micro chapters 1-2 diseases

what are some of the 5 different classes of microbiology pathogens

• COVID-19

• Pneumococcal Pneumonia

• Primary Amoebic Meningoencephalitis (PAM)

• Oral Candidiasis (Thrush)

• Enterobiasis (Pinworm infection)

what is etiology

Etiology is the study of disease causes. It examines genetic, environmental, behavioral, and physiological factors that contribute to its development.

what is epidemiology

the branch of medicine which deals with the incidence, distribution, and possible control of diseases and other factors relating to health.

what kind of pathogen is covid-19

a viral pathogen

what is covid-19

• it is a respiratory infectious disease in humans caused by the recently found out coronavirus strain

whats the formal name of covid-19

it is Severe Acute Respiratory Syndrome Coronavirus 2 or SARS-CoV-2; because it is related to the virus that caused the SARS outbreak in 2003

where did covid-19 originate

the outbreak originated in Wuhan, China in December 2019; there was no public information about this particular strain of virus

what are the types of coronaviruses

• known clinically to be the “common cold”; respiratory infections

• 2002-03: SARS-CoV emerged in China, infected 8,098 with 10% fatality

• 2012: MERS-CoV (middle eastern respiratory syndrome-CoV) 2,500 cases with 34% fatality

what animals can get infected by corona

• humans

• pigs

• cows

• chickens

• dogs

• cats

what are the symptoms of corona

• fever, dry cough, and tiredness.

• headaches, chills, body aches, and difficulty in taking a deep breath

• mild cases report a runny nose or a sore throat

• extreme fatigue for days or weeks

what is the severity of corona

• patients can develop difficulty breathing, requiring a respirator, and some have developed multi-organ system failure

• most patients recover from flu-like symptoms within a few days, and fatigue and tightness of breath resolve within another week or two

what are the preventative measure for covid

• stay home if sick or avoid sick people

• social distancing, use a mask in public and keep 6-feet distance from other

what are the treatments for covid

• treat like a cold or flu; tylenol for high fever and aches

• OTC decongestant, fluids and rest; NSAIDs like advil are NOT recommended due to an increase in the inflammatory repsonse which can make the viral symptoms worse

• pulmonary hygiene such as deep breathing of shower steam or humidifier recommended to prevent respiratory problems

• initial treatments using anti-malarial drugs ivermectin in India and hydrochloroquine are shown to be 99% effective in curing high-risk patients not used in the US

what kind of pathogen is Pneumococcal pneumonia

a bacterial pathogen

whats the genus and species name for Pneumococcal pneumonia

Streptococcus pneumoniae

what causes Pneumonia

• a wide variety of microorganisms

• the bacteria Mycoplasma pneumoniae

• fungi; most often in immunocompromised people

whats the etiologu of Pneumococcal pneumonia

• accounts for 40% of community-acquired cases

• small, gram-positive flattened coccus that appears in pairs

• polysaccharide capsule prevents effective phagocytosis

  • blocks action of complement proteins

  • causes inflammatory fluids to build up in the lung

what are some diseases caused by Streptococcus pneumoniae

• ear infections

• sinus infection

• meningitis

• bacteremia

• it causes more microbial diseases in humans than any other microbe

what are the risk factors of Pneumococcal pneumonia (Streptococcus penumoniae)

• children:

  • under 2 years old

  • in child care settings

  • are immunocompromised by another infection

  • with cochlear implants

• adults 19-64:

  • with underlying chronic illnesses or are immunocompromised by another infection

  • in ling-term living facilities (nursing homes)

  • with cochlear implants

  • who smoke

• adults over 65

what is the epidemoiology of pneumonia

• part of the normal biota of the respiratory tract

• infection occurs when bacterium inhaled into the deep areas of the lung

  • factors that enhance disease:

  • old age

  • season

  • underlying viral respiratory disease

  • diabetes

  • chronic abuse of alcohol or drugs

• transmission is through a droplet contact with respiratory secretions

what are the symptoms and complications of pneumonia

• begin with runny nose and congestion, headache and fever

• chest pain, fever, cough, production of discolored discolored sputum as it enter lungs

• patient appears pale and sickly due to pain and difficulty breathing

• severity and speed of onset of symptoms depend on the etiologic agent

what are the diagnosis and treatment of pneumonia

• inflammatory condition of the lung in which fluid fills the alveoli

• if invasive, blood samples or a spinal tap to collect cerebrospinal fluid (CSF) may be required

• in non-invasive, standard physical examination by clinician

• treated using “broad-spectrum” antibiotics

  • many strains of pneumonia is resistant to penicillin and its derivatives

what are the preventative measure of pneumonia

• Pneumococcal conjugated vaccine (PCV13 or Prevnar13)

  • recommended for adults over 19 with pre=existing medical conditions

  • vaccine is also encouraged for adults over 65

• Pneumococcal polysaccharide vaccine (PPSV23 or Pneumovax 23)

  • recommended for adults over 19 who smoke or have asthma

  • vaccine is also encourage for adults over 65

what kind of pathogen is Primary Amoebic Meningoencephalitis (PAM)

a protozoan pathogen

what is the genus and species name for Primary Amoebic Meningoencephalitis (PAM)

Naegleria fowleri

what is PAM

• inflammation of the brain and spinal cord

  • because the close association of the brain and spinal cord, infection of one structure may involve the other

what is the etiology of PAM

• small, flask-shaped amoeba that moves by means of a single pseudopod

  • rounded, thick-walled cyst that is resistant to temperature extremes and chlorination

• often found in warm freshwater and soil

  • particularly problematic during hot, dry Florida summers in our local, slow-moving waterways

what are the illnesses and symptoms of PAM

• cases are rare but the disease advances so rapidly that treatment is futile

  • only 4 in 133 cases in the US have survived

• stage 1: sever frontal headache, fever, nausea, and vomiting

• stage 2: stiff neck, seizures, altered mental state, hallucinations and coma

what are the sources of infection and risk factors for PAM

• infections reported in people who have been swimming in warm, natural bodies of fresh water

• amoebas forced into nasal passages utilize the olfactory nerve to enter the brain

  • causes rapid, massive destruction of brain and spinal tissue

what is the diagnoses and detection of PAM

• spinal tap of CSF often shows presence of the motile amoeba

• Polymerase chain reaction (PCR) can detect the presence of the DNA associated with the amoeba

• amoeba can be cultured in the lab or detected in the water supply to increase effectiveness of the two methods

what is the treatment of PAM

• traditionally, only supportive care has been given due to the rapid progression of the disease

• Miltefosine, an anti-cancer drug, has shown to have anti-amoebic effect when used with other drugs

• therapeutic hypothermia also saved a 12 year old girl

what are the preventative measures for PAM

• infection can only occur if the amoeba enters your nose; drinking contaminated water has not been shown to lead to infection

• hold nose or use nose-clips when swimming in freshwater environment, avoid submerging your head in warm freshwater environments, avoid freshwater during very hot, dry seasons, avoid stirring up sediment in freshwater environments

what kind of pathogen is oral candidiasis (thrush)

a fungal pathogen

what is the species and genus name for oral candidiasis (thrush)

Candida albicans

what are the sources of infection for oral candidiasis

• disruption of the normal biota causes oral candidiasis within the mouth, GI tract, and vagina

what is the etiology of oral candidiasis

• it is the most common source of human infections

• dimorphic fungus

what are the symptoms of oral candidiasis

• redness or soreness at the site of infection

• difficulty swallowing

• cracks at the corner of the mouth

what are the risk factors and preventative measure for oral candidiasis

• uncommon infection in healthy adults

• often affects immunocompromised people

  • HIV/AIDS, cancer, autoimmune disease

• also affects people with organ transplants, diabetes, dentures, or people using corticosteroids or broad-spectrum antibiotics

• most easily prevented through good oral hygiene

• using chlorhexidine mouthwash for people currently suffering oral thrush is effectove

what helps determines the diagnoses for oral candidiasis

• easily detectable on a wet prep

• grows in thick, curdlike colonies on the walls in the mouth or throat

what is the treatment for oral candidiasis

• antifungal medication like clotrimazole, fluconazole, or itraconazole

• amphoetericin B is required for severe or resistant case

• removal of sugar and breads from the diet and adding yogurt, fermented foods, and probiotics can prevent recurrence

what kind of pathogen is Enterobiasis (pinworm infection)

a helmenthic pathogen

what is the species and genus name for Enterobiasis (pinworm infection)

Enterobius vermicularis

what is Enterobiasis (pinworm infection)

a helmenthic parasite

what is the epidemiology and risk factors of Enterobiasis

• humans are the only known reservoir for this parasite

• most common worm disease of children in temperate zones

• transmission in through ingestion of the worm’s eggs or indirectly through contact

  • commonly found in playground sand, on farms and in soil

  • even possible to ingest while breathing (while mowing the yard or gardening)

  • hands, toys, bedding, clothing, toilet seats

what is the biology and life cycle of the Enterobiasis worm

• female worms exit the anus and lay eggs at night

• eggs are then ingested by new host starting a new cycle of infection

what are the symptoms or signs of enterobiasis

• pronounced anal itching, abdominal discomfort, difficulty sleeping

  • adult worms come outside the anus to lay eggs, which result in itching

  • secondary infection may result from abrasions of the perianal region from excessive scratching

• infection is not fatal and most cases are symptomatic

  • however, females may also experience infection of the vaginal canal

what helps determines the diagnoses of enterobiasis (worms)

• use transparent tape to collect eggs and examine using a microscope

• examine samples from fingernails under a microscope

• look for worms in perianal region 2-3 hours after the infected person is asleep

what is the treatment for enterobiasis

• mebendazole, pyrantel pamoate, and albendazole

  • given as one dose and then again as a single dose 2 weeks later

  • does not probably kill eggs, so second dose helps prevent reinfection

• children who live on farms or play in soil often should have regular treatment

• infections occurring in households should be treated simultaneously among all members

what are the preventative measure for enterobiasis

• proper hand washing anytime after contact with the perianal region is the most effective way to prevent the infection

• showering every morning, especially recovering from and infection, is also effective

• frequent changing of bedclothes among infected individuals is also recommended

what kind of disease is Creutzfeldt - Jakobs disease (mad cow disease)

infectious proteins - prions

what is mad cow disease

• a SPONGIFORM ENCEPHALOPATHIES

  • a group of rare degenerative brain disorders characterized by tiny holes that give the brain a “spongy” appearance

• it’s implicated in chronic, persistent disease in humans and animals

• brain tissue removed from affected animals resembles a sponge

what is the etiology of mad cow disease

• caused by prions

  • distinct protein fibrils deposited in brain tissue of affected animals

  • protein composition of prions have revolutionized ideas of what can constitute an infectious agent

• several animals are victims of similar diseases:

  • scrapies: sheep, mink elk

  • bovine spongiform encephalopathy: cows (which is strongly shown to be related to variant CJD in humans)

what is the epidemoiology of mad cow disease

• 1-2 cases per 1 million people in US

• exact mode of infection is unknown

• scientists still don’t know how prions replicate given that they have no nucleic acid

• transmissable by an unknown mechanism for classic CJD or by ingesting infected meats for variant CJD

what are some places that had mad cow disease

• from 1995- 2006:

  • UK had 162 cases

  • France had 20 cases

  • Ireland had 4 cases

  • US had 2 cases

  • Canada, Italy, japan, Netherlands, Portugal, saudi arabia, spain all only had 1 each

what are the symptoms of mad cow disease

• affects the central nervous system of humans

• causes gradual degeneration leading to dementia and eventually death

• 4-5 months to live with classic CJD and 13-14 months left with variant CJD

how to prevent mad cow disease

• surveillance, culling of sick herds, and banning of high risk material have been very effective in countries at risk for BSE and CJD

• avoid beef and beef products altogether when visiting countries with history of BSE or CJD

what are the treatments for mad cow disease

• supportive care only as there are no known effective treatments