mature in adult worm and remain there to feed. Some symptoms of ascariasis may include; fever, wheezing, coughing, abdominal discomfort, malabsorption, intestinal blockage, vomiting, and restlessness.

SIGNS AND SYMPTOMS.

• Breathing difficulty
• Dyspnea
• Nausea
• Terrible or sometimes mild coughing
• Difficulty in passing feces
• Weakness and restlessness

TREATMENT.

• Albenzdazole
• Menbendazole.

10) NEOSPORIOSIS

This is caused by the Neospora caninum protozoan parasites. Dogs are a definite host. This disease in animals is characterized by encephalitis, abortion and other conditions that clinically and pathologically resemble toxoplasmosis. The significance of human exposure to and possible infection with this parasite is unknown and warrants further study. There are no reports of human infection with the protozoal parasites, but it is possible that the cases of neosporosis have been misdiagnosed as toxoplasmosis. Humans infected with T- gondii are usually asymptomatic or suffer flu-like illness. Women who are first infected during pregnancy may miscarry or give birth to infants with hydrocephalus.

SIGNS AND SYMPTOMS.

• Weakness
• Severe abdominal discomfort
• Body ache
• Nausea

11) NAEGLERIASIS.

This is also known as primary amoebic meningeoncephalitis (PAM). This is an infection of the brain by free living protest Naegleria fowleri, also known as the (brain-eating amoeba.). This parasite is usually found in warm bodies of fresh water such as ponds, lakes, rivers and hot springs. It is also found in soil, poorly maintained municipal water supplies, hot water heaters, near warm water discharge of industrial plants. There is no evidence of it in living salt water. It always results in death. Note that the onset of symptoms can start from one to seven days after exposure. Initial symptoms include changes in taste and smell, headache, fever, nausea, vomiting, and a stiff neck. Treatment has often been combination of therapy with multiple other antibiotics in addition to amphotericin such as fluconazole.

SIGNS AND SYMPTOMS.

• Fever
• Chills
• Body ache
• Breathing difficulty
• Body stiffness, especially the neck region

12) ACANTHAMOEBA KERATITIS.

This is a rare disease in which amoeba invade the cornea of the eye. It may result in permanent visual impairment or blindness. Personal hygene which includes; washing of hands before handling contact lenses are adviced in order to prevent this disease. Also, one is advised to rub and rinse the surface of the contact lens before storing. Polyhexamethylene biguanide, can be used to treat this disease.

SIGNS AND SYMPTOMS.

• Redness of the eye
• Itching
• Watery discharge from the eye
• Visiual impairment

13) AMOEBIC DYSENTRY.

This is a type of bloody diarrhea caused by the amoeba entamoeba histolytica. This disease is transmitted through contaminated food and water. Amoeba spreads by forming infectine cysts which can be found in stools and spread if whoever touches them does not sanitize his hands. Trophozoites are the ones responsible for the symptoms. Liver infections and subsequent amoebic abscesses can occur. Blood may be present in stools. Some of the signs and symptoms include: violent diarrhea, blood in stool, severe colitis, dehydration. This disease is often treated with two antimicrobial drug such as metronidazole and iodoquinol.

SIGNS AND SYMPTOMS.

• Bloody stool
• Abdominal pain and discomfort
• Weakness and fatigue
• Frequent stooling
• Sometimes vomiting
• Nausea

14) CHAGAS DISEASE.

This is also known as American trypanosomiasis. It is a tropical parasitic disease caused by a protozoan called trypanosome cruzi. It is spread mostly by insects known as kissing bugs. The symptoms change over the course of the infection. In the early stage, symptoms are typically not present or mild and may include fever, swollen lymph nodes, headaches or local swellings at the site of bite. As the disease spreads, other severe symptoms tends to manifest. Early infections are treatable with the medication benznidazole.

SIGNS AND SYMPTOMS.

• Severe headache
• Weakness
• Fever
• Body ache.

15) BLASTOCYTOSIS.

A human protozoan infection caused by a unicellular protozoa parasite of blastosoma species. It inhabits the GIT of humans and other animals. It can be spread from animals to humans and also by contaminated water, food and feces. Risk factors for this infection may include; consumption of untreated water, poor day care facilities and travelling to less developed countries.

Diagnosis involves ova and parasite examination as well as direct microscopy. 

SIGNS AND SYMPTOMS

• Abdominal pain
• Diarrhea
• Flatulence
• Weight loss
• Constipation
• Anal itching
• Skin rashes
• Intestinal inflammation and arthritic symptoms.

TREATMENT.

• This involves use of chemotherapy such as metronidazole, trimethoprim, tetracycline, doxycycline, ivermectin and micanozole.

16) CYCLOSPORIASIS.

This is a human protozoan infection caused by cyclospora cayetanesis that enters the small intestine invading the mucosa. It is not spread from person to person, it is rather spread by feces or feces contaminated fresh produce and water.

Prevention of this infection involves proper cooking of food and avoiding stream water. Diagnosis involves laboratory methods such as; PCR-based DNA test, and acid fast staining.

SIGNS AND SYMPTOMS 

• Watery diarrhea
• Abdominal bloating
• Stomach cramps
• Muscle aches
• Fever

TREATMENT. This infection is often treated using trimethaprine-sulfamethaxole. However, no vaccine is available for its control.

17) CRYPTOSPORIDIOSIS.

This infection simply known as crypto, is caused by cryptosporidium a genus of protozoan parasite in the phylum apicomplexa. it affects the distal intestine and respiratory tract in immune-compromised individuals. Its often transmitted through fecal-oral route by contaminated water. Other modes of transmission includes; contact with contaminated materials such as soil, cross contaminated and uncooked food.

Diagnosis involves ultra sonography, fluorescent microscopy, staining and detection of antibodies. Persons at risk of this infection include; cattle rearers, parents of infected children, international workers and child care workers. Preventive measures includes; insuring good hygiene and sanitation as well as decontaminating drinking water.

SIGNS AND SYMPTOMS.

Based on the type of cryptosporiodosis, intestinal type has symptoms such as;

• Low grade fever
• Crampy abdominal pain
• Dehydration
• Nausea and vomiting
• Fatigue and weight loss

The upper respiratory type has symptoms such as

• Inflammation of nasal mucosa, sinuses, larynx or trachea
• Nasal discharge
• Voice change

The lower respiratory type has symptoms such as

• Cough
• Shortness of breath
• Fever
• Hypoxemia

TREATMENT. This involves

• Fluid rehydration
• Electrolyte replacement and anti-motility agents such as loperamide
• Paramomycin and azithromycin can be used for immune-compromised person

18) BALANTIDIASIS

A parasitic protozoan infection caused by Balantidium coli. The major reservoir of this infection is pigs but the commonest route is by intake of infected water. It can also be transmitted by contaminated food and water. Persons co habiting with pigs are more susceptible to this infection. 

Diagnosis involves microscopic examination of tissue or stool simple. Preventive measures involve purification of drinking water, proper handling of food and careful disposal of feces.

SIGNS AND SYMPTOMS

• Diarrhea
• Constipation
• Abdominal pain
• Weight loss and fatigue.

TREATMENT

This involves chemotherapy such as tetracycline, carbasone, metronidazole or diodohydroxyquin.

HUMAN HELMINTHES INFECTIONS

Helminthes commonly known as parasitic worms are large multicellular organisms visible to the naked eyes in their adult stage. Like protozoa, helminthes can be free living or parasitic in nature. They are usually referred to as intestinal worms. The number of helminthes specie is large and estimated to be about one million with the nematode being the most diverse of the species.

Helminthic cannot multiply in humans when in their adult forms. They live and feed on their host, receiving nourishment and protection while disrupting host nutrient and absorption causing weakness and disease. Helminthes includes the various groups such as nematodes, trematodes and cestodes.

HELMINTHES DISEASES.

1) ECHINOCOCCOSIS: 

A helminthic disease also called hydatidosis. It is of two main types mainly cystic aviola echinococcosis .less common types include polycystic and unicystic echinococcosis. It is caused by species of echinococus such as E. granulosus, E. multiocularis, E. vogeli and E. oligarthils. 

It is often transmitted through water, food containing eggs of the parasites or by close contact. It is often diagnosed by ultra sound through CT or MRI, by blood test and biopsy. 

SIGNS AND SYMPTOMS

• In the lungs symptoms include cough, shortness of breathe and chest pain
• In the liver symptoms include fever, jaundice, abdominal pain anaphylactic reactions and hepatomegaly.

TREATMENT 

• Cystic echinococcis is treated mostly by open surgical removal of cyst alongside chemotherapy such as mebendazole or albendazole before and after surgery.
• Alveolar echinococcosis is treated by surgical cyst removal with albendazole or mebendazole upto 2 years . 

2) SPARGANOSIS

This is a human helminthic infection caused by pleroceroid larvae of diphyllobothroid tapeworm belonging to spirometra. Humans are accidental host of this parasite while animals are intermediate host, it can be transmitted to humans by drinking contaminated water, consumption of intermediate host such as snakes and placing raw poultrice of intermediate host on open wounds,, lesions or eyes. 

Diagnoses involves biopsy, CTI and MRI scanning. Preventive measures include proper sanitation and providing easy access to clean water.

SIGNS AND SYMPTOMS

• Seizures
• Hemiparesis and headaches
• Ocular sparganosis show symptoms such as eye pain, epiphoria, lacrimation, orbital cellulitis and corneal ulcer.

TREATMENT

Use of praziquantel is most effective therapy for treatment of spargonosis.

3) FASCIOLOPSIASIS

This is a human parasitic infection caused by largest intestinal flukes of humans called trematode fasciolopsus buski. The intermediate host for this infection is amphibic snails from where it infect aquatic plant such as water spinach eaten by man. It can also be transmitted by drinking untreated water infected by parasites and eating poorly cooked pig meat. 

Diagnosis involves microscopic identification of eggs. Preventive measures includes; snake control, avoiding use of feces as fertilizer and immersion of vegetables in boiling water.

SIGNS AND SYMPTOMS

• Abdominal pain
• chronic diarrhea
• Anaemia
• Ascites
• Toxemia
• Allergic responses
• Sensization
• Intestinal obstruction

TREATMENT

Use of praziquantel. Use of tetrachloroethylene capable of reducing fecal egg count is an effective treatment. Also, use of anti-helminthes such as thiabendazole, mebendazole , levamisole and pyrantel pamoate is also effective.

4) HYMENOLEPSIASIS

This infection is also called dwarf tapeworm or rat tapeworm infection and is often classified as a neglected tropical disease. It is caused by 2 species of tapeworm species namely hymenolepsis nana and hymenolepsis diminutia. It lives in the intestine of rats and is generally found in their feces which is consumed by the secondary host beetles. Humans become infected when they come in contact with infected feces or eat materials contaminated by the insects. 

Major means is diagnosis is through examination of eggs and parasites. Preventive measures include good hygiene, establishing public health and sanitation programs, rodent and insect control.

SIGNS AND SYMPTOMS

• Abdominal pains.
• Loss of appetite.
• Itching and irritability.
• Diarrhea.

TREATMENT

This includes chemotherapy such as praziquantel, niclosamide and albendazole.

5) BERTIELLIASIS

A human helminthic infection caused by Bertiellia, a cestode tapeworm parasite with 2 species documented to cause human infections namely B. studeri and B. micronata. It is transmitted to humans by the accidental consumption of oribatid mites found in soil. In some cases, it has been related to the consumption of guava from the ground.

Diagnosis involves identification of the eggs in stool. Effective preventive measures includes avoiding contact with non -human parasites and soil.

SIGNS AND SYMPTOMS

• Intermittent epigastric pains
• Nausea
• Anorexia
• Weight loss
• Fever
• Diarrhea and tender abdomen

TREATMENT 

Chemotherapy using praziquantel and niclosamide is highly effective.

6) TAENIASIS

A zoonotic human infection caused by Taenia saginata commonly called beef tapeworm belonging to the order cyclophllidea and the genud taenia. Cattles are the intermediate host while humans are the definite host usually infected by eating raw or poorly cooked beef containing the larvae.

Diagnosis is basically done by examination of stool sample. preventive measures involves proper cooking of beef to destroy the parasite, refrigeration, freezing or long time salting periods to kill cyst. Also inspection of beef an proper disposal of human excreta can be done.

SIGNS AND SYMPTOMS

• Weight loss
• Chronic indigestion and diarrhea
• Constipation
• Nausea
• Abdominal pain
• Headache

TREATMENT

This infection is easily treated with praziquantel and niclosamide. Use of albendazole is also effective.

7) CENUROSIS.

This is a parasitic infection that results when humans ingest the eggs of dog’s tapeworm species Taenia multiceps, T. seralis, T. bravni, or T. glomerate. Humans are the definite host for some tapeworm species, the most common being T. saginata and T. solium. This means that these species can develop into full grown, reproductively capable adult worms within the human body. People infected with these species have a tapeworm infection.

Because this disease is so rare in humans accurate diagnostic technique have not been developed. CT smears and MRI are useful for detecting fluid filled cystsin all areas of the body, and some serological and microscopic tests can confirm the presence of taenia larvae.

SIGNS AND SYMPTOMS

In humans, this parasitic infections causes a variety of symptoms, depending on where the cyst occurs. The tapeworm larvae group together to form fluid filled cysts in various body tissue.

When the cyst occurs, the spinal cord, it can cause severe pain and inflammation, and loss of feeling in some nerve.

TREATMENT

• Praziquantel
• Albendazole
• Glucocorhicoids.