Report on Host Parasite Interaction

  The parasites are capable to change their surface identity as antibodies and T-cells in the immune system. They can be recognized by the specific epitopes of the immune system. The parasite escapes the recognition by changing the antigenic surface in the case of infection. The successful survival depends on the evading of the host immune system. The penetration and multiplying are within the cells. When considering how parasites evade the immune system it shows successful survival that depend on the evading process of the host immune system. The process is based on different steps including penetration, multiplying of the cells, variation in the surface antigens, modulating immune response, and elimination of the protein coat. The process of how parasite invade their host is based on protozoan of host tissue and cells, replication, and dissemination of host cells that can be systematically and locally through the lymphatic and blood system. Without host, a parasite cannot survive, multiply and grow. The issues are spreading of diseases because, unlike predators, the parasites are usually smaller in size as compared to the host and the reproduction rate is faster.

Halicephalobus Gingivalis

            Halicephalobus Gingivalis is actually a species of sapropghaous nematode. Stefanski was the one to name and identify it in 1954. In horses, it is a facultative parasite and it invades the nasal cavity. Sometimes other areas are also invaded by it where granulomatous masses are produced by it (Bröjer, Parsons, Linder, Peregrine, & Dobson, 2000). Although it is rare, it can influence and infect humans. Among humans, this infection is invariably fatal. In tissue samples, both immature larvae and eggs have been found which indicates a cycle of asexual reproduction. For these parasites, the site of entry is believed to be through small breaks in the skin.

            Considering the fact that it is a facultative parasite, its stages are still unclear. It seems to reside in plants, soil, and other environments which are rich organically including compost and manure. H. Gingivalis is rare in humans but its unique effects are considered to be quite lethal because in the central nervous system, there is intense inflammation that leads to brain dysfunction. In horses, brain infection is quite common which is followed by adrenal glands, spinal cord, lungs, lymph nodes, nasal and oral cavities, and kidneys. There is also infection in bone, stomach, liver, and heart. In accordance with a 1997 research, in generally, neurohelminthiases are seemingly more prevalent while poor sanitation and environmental factors contribute to the spread of this parasite among animals and humans. Improved transport and population shifts have also facilitated the spread of this virus. It is important to note that neurohelminthiases are not common and that is the reason why diagnostic tests for them are not commonly available.

            Actually, all recognised and reported cases of infections in humans were only determined post mortem and they had been fatal. In addition to it, anthelminthic drugs and medicines such as benzimidazole and ivermectin were not used in these cases for treating the patients. These drugs, in animals, are most ineffective and they do not produce effective results because they do not seem to penetrate the blood-brain barrier. Thus, it is important to note that when a nuerohelminthic disease occurs, it is quite dangerous and intense because there are no tests which can be performed for identifying these species and applying the necessary treatment that can cure the infection. Neurotropsim is exhibited by these nematodes but their risk factors, mode of infection, and life cycle are not understood as of now. Thus, more research is needed in these areas (Pearce, Bouré, Taylor, & Peregrine, 2001).

            It is important to understand that it may be easier to diagnose a few parasites, but Halicephalobus Gingivalis is one of the parasites, which is not easily diagnosed. Its diagnosis is very difficult because it is very rare for humans to get infected because it is mainly associated with the infection for horses. A combination of different methods is used to diagnose this parasite presence in humans. That’s why its diagnosis is more difficult than the others because there is no single method to diagnose it. The combination of serum biochemical parameters, haematology, as well as, magnetic resonance imaging (MRI) is evaluated coming from previous reports. Moreover, the histopathological and gross lesions are observed by analysing the tissues or organs, which have been affected. To detect the DNA of the parasite, the Polymerase chain reaction (PCR) method is also used. The combination of these methods may give an indication about its presence in the body, so it is needed to develop a single method to do so (Onyiche, Okute, Oseni, Okoro, Biu, & Mbaya, 2018)

Taenia Solium of the Host-Parasite Interaction

            In general, Taenia Solium is also referred to as pork tapeworm. It is a tapeworm that belongs to taeniddae family. Taenia Solium is found in different parts of the world, especially in nations where people eat pork. It has two forms: one is because of eating half-cooked pork that causes adult worms while the other is referred to cysticercosis that is because of consuming water or food that has feces in it. Its lifecycle is completed by it in humans as first or definite host and in pigs as secondary or intermediate host. Actually, morula is ingested by pigs which tend to develop into larvae. Ultimately, it converts into infective larvae. An adult worm is developed from a cysticercus in small intestines of humans. No pathological symptoms are presented by primary hosts. However, secondary hosts develop complications and they suffer from neurocysticerosis. Medications can be effective in treating primary hosts while the treatment of secondary hosts is complex.

            The lifecycle of this parasite is indirect. It is passed into humans through animals such as pigs. In humans, it can be both long-lasting and relatively short. It can even last for the whole life if it reaches brain. The eggs, for humans, are seemingly released in the atmosphere where they are ingested by another host. When it comes to secondary hosts, these eggs become oncospheres and they penetrate the intestinal wall. After penetration, they migrate to other body parts where cysticerci is formed. In animals, it is capable of living for years. When humans are colonised by eggs, they become secondary hosts while in pigs, blood circulation is exposed to oncospheres. Moving on, cysts are developed by them, its clinical symptoms appear. Taeniasis is intestinal infection it normally has non-specific or mild symptoms. This might involve constipation, diarrhoea, nausea, and abdominal pain. They continue until tapeworms die. When cases are severe, hypertension and dementia can occur because of perturbation of cerebrospinal fluid’s normal circulation. In common cases, in the brain, this infection can lead to lesions, seizures, and epilepsy.

            When it comes to diagnosis, stool tests involve microbiology testing. Stoll examination aims to identify the amount of eggs. The sensitivity of diagnosis s increased with the use of ELISA. Another diagnosis method is Stool PCR that offers a specie-specific diagnosis. It is important to note that in controlled field trials, this method has not been experimented. Another diagnosis method is serum antibody tests. Another important thing to note is that cysticercosis treatment should be monitored carefully for dying worms and inflammation (Lightowlers, 2013). It is vital to understand that when different diagnostic methods are applied, they can vary in results, because every case will be different from the others. The things can get complex in the diagnostic process, which effects overall efficacy of the results.

Naelgeria Fowleri of the Host-Parasite Interaction

            In general, Naegleria Fowleri is also referred to as brain-eating or damaging amoeba. It belongs to the class of genus Naegleria that belongs to phylum Percolozoa. It is not recognised as an actual amoeba but it is considered a shapeshifting excavate amoeboflagellate. Actually, it can be said that it is a bacteria-eating and free-living microorganism. It can be pathogenic and it can cause severe and rare fulminant brain infection referred to as naegleriasis. It is also referred to as primary amoebic meminoencephalitis. Typically, this microorganism is found in freshwater bodies like rivers, lakes, and ponds. This parasite is found in industrial plant discharges of warm-water. It can be observed in a temporary or amoeboid flagellate stage (Jonckheere, 2011).

            Naegleria Fowleri is a free-living and thermophilic amoeba. Usually, it is identified in hot and warm freshwater ponds, rivers, lakes, and in other warm waters. With an increase in water temperature, its number rises. Naegleria Fowleri has three forms including biflagellate, trophozoite, and cyst. In human tissue, a cyst is not formed where only the stage of amoeboid trophoziote exists. In cerebrospinal fluid, it is possible for flagellate form to occur. Naegleria Fowleri is capable of causing brain’s lethal infection referred to as naegleriasis. Most often, infections occur when water is inhaled through the nose, containing Naegleria Fowleri, where it enters the olfactory and nasal nerve tissue, penetrating the cribriform plate to enter the brain. Normally, bacteria is consumed by Naegleria Fowleri. However, during infections, it eats neurons and astrocytes. Generally, it takes one to nine days for the symptoms to appear after nose is exposed to the parasite. Some symptoms might include nausea, fever, and headache. It is possible for later symptoms to include hallucinations, seizures, loss of balance, confusion, and even stiff neck. Once the person is infected, he will usually die within the span of two weeks. It is important to note that a person with Naegleria Fowleri cannot infect another person.

            Amphotericin B antifungal drug is included in the core antimicrobial treatment that is capable of inhibiting the pathogen by limiting or binding to the sterols of cell membrane, which leads to the disruption of cell membrane and pathogen death. It is quite important to note that even with this treatment, the rate of fatality is more than 95 percent. Therefore, it is very important to seek new treatments. In few cases, miltefosine has been utilised that is capable of inhibiting pathogen through the disruption of survival signal pathway of cell (Grace, Asbill, & Virga, 2015).

            It is vital to know if some are infected with N. fowleri, then overall symptoms will start to show from 2nd to 8th day. However, the exception is there that few cases show symptoms within 24 hours. However, the specific signs did not show with this parasite to show the level of infection, but still, there are few signs to make an estimate about it and those signs are chills, fever, severe headache, confusion, photophobia, as well as, possible issue of coma. So, it is vital to come up with a proper diagnosis process to ensure, whether the infection is there or not. Imaging tests are the most common method of diagnosis. MRI or CT scan can reveal that there is bleeding and swelling in the brain, which is a sign that N. fowleri has infected the human. In the CT scan, the process is combined with some X-rays by using a variety of directions so that cross-sectional images are taken for better analysis. On the other hand, MRI is used to take extensively detail images to analyse the tissues of the brain. There is a fluid, which surrounds the area of the brain, and a microscope can be able to see the Naegleria amoeba in this fluid. So, these are some of the diagnosis processes with its structure to perform so that N. fowleri is properly diagnosed (Mayo Clinic, 2020)

Lungworm of the Host-Parasite Interaction

            Parasitic nematode worms are also referred to as lungworms because they infest vertebrates’ lungs. Actually, the name is utilised for a number of different classes of nematodes, some of which have other names as well. What these classes have in common is that they seem to migrate to the respiratory tracts and lungs of hosts and they cause pneumonia or bronchitis. Gradually, the lungworm will damage the lung tissue or airways by spurring an inflammatory reaction within the tissue. The parasites, ultimately, survive and they reproduce within tissues.

            The usual lifecycle of lungworms seems to begin with ineffective larvae’s ingestion. Then, the ineffective larvae penetrates the intestinal wall were it reaches lungs by traveling through the bloodstream. In the lungs, the infected larvae lives until it is developed into a proper and adult lungworm. Its eggs hatch and L1 larvae is produced. These larvae are coughed up before they are ingested back. Through the faeces, they are released or pushed into the environment. All the infected animals will contaminate the environment and this will increase the chance of others being infected as well.

            For lungworm, a common symptom is coughing up while some other typical symptoms include weight loss and wheezing. These symptoms are seemingly caused by larvae that is present within the lungs. It adversely influences immunity while the accumulation of mucus causes difficulties in breathing because blockage is created in the path of airway. Generally, if an animal is suspected of being influenced by this parasite, there are a number of ways of defecting it like performing a chest x-ray, detection of larvae or ova, or faecal examination. For the treatment of this infection, corticosteroids might be given to the animal for three to ten days. Meanwhile, for the treatment of tissue inflammation, prednisone is given to the animal for five to ten days but there are some side effects or drawbacks to this treatment such increased appetite or urination. Usually, moxidectin or fenbendazole is administered for killing the parasite. Over the years, a number of lungworm parasites have been determined. Even though they seem to originate from a basic source of lungworm parasite, their testing is different from each other and it needs a combination of several drugs for treating the parasite. For the prevention of this parasite, repeated x-rays are needed. Faecal sample is also required to be monitored for checking whether there is ova or larvae in it within two to four weeks (Nisbet, et al., 2013).

            It is again vital to have a diagnosis procedure with some features and characteristics to properly diagnose the Lungworm. It has been observed that there are no proper diagnostic procedures to continue with the diagnosis of the Lungworm, especially no blood tests are readily available. However, it has been seen that the PCR test was successful in some cases to diagnose the infection. Other than this method, it is very difficult to come up with a confirmed diagnosis, rather the history of the patient is taken to see if he/she was exposed to any parasitic places, and if any undercooked or raw food has been eaten by the patient, then other signs will be combined to make a proper estimate. If it is suspected that an animal is having Lungworm, then it can be detected by doing few processes such as respiratory secretions’ examination for ova, detecting ova with the help of fecal examination, chest x-ray, or having a detailed analysis of medical history linked with the lung auscultation (CountryFile, 2020)

Spirometra erinaceieuropaei of the Host-Parasite Interaction

            Generally, spirometra erinaceieuropaei is considered a parasitic tapeworm, capable of infecting humans and domestic animals. For this infection, the medical term is spaganosis. These worms are quite similar to worms in spirometra. In three main ways, this parasite can be contracted by humans including contaminated flesh with poultices, drinking contaminated water, and consumption of undercooked or raw meat. Over the years, humans have been recognised as paratenic host but the first case of a person with adult spirometra erinaceieuropaei infection was identified three years ago. This inflection is quite common in animals while they are unique in humans.

            The lifecycle of spirometra erinaceieuropaei is quite complex and it has three hosts. It starts when faeces discharge eggs and definitive host is responsible for it. Upon discharge, these eggs are quite immature only until they get to a water source. Reaching fresh water, they become coracidia. Then, copepods ingest them and they become intermediate hose. Next, they are consumed by either reptiles of fish to become the second intermediate host. Inside them, larvae penetrate the intestinal wall and they reach the final stage to become plerocercoid larvae. From there onwards, they reach subcutaneous muscles or tissues. Finally, this host is consumed by the definitive host. It takes a few weeks for these parasites to become mature and transform into adult tapeworms. This is how the lifecycle of these tapeworms continues. They are capable of surviving up to thirty years in definitive hosts.

            Sparagnosis is the term that refers to spirometra erinaceieuropaei infection. It is important to note that this infection is not common. Typically, cats and dogs are infected by adult spirometra. In their intestines, they will reproduce and in their faeces, their eggs will shed. Even though it is possible for humans to be infected by it as well, it cannot be contracted by them through the faeces of infected dogs or cats. In humans, typically, larvae are present in subcutaneous muscle or tissues, and will create growing masses. It is possible for the infection to involve scrotum, abdominal cavity, and genitourinary tract. Some symptoms include abdominal skin sensations, tingling, numbness, seizures, headache, and weakness.

            Through the use of imaging, infections can be detected in humans. However, since parasites might be apparent as a mass, it is after surgical removal that most diagnosis takes place. In animals, diagnosis is normally performed by the categorisation of eggs in faeces (Bennett, et al., 2014).

            The diagnosis of Spirometra erinaceieuropaei is a complex process, but the good thing is the procedure is there, and a patient having signs, as well as, symptoms of Spirometra erinaceieuropaei can be diagnosed with the help of genetic and morphological analyses. It is good to include an example for a case to show how Spirometra erinaceieuropaei was diagnosed in an actual patient. There was a 23 years' old patient from Vietnam, who was admitted in the hospital, and it was told that he was having epigastric discomfort, weight loss along with fever, and he was not feeling comfortable at all. When the preliminary diagnosis process was carried out, an incorrect estimate was made that he is having an infection that has been caused by a fluke. After two days, his stool was noticed passing proglottids, which clarified the infection coming from tapeworm, and after doing some necessary procedures such as liver function tests, blood tests, it was identified that he is having Spirometra erinaceieuropaei (Le, Thi Do, Nguyen, & Do , 2017)

References of the Host-Parasite Interaction

Bennett, H. M., Mok, H. P., Gkrania-Klotsas, E., Tsai, I. J., Stanley, E. J., Antoun, N. M., et al. (2014). The genome of the sparganosis tapeworm Spirometra erinaceieuropaei isolated from the biopsy of a migrating brain lesion. Genome biology, 15(11).

Bröjer, J. T., Parsons, D. A., Linder, K. E., Peregrine, A. S., & Dobson, H. (2000). Halicephalobus gingivalis encephalomyelitis in a horse. The Canadian Veterinary Journal, 41(7).

CountryFile. (2020). Guide to Lungworm: what is it, how to spot the signs and protect your dog. Retrieved May 10, 2020, from https://www.countryfile.com/countryfile/guide-to-lungworm-what-is-it-how-to-spot-the-signs-and-protect-your-dog/

Grace, E., Asbill, S., & Virga, K. (2015). Naegleria fowleri: pathogenesis, diagnosis, and treatment options. Antimicrobial agents and chemotherapy, 59(11), 6677-6681.

Jonckheere, J. F. (2011). Origin and evolution of the worldwide distributed pathogenic amoeboflagellate Naegleria fowleri. Infection, Genetics and Evolution, 11(7), 1520-1528.

Le, A. T., Thi Do, L.-Q., Nguyen, H.-B. T., & Do , A. N. (2017). Case report: the first case of human infection by adult of SPIROMETRA ERINACEIEUROPAEI in VIETNAM. BMC Infectious Diseases, 17(669).

Lightowlers, M. W. (2013). Control of Taenia solium taeniasis/cysticercosis: past practices and new possibilities. Parasitology , 140(13), 1566-1577.

Mayo Clinic. (2020). Naegleria infection. Retrieved May 10, 2020, from https://www.mayoclinic.org/diseases-conditions/naegleria-infection/diagnosis-treatment/drc-20375474

Nisbet, A. J., McNeilly, T. N., Wildblood, L. A., Morrison, A. A., Bartley, D. J., Bartley, Y., et al. (2013). Successful immunization against a parasitic nematode by vaccination with recombinant proteins. Vaccine , 31(37), 4017-4023.

Onyiche, T. E., Okute, T. O., Oseni, O. S., Okoro, D. O., Biu, A. A., & Mbaya, A. W. (2018). Parasitic and zoonotic meningoencephalitis in humans and equids: Current knowledge and the role of Halicephalobus gingivalis. Parasite Epidemiol Control., 3(1), 36–42.

Pearce, S. G., Bouré, L. P., Taylor, J. A., & Peregrine, A. S. (2001). Treatment of a granuloma caused by Halicephalobus gingivalis in a horse. Journal of the American Veterinary Medical Association, 219(12 ), 1735-1738.