Overview of Parasitology PDF

Pharmaceutical Microbiology & Parasitology: Protozoa, Helminths, and Anthropod Owned By: Shane Marni G. Ligan, RPh Overview of Parasitology Symbiosis Types: Definition: Parasitism is one form of symbiosis, whe...

Pharmaceutical Microbiology & Parasitology: Protozoa, Helminths, and Anthropod Owned By: Shane Marni G. Ligan, RPh Overview of Parasitology Symbiosis Types: Definition: Parasitism is one form of symbiosis, where one Parasitology is the study of parasites, their hosts, organism benefits at the expense of another. Other and the relationship between them. It focuses on forms include: organisms that live on or inside another organism (the host) and cause harm. o Mutualism: Both organism’s benefit. ▪ Example: Gut bacteria in Key Concepts: ruminants help digest cellulose. Host: o Commensalism: One benefits without harming the other. Hosts are organisms that provide sustenance and ▪ Example: Entamoeba coli, a shelter for parasites. Hosts are classified as follows: non-pathogenic amoeba in human intestines. o Definitive Host (where sexual o Parasitism: One benefits at the reproduction occurs): The host in expense of the other. which the parasite reaches maturity or ▪ Example: Plasmodium undergoes sexual reproduction. falciparum causes severe ▪ Example: Humans act as malaria in humans. definitive hosts for Plasmodium spp. (malaria) Importance of Parasitology: where sexual reproduction occurs in mosquitoes. Medical: Understanding parasitic diseases o Intermediate Host (where immature like malaria, schistosomiasis, and filariasis. forms develop: Hosts in which the o Focuses on parasitic diseases that parasite undergoes development but affect humans. does not reach maturity. o Example: ▪ Example: Snails serve as ▪ Plasmodium spp. causes intermediate hosts for malaria, a leading cause of Schistosoma species. death globally. o Reservoir Host or incidental (not ▪ Giardia lamblia causes typical hosts but can be infected): giardiasis, leading to diarrhea Hosts that harbor parasites without and malabsorption. showing symptoms, acting as a Veterinary: Studying parasites affecting source of infection. livestock, wildlife and pets. ▪ Example: Rodents as o Example: reservoir hosts for o Haemonchus contortus (barber's pole Leishmania. worm) affects sheep and causes anemia. o Ctenocephalides spp. (fleas) infest dogs and cats. Parasite: The organism that lives at the Ecological: Examining parasites' roles in expense of the host. Parasites are classified ecosystems and their impact on biodiversity. based on their location in or on the host and o Example: their dependency: ▪ Parasites like Ribeiroia o Endoparasites: Live inside the host ondatrae can deform (e.g., helminths, protozoa). amphibians, affecting ▪ Ascaris lumbricoides population dynamics. (roundworm) inhabits the ▪ Parasites regulate host intestines. populations, maintaining ▪ Echinococcus granulosus ecosystem balance. forms cysts in the liver and Public Health: Studies how parasites spread lungs. and how to control outbreaks. o Ectoparasites: Live on the external o Example: surface of the host (e.g., lice, mites). ▪ Control programs for ▪ Pediculus humanus capitis Schistosoma focus on (head lice) infests human sanitation and snail control. scalp. ▪ Onchocerca volvulus, causing ▪ Sarcoptes scabiei (itch mite) river blindness, is managed causes scabies on skin. with mass ivermectin distribution. Pharmaceutical Microbiology & Parasitology: Protozoa, Helminths, and Anthropod Owned By: Shane Marni G. Ligan, RPh Key Terminologies in Parasitology apparatus, and endoplasmic reticulum. 1. Vector: An organism that transmits parasites o They are capable of diverse forms of between hosts. locomotion using structures like o Example: Anopheles mosquitoes flagella, cilia, or pseudopodia. transmit Plasmodium spp. (malaria). 2. Life Cycle Stages: 2. Zoonosis: Diseases transmitted from animals o Trophozoite: The active, feeding, and to humans. multiplying stage. o Example: Hydatid disease caused by o Cyst: The dormant, resistant stage Echinococcus granulosus. that enables survival outside the host. 3. Epidemiology: The study of disease ▪ Example: Entamoeba distribution and control in populations. histolytica cysts are o Example: Mapping malaria transmitted through prevalence to guide control contaminated food or water. measures. 3. Modes of Reproduction: 4. Life Cycle: The sequence of stages a parasite o Asexual Reproduction: Commonly by undergoes in its development. binary fission. o Example: ▪ Example: Plasmodium spp. ▪ Plasmodium involves a multiply in the liver and red complex life cycle with human blood cells through asexual and mosquito stages. reproduction. ▪ Taenia solium alternates o Sexual Reproduction: Occurs in between pigs and humans. certain life cycle stages, often within definitive hosts. Importance in Global Health ▪ Example: Plasmodium undergoes sexual reproduction in the mosquito's Neglected Tropical Diseases (NTDs): gut. Parasitic infections like schistosomiasis, 4. Locomotion: lymphatic filariasis, and soil-transmitted o Protozoa are classified based on their helminths affect millions in low-income method of movement: regions. ▪ Amoeboid: Use pseudopodia o Example: Schistosoma mansoni (e.g., Entamoeba histolytica). causes intestinal schistosomiasis in ▪ Flagellated: Use flagella (e.g., sub-Saharan Africa. Giardia lamblia). Emerging Parasitic Infections: ▪ Ciliated: Use cilia (e.g., Climate change and globalization have Balantidium coli). increased the spread of vector-borne ▪ Apicomplexan: Non-motile in diseases. their mature form but have o Example: Dengue fever caused by specialized organelles for host Aedes aegypti is spreading to new cell invasion (e.g., regions. Plasmodium spp.). One Health Approach: Recognizes the interconnectedness of human, animal, and environmental health in Classification: controlling parasitic diseases. o Example: Rabies control involves 1. Amoebae: both human vaccination and stray dog population management. Characteristics: o Move via pseudopodia. Protozoa o Live in aquatic environments or host tissues. Definition: Example: Entamoeba histolytica (causes Protozoa are single-celled eukaryotic organisms amoebiasis). capable of independent existence or that can either o Transmission: Fecal-oral route via live freely in the environment or exist as parasites in contaminated food or water. various hosts. Many protozoa have complex life o Pathology: Dysentery, liver cycles and unique adaptations to survive and thrive abscesses. within their hosts. o Diagnosis: Microscopy of stool samples showing trophozoites or Key Characteristics of Protozoa cysts. 1. Cell Structure: 2. Flagellates: o Protozoa are eukaryotic, meaning they have a nucleus and organelles Characteristics: such as mitochondria, a Golgi o Move using one or more whip-like flagella. Pharmaceutical Microbiology & Parasitology: Protozoa, Helminths, and Anthropod Owned By: Shane Marni G. Ligan, RPh o Found in blood, intestines, or o Non-motile in their mature forms urogenital tract. but have an apical complex for Examples: host cell invasion. o Complex life cycles often ▪ Giardia lamblia involving multiple hosts. o Transmission: Vector-borne ▪ Causes giardiasis, (mosquitoes), ingestion of leading to diarrhea and contaminated water or malabsorption. undercooked meat. ▪ Transmission: o Pathology: Fever, anemia, organ Ingestion of cysts from damage, opportunistic infections contaminated water or in immunocompromised patients. food. ▪ Symptoms: Watery Examples: stools, abdominal o Plasmodium spp. (causes cramps, and fatigue. malaria) ▪ Transmission: Anopheles ▪ Trypanosoma brucei mosquito bite. ▪ Pathology: Fever, chills, ▪ Causes African anemia, organ damage. sleeping sickness. o Toxoplasma gondii (causes ▪ Transmission: Tsetse toxoplasmosis) fly bite. ▪ Transmission: Ingestion of ▪ Symptoms: Fever, oocysts from cat feces or lymphadenopathy, tissue cysts in and neurological undercooked meat. disturbances. ▪ Pathology: Congenital infections, severe disease in immunocompromised ▪ Leishmania donovani (causes individuals. visceral leishmaniasis or kala- o Cryptosporidium parvum (causes azar) cryptosporidiosis) ▪ Causes cryptosporidiosis, ▪ Causes visceral leading to severe watery leishmaniasis (kala- diarrhea. azar). ▪ Transmission: Ingestion of ▪ Transmission: Fecal- oocysts in contaminated oral route, vector- water. borne (tsetse flies, sandflies). Examples of Protozoal Diseases ▪ Symptoms: Fever, splenomegaly, anemia. 1. Malaria (caused by Plasmodium spp.): o Symptoms: Cyclical fever, chills, ▪ Pathology: Diarrhea, malabsorption, sweating, anemia. o Transmission: Anopheles mosquito. systemic infections. o Prevention: Use of insecticide-treated nets (ITNs), prophylactic drugs (e.g., 3. Ciliates: chloroquine). o Treatment: Antimalarial drugs (e.g., Characteristics: artemisinin-based combination o Covered in tiny hair-like structures therapies). called cilia for movement. 2. Giardiasis (caused by Giardia lamblia): o Rarely pathogenic in humans. o Symptoms: Watery diarrhea, bloating, Example: Balantidium coli abdominal cramps. o The only ciliate known to infect o Transmission: Ingesting cysts from human. contaminated water. o Transmission: Ingestion of o Prevention: Boiling water, avoiding contaminated water or food, often contaminated food. associated with pig farming. o Treatment: Metronidazole. o Pathology: Causes balantidiasis, 3. Amoebiasis (caused by Entamoeba characterized by diarrhea and histolytica): colonic ulcers. o Symptoms: Dysentery, abdominal pain, liver abscess. 4. Apicomplexans: o Transmission: Contaminated food or water. Characteristics: o Prevention: Improved sanitation, safe drinking water. Pharmaceutical Microbiology & Parasitology: Protozoa, Helminths, and Anthropod Owned By: Shane Marni G. Ligan, RPh o Treatment: Metronidazole for invasive ▪ Example: Adult Ascaris forms. lumbricoides worms live in the 4. Cryptosporidiosis (caused by intestines. Cryptosporidium parvum): 3. Reproductive Capacity: o Symptoms: Severe diarrhea, o Helminths are prolific reproducers, especially in immunocompromised laying thousands to millions of eggs individuals. during their lifetime. o Transmission: Ingestion of oocysts ▪ Example: A single female from contaminated water. Ascaris worm can produce up o Prevention: Water treatment, to 200,000 eggs daily. hygiene. 4. Transmission: o Treatment: Nitazoxanide (limited o Helminths infect hosts through efficacy in immunosuppressed ingestion, skin penetration, or via patients). vectors. 5. African Trypanosomiasis (caused by 5. Host Location: Trypanosoma brucei): o Helminths are classified based on the o Symptoms: Fever, lymphadenopathy, tissues or organs they inhabit: sleep disturbances. ▪ Intestinal helminths: Found in o Transmission: Bite of infected tsetse the gastrointestinal tract. fly. ▪ Example: Hookworms o Prevention: Vector control, protective attach to the intestinal clothing. lining. o Treatment: Pentamidine or ▪ Tissue helminths: Found in melarsoprol (depending on the various tissues like muscles, stage). lungs, or liver. ▪ Example: Importance of Protozoa in Public Health Schistosoma mansoni resides in blood Protozoal infections are significant contributors to vessels of the liver. global disease burdens, particularly in tropical and subtropical regions. They can cause: Classification: Acute illnesses (e.g., malaria, amoebiasis). 1. Nematodes (Roundworms): Chronic diseases (e.g., visceral o Characteristics: Cylindrical, leishmaniasis). unsegmented, bilaterally symmetrical Opportunistic infections in with a complete digestive system. immunocompromised individuals (e.g., o Reproduce sexually; sexes are Toxoplasma gondii in HIV/AIDS). usually separate (dioecious). o Transmission: Fecal-oral, vector- Helminths borne, skin penetration. o Pathology: Intestinal obstruction, Definition: anemia, eosinophilia, lymphatic Helminths are parasitic worms that are large, blockages. multicellular organisms. They are large organisms o Examples: that are visible to the naked eye in their adult forms ▪ Ascaris lumbricoides (causes and are classified based on their body structure and ascariasis) life cycles. They typically reside in the gastrointestinal tract but can migrate to other tissues. a) Transmission: Ingestion of eggs in Key Characteristics of Helminths contaminated food or water. 1. Multicellular Structure: b) Pathology: Intestinal o Unlike protozoa, helminths are blockage, malnutrition, multicellular organisms with tissues and pulmonary and organs. symptoms (Löffler’s o They have specialized systems for syndrome during larval digestion, reproduction, and migration). excretion, but rely on their hosts for nutrients. ▪ Hookworms (Necator 2. Life Cycle Stages: americanus, Ancylostoma o Eggs: Laid by adult female helminths, duodenale): often passed in host feces or urine. o Larvae: The developmental stage, a) Causes hookworm often the infective form. disease. o Adults: Mature worms residing in b) Transmission: Skin specific host tissues. penetration by larvae in contaminated soil. Pharmaceutical Microbiology & Parasitology: Protozoa, Helminths, and Anthropod Owned By: Shane Marni G. Ligan, RPh c) Pathology: Anemia discomfort, and protein loss due to weight loss. blood feeding by adult 2. Cysticercosis: worms. Cysts in muscles, brain ▪ Enterobius vermicularis (neurocysticer (causes pinworm infection) cosis). ▪ Taenia saginata (Beef a) Causes enterobiasis. tapeworm): b) Transmission: a) Causes taeniasis. Ingestion of eggs via b) Transmission: contaminated hands Ingesting or objects. undercooked beef with c) Pathology: Intense larvae. anal itching, especially c) Pathology: Mild at night. gastrointestinal symptoms. ▪ Wuchereria bancrofti (causes ▪ Echinococcus granulosus lymphatic filariasis) (causes hydatid cyst disease) a) Causes lymphatic a) Transmission: filariasis Ingestion of eggs from (elephantiasis). contaminated soil or b) Transmission: direct contact with Mosquito bite (vector). infected dogs. c) Pathology: b) Pathology: Cysts in Lymphedema, leading liver, lungs, or other to gross swelling of organs causing limbs and genitals. pressure symptoms. 2. Cestodes (Tapeworms): 3. Trematodes (Flukes): o Characteristics: Flat, ribbon-like, o Characteristics: Leaf-shaped, segmented body; head (scolex) with unsegmented body; complex life suckers/hooks. cycle involving snails as intermediate o Lack a digestive system; absorb hosts. nutrients through their body surface. o Most are hermaphroditic, except for o Usually hermaphroditic (each blood flukes (e.g., Schistosoma spp.). segment has both male and female o Transmission: Contact with reproductive organs). freshwater containing infected snails. o Transmission: Ingestion of o Pathology: Liver damage, bladder undercooked meat or contaminated dysfunction, inflammation. food. o Examples: o Pathology: Nutritional deficiencies, ▪ Schistosoma spp. (Blood cyst formation in organs. flukes): o Examples: a) Causes ▪ Taenia solium (pork schistosomiasis. tapeworm, causes b) Transmission: Skin cysticercosis) penetration by a) Causes taeniasis cercariae in (intestinal infection) contaminated and cysticercosis freshwater. (tissue infection). c) Pathology: b) Transmission: 1. Schistosoma 1. Taeniasis: mansoni and Ingesting S. japonicum: undercooked Intestinal and pork containing hepatic larvae. damage. 2. Cysticercosis: 2. Schistosoma Ingesting eggs haematobium: from Bladder contaminated inflammation food or water. and hematuria. c) Pathology: ▪ Fasciola hepatica (Liver 1. Taeniasis: fluke): Abdominal a) Causes fascioliasis. Pharmaceutical Microbiology & Parasitology: Protozoa, Helminths, and Anthropod Owned By: Shane Marni G. Ligan, RPh b) Transmission: 5. Public Health Education: Ingestion of o Raising awareness about metacercariae on transmission routes and prevention contaminated water methods. plants (e.g., watercress). Arthropods c) Pathology: Liver inflammation and Definition: biliary obstruction. Arthropods are invertebrate animals with jointed limbs, segmented bodies, and a chitinous ▪ Clonorchis sinensis (Chinese liver exoskeleton. In parasitology, arthropods are fluke): significant as vectors, parasites, and pathogens that a) Causes clonorchiasis. directly or indirectly cause disease in humans and b) Transmission: animals. They belong to the phylum Arthropoda, the Ingestion of largest group in the animal kingdom. metacercariae in raw or undercooked Key Characteristics of Arthropods freshwater fish. c) Pathology: Biliary 1. Body Structure: obstruction, o Segmented body divided into: cholangiocarcinoma. ▪ Head: Contains sensory organs (e.g., antennae, Examples of Helminth Infections and Their Impact compound eyes). ▪ Thorax: Bears appendages 1. Soil-Transmitted Helminths (STH): for movement (e.g., legs, o Includes Ascaris lumbricoides, wings). Trichuris trichiura (whipworm), and ▪ Abdomen: Contains hookworms. reproductive and other vital o Common in tropical and subtropical organs. regions with poor sanitation. o Possess a hard exoskeleton made of o Symptoms: Malnutrition, anemia, chitin, providing protection and impaired growth and cognitive support. development in children. 2. Adaptations: 2. Lymphatic Filariasis: o Highly adaptable to various o Caused by Wuchereria bancrofti or environments (aquatic, terrestrial, or Brugia malayi. parasitic). o A leading cause of permanent o Specialized mouthparts for feeding, disability globally. such as piercing-sucking o Symptoms: Lymphedema and (mosquitoes) or biting-chewing elephantiasis. (ticks). 3. Cysticercosis: 3. Reproduction: o Leading cause of preventable o Most reproduce sexually with high epilepsy in endemic areas. fecundity. o Life-threatening when cysts form in o Undergo metamorphosis (complete the brain. or incomplete) during development. 4. Hydatid Disease: ▪ Complete metamorphosis: o Caused by Echinococcus granulosus. Egg → Larva → Pupa → Adult o Cysts can grow large, causing (e.g., mosquitoes). pressure effects in vital organs. ▪ Incomplete metamorphosis: Egg → Nymph → Adult (e.g., Prevention and Control of Helminth Infections lice). 4. Significance in Parasitology: 1. Sanitation and Hygiene: o Vectors: Transmit pathogens o Improved access to clean water and (viruses, bacteria, protozoa, proper disposal of human waste. helminths). o Handwashing with soap, especially in o Ectoparasites: Feed on the blood or endemic areas. tissues of hosts, causing direct harm. 2. Cooking Practices: o Pathogens: Cause diseases o Proper cooking of meat and fish to themselves (e.g., scabies from mites). destroy infective larvae. 3. Mass Drug Administration (MDA): Classification of Medically Important Arthropods o Periodic deworming programs using antiparasitic drugs like albendazole or 1. Insects ivermectin. 4. Vector Control: Characterized by a body divided into three o Use of insecticide-treated nets and parts (head, thorax, abdomen), six legs, and mosquito control for filariasis. usually one or two pairs of wings. Pharmaceutical Microbiology & Parasitology: Protozoa, Helminths, and Anthropod Owned By: Shane Marni G. Ligan, RPh Examples: 3. Crustaceans Mosquitoes (Anopheles, Aedes, Culex) as Aquatic arthropods with segmented bodies, vectors: jointed limbs, and a hard exoskeleton. o Anopheles: Transmits malaria Some serve as intermediate hosts for (Plasmodium spp.). helminths. o Aedes aegypti: Transmits dengue, Zika virus, chikungunya, and yellow Examples: fever. o Culex: Transmits lymphatic filariasis Copepods (Cyclops spp.): and West Nile virus. o Intermediate hosts for Dracunculus Fleas (Xenopsylla cheopis): medinensis (guinea worm) and o Transmit Yersinia pestis (plague) and Diphyllobothrium latum (fish Rickettsia typhi (murine typhus). tapeworm). Lice: Crabs and Crayfish: o Head louse (Pediculus humanus o Intermediate hosts for Paragonimus capitis): Causes pediculosis. westermani (lung fluke). o Body louse (Pediculus humanus corporis): Transmits epidemic typhus Medically Important Arthropod-Associated Diseases (Rickettsia prowazekii). o Pubic louse (Pthirus pubis): Causes 1. Vector-Borne Diseases: itching and irritation in pubic areas o Malaria: Mosquito-borne (crabs). (Anopheles). Sandflies (Phlebotomus, Lutzomyia): o Dengue and Zika virus: Transmitted o Transmit Leishmania spp. by Aedes aegypti. (leishmaniasis). o Plague: Spread by fleas (Xenopsylla Tsetse flies (Glossina spp.): cheopis). o Transmit Trypanosoma brucei o Lyme Disease: Tick-borne (Ixodes). (African sleeping sickness). o Leishmaniasis: Sandfly-borne (Phlebotomus). 2. Arachnids o Sleeping Sickness: Tsetse fly-borne (Glossina). Characterized by a body divided into two 2. Ectoparasitic Infestations: parts (cephalothorax and abdomen), eight o Scabies: Caused by Sarcoptes legs, and no wings or antennae. scabiei. o Pediculosis: Infestation by lice Examples: (Pediculus humanus). 3. Allergic Reactions: Ticks (Ixodes, Rhipicephalus, Amblyomma): o Caused by bites/stings (e.g., bee o Transmit diseases such as: stings) or allergens from mites. ▪ Lyme disease (Borrelia 4. Direct Pathogenic Effects: burgdorferi). o Spider bites (Latrodectus, ▪ Rocky Mountain spotted fever Loxosceles) and scorpion stings (Rickettsia rickettsii). (Androctonus spp.) causing systemic ▪ Tularemia (Francisella symptoms or envenomation. tularensis). Mites: Prevention and Control of Arthropod-Borne Diseases o Scabies mite (Sarcoptes scabiei): ▪ Causes scabies by burrowing 1. Personal Protection: into the skin. o Use insect repellent, wear long ▪ Symptoms: Intense itching, clothing, and sleep under insecticide- skin rash. treated nets (ITNs). o House dust mites 2. Environmental Control: (Dermatophagoides spp.): o Reduce breeding sites of vectors ▪ Cause allergic reactions (e.g., stagnant water for mosquitoes). (asthma, rhinitis). o Use larvicides and pesticides to Spiders and Scorpions: control populations. o Venomous species can cause 3. Hygiene and Sanitation: envenomation leading to pain, o Maintain cleanliness to prevent systemic reactions, or even death. infestations by lice, fleas, and mites. ▪ Example: Black widow spider 4. Vector Control Programs: (Latrodectus spp.), scorpions o Government initiatives to control (Centruroides spp.). vector populations, such as spraying insecticides and implementing mass drug administration in endemic areas. 5. Public Awareness: Pharmaceutical Microbiology & Parasitology: Protozoa, Helminths, and Anthropod Owned By: Shane Marni G. Ligan, RPh o Educate communities on the importance of controlling arthropod populations and preventing bites or infestations.