MS-m5l1 PDF Lecture Outline - Infectious Diseases

PRNU131 | Care of Clients with Problems in the Oxygenation, Fluid & Electrolyte, Infectious, Inflammatory,.Immunologic Response, Cellular Aberrations, Acute & Chronic – NCM 112 Third Year | First Semester M5 – Infectious /...

PRNU131 | Care of Clients with Problems in the Oxygenation, Fluid & Electrolyte, Infectious, Inflammatory,.Immunologic Response, Cellular Aberrations, Acute & Chronic – NCM 112 Third Year | First Semester M5 – Infectious / Communicable Disease LECTURE OUTLINE  Epidemics and Pandemics – Some communicable I. Understanding and Managing Communicable diseases have the potential to cause outbreaks, epidemics, and Infectious Diseases or even global pandemics when they spread widely across II. Communicable Diseases Affecting the Respiratory System different regions or countries III. Common Communicable Diseases Affecting Epidemiologic Triangle Model Triad of Disease Causation the Integumentary System IV. Common Infectious/Communicable Disease of the Gastrointestinal System V. Common Infectious/Communicable Disease of the Genitourinary And Lymphatic System Understanding and Managing Communicable and Infectious Diseases  Also known as an infectious or contagious disease, is an illness caused by microorganisms such as bacteria, viruses, parasites, or fungi that can be spread from one person, animal, or environment to another.  These diseases are typically transmitted through various means, including direct and indirect contact, airborne and vector-borne transmission.  Communicable diseases can range from mild to severe and may have the potential to lead to outbreaks or epidemics if not controlled properly.  A framework used to explain how communicable diseases  Infectious – this disease is caused by pathogenic microbial occur and spread. It consists of three interconnected agents, such as viruses, bacteria, or other microorganisms. components: Agent, Host, and Environment. Infectious diseases can be spread in a variety of ways. Understanding these elements helps in identifying the Some infectious diseases spread in more than one way. factors involved in disease outbreaks and developing Major ways include: strategies for prevention and control.  The agent is the cause of disease - Direct contact with an infected person, animal, or their  The host is an organism, usually a human or an animal, that discharges - Direct contact with a contaminated object harbors the disease - Contaminated food and water  The environment are those surroundings and conditions - Disease-carrying insects external to the human or animal that cause or allow disease  Contagious – a disease is contagious when it spreads transmission; and time accounts for incubation periods, the through direct, bodily contact with an infected person, their life expectancy of the host or pathogen, and duration of the discharges, or an object or surface they have contaminated course of illness or condition Significance and Impact of CDs on individuals, communities, and  Causative Agents – CDs are caused by infectious agents, societies which can include bacteria (TB), viruses (influenza),  Public Health Threat: CDs pose a significant threat to parasites (malaria), or fungi (athlete's foot). public health, as they can spread rapidly within communities  Modes of Transmission – These diseases can be and across borders. Outbreaks and epidemics can strain transmitted through various routes, including person-to- healthcare systems and resources. person contact, contaminated surfaces or objects,  Morbidity and Mortality: CDs can cause illness and death. respiratory droplets, sexual contact, insect vectors, etc. The severity of these diseases varies, with some causing - Direct Transmission – Person-to-person contact mild symptoms while others can be life-threatening. (e.g., touching, kissing, sexual contact) Diseases like HIV/AIDS, TB, and malaria have claimed - Indirect Transmission – Coughing, sneezing, or millions of lives. talking produces droplets that can spread diseases like  Economic Impact: CDs can have substantial economic the flu or COVID-19 consequences. The costs associated with healthcare, - Airborne Transmission – Microorganisms remain treatment, lost productivity due to illness, and reduced suspended in the air and can be inhaled (e.g., economic activity during outbreaks can be substantial. tuberculosis, measles) These economic losses can affect individuals, businesses, - Vector-borne Transmission – Spread through insects and governments. or animals (e.g., malaria, dengue, Lyme disease).  Social Disruption: During outbreaks, social disruption can  Contagiousness – many communicable diseases are occur as schools, businesses, and public gatherings are contagious, meaning they can easily spread from an closed or restricted to limit the spread of disease. infected person to others. The level of contagiousness can Quarantine measures and travel restrictions can disrupt vary among diseases. daily life and have social and psychological consequences.  Incubation Period – CDs often have an incubation period  Healthcare Burden: CDs can overwhelm healthcare during which an infected individual may not yet show systems. Hospitals and clinics may be inundated with symptoms but can still transmit the disease to others patients, leading to a shortage of resources and healthcare  Symptoms – symptoms of communicable diseases can workers. This can hinder the treatment of other medical vary widely and may include fever, cough, rash, diarrhea, conditions. fatigue, and more, depending on the specific disease  Stigmatization: People with certain CDs, such as  Prevention and Control – strategies for preventing and HIV/AIDS, have faced stigma and discrimination. This can controlling communicable diseases include vaccination, prevent individuals from seeking testing, treatment, and good hygiene practices (e.g., handwashing), use of support, which, in turn, can hinder disease control efforts. protective barriers (e.g., condoms), isolation and quarantine measures, and public health interventions Maglanque, E.|Nicerio, I.|Tolentino, H.|69  PRNU131 | Care of Clients with Problems in the Oxygenation, Fluid & Electrolyte, Infectious, Inflammatory,.Immunologic Response, Cellular Aberrations, Acute & Chronic – NCM 112 Third Year | First Semester  Vulnerable Populations: Vulnerable populations, including The Environment the elderly, children, pregnant women, and those with  The environment includes the external factors that affect weakened immune systems, are at greater risk of severe the agent and host interaction. This can be physical (e.g., illness from CDs. Health disparities can be exacerbated climate, geography), biological (e.g., presence of vectors during outbreaks. like mosquitoes), or social (e.g., crowded living conditions,  Global Health Security: CDs are a global health security healthcare access). concern. Cross-border transmission can lead to pandemics  The environment plays a role in supporting or inhibiting the that affect multiple countries. This highlights the need for spread of disease. international collaboration and information sharing to control  Example: Malaria is more common in tropical environments outbreaks. where mosquitoes thrive, whereas poor ventilation can  Preventable with Vaccination: Many CDs are preventable increase the risk of tuberculosis transmission through vaccination. Immunization programs have  Climate and Weather: Environmental factors like successfully reduced the prevalence of diseases like polio, temperature, humidity, and precipitation can influence the measles, and hepatitis B, demonstrating the potential to survival and transmission of pathogens. For example, some eliminate or control these diseases. diseases, like influenza, tend to be more common in colder,  Research and Innovation: CDs drive research and drier conditions. innovation in healthcare. Efforts to understand and combat  Geography and Topography: The geographical features these diseases have led to advancements in diagnostics, of an area, such as mountains, rivers, and forests, can treatments, and vaccine development. impact the distribution of disease vectors and reservoirs,  Behavioral Changes: Outbreaks of CDs often lead to affecting disease prevalence. changes in public behavior, such as increased  Vector-Borne Diseases: The environment can influence handwashing, mask-wearing, and social distancing. These the habitat and breeding conditions of disease vectors such behavioral changes can persist even after the outbreak as mosquitoes or ticks (for diseases like Lyme disease). subsides. Changes in environmental conditions can impact vector The Agent/Etiologic Agent/Causative Agent populations and distribution.  Agents of infectious diseases include bacteria, viruses,  Water and Sanitation: Access to clean water and proper parasites, fungi, and molds sanitation facilities is critical for preventing waterborne  Example: For malaria, the agent is the Plasmodium diseases like cholera and dysentery. The environment, parasite; for tuberculosis, it's Mycobacterium tuberculosis including water sources and sewage systems, plays a  The agent must be present for disease to occur, but other crucial role in disease transmission. factors, such as the strength of the pathogen (virulence) and  Urbanization and Population Density: High population the dose, influence whether infection occurs density in urban areas can facilitate the rapid spread of CDs. - Pathogenicity – ability to cause disease Environmental factors within cities, such as sanitation - Virulence – potency of organism which influence infrastructure and housing conditions, can also impact course of the disease disease transmission. - Dose – the number of causative agent  Zoonotic Diseases: which are transmitted between - Infectivity – ability to enter the body and move to animals and humans, often have environmental tissues components. Changes in land use, deforestation, and - Antigenicity – ability to stimulate antibody response human encroachment into wildlife habitats can increase the The Host risk of zoonotic disease transmission.  The host is the individual or organism that harbors the  Travel and Trade: Globalization and ↑ human mobility disease-causing agent contribute to the spread of CDs. Air travel, trade, and  The level of immunity, genetic makeup, level of exposure, migration can quickly transport pathogens from one region state of health, and overall fitness of the host can determine to another, affecting disease dynamics. the effect a disease organism will have on it. The Time  Host factors that affect susceptibility to disease include:  Time includes the severity of illness in relation to how long - Genetics – inherited resistance or vulnerability to a person is infected or until the condition causes death or certain infections passes the threshold of danger towards recovery - Immune Status – immunocompromised individuals  Delays in time from infection to when symptoms develop, are more at risk duration of illness, and threshold of an epidemic in a - Age, sex, lifestyle, and pre-existing conditions – population are time elements with which the epidemiologist smoking, poor nutrion is concerned  Example: in HIV infection, the host is the person exposed to  Incubation Period: The incubation period is the time the virus between when a person is exposed to a pathogen and when  Primary Host: The primary host is the organism in which a they start showing symptoms of the disease. The length of pathogen naturally lives and reproduces. For many human the incubation period can vary depending on the specific diseases, humans are the primary host. In such cases, the disease and the individual's immune response. pathogen has evolved to specifically infect and reproduce  Latent Period: In some diseases, there is a latent period within human hosts. during which the pathogen is present in the host's body but  Secondary Host: In some cases, pathogens have multiple is not actively causing symptoms. This is commonly seen in hosts in their life cycle. For example, a parasite might infect diseases like HIV, where the virus can remain latent for a primary host (e.g., a mosquito) and then be transmitted to years before symptoms appear. a secondary host (e.g., a human) when the mosquito bites  Disease Progression: The time it takes for a CDs to the secondary host. progress from mild symptoms to severe illness can vary. Understanding this progression is important for healthcare providers to make informed decisions about treatment and care. Maglanque, E.|Nicerio, I.|Tolentino, H.|70  PRNU131 | Care of Clients with Problems in the Oxygenation, Fluid & Electrolyte, Infectious, Inflammatory,.Immunologic Response, Cellular Aberrations, Acute & Chronic – NCM 112 Third Year | First Semester  Transmission Dynamics: Time is a crucial factor in  The Infection Cycle is like a chain consisting of six links. To understanding how CDs spread within populations. For produce disease, each link of the infectious process must example, the time an infected individual remains contagious be present in a logical sequence. Removing one link in the and capable of transmitting the disease to others is an chain will control the cycle of infection. important consideration for public health interventions.  The "Chain of Infection" is a concept used in epidemiology  Epidemic Curve: Epidemiologists use time-based data to and public health to describe the sequence of events that create epidemic curves, which show the number of new must occur for an infectious disease to spread from one cases of a disease over time. These curves help identify person to another. It consists of a series of interconnected trends, estimate the rate of disease spread, and assess the links or stages that, if broken or interrupted, can prevent the impact of control measures. transmission of the infectious agent.  Recovery and Immunity: The time it takes for an individual Chain of Infection to recover from a CDs and develop immunity against future  Agent – The microorganism that causes the disease infections varies. In some cases, individuals may remain (bacteria, virus) immune for a lifetime, while in others, immunity may wane  Reservoir – The habitat where the agent lives (humans, over time. animals, environment)  Public Health Response: Time is of the essence in  Portal of Exit – The way the agent leaves the reservoir responding to outbreaks and epidemics. Rapid identification (respiratory secretions, feces) of cases, contact tracing, isolation of infected individuals,  Mode of Transmission – How the agent spreads from one and vaccination campaigns all rely on timely actions to host to another control the spread of disease. - Direct Contact  Vaccine Development: The development of vaccines - Indirect Contact against CDs involves a series of stages and often takes - Airborne Transmission years. Researchers need time to conduct preclinical - Vector-Borne Transmission studies, clinical trials, and safety assessments before  Portal of Entry – The way the agent enters a new host vaccines can be approved and distributed. (broken skin, respiratory tract)  Seasonal Patterns: Some CDs exhibit seasonal patterns,  Susceptible Host – A person who is vulnerable to infection with higher transmission rates during specific times of the (Individuals with weakened immune systems) year. Understanding these patterns is essential for ETIOLOGIC AGENT/CAUSATIVE AGENT METAZOA preparedness and response efforts.  Multicellular animals, many of which are parasites  Long-Term Trends: Analyzing CDs data over time allows  These organisms are characterized by their complex, public health officials to identify long-term trends, such as multicellular structure, as opposed to single-celled animals changes in disease incidence, emergence of drug like protozoa. The term "Metazoa" is used to distinguish resistance, and shifts in disease distribution. THE INFECTION CYCLE/CHAIN OF INFECTION these animals from single-celled life forms and to highlight their shared characteristics as multicellular organisms.  Reproduction: Reproduce sexually, although some may also have asexual reproduction methods. Sexual reproduction involves the fusion of specialized reproductive cells (sperm and eggs) to produce offspring. Key Characteristics of Metazoa  Multicellularity – Metazoans are composed of multiple cells that perform specialized functions.  Differentiated Tissues – cells in metazoans are organized into tissues such as muscles, nerves, and epithelial tissues, each with specific roles  Eukaryotic Cells – like all animals, metazoans have cells with a true nucleus and membrane-bound organelles  Heterotrophy – they are heterotrophs, meaning they obtain energy by consuming other organisms rather than through photosynthesis or chemosynthesis.  Development – metazoans go through a developmental process, starting from a fertilized egg (zygote) that divides and differentiates into various cell types and tissues. Classification of Metazoa  Metazoans are divided into various phyla based on body  When a pathogen enters its host and multiplies inside of it, plans, symmetry, and organ systems. we term that process an infection. A pathogen can be  Porifera (sponges) – the simplest metazoans, lacking true anything you can imagine, such as a virus, bacterium, tissues and organs. fungus, parasite, or even a prion (an abnormally shaped  Cnidaria (jellyfish, corals) – organisms with radial symmetry protein that causes disease). When tissues /organs are and specialized stinging cells (cnidocytes) damaged as a result of infection and the body failed to  Platyhelminthes (flatworms) – simple, bilaterally function normally then the client enters a Disease state. symmetrical animals with no body cavity (acoelomates).  The infection cycle, also known as the disease transmission  Arthropoda (insects, crustaceans) – the largest phylum, cycle, refers to the series of events and interactions that consisting of animals with exoskeletons, segmented bodies, occur in the spread of an infectious agent from one host to and jointed limbs another. Understanding the infection cycle is vital for  Mollusca (snails, octuposes) – soft-bodied animals, often identifying points at which interventions can be with a hard external shell implemented to prevent or control the transmission of CDs Maglanque, E.|Nicerio, I.|Tolentino, H.|71  PRNU131 | Care of Clients with Problems in the Oxygenation, Fluid & Electrolyte, Infectious, Inflammatory,.Immunologic Response, Cellular Aberrations, Acute & Chronic – NCM 112 Third Year | First Semester  Chordata (vertebrates like fish, birds, mammals) –  Lifecycle organisms with a notochord, a dorsal nerve cord, and in - Eggs are ingested and hatch into larvae in the most cases, a vertebral column intestines. Human Relevance - Larvae then migrate to the lungs via the bloodstream,  Many metazoans, including livestock and fish, are vital for where they mature, are coughed up, and swallowed. food production, while others, like parasites (e.g., worms), - They return to the intestines as adult worms, where can cause diseases in humans and animals. they live and reproduce. Examples of Metazoans  Symptoms  Simple Metazoans – sponges and jellyfish, which lack - Mild infections may cause no symptoms. complex organ systems - Heavy infections can lead to abdominal pain,  Complex Metazoans – insects, reptiles, birds, and malnutrition, bloating, and sometimes intestinal mammals, which have intricate organ systems such as blockage. circulatory, respiratory, and nervous systems. - During the lung migration phase, some may experience Trichinella spiralis coughing, wheezing, or fever.  Prevention - Practice good hand hygiene, especially before eating and after using the bathroom. - Wash fruits and vegetables thoroughly and ensure safe sanitation.  Treatment  Parasitic roundworm causing Trichinellosis, transmitted - Antiparasitic medications like albendazole or through undercooked meat mebendazole are effective in eliminating the worms.  Lifecycle Necator americanus - After ingestion, larvae are released in the stomach, mature into adult worms in the intestines, and reproduce. - New larvae then penetrate the intestinal wall and travel through the bloodstream to muscles, where they encyst (form cysts) and can live for years.  Symptoms - Early: Nausea, diarrhea, abdominal pain. - Later: Muscle pain, swelling, fever, and weakness as larvae invade muscles.  Prevention  Transmitted through feces-contaminated water and soil. - Thoroughly cook meat, especially pork, to kill larvae. Infestation can cause chronic anemia that often results in - Freezing meat can also help destroy larvae. retarded mental and physical development of children.  Treatment  Hookworms are parasitic nematode worms that infect the - Antiparasitic medications like albendazole are used intestines of humans and other animals. There are several to treat trichinosis, especially in the early stages. species of hookworms that can cause infections in humans, Ascaris lumbricoides but the two most common species are Ancylostoma duodenale and Necator americanus.  Lifecycle - Infective Larvae: Hookworm larvae in the soil become infective when they mature to a specific stage. They can penetrate the skin of humans or animals that come into contact with contaminated soil, typically through bare feet or hands. - Migration to the Lungs: Once inside the host, the larvae migrate through the bloodstream to the lungs. In  Ascariasis, a disease usually accompanied by colicky pains the lungs, they move up the respiratory tract, causing and diarrhea, caused by the presence of Ascaris symptoms such as coughing and throat irritation. They (nematode, roundworm) in the GI canal are then swallowed and reach the small intestine.  Ascaris are pale white or pinkish in color and can grow up - Adult worms: In the small intestine, the larvae mature to 35 cm (14 inches) in length into adult worms. These worms attach themselves to  A nematode is a type of roundworm belonging to the the intestinal wall using hook-like mouthparts and feed phylum Nematoda. Nematodes are unsegmented, on the host's blood. cylindrical worms with a complete digestive system - Egg Production: Adult female hookworms lay eggs, (mouth to anus). They are one of the most diverse and which are then passed in the host's feces. These eggs abundant groups of animals on Earth, found in various can contaminate the soil. environments, including soil, freshwater, marine habitats, - Continued Transmission: When people defecate in and as parasites in plants, animals, and humans. areas with poor sanitation or when human waste is  Transmission: Primarily transmitted through the ingestion used as fertilizer, the contaminated soil can contain of Ascaris eggs present in contaminated food, water, or soil. hookworm eggs. This perpetuates the cycle by allowing The eggs are passed in the feces of infected individuals and new hosts to become infected when they come into can survive in the environment for extended periods. contact with the soil. Infection occurs when a person consumes food or water contaminated with these eggs. Maglanque, E.|Nicerio, I.|Tolentino, H.|72  PRNU131 | Care of Clients with Problems in the Oxygenation, Fluid & Electrolyte, Infectious, Inflammatory,.Immunologic Response, Cellular Aberrations, Acute & Chronic – NCM 112 Third Year | First Semester  Symptoms - Egg Production: Adult female worms lay eggs, which - Anemia (due to blood loss caused by the worms) are excreted in the urine (S. haematobium) or feces (S. - Abdominal pain mansoni and S. japonicum) of infected individuals. - Diarrhea - Eggs in Water: Eggs released into the environment - Malnutrition and stunted growth (especially in children) hatch into miracidia in freshwater, and miracidia infect - Skin rashes or itching at the site of larval penetration snail intermediate hosts. (often called "ground itch") - Cercarial Production: Inside snails, miracidia develop - Fatigue and weakness into cercariae, which are released into the water,  Diagnosis completing the life cycle. - Usually based on identifying eggs in a stool sample.  Symptoms Blood tests can also detect anemia or eosinophilia (an - Can vary depending on the species of Schistosoma increased number of a type of white blood cell) and the stage of infection. Early-stage infections may associated with the infection. be asymptomatic, but chronic infections can lead to:  Treatment - Abdominal pain - Treated with antiparasitic medications such as - Diarrhea albendazole or mebendazole. These medications kill - Bloody urine (hematuria in S. haematobium infection) the adult worms and larvae, allowing the body to expel - Liver enlargement and damage (hepatosplenic disease them naturally. in S. mansoni and S. japonicum infections)  Prevention - Bladder wall damage (in S. haematobium infection) - Improved sanitation and sewage disposal to reduce - Malnutrition and growth impairment in children contamination of soil with hookworm eggs. - Organ damage and potentially life-threatening - Wearing shoes or protective footwear to prevent larval complications in severe cases penetration through the skin.  Diagnosis - Deworming programs in endemic areas to treat and - Typically made by identifying schistosome eggs in prevent infections, especially in children. urine or stool samples or by detecting antibodies - Health education to promote proper hygiene practices. against the parasite in blood tests. Imaging studies, Schistosoma japonicum, S. haematobium, and S. mansoni such as ultrasound, may be used to assess organ damage.  Treatment - Schistosomiasis can be treated with specific antiparasitic drugs, such as praziquantel, which effectively kill the adult worms. Mass drug administration (MDA) programs are implemented in endemic areas to treat and control the disease.  Prevention  Schistosomiasis, also known as bilharzia, is caused by a - Preventing schistosomiasis involves: blood fluke and transmitted through contaminated water. - Avoiding contact with contaminated freshwater. Symptoms are related to the number and location of eggs - Providing safe drinking water sources. in the human body, and may involve the liver, intestines, - Health education on the risks of contamination. spleen, urinary tract, and reproductive system. - Snail control programs to reduce the number of  Schistosoma mansoni: Primarily found in Africa and South infected intermediate hosts. America. - Regular deworming of at-risk populations.  Schistosoma japonicum: Found in East Asia. PROTOZOA  Schistosoma haematobium: Common in Africa and the  They are classified in the kingdom Protista, although this Middle East. classification is somewhat outdated, as many protozoa are  In the Philippines, schistosomiasis is primarily found in now grouped into various subgroups based on genetic and certain regions, particularly in areas with freshwater bodies morphological characteristics. that are conducive to the lifecycle of the schistosomiasis- Cell Structure and Characteristics causing parasites. Key areas include:  Eukaryotic: Protozoa are eukaryotic organisms, which  Western Visayas: Particularly in the provinces of Iloilo, means they have a true nucleus and membrane-bound Capiz, and Aklan. organelles.  Central Luzon: Regions like Pampanga and Bulacan have  Single-Celled: Most protozoa are unicellular, although reported cases. some colonial forms exist.  Mindanao: Areas such as Zamboanga Peninsula and  Diversity: Protozoa exhibit a wide range of shapes, sizes, Davao. and structures. They can be amoeboid, flagellated, ciliated,  Lifecycle: or non-motile. - Cercarial Stage: The infectious stage of the parasite is Habitats the cercaria, which is released by snail hosts that have  Aquatic: Many protozoa inhabit freshwater and marine become infected with schistosome larvae. environments, including lakes, rivers, oceans, and ponds. - Penetration of Human Skin: When individuals meet  Terrestrial: Some protozoa can be found in soil and contaminated water, cercariae penetrate the skin and decaying organic matter in terrestrial ecosystems. transform into schistosomulae, which enter the  Symbiotic: Certain protozoa are symbiotic, meaning they bloodstream. live in close association with other organisms, such as in the - Migration and Maturity: The schistosomulae migrate guts of animals or in the tissues of plants. to the veins of the liver (S. mansoni and S. japonicum) or the bladder (S. haematobium), where they mature into adult worms. Maglanque, E.|Nicerio, I.|Tolentino, H.|73  PRNU131 | Care of Clients with Problems in the Oxygenation, Fluid & Electrolyte, Infectious, Inflammatory,.Immunologic Response, Cellular Aberrations, Acute & Chronic – NCM 112 Third Year | First Semester Key Characteristics:  Amoebic Dysentery: Caused by Entamoeba histolytica,  Cell Structure leading to severe gastrointestinal issues. - Protozoa are unicellular and have complex cellular  Giardiasis: Caused by Giardia lamblia, resulting in diarrhea structures, including a nucleus and organelles. and abdominal pain. - They can exhibit different shapes and sizes.  Nutrition - They can be heterotrophic (feeding on organic matter) or autotrophic (performing photosynthesis). - Many protozoa engulf food through a process called phagocytosis.  Movement - Flagella: whip-like structures for swimming.  Sleeping Sickness: Caused by Trypanosoma brucei, - Cilia: tiny hair-like structures for locomotion and transmitted by tsetse flies. Importance in Ecosystems feeding.  Protozoa play a crucial role in nutrient cycling and as a food - Pseudopodia: temporary extensions of the cell body source for larger organisms in the food web. for movement and capturing food.  They can also help decompose organic matter, contributing  Reproduction to soil health. - Asexual Reproduction: Protozoa primarily reproduce Ecological Roles: asexually by methods such as binary fission (splitting  Predators: Many protozoa are important predators in into two daughter cells), budding, or multiple fission microbial ecosystems, controlling the populations of (forming multiple daughter cells). bacteria and algae. - Sexual Reproduction: Some protozoa have the  Decomposers: Some protozoa contribute to the capacity for sexual reproduction, involving the decomposition of organic matter, aiding in nutrient exchange of genetic material between two individuals. recycling. This process can contribute to genetic diversity Pathogenic Protozoa:  Transmission  Human Diseases: Several species of protozoa are known - Giardiasis is typically spread through contaminated to cause diseases in humans, including malaria water, including lakes, streams, and poorly treated (Plasmodium), amoebic dysentery (Entamoeba histolytica), municipal water supplies. sleeping sickness (Trypanosoma), and giardiasis (Giardia - It can also be transmitted through food, close contact lamblia), among others. with infected individuals, or by fecal-oral transmission.  Giardiasis is an intestinal infection caused by the  Lifecycle protozoan parasite Giardia lamblia (also known as Giardia - The parasite exists in two forms: trophozoites (active intestinalis). It is one of the most common waterborne form) and cysts (inactive, resilient form). diseases worldwide. - After ingestion, cysts release trophozoites in the Amoebiasis intestines, where they multiply and can cause symptoms.  Symptoms - Usually appear 1 to 3 weeks after exposure and may include: - Diarrhea (often watery and foul-smelling) - Abdominal cramps and bloating - Nausea and vomiting - Fatigue and weight loss - Some individuals may be asymptomatic but can still spread the infection.  Also known as amebiasis or amoebic dysentery, is a - Animal Diseases: Protozoa can also cause diseases in parasitic infection caused by the protozoan parasite animals, such as coccidiosis in poultry and Entamoeba histolytica. It is a significant global health toxoplasmosis in cats. concern, particularly in areas with poor sanitation and Types of Protozoa limited access to clean water.  Amoeboids – Move using pseudopodia (e.g., Amoeba).  Transmission  Flagellates – Move using flagella (e.g., Trypanosoma, - Primarily transmitted through the ingestion of water or which causes sleeping sickness). food contaminated with the cysts of Entamoeba  Ciliates – Move using cilia (e.g., Paramecium). histolytica. Cysts are the dormant, resistant form of the  Sporozoans – Non-motile and often parasitic (e.g., parasite that can survive in the environment for Plasmodium, which causes malaria). extended periods. Person-to-person transmission can Medical Significance also occur through the fecal-oral route  Malaria: Caused by Plasmodium species, transmitted by  Life Cycle Anopheles mosquitoes. - Ingestion of Cysts: Infection begins when a person ingests food or water containing the cysts of Entamoeba histolytica. - Cyst Excystation: In the small intestine, the cysts release trophozoites, which are the active, motile form of the parasite. - Trophozoite Colonization: The trophozoites colonize the large intestine (colon) and feed on bacteria and host tissues. Maglanque, E.|Nicerio, I.|Tolentino, H.|74  PRNU131 | Care of Clients with Problems in the Oxygenation, Fluid & Electrolyte, Infectious, Inflammatory,.Immunologic Response, Cellular Aberrations, Acute & Chronic – NCM 112 Third Year | First Semester - Tissue Invasion: In some cases, trophozoites can  Saprophytic: Decomposing dead organic material invade the lining of the colon, leading to tissue damage (e.g., mold). and inflammation.  Parasitic: Feeding on living hosts, which can - Formation of Cysts: Under certain conditions, some cause disease (e.g., athlete's foot). trophozoites can encyst and form new cysts. These  Mutualistic: Engaging in beneficial relationships cysts are excreted in the feces and can contaminate with other organisms (e.g., mycorrhizal fungi with the environment. plants).  Symptoms  Reproduction - Can vary in severity, with some individuals remaining - Fungi can reproduce both sexually and asexually. asymptomatic (having no symptoms). However, when Asexual reproduction often occurs through spores, symptoms do occur, they may include: which can spread and germinate in suitable conditions. - Abdominal pain and cramping Types of Fungi - Diarrhea, which may contain blood or mucus  Yeasts: Unicellular fungi used in fermentation (e.g., - Fatigue Saccharomyces cerevisiae for baking and brewing). - Weight loss  Molds: Multicellular fungi that grow in filaments (e.g., - Fever Aspergillus and Penicillium). - Tenesmus (a constant feeling of needing to have a  Mushrooms: The fruiting bodies of certain fungi, often bowel movement) visible and edible (e.g., button mushrooms). - Abdominal tenderness Medical Significance  Complications:  Fungi can cause various human infections, particularly in - In severe cases or when the infection is not treated immunocompromised individuals. Common fungal promptly, amoebiasis can lead to complications such infections include: as: - Athlete's foot: A skin infection caused by - Extraintestinal disease: Entamoeba histolytica can dermatophytes. spread to other organs, most commonly the liver, - Candida infections: Caused by Candida species, causing abscesses. leading to conditions like thrush or vaginal yeast - Fulminant colitis: A rare but life-threatening condition infections. characterized by severe inflammation of the colon. - Aspergillosis: A respiratory infection caused by - Perforation of the colon. Aspergillus species.  Diagnosis Ecological Importance - Typically made by identifying Entamoeba histolytica  Fungi play a crucial role in nutrient cycling by decomposing cysts or trophozoites in stool samples or through organic matter, recycling nutrients in ecosystems. serological tests that detect antibodies against the  They form symbiotic relationships with plants (mycorrhizae), parasite. Imaging studies like ultrasound or CT scans aiding in nutrient absorption. Economic Importance may be used to assess liver involvement.  Fungi are used in food production (baking, brewing),  Treatment pharmaceuticals (antibiotics like penicillin), and - Can be treated with specific antiparasitic medications, biotechnological applications (bioremediation). such as metronidazole or tinidazole, which are effective Candidiasis against both the intestinal and extraintestinal forms of the parasite.  Prevention - Involves practicing good hygiene, including:  Drinking safe, clean water.  Washing hands with soap and clean water, especially before eating and after using the toilet.  Properly disposing of feces in sanitary facilities.  Avoiding the consumption of raw or uncooked food  An infection caused by Candida, a type of yeast (fungus). and water in regions with a high risk of The most common species associated with human contamination. infections is Candida albicans. FUNGI  Types of Candidiasis  A diverse group of eukaryotic organisms that play essential - Oral Candidiasis (Thrush): White patches in the roles in ecosystems. They include yeasts, molds, and mouth and throat. mushrooms. Unlike plants, fungi do not perform - Vaginal Candidiasis (Yeast Infection): Symptoms photosynthesis; instead, they obtain nutrients through include itching, burning, and a thick, white discharge. absorption. - Invasive Candidiasis: A more serious condition where Key Characteristics:  Cell Structure Candida enters the bloodstream, potentially affecting - Fungi have a cell wall made primarily of chitin, which organs. distinguishes them from plants (which have cell walls  Causes made of cellulose). - Candidiasis can occur when there is an imbalance in - They are composed of hyphae, which are thread-like the body’s normal flora, often due to factors like: structures that form a mycelium (the main body of the - Antibiotic use, which can disrupt healthy bacteria. fungus). - Weakened immune system.  Nutrition - Diabetes or hormonal changes. - Fungi are heterotrophic, meaning they obtain their nutrients by breaking down organic matter. They can be: Maglanque, E.|Nicerio, I.|Tolentino, H.|75  PRNU131 | Care of Clients with Problems in the Oxygenation, Fluid & Electrolyte, Infectious, Inflammatory,.Immunologic Response, Cellular Aberrations, Acute & Chronic – NCM 112 Third Year | First Semester  Symptoms  Reproduction - Oral thrush: White lesions in the mouth, soreness. - Asexual Reproduction: Bacteria reproduce asexually - Vaginal yeast infection: Itching, redness, swelling, and through a process called binary fission, where one cell discharge. divides into two genetically identical daughter cells. - Invasive candidiasis: Fever and chills that don’t This process is rapid and can result in exponential improve with antibiotics. population growth.  Diagnosis - Genetic Variation: Bacteria can also exchange - Often based on clinical symptoms and can be genetic material through horizontal gene transfer confirmed by laboratory tests (e.g., cultures). mechanisms, such as conjugation, transformation, and  Treatment transduction, which contribute to genetic diversity. - Candidiasis is typically treated with antifungal  Ecological Roles: medications such as fluconazole or nystatin. - Decomposers: Bacteria are essential decomposers in  Prevention ecosystems, breaking down dead organic matter and - Good hygiene, managing underlying conditions (like recycling nutrients back into the environment. diabetes), and avoiding unnecessary antibiotic use can - Nitrogen Fixation: Certain bacteria, like rhizobia, can help prevent candidiasis. form symbiotic relationships with plants and convert BACTERIA atmospheric nitrogen into a form that plants can use,  Single-celled, prokaryotic microorganisms that are among aiding in nitrogen cycling. the most abundant and diverse forms of life on Earth. They - Bioremediation: Bacteria are used in bioremediation play crucial roles in various ecosystems, including human to clean up environmental pollutants and contaminants health through their metabolic activities. Key Characteristics  Pathogenic Bacteria:  Cell Structure - Human Diseases: Some bacteria can cause diseases - Bacteria lack a nucleus and other membrane-bound in humans and animals. Examples include organelles. Their genetic material is contained in a Streptococcus (causing strep throat), Staphylococcus single, circular DNA molecule. (causing skin infections), Escherichia coli (causing food - They have a cell wall, which provides structure and poisoning), and Mycobacterium tuberculosis (causing protection; the composition varies between different tuberculosis). bacterial groups (e.g., peptidoglycan in most). - Plant and Animal Diseases: Bacterial pathogens can  Shapes also infect plants and animals, causing diseases that - Cocci: spherical (e.g., Staphylococcus). affect agriculture and ecosystems. - Bacilli: rod-shaped (e.g., Escherichia coli). - Spirilla: spiral-shaped (e.g., Spirillum).  Reproduction - Bacteria primarily reproduce asexually through binary fission, where a single cell divides into 2 identical cells.  Metabolism - Aerobic: Require oxygen. - Anaerobic: Can live without oxygen. - Facultative anaerobes: Can use oxygen but can also grow without it.  Role in Ecosystems - Bacteria are essential for nutrient cycling, decomposing organic matter, and fixing nitrogen in soil. Diseases - They can also form symbiotic relationships with other  Tuberculosis (caused by Mycobacterium tuberculosis), a organisms, including humans. chronic lung disease that is a major cause of disability and  Medical Significance death in many parts of the world. - Pathogenic Bacteria: Some bacteria are harmful and  Staphylococcal disease (caused by Staphylococcus aureus can cause diseases, such as: and other its other species), which can affect almost every  Streptococcus (strep throat). organ system. Severity ranges from a single pustule of  Escherichia coli (foodborne illness). impetigo, through pneumonia, arthritis, endocarditis, etc., to  Mycobacterium tuberculosis (tuberculosis). sepsis and death. - Beneficial Bacteria  Chlamydia and gonorrhea (caused by Chlamydia  Many bacteria are beneficial, playing a role in trachomatis and Neisseria gonorrhea), the most widespread digestion (gut flora), producing vitamins, and sexually transmitted diseases. contributing to the immune system.  Tetanus and diphtheria (caused by Clostridum tetani and - Antibiotics: Corynebacterium diphtheriae)  Used to treat bacterial infections, but resistance to Rickettsia these drugs is a growing concern.  A genus of small, gram-negative bacteria that are obligate  Applications intracellular parasites. They are primarily transmitted to - Biotechnology: Bacteria are used in various humans through arthropod vectors, such as ticks, fleas, and applications, including genetic engineering, lice. fermentation (e.g., yogurt, cheese), and bioremediation  Structure (cleaning up environmental contaminants). - Rickettsia are similar to both bacteria and viruses in - Research: Bacteria are model organisms in research, that they are small and can only reproduce inside host particularly in genetics and molecular biology, due to cells. their simplicity and rapid growth. Maglanque, E.|Nicerio, I.|Tolentino, H.|76  PRNU131 | Care of Clients with Problems in the Oxygenation, Fluid & Electrolyte, Infectious, Inflammatory,.Immunologic Response, Cellular Aberrations, Acute & Chronic – NCM 112 Third Year | First Semester - They have a cell wall but lack many features typical of  Summary free-living bacteria, making them dependent on host - Ticks are the vectors that can transmit various cells for survival. diseases, including Lyme disease.  Transmission - Lyme disease is a specific illness caused by a - Rocky Mountain spotted fever (transmitted by ticks). bacterium transmitted through the bite of infected ticks. - Typhus fever (transmitted by lice and fleas). - Typhus: Several forms of typhus are caused by - Rickettsialpox (transmitted by mites). different species of Rickettsia, including Epidemic  Pathogenicity Typhus (Rickettsia prowazekii), Murine Typhus - Once inside the host, Rickettsia can invade endothelial (Rickettsia typhi), and Scrub Typhus (Orientia cells lining blood vessels, leading to symptoms such as tsutsugamushi). These diseases are characterized by fever, rash, and in severe cases, organ damage. fever, rash, and other symptoms and are often  Symptoms associated with overcrowded and unsanitary - Fever and chills. conditions. - Rash (often spotted). - Spotted Fever Group Rickettsioses: This group - Headaches and muscle aches. includes various diseases caused by different - Severe cases can lead to complications such as kidney Rickettsia species. Symptoms can include fever, rash, failure or septic shock. and other flu-like symptoms. Transmission is primarily  Diagnosis through ticks. - Often relies on clinical symptoms and can be confirmed - Pathogenesis: Rickettsia bacteria invade endothelial through serological tests, PCR, or skin biopsies. cells (cells lining blood vessels) and reproduce within  Treatment them, leading to vascular damage and inflammation. - Typically treated with antibiotics, such as doxycycline. This can result in the characteristic symptoms of  Prevention rickettsioses, including rashes, fever, and systemic - Preventive measures focus on avoiding exposure to effects. arthropod vectors, such as using insect repellent,  Diagnosis wearing protective clothing, and taking measures to - Diagnosis of rickettsial infections often involves clinical reduce tick populations in areas where they are evaluation, serological tests to detect antibodies common. against the bacteria, and molecular techniques such as Rocky Mountain Spotted Fever (RMSF) polymerase chain reaction (PCR) to detect the presence of Rickettsia DNA.  Treatment - Rickettsial infections are typically treated with antibiotics, such as doxycycline or tetracycline, which are effective against these intracellular bacteria. Early diagnosis and prompt treatment are important to  A serious bacterial infection caused by the bacterium prevent severe complications. Rickettsia rickettsii, primarily transmitted through tick  Prevention bites. - Reducing exposure to arthropod vectors (e.g., using  Transmission insect repellent and wearing protective clothing). - RMSF is primarily spread by dog ticks (Dermacentor - Checking for and removing ticks after outdoor activities. variabilis) and wood ticks (Dermacentor andersoni). - Maintaining good hygiene and sanitation to prevent lice - Infected ticks can transmit the bacteria after being and flea infestations in crowded settings. VIRUSES attached to a host for several hours.  Very small, consisting of an RNA or DNA core and an outer  Symptoms coat of protein. They can reproduce and grow only inside of - Fever and chills. living cells. - Severe headache.  Structure - Muscle aches. - Genetic Material: Viruses contain genetic material, - Nausea and vomiting. which can be either DNA or RNA. This genetic material - Rash (which usually appears a few days after fever carries the instructions for virus replication. onset and can start at the wrists and ankles, spreading - Protein Coat (Capsid): Viruses are surrounded by a to the trunk). protein coat called a capsid. The capsid provides  Diagnosis protection to the genetic material and helps the virus - Often based on clinical symptoms, history of tick attach to and enter host cells. exposure, and laboratory tests (such as serology or - Envelopes: Some viruses have an outer lipid envelope PCR) to detect Rickettsia. derived from the host cell membrane. This envelope  Treatment can play a role in viral entry into host cells. - RMSF is treated with antibiotics, typically doxycycline,  Reproduction which is most effective when started early. - Obligate Intracellular Parasites: Viruses cannot  Complications reproduce or carry out metabolic processes - If left untreated, RMSF can lead to severe independently. They must infect a host cell to replicate. complications, including organ failure, respiratory - Attachment and Entry: Viruses attach to specific distress, and death. receptors on the surface of host cells and enter the  Prevention cells. The method of entry varies among viruses. - Avoiding tick-infested areas, using insect repellents, - Replication: Once inside a host cell, the virus's genetic wearing protective clothing, and conducting tick material is replicated, and new virus particles are checks after outdoor activities. assembled. Maglanque, E.|Nicerio, I.|Tolentino, H.|77