oral para inf

Parasitic infections of oral cavity : 

Parasitic infections of oral cavity

Introduction to Parasitology : 

Introduction to Parasitology Parasitology Conceptions related to parasitology Relationships between parasite and host The basic factors of transmission of parasitic diseases The preventive measures of parasitic diseases Protozoa & diseases Trypanosomiasis i.e.- chaga’s disease Helminths & diseases Cysticercosis Myasis Maleria

Who is a parasite? : 

Who is a parasite? Parasites are usually much smaller than their hosts.

Slide 4: 

Parasite Damages Bact, virus, protozoa, worms

Slide 5: 

Endoparasite..protozoa, Helminths Ectoparasite..bed bugs,CRAB-permanent

Obligate/facultative, and permanent/intermittent parasites : 

Obligate/facultative, and permanent/intermittent parasites Most parasite are obligate parasites (exceptions include e.g. Naegleria) In some species only some life cycle stages, e.g. the larvae are parasitic, in others parasitic and free living generations can alternate depending on environmental conditions (Strongiloides stercoralis) . Indirect Direct

Parasites are found in all groups of organisms : 

Parasites are found in all groups of organisms

Slide 9: 

The border between parasitism and micropredation is blurry Parasites usually live in a very intimate relationship with their host depending on more than food from it The host is food source and more or less permanent habitat at the same time Many parasites show strict specificity for a single host

Infection vs. disease : 

Infection vs. disease successful parasites live in, but do not kill their hosts protozoa multiply within hosts expression of disease depends on host factors helminths do not multiply within hosts severity of disease depends on parasite burden and immunologic response to parasites

Parasite modes of entry : 

Parasite modes of entry Ingestion Arthropod bites Penetration of intact skin or mucous membranes

Spread and tropisms : 

Spread and tropisms Some parasites must migrate to certain locations within the host in order to complete their life cycle Non-human parasites, in humans, often fail to migrate properly and become “dead-end infections”

Hosts : 

Hosts The definitive host is by definition the one in which the parasite reproduces sexually Additional hosts are then designated intermediate hosts Host which actively transmit parasites to humans are often called vectors In paratenic or transport hosts no parasite development occurs Reservoir host are alternate animal host from which the parasite can be transmitted to humans (zoonosis) or domestic animals Accidental host, not suitable for parasite development, but can cause disease

Conceptions related to medical parasitology : 

Conceptions related to medical parasitology Parasitology Parasiticide e.g.Acaricide,Trypanocide, Antihelminthic Chaga’s disease- fatal..america

Mutualism : 

Mutualism ------ An association which is beneficial to both living things. Fig. A selection of ciliates from the rumen. The rumen contains enormous numbers of ciliates that break down cellulose in the feed.

Parasitism : 

Parasitism ------ An association which is beneficial to one partner and harmful to the other partner. The former that is beneficial to is called parasite, the latter that is harmful to is called host. Human / Hookworm

Slide 18: 

Type of parasites Protozoa Nematodes Parasites Helminths Trematodes Endo- Cestodes Arthropods ---------------- Ecto-

Symbiosis : 

Symbiosis ------The relationship beween two living things (animals). Two living things live together and involve protection or other advantages to one or both partner

Commensalism : 

Commensalism ------ Both partners are able to lead indepenent lives, but one may gain advantage from the association when they are together and least not damage to the other. Fig. A female pea crab in the mantle cavity of its mussel host. The crab does not damage the mussel and uses its shell purely for protection

Life cycle and type of life cycle : 

Life cycle and type of life cycle Life cycle : The whole process of parasite growing and developing. The direct life-cycle : Only one host (no intermediate host). The indirect life cycle : Life cycle with more than one host (intermediat host and final host).

Relationship (Effect) between parasite and host : 

Relationship (Effect) between parasite and host injure to Parasites harbour in Host (animal or human) to response immune produce Effects of the parasites on the host Effects of the host on the parasites

Effects of parasites on the host : 

Effects of parasites on the host Depriving the host of essential substance Hookworm Suck blood Anemia Mechanical effects of parasites on the host Ascaris Perforate/Obstruction Toxic and allergy effect E.h Proteolytic enzyme Necrosis Parasite antigen Immune system e.g Anaphylaxix Immune response Allergy/ Hypersensitivity

Tissue damage and host response : 

Tissue damage and host response direct destruction of tissue hypersensitivity reactions eosinophilia occurs with helminths, not protozoa results from tissue migration

Effects of the host on the parasites : 

Effects of the host on the parasites ----The host can produce certain degree resistance to parasites in human body or re-infection. The resistance (Immunity) is not very strong. In general, It don’t wipe out parasites completely, but may limit the number of parasites and establish balance with parasites. Innate immunity Acquired immunity

Innate immunity : 

Innate immunity Barrier : Prevent parasites to invade in certain degree. Skin/Mucous membrance/Placenta. Acid in skin or stomach can cause damage of the parasites. Phagocytosis of phagocyte. ----Non-specific/effective against a wide range of parasitic infection/controlled by genetical factors. But not very strong!

Acquired immunity : 

Acquired immunity Mechanism : cellular and humoral immunity. Sterilizing immunity : Wipe out the parasites completely, meanwhile get a long-term specific resistance to re-infection. Rare! Non-sterilizing immunity : Wipe out most of the parasites, but not completely. Common! No parasite, no immunity!

The basic factor of transmission of parasitic diseases : 

The basic factor of transmission of parasitic diseases Parasitic diseases Infectious diseases Transmission The source of the infection The routes of transmission The susceptible host ----The combined effect of those factors determine the dipersibility and the prevalence of the parasites at a given time and place and regulate the incidence of the parasitic diseases in certain local population.

The source of the infection : 

The source of the infection Patient : Persons who have parasites in their body and show clinical symptoms. Carrier : Persons who have parasites in their body, not show symptoms. Reservoir host : Animals that harbors the same species of parasites as man. Sometimes, the parasites in animals can transmit into human.

The avenues of invasion : 

The avenues of invasion Digestive tract : Most common avenue of entrance. (Food/ Water transmission) Skin : Infective larvae perforate skin and reach to body and establish infection. (soil/ water transmission) Blood : Bloodsucking insects containing infective parasites bite the skin and inject parasites into human blood. (Arthropod transmission---malaria).

The routes of transmission I : 

The routes of transmission I Congenital transmission : From mother to infant. Toxoplasmosis Contact transmission : Direct contact---Trichomonas vaginalis; Indirect contact---Ascaris lumbricodes Food transmission : The infectious stage of parasites contaminated food / The meat of the intermediate hosts containing infectious stage of parasites.

The routes of transmission II : 

The routes of transmission II Water transmission : Drink or contact the water contaminated the infectious stage of parasites. Soil transmission : Contamintion of the soil by feces containing the certain stage of parasites and this stage can develop into stage. Arthropod transmission : Vectors of certain parasitic diseases.

The prevention measures of the parasitic diseases : 

The prevention measures of the parasitic diseases Controlling the source of the infection. ----Treatment of the patients, carriers and reservoir hosts. Intervention at the routes of transmission ----Managing feces and water resource,controlling or eliminating vectors and intermediate hosts. Protecting the susceptible hosts. ----Paying attention to personal hygiene, changing bad eating habit, taking medicine.

The susceptible host : 

The susceptible host ----In general, most people is the susceptible host (Why?). The parasite reaching a susceptible host must gain entrance and set up a favorable residence in order to complete its life cycle and cause the transmission of parasitic diseases.

Protozoa : 

Protozoa Single celled, Organized cellular structure May ingest solid particles Require aquatic environment Reproduce by binary fission at some point in life cycle

Protozoa : 

Protozoa 1. Plasmodroma 2. Chyalophora Diseases trypanosomiasis leishmaniasis trichomoniasis toxoplasmosis

Slide 37: 

Trypanosoma Cause Trypanosomiasis (Sleeping sickness - Africa; Chagas Disease - South America) Disease - Fever, encephalitis; cardiac complications (Chagas Disease). Transmission - Tse-Tse fly (Africa), Reduvid Bug (South America). Detection - Parasites stained on blood smears, serology.

Slide 39: 

Trypanosomiasis or trypanosomosis is the name of several diseases in vertebrates caused by parasitic protozoan trypanosomes of the genus Trypanosoma. Approximately 500.000 men, women and children in 36 countries of sub-Saharan Africa suffer from` human African trypanosomiasis which is caused by either Trypanosoma brucei gambiense or Trypanosoma brucei rhodesiense. The other human form of trypanosomiasis, called Chagas disease, causes 21,000 deaths per year mainly in Latin America. Human African trypanosomiasis, transmitted by the tsetse fly infected with Trypanosoma brucei, ..African trypanosomiasis (sleeping sickness) Human American trypanosomiasis, transmitted by the assassin bug infected with Trypanosoma cruzi.. Chagas disease

Slide 40: 

It is transmitted by trypanosomes present in the faeces of nocturnal blood sucking reduvid bugs in poor rural areas of south america, come into contact with wounds & scratches on the skin or delicate internal tissues of nose & mouth May prove fatal Esp children & young adultssleeping seeckness – africa TrIpanoside- AS containig compounds nifurtimox

Slide 41: 

Diagnosing trypanosomiasis requires the documentation of T.brucei in blood smears, lymph node aspirates, or CSF American trypanosomiasis is currently treated with a variety of antifungal agents, including benznidazole and nifurtimox. Melarsoprol is another drug which is used for the treatment of T. b. gambiensie.

Slide 42: 

Leishmaniasis is a disease caused by protozoan parasites that belong to the genus Leishmania and is transmitted by the bite of certain species of sand fly (subfamily Phlebotominae). Most forms of the disease are transmissible only from animals (zoonosis), but some can be spread between humans. Human infection is caused by about 21 of 30 species that infect mammals. The different species are morphologically indistinguishable, but they can be differentiated by isoenzyme analysis, DNA sequence analysis, or monoclonal antibodies. Cutaneous leishmaniasis is the most common form of leishmaniasis. Visceral leishmaniasis is a severe form in which the parasites have migrated to the vital organs.

Slide 43: 

The symptoms of leishmaniasis are skin sores which erupt weeks to months after the person affected is bitten by sand flies. Other consequences, which can manifest anywhere from a few months to years after infection, include fever, damage to the spleen and liver, and anaemia. In clinical medicine, leishmaniasis is considered one of the classic causes of a markedly enlarged (and therefore palpable) spleen; the organ, which is not normally felt during examination of the abdomen, may become larger even than the liver in severe cases.

Cutaneous leishmaniasis ulcer on left forearm : 

Cutaneous leishmaniasis ulcer on left forearm

Slide 45: 

There are four main forms of leishmaniasis: Visceral leishmaniasis – the most serious form and potentially fatal if untreated. Cutaneous leishmaniasis – the most common form which causes a sore at the bite site, which heal in a few months to a year, leaving an unpleasant looking scar. This form can progress to any of the other three forms. Diffuse cutaneous leishmaniasis – this form produces widespread skin lesions which resemble leprosy and is particularly difficult to treat. Mucocutaneous leishmaniasis – commences wiith skin ulcers which spread causing tissue damage to (particularly) nose and mouth.

Slide 46: 

There are two common therapies containing antimony (known as pentavalent antimonials), meglumine antimoniate (Glucantime) and sodium stibogluconate (Pentostam). Miltefosine (Impavido), is a new drug for visceral and cutaneous leishmaniasis.

Slide 47: 

Toxoplasmosis is a parasitic disease caused by the protozoan Toxoplasma gondii. The parasite infects most genera of warm-blooded animals, including humans, but the primary host is the felid (cat) family. Animals are infected by eating infected meat, by ingestion of feces of a cat that has itself recently been infected, or by transmission from mother to fetus. Although cats are often blamed for spreading toxoplasmosis, contact with raw meat is a more significant source of human infections in many countries, and fecal contamination of hands is a greater risk factor. Up to one third of the world's human population is estimated to carry a Toxoplasma infection.The Centers for Disease Control and Prevention notes that overall seroprevalence in the United States as determined with specimens collected by the National Health and Nutritional Examination Survey (NHANES) between 1999 and 2004 was found to be 10.8%, with seroprevalence among women of childbearing age (15 to 44 years) of 11%.

Slide 48: 

Disease - Mostly asymptomatic infection, but new infection in pregnancy causes fetal malformations; also infection in immuno-suppressed. Transmission - By poorly cooked meat, from cat stool, rarely water. Detection - By serology.

Slide 49: 

Detection of Toxoplasma gondii in human blood samples may be achieved by using the polymerase chain reaction (PCR). Inactive cysts may exist in a host which would evade detection. Toxoplasmosis can be detected with immunostaining. Lymph nodes affected by toxoplasma have characteristic changes, including poorly demarcated reactive germinal centers, clusters of monocytoid B cells and scattered epithelioid histiocytes.

Slide 52: 

PATHOGENESIS: During the first few weeks, the infection typically causes a mild flu-like illness or no illness. After the first few weeks of infection have passed, the parasite rarely causes any symptoms in otherwise healthy adults. However, people with a weakened immune system, such as those infected with advanced HIV disease or those who are pregnant, may become seriously ill, and it can occasionally be fatal. The parasite can cause encephalitis (inflammation of the brain) and neurologic diseases and can affect the heart, liver, inner ears and eyes (chorioretinitis).

Slide 53: 

LAB FINDINGS Detection of Toxoplasma gondii in human blood samples may be achieved by using the polymerase chain reaction (PCR). Inactive cysts may exist in a host which would evade detection. Toxoplasmosis can be detected with immunostaining. Lymph nodes affected by toxoplasma have characteristic changes, including poorly demarcated reactive germinal centers, clusters of monocytoid B cells and scattered epithelioid histiocytes.

Slide 54: 

Treatment is often only recommended for people with serious health problems, because the disease is most serious when one's immune system is weak,Medications that are prescribed for acute toxoplasmosis are: Pyrimethamine — an antimalarial medication. Sulfadiazine — an antibiotic used in combination with pyrimethamine to treat toxoplasmosis. clindamycin — an antibiotic used most often for people with HIV/AIDS. Cotrimoxazole — combitation of Pyrimethamine and Sulfadiazine in one tablet another option for people with problems like thrombocytopenia. Medications that are prescribed for latent toxoplasmosis are: atovaquone — an antibiotic that has been used to kill Toxoplasma cysts inside AIDS patients clindamycin — an antibiotic which, in combination with atovaquone, seemed to optimally kill cysts in mice.[

Slide 55: 

Trichomoniasis, sometimes referred to as "trich", is a common cause of vaginitis. It is a sexually transmitted disease. It is caused by the single-celled protozoan parasite Trichomonas vaginalis by producing mechanical stress on host cells and then ingesting cell fragments after cell death .Trichomoniasis is primarily an infection of the urogenital tract; the most common site of infection is the urethra and the vagina in women. Trichomoniasis is associated with increased risk of transmission of HIV. Trichomoniasis may cause a woman to deliver a low-birth-weight or premature infant. Trichomoniasis is also associated with increased chances of cervical cancer Evidence implies that infection in males potentially raises the risks of prostate cancer development and spread due to inflammation.

Slide 56: 

Typically, only women experience symptoms associated with Trichomonas infection. Symptoms include inflammation of the cervix (cervicitis), urethra (urethritis), and vagina (vaginitis) which produce an itching or burning sensation. Discomfort may increase during intercourse and urination. There may also be a yellow-green, itchy, frothy foul-smelling vaginal discharge. In rare cases, lower abdominal pain can occur. Symptoms usually appear in women within 5 to 28 days of exposure. In many cases women may hold the parasite for some years without any signs (dormant). While symptoms are most common in women, some men may temporarily exhibit symptoms such as an irritation inside the penis, mild discharge, or slight burning after urination or ejaculation.

LAB FINDINGS-Trichomoniasis is diagnosed by visually observing the trichomonads via a microscope.Trichomoniasis is a sexually transmitted infection (or sexually-transmitted disease, STD) caused by a protozoan (a microscopic parasite), usually found in the vagina and urethral tissues. : 

LAB FINDINGS-Trichomoniasis is diagnosed by visually observing the trichomonads via a microscope.Trichomoniasis is a sexually transmitted infection (or sexually-transmitted disease, STD) caused by a protozoan (a microscopic parasite), usually found in the vagina and urethral tissues.

Slide 59: 

PATHOGENESIS Trichomonis can be transmitted through sexual intercourse. While trichomoniasis is usually passed sexually. Unlike most STDs, the parasite can live for about an hour on damp towels, washcloths and bathing suits. If someone uses these towels or washcloths or puts on the bathing suit, the disease may be passed on that way. The good news is that trichomoniasis is curable but often goes undiagnosed because symptoms may not be noticed or even experienced. Treatment for both pregnant and non-pregnant patients usually utilizes metronidazole(Flagyl) 2000 mg by mouth at once. Sexual partners, even if asymptomatic, should be concurrently treated

Helminths : 

Helminths Multicellular, Organized internal structure Diseases cysticercosis, trichinosis schistosomiasis, hydatid ascaris, taeniasis ,strongiloidosis, myasis

Classification of helminths : 

Classification of helminths Nematodes (roundworms) Platyhelminthes (flatworms) Trematodes (“flukes”) Cestodes (“tapeworms”)

Helminthic diseases : 

Helminthic diseases Intestinal Others Strongyloides Invasive Trichinosis Filaria Schistosomiasis Cysticercosis Echinococcus (autoinfection cycle) (muscle pain, uncooked carnivores) (worms in lymphatics or under skin) (liver or urinary tract granulomas and fibrosis) (cysts in brain, seizures) (massive cysts in liver or lung)

Tapeworms : 

Tapeworms HOSTS Definitive hosts: harbor adult worms Intermediate hosts: harbor tissue cysts (containing worm heads) Humans acquire infection two ways: ingestion of eggs from feces (to acquire tissue cysts) ingestion of tissue cysts in undercooked meat (to acquire a tapeworm) = Intermediate host = Definitive host

Taeniasis : 

Taeniasis Tapeworm Cysticercosis poor hygiene poor sanitation ingestion of undercooked pork

Slide 66: 

Oral lesions Dignosis Treatment- well cooked food, dichlorophen & niclosamide.

CYSTICERCOSIS : 

CYSTICERCOSIS Cysticercosis (T. solium larvae) Common in brazil, s africa, mexico, india. Disease -Ccysts throughout the body tissues. Transmission - Ova are ingested; Detection - Serology, also x-ray, ultrasound, and other methods to detect mass lesions The traditional method of demonstrating T. solium eggs in stool samples diagnoses only taeniasis Neuroimaging with CT or MRI is the most useful method to diagnose neurocysticercosisCT scan shows both calcified and uncalcified cysts, as well as distinguishing active and inactive cysts

Oral manifestations : 

Oral manifestations Intraorally this involves lips , cheeks, & tongue. Most cases present a solitary or multiple painless , well, circumscribed, flactuant, swelling& often mimic mucoceles. Microscopically this appears as a fibrous capsule surrounding a cysticercus The bladder wall of larvae appears as light eosinophilic wavy membrane with multiple tiny ovoid nuclei in fibrillar stroma beneath

Slide 71: 

The host reaction to a viable cyt is often minimal. The dead parasite disintegrates & often gets calcified within a residuasl fibrous scar.

TREATMENT : 

TREATMENT Surgical treatment includes direct excision of ventricular cysts, shunting procedures, and removal of cysts via endoscopy. Albendazole is preferable over praziquantel due to its lower cost and corticosteroids and anticonvulsants do not reduce CSF and brain drug levels Treatment recommendations for subcutaneous cysticercosis includes surgery, praziquantel and albendazole.

Echinococcosis : 

Echinococcosis Cystic Hydatid Disease contact with dogs ingestion of entrails ingestion of eggs in pastures

Treatment of cysticercosis and echinococcosis : 

Treatment of cysticercosis and echinococcosis Antihelminthic therapy (e.g., albendazole, praziquantel) (Echinococcus only) Surgical removal Irrigation-evacuation of cysts

Comparison of pork tapeworm and Echinococcus life cycles : 

Comparison of pork tapeworm and Echinococcus life cycles Definitive hosts (adult tapeworms) Intermediate hosts (tissue cysts) Dead-end hosts

Slide 76: 

Cysticerci Hydatid Cyst

Slide 77: 

Isolated cysticerci Hydatid cyst

Flukes(trematodes) : 

Flukes(trematodes)

Schistosomiasis- clinical features : 

Schistosomiasis- clinical features Cercarial dermatitis Intestinal schistosomiasis (granulomas --> polyps, protein loss, malabsorption, strictures) Hepatosplenic schistosomiasis (portal hypertension --> ascites, varices, splenomegaly, normal hepatic function) Urinary schistosomiasis (hematuria, chronic infection, obstruction) Other (cardiopulmonary, CNS, etc.)

Geographic distribution of schistosomiasis : 

Geographic distribution of schistosomiasis S. mansoni S. hematobium S. japonicum

Schistosomiasis - life cycle : 

Schistosomiasis - life cycle

Schistosomiasis - pathogenesis : 

Schistosomiasis - pathogenesis egg granuloma (type IV reaction)--> fibrosis morbidity ~ worm (egg) burden concomitant immunity to schistosomula adult worms: invisible to the immune system (survive for years)

Drug treatment of schistosomiasis : 

Drug treatment of schistosomiasis Praziquantel increases permeability of adult parasite to Ca++. Tetanospasm --> death

Control of Schistosomiasis : 

Control of Schistosomiasis REDUCE CARRIERS mass rx program ELIMINATE SNAILS molluscicides destroy snail habitats snail-eating fish PREVENT WATER CONTAMINATION latrines, toilets public health education PREVENT HUMAN EXPOSURE water systems

Roundworms(nematodes) : 

Roundworms(nematodes)

Intestinal nematodes : 

Intestinal nematodes

Trichinella spiralis - life cycle : 

Trichinella spiralis - life cycle “cycle of carnivorism” among hogs and rats humans ingest encysted larvae in infected, undercooked pork larvae exist in stomach and burrow into small intestinal mucosa adult males and female reemerge and produce larvae which penetrate intestine and circulate in bloodstream larvae enter skeletal muscle cells and encyst

Clinical features of trichinosis : 

Clinical features of trichinosis Most common sxs: muscle pain and tenderness fever +/- chills edema (often periorbital) >10% eosinophilia (often ~50%) elevated CPK +/- chronic neurologic/myocardial sxs self-limited (2% mortality)

Slide 91: 

LAB FINDINGS An epidemiological investigation can be done to determine a patient's exposure to raw infected meat. Symptoms include circumorbital edema, splinter hemorrhage, non-specific gastroenteritis, and muscle pain. Serological tests include a blood test for eosinophilia, increased levels of creatine phosphokinase, IgG, and antibodies against newborn larvae. Immunoassays such as ELISA can also be used

Treatment of trichinosis : 

Treatment of trichinosis antihelminthic (albendazole) to kill any intestinal adults steroids to relieve inflammatory reactions antipyretics

Strongyloides - clinical features : 

Strongyloides - clinical features uncomplicated GI upset autoinfection hyperinfection rash bronchspasm, CXR infiltrates diarrhea profound eosinophilia recurrent Gram-negative bacteremia

Strongyloides life cycle : 

Strongyloides life cycle Adult worms in the the intestine Eggs 1st stage larvae hatch from eggs Larvae penetrate through intact skin Larvae enter bloodstream Larvae pass through lungs Larvae molt twice to form filariform larvae (infectious) Autoinfection

Slide 95: 

LAB FINDINGS Diagnosis rests on the microscopic identification of larvae (rhabditiform and occasionally filariform) in the stool or duodenal fluid. Examination of serial samples may be necessary, and not always sufficient, because direct stool examination is relatively insensitive. Culture techniques are the most sensitive, but are not routinely available in the West. Direct examination must be done on stool that is freshly collected and not allowed to cool down, because hookworm eggs hatch on cooling and the larvae are very difficult to distinguish from strongyloides. The duodenal fluid can be examined using techniques such as the Enterotest string or duodenal aspiration. Larvae may be detected in sputum from patients with disseminated strongyloidiasis.

Slide 96: 

TREATMENT Ivermectin-There is an auto-infective cycle of roughly two weeks in which Ivermectin should be re-administered however additional dosaging may still be necessary as it will not kill strongyloides in the blood or larvae deep within the bowels or diverticuli. Other drugs that are effective are albendazole and thiabendazole (25 mg/kg twice daily for 5 days-- 400mg maximum (generally))

Ascaris : 

Nematodes - Round worms” Separate sexes, GI tract. Pathogens: e.g. Ascaris lumbricoides Some are adapted to attach to gut wall, e.g. Hookworms. Ascaris

Slide 98: 

Nematodes (roundworms) Disease - Abdominal pain/discomfort (most found in the gut). Transmission - Fecal-oral via ova in stool. Detection Recognition of ova using stool microscopy. Identification of adult worms.

Ascaris lumbricoides : 

Ascaris lumbricoides Large Roundworm affects 1.5billion people worldwide -eggs ingested, worms hatch, migrate to lungs, then back to intestines worms from inhabitants of a single village (mainly children)

Slide 100: 

Ascaris is a genus of parasitic nematode worms known as the "giant intestinal roundworms". A. lumbricoides is the largest intestinal roundworm and is the most common helminth infection of humans worldwide, an infection known as ascariasis. Infestation can cause morbidity, and sometimes death, by compromising nutritional status, affecting cognitive processes, inducing tissue reactions, such as granuloma, and provoking intestinal obstruction or rectal prolapse. Symptoms Bloody sputum Cough Low-grade fever Vomiting worms Passing of worm in stool Gallstone formation Liver abscesses

Slide 101: 

Examination Abdominal X-ray Complete blood count Stool ova and parasite exam Pathology Lung phase A.lumbricoides is known as Ascaris pneumonitis. In the lung it causes hemorrhage, inflammation, bacterial infection. It also causes allergy in areas with seasonal transmission. Typically occurs at 6–14 days after initial exposure. Intestinal phase The intestinal phase causes malnourishment, intestinal blockage, verminous intoxication. A.lumbricoides will move around in the body in response to chemotherapy or fever. Typically occurs at 6 to 8 weeks after initial exposure treatment pyrantel pamoate given as a single dose of 10 mg/kg levamisole given as a single dose of 2.5 mg/kg mebendazole given as a single dose of 500 mg albendazole given as a single dose of 400 mg.sup The drugs prevent the worm from absorbing sugar in the intestine which is essential for its survival.

Slide 102: 

Filaria - filariasis Disease - Fevers, elephantiasis, swelling and deformity of limbs, genitalia. Transmission - Mosquito borne. Detection - Marasites (microfilaria) stained on blood film.

Slide 104: 

Pathogens - Schistosoma spp. (schistosomiasis). Disease - Effects of inflammation, hematuria. Transmission - Penetration of skin . Detection - Ova in stool/urine depending on species of schistosome.

Slide 106: 

= albendazole (a broad spectrum anthelmintic) combined with ivermectin =.A combination of diethylcarbamazine (DEC) and albendazole is also effective. TREATMENT

Myasis : 

Myasis It is the infestation of body tissues of animals by the larvae commonly known as maggots of two winged flies the diptheria Myasis occurs mainly in the tropics & is asssosiated with poor personal hygiene. Usually the female fly infests ova in open wounds or the natural body cavities. The flies lay over 500 eggs directly on diseased tissue the infestation of live human and vertebrate animals with dipterous larvae, which at least for a period, feed on the host's dead or living tissue, liquid body substances, or ingested food

Slide 110: 

Oral myiasis is a rare condition caused by the invasion of tissues by larvae of flies. A case of gingival myiasis is presented in a 12-year-old boy with learning disability. The patient was unaware of the lesion, although it produced a swelling partially covering the teeth. The lesion was treated with ether, which forced the larvae out, and irrigated with warm saline solution. Follow-up examination revealed complete subsidence and healing of the lesion.

Slide 111: 

Diagnostics one or more non-healing lesions on the skin, itchiness, movement under the skin or pain, discharge from a central punctum (tiny hole), or a small, white structure protruding from the lesion Treatment First the larvae must be eliminated through pressure around the lesion and the use of forceps. Secondly the wound must be cleaned and disinfected. slow release boluses containing ivermectin

Detection of GI protozoa – amoebae / flagellates : 

Detection of GI protozoa – amoebae / flagellates Stool mixed with parasite preservative, e.g. SAF (formalin based). Microscopic identification of organisms from a concentrated extract of stool. Microscopic identification of organisms using a stained slide made from a filtered stool suspension. Note: Parasite preservative kills all organisms; therefore, a preserved specimen cannot be used for culture.

Number of people infected/affected by parasitic diseases : 

Number of people infected/affected by parasitic diseases Diseases causing high mortality: Malaria (400M) Sleeping Sickness (0.5 M) Chagas (18M) Visceral Leishmaniasis (4M) Diseases causing morbidity & QL losses: Geohelminths (2B) Water & Foodborne Protozoans (1.5B) Schistosomiasis (200M) Lymphatic filariasis (120 M) Cysticercosis (?50M) Onchocerciasis (18M) Cutaneous Leishmaniasis (8M) Guinea worm (4M, now 60K)

MALERIA : 

MALERIA Malaria is a mosquito-borne infectious disease caused by a eukaryotic protist of the genus Plasmodium.. It is widespread in tropical and subtropical regions, including parts of the America. Five species of the plasmodium parasite can infect humans; the most serious forms of the disease are caused by Plasmodium falciparum. Malaria caused by Plasmodium vivax, Plasmodium ovale and Plasmodium malariae causes milder disease in humans that is not generally fatal. A fifth species, Plasmodium knowlesi, is a zoonosis that causes malaria in macaques but can also infect humans.

Plasmodium falciparum : 

Plasmodium falciparum - Malaria kills more people than any other infectious disease (1000-2000 per day) - protozoan (single-celled eukaryote, not a bacterium)

Oral manifestations : 

Oral manifestations These are due to systemic effects of disease as well as the side effects of prescribed medications & traditional treatments High fever – xerostomia & dehydration Oral dryness, tongue sticking to palate Difficulty with mastication , speech or swallowing Impaired taste, thirst licking of lip[s Burning & soreness of mucosa & tongue Lack of saliva- discomfort, increased susceptibility to caries, difficulty in eating & swallowing

Slide 118: 

Xerostomia - saliva substitutes, saliva stimulants, dentifrices, spray, gels, lozenges, mouthrinses, and a few behavior modifications. 1.1% NaF toothpaste at 5,000 ppm is particularly effective since it contains a built-in cleaning system and can be used once daily to promote tooth remineralization. Products containing amorphous calcium phosphate (ACP), casein phosphopeptide-ACP (CPP-ACP), and calcium sodium phosphosilicate may help remineralize enamel in patients who have xerostomia. Chewing xylitol-containing gum and/or consuming xylitol-containing lozenges to stimulate the salivary glands and inhibit the growth of Streptococcus mutans can also be helpful. Patients may find relief in sucking on ice chips or frequently sipping water throughout the day Patients should also refrain from consuming alcohol and caffeinated beverages because both have a dehydrating effect on the body.

Slide 119: 

anemia, which manifests as pallor of the tongue and buccal mucosa in the oral cavity. There are several causes of anemia in malaria patients, therefore, several oral manifestations of anemia exist. malaria-induced anemia: mucosal pallor, angular cheilitis, erythema, atrotemphy of the oral mucosa, and loss of filiform and fungiform papillae on the dorsum of the tongue.Mucosa and other oral variations of anemia can occur when the malaria infection suppresses bone marrow stem cells, prohibiting the production of red blood cells and when nutritional deficiencies exist, for example, iron, folic acid, or vitamin B12, prohibiting the normal development of red blood cells. Once the anemia diagnosis is made, the dental hygienist can provide nutritional counseling on iron-rich foods and accurately record sites of pallor or other changes in the mouth.

Slide 120: 

Oral Treatment There is no vaccine against malaria; individuals can only practice preventive behaviors and take recommended drugs to aid in preventing and/or managing malaria infection. Avoidance behaviors include: using indoor/outdoor residual sprays, eliminating water breeding grounds, using personal protection, using insecticidetreated bed nets, and avoiding mosquito biting prime times—particularly dusk and dawn. Suppression includes using antimalarial drugs. The drugs do not prevent initial infection through a mosquito bite (as a topical spray should) but instead prevent the development of malaria parasites in the blood. The seriousness of malaria is exacerbated by the spread of drug-resistant parasites. Therefore, recommended antimalaria medicines may be different due to availability, travel destinations, and durations or individual tolerance of the drug.

Slide 121: 

Preventions Strategies Dental hygienists should emphasize to patients receiving treatment for malaria that they must precisely follow anti-malaria treatment therapy doses and schedules, including advising against cutting pills in half or using only until symptoms disappear. When patients do not take the prescribed antimalarials as recommended, they increase the risk of treatment failure and potentially induce parasite resistance to the drugs. All medications must be used as prescribed. Dental hygienists can also bring awareness to malaria transmission through contaminated needles by promoting prevention strategies. Needles should never be reused, manipulated, or bent, and should be disposed of and handled in order to prevent injury and cross contamination. Health care workers should use the "scoop method" when recapping needles by using one hand to slide the needle end into the needle cap. Used needles should always be disposed of in a designated puncture-resistant sharps container.

Slide 122: 

Dental hygienists are well suited to aid in the research of malaria infections, their oral implications, and effective mouth care for individuals who have malaria. As our society becomes more and more global, an increased awareness of the oral implications of malaria is necessary for managing oral manifestations of malaria and ultimately improving care for at risk populations.

Classification : 

Classification Kingdom: Animalia (animals) Phylum: Acanthocephala (spiny-headed worms) Phylum: Annelida (segmented worms) Class: Hirudinea (leeches) Phylum: Arthropoda (insects) Subphylum: Chelicerata Class: Arachnida Order: Astigmata (mites) Order: Metastigmata (ticks) Subphylum: Crustacea Class: Branchiura Order: Arguloida Class: Cirripedia Order: Rhizocephala Subphylum: Atelocerata Class: Hexapoda Order: Anoplura (sucking lice) Order: Diptera (flies) Order: Hymenoptera (bees,wasps,ants) Order: Mallophaga (chewing lice) Order: Siphunculata (fleas)

Slide 124: 

Phylum: Nematoda (roundworms) Class: Adenophorea Class: Secernentea Class: Strongylida Class: Tylenchida Phylum: Platyhelminthes (flatworms,tapeworms,flukes) Class: Cestoda (tapeworms) Subclass: Cotyloda (pseudotapeworms) Class: Trematoda (flukes) Subclass: Digenea (flukes) Subclass: Monogenea (flukes) Class: Turbellaria (flatworms)

Slide 125: 

Kingdom: Protista (single-celled organisms) Phylum: Alveolates Group: Apicomplexa Group: Foraminifera Group: Dinoflagellata Group: Ciliata Class: Litostomatea Group: Diplomonadida Group: Euglenida Group: Kinetoplastida Group: Parabasalia

REFERENCES : 

REFERENCES Textbook of oral pathology- Shafer oral diseases in tropics- prbhu , daftari shear Textbook of general medicine – Davidson General medicine – P.J.Mehta Internet resources

Slide 127: 

THANK YOU FOR YOUR ATTENTION!