Microbe Mission/Diseases List

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This page is incomplete. It does not cover all important aspects of this subject. Please keep this in mind when reading the page and add relevant information if possible.

This page is for detailed information about each disease on the Microbe Mission Diseases List.

The event Microbe Mission specifies a list of diseases that may be tested on. The 2018 list may be found here. Lists from past years are linked in the Resources section.



Viral Diseases

Some different viruses

Viruses are nonliving obligate intracellular parasites that utilize either DNA or RNA as their genetic material. A virus usually has a proteinaceous capsid studded with different glycoproteins, which facilitate entry into a host cell. The capsid itself protects the genetic material of the virus.

Viruses are usually extremely species-specific, rarely infecting different species. Virus replication may be halted by antiviral medications such as aciclovir. Furthermore, vaccines, comprised of heat-killed or live attenuated viruses and/or antigens, may be injected into a host animal to provoke a humoral immune response. Antibodies produced will circulate and memory T/B cells proliferate, protecting the host from further infection.

Viruses are usually classified by the Baltimore Classification System, which separates viruses into groups by nucleic acid properties:

  • Type I viruses are double-stranded DNA viruses
  • Type II viruses are single-stranded DNA viruses
  • Type III viruses are double-stranded RNA viruses
  • Type IV viruses are positive-sense single-stranded RNA viruses
  • Type V viruses are negative-sense single-stranded RNA viruses
  • Type VI viruses are RNA retroviruses
  • Type VII viruses are DNA retroviruses

There are also several types of viruses classified by structure. Naked viruses are generally icosahedral in structure, having a capsid made of repeating protein units. Adenoviruses, which cause several foodborne diseases, are naked icosahedral viruses. Helical viruses also have a repeating capsid, but they are arranged into a helical structure. Many plant viruses, such as tobacco mosaic virus (TMV), the first virus discovered, are helical. Enveloped viruses are covered with a layer of phospholipid membrane, usually derived from their previous hosts. These viruses bud off from the membrane of animal cells. Complex viruses have a complex shape, such as bacteriophages.

AIDS

Caused by an RNA retrovirus, Human Immunodeficiency Virus (HIV), which emerged in the 1980s. HIV attacks CD4+ T-cells of the immune system, crippling its ability to defend against opportunistic infections. Several classes of retroviral medications may be given to patients, but no cure is currently available. Late-stage AIDS is marked by opportunistic infections and Kaposi's Sarcoma, a cancer caused by a human herpesvirus. AIDS is an STD, although blood transfusions and needle sharing also spreads the disease. The disease is generally diagnosed with Enzyme-Linked Immunosorbent Assay (ELISA). AIDS is the most severe stage of HIV.

Origin: 1st discovered in 1981 in San Francisco & New York City; theorized to come from primates

Classification of HIV:

  • Baltimore Classification: Group VI
  • Order: virales
  • Family: Retroviridae
  • Subfamily: Orthoretrovirinae
  • Genus: Lentivirus
  • Two types: HIV-1 & HIV-2.

Types:

  • HIV-1: initially discovered and is more virulent and infectious than HIV-2. It's also called LAV (Lymphadenopathy associated virus) & HTLV-III (Human T Lymphotropic Virus III)
  • HIV-2: largely confined to West Africa because of its relatively poor capacity for transmission

Symptoms:

  • Increased infections
  • Fatigue
  • Fever
  • Weight loss

Transmission:

  • Horizontal: from sex, blood transfusions, and sharing needles
  • Vertical: during pregnancy, delivery, or breastfeeding

Pathogenesis: HIV-1 entry to macrophages and CD4+ T cells mediated through interaction of the virion envelope glycoproteins (gp120) w/ CD4 on the target cells' membrane & chemokine co-receptors.

Replication:

  • 1. Membranes of virus & host cell fuse, & viral RNA & reverse transcriptase enter the host's cytoplasm
  • 2. Reverse transcriptase makes viral RNA to DNA.
  • 3. Viral DNA is combined into the host chromosome as provirus by integrase
  • 4. Transcription & translation of viral prots: viral RNA becomes incorporated into viral particles & is transcribed
  • 5. Virions get env

Diagnosis:

  • Antibodies to HIV (ELISA, PCR, Western Blot, immunofluorescence assay)
  • Viral RNA detection, nucleic acid test for negative results
  • CD4 T Cell Count < 200 (normal range is 500-1500/mm3 of blood)

Prevention:

  • use contraceptives
  • emtricitabine-tenofovir (Truvada)
  • check history of partner
  • use a clean needle

Treatment: no cure but can alleviate symptoms

  • Non-nucleoside reverse transcriptase inhibitors (NNRTIs): disable a prot needed by HIV to make copies of itself, e.g. efavirenz, etravirine & nevirapine
  • Nucleoside or nucleotide reverse transcriptase inhibitors (NRTIs): faulty versions of building blocks tht HIV needs to make copies of itself
  • Protease inhibitors (PIs): disable protease
  • Entry or fusion inhibitors: drugs block HIV entry into CD4 cells
  • Integrase inhibitors: disables integrase, a prot tht HIV uses to insert its genetic material into CD4 cells
  • Antiretroviral therapy (ART): slows it down.

In the United States, most people with HIV do not develop AIDS because of ART therapy.

Fun Facts:

  • Even though there are no cures for HIV/AIDS, Timothy Ray Brown, a Berlin patient who contracted HIV in 2008, is the only person to be cured of HIV.
  • CCR5-delta 32: genetic mutation in some peopple of eurasian descent; causes CCR5 co-receptor to develop smaller than usual & no longer sits outside of cell; won’t let HIV enter cell so resists infection

Chicken Pox and Shingles

An image of the varicella-zoster virus (VZV)

Varicella Zoster causes both Chicken Pox and Shingles. It is less contagious than measles but more contagious than mumps and rubella.

Origin: not clear, closely related to simian varicella virus (SVV) rhesus macaques; closely related to herpes simplex viruses (HSV)

Classification:

  • Baltimore Classification: Group I
  • Order: Herpesvirales
  • Family: Herpesviridae
  • Subfamily: Alphaherpesviridae
  • Genus: Varicellovirus
  • Species: Human herpesvirus 3, common name Varicella Zoster (VZV)
  • 5+ clades

Chicken Pox is highly contagious and infectious.

Transmission: direct contact or inhalation of aerosols from vesicular fluid of skin lesions

Symptoms:

  • blister-like rash
  • tiredness
  • Itching
  • fever
  • Swollen Lymph Nodes

Pathogenesis: Incubation Period of 10-21 days (avg 14 days), targets skin & peripheral nerve; period of illness is 3-4 days; most contagious 1-2 days before rashes appear; virus transmitted from mucosal sites to regional lymph nodes where T cells become infected; afterwards, remains dormant in trigeminal & dorsal root ganglia; highly sensitive to temp (inactivated @ 56-60 C); species-specific infection

Diagnosis: characteristic vesicular lesions (blisters)

Preventions:

  • Chicken Pox Vaccine (90% effective)

Treatments:

  • Over-the-counter medication
  • Doctor-prescribed treatments
  • For itching:
    • Colloidal oatmeal baths
    • Calamime lotion

Shingles, also known as herpes zoster, can develop anytime after someone recovers from chicken pox. The risk for shingles increases as a person ages, which accounts for why it is mostly seen in the elderly.

Symptoms:

  • rash
  • itching
  • chills
  • fever
  • pain
  • headache
  • upset stomach

Pathogenesis: Inflammation & necrosis from this reactivation may extend into anterior horn cells, negatively affecting motor function; infection may cause the death of primary neurons so chronic pain. In healthy individuals, affected dermatome can heal completely in 2 weeks (often 4-6 weeks), but 5-10% of patients hypersensitivity persists for several months

Prevention:

  • shingles vaccination (Zostavax)

Treatments:

  • antiviral medications
    • acyclovir
    • valacyclovir
    • famciclovir
  • analgesics (pain medicine)
  • For itching:
    • calamime lotion
    • wet compresses
    • colloidal oatmeal baths

Common Cold

The common cold, or rhinovirus, is a viral infection of the throat and nose. Caused by about 200 different types of rhinovirus, it makes medicine/vaccinations unable to develop. The disease tends to not be serious.

Symptoms:

  • coughing
  • sore throat
  • runny nose
  • sneezing
  • watery eyes

There is no cure for the common cold, but there are many ways to obtain relief from the illness. These include:

  • drinking lots of fluids (mainly water)
  • over the counter medicine
  • cough drops or throat sprays
  • getting plenty of rest
  • gargling warm salt water

Dengue Fever

Dengue is a viral infection spread by mosquitoes. It is very rare in the United States. It causes flu-like illness and can occasionally develop into severe dengue, a potentially lethal condition. An alternate name is "Breakbone Fever" coined by Benjamin Rush.

Origin: unclear; appeared ~1000 years ago, 1st possible case in Jin Dynasty (265-420 AD); the Earliest outbreak in 1779; viral cause discovered in the early 20th century.

Classification:

  • Baltimore Classification: Group IV
  • Family: Flaviviridae
  • Genus: Flavivirus
  • Species: Dengue virus
  • Serotypes: DENV-1,2,3,4,5 (in 2013), based on antigenicity; also referred to as arbovirus (arthropod-borne virus)


Symptoms:

  • Incubation Period: 4-10 days, 80% asymptomatic, 5% severe
  • General:
    • fever
    • pain in bones
    • joints
    • muscles
    • nausea
    • headache (behind eyes)
    • rashes
    • bleeding
  • Febrile Phase:
    • high fever (biphasic; comes & goes)
    • pain & headache (2-7 days)
    • nausea & vomiting
    • flushed skin then a rash (islands of white in a sea of red)
    • petechiae (small red spots that don’t disappear when skin is pressed; caused by broken capillaries)
    • mild bleeding from the mucous membrane of mouth & nose
  • Critical Phase:
    • leakage of plasma from blood vessels & accumulation in chest & abdominal cavity & depletion of blood to organs
    • organ dysfunction & bleeding (mainly GI tract)
    • shock & hemorrhage in < 5% all cases
    • rare but more common in children & teens
  • Recovery Phase:
    • reabsorption of fluid to blood (2-3 days)
    • severe itching & slow heart rate
    • rashes that are maculopapular or vasculitic
    • peeling of skin, if fluid overload affects the brain (less consciousness & seizures)
    • fatigue

Complications:

  • Dengue hemorrhagic fever (bleeding, low lvls platelets, blood plasma leakage)
  • Dengue shock syndrome (dangerous hypotension)
  • Transverse myelitis (spinal cord inflammation)
  • Guillain-Barre syndrome: rapid onset of muscle weakness bc autoimmune against PNS
  • Heart infection
  • Acute liver failure

Risk Factors:

  • previous infection with a different serotype
  • young age
  • relatively well nourished
  • female
  • high BMI
  • viral load
  • chronic disease

Pathogenesis:

  • female mosquito: takes a blood meal from a person infected w/ dengue, during the initial 2-10-day febrile period, becomes infected w/ virus in cells lining its gut. 8~10 days later, the virus spreads to other tissues including mosquito's salivary glands & is then released into its saliva.
  • Mechanism: Fluid in bloodstream leak into body cavities bc of capillary permeability; hypovolemia & hypotension so can’t supply sufficient blood to vital organs; dysfunction of bone marrow due to infection of stromal cells leads to fewer platelets so less blood clot; increases risk of bleeding

Diagnosis:

  • fever + 2 others:
    • symptoms
    • leukopenia (low WBC)
    • positive tourniquet test: blood pressure cuff at between diastolic & systolic pressure for 5 min & counting petechial hemorrhages
    • higher # makes diagnosis of dengue more likely w/ cut off being > 10 to 20 per 1 in sq
  • warning signs: worsening ab pain, ongoing vomit, liver enlarge, mucosal bleed, high hematocrit w. low platelets, lethargy, serosal effusions
  • Lab: early changes: leukopenia, thrombocytopenia, metabolic acidosis, elevated lvl of aminotransferase (AST & ALT) from liver, hemoconcentration & hypoalbuminemia, pleural effusion & ascites, ultrasound of fluid, shock if pulse pressure <= 20 mmHg & peripheral vascular collapse (in child via delayed capillary refill, fast heart rate, cold extremities)
  • Tests: virus isolation by cell culture, nucleic acid

Although there is no specific treatment for dengue, medical care from physicians and nurses experience with the disease can help save lives.

Prevention of dengue can be obtained from a dengue vaccine. It is not required in the United States and is only recommended for countries where dengue is widespread.

Ebola Hemorrhagic Fever

Ebola is a severe and often fatal illness. It is caused by one of the filoviruses, a group notorious for causing highly lethal hemorrhagic fevers. It is transferred from wild animals to humans.

Transmission Electron Micrograph of the Ebola virus (EBOV)

Symptoms:

  • First Symptoms
    • sore throat
    • fever
    • muscle pain
    • diarrhea
    • fatigue
  • Followed by
    • rash
    • symptoms of impaired liver/kidney function
    • vomiting
    • diarrhea
    • internal/external bleeding
  • Lab Findings
    • elevated liver enzymes
    • low white blood cell count

There is no proven treatment for Ebola. However, there are a few things someone may do to try and help. These include:

  • treatment of specific symptoms
  • supportive care rehydration

Hepatitis

Hepatitis is an inflammation of the liver. There are five main types of hepatitis virus, known as A, B, C, D, and E. Hepatitis A and E are usually caused by contaminated food and water. Hepatitis B, C, and D are usually caused by contact with infected body fluids. Hepatitis D virus is known as a satellite virus because it can only infect individuals already infected with Hepatitis B virus.

Five separate viruses, collectively known as the hepatoviruses. The viruses affect the liver, causing fever, vomiting, pains, and potential liver failure, resulting in jaundice. In addition, infection may lead to chronic liver cirrhosis and eventually hepatocarcinoma.

Influenza

Commonly known as the flu. Influenza is a common contagious respiratory illness. Most common symptoms include a fever, runny nose, sore throat, and aches. There are three types of influenza virus that can infect humans, known as Type A, Type B, and Type C. Influenza is droplet-borne and can be spread to those within a 6-foot range.

Measles

Measles is also known as rubeola, not to be confused with rubella. It is caused by an RNA virus known as the measles virus. Measles is highly contagious. It infects the respiratory system, causing coughing, runny nose, red eyes, and fever, in addition to the disease's characteristic rash. There are no treatments for measles, but it can be prevented by administration of the MMR vaccine.

Mononucleosis

Commonly referred to as "Mono" or "Kissing Disease", and caused by the Epstein-Barr virus (EBV). The disease is spread via saliva, hence its nickname, but can also be transmitted via blood or semen. Young adults are at the most risk. The disease is typically short term, with common symptoms including malaise, fatigue, and swollen glands.

Mumps

Mumps, also known as parotitis, is a viral and contagious infection. It is caused by a paramyxovirus, which is a member of the Rubulavirus family. Mumps is a droplet-borne infection. An individual with mumps may be asymptomatic, but symptoms range from fatigue to swollen lymph nodes. It can be prevented, however, by the MMR vaccine.

Norovirus

Norovirus, also know as the Norwalk virus or winter bug virus, is caused by caliciviruses. About 90% of outbreaks on cruise ships are due to norovirus, which is transmitted via the fecal-oral route. The incubation period is 12-48 hours, and the symptoms, most notably vomiting, last 2-3 days. This disease can be prevented by common sanitation procedures.

Polio

Poliovirus

Polio is a rare virus that is caused by the Poliovirus. In 1979, the disease had been eradicated in the US. Global efforts are being taken to eradicate the disease worldwide. The disease had only 36 cases in 2016. It is preventable by vaccine, but is incurable after infection. Polio is known to cause paralysis, which often leads to death.

Rabies

Rabies is a rare disease spread to humans by the saliva of infected animals. Once symptoms appear, it is almost always lethal. These symptoms include spasms, fever, headache, and confusion. However, the disease is preventable by vaccination.

Rubella

Also known as German Measles, rubella is a disease caused by the rubella virus, which is a togavirus. The disease causes the appearance of a distinctive rash on the skin, which starts on the face and moves downwards. The disease is typically short term because once symptoms start showing, the illness is almost always fatal. To prevent this, the MMR vaccine exists.

Yellow Fever

Yellow fever is a subtropical illness caused by the yellow fever virus (shocker, right?). It is mosquito-borne, and is most commonly associated with Aedes aegypti. Symptoms include loss of appetite, delirium, vomiting, and malaise. However, the most common symptom is jaundice, which is how the disease got its name.

Zika

Zika is a disease caused by the zika virus, which is part of the Flaviviridae family. As many of its mosquito-borne friends, it is transmitted through Aedes mosquito bites and can also be vertically transmitted from mother to child. Many individuals are asymptomatic; however, microcephaly is a common symptom in the children of infected pregnant women. The most notable outbreak of this illness started in early 2015, where many cases were identified in Brazil and other South American countries.

Bacterial Diseases

Anthrax

Anthrax is a serious and rare infectious disease caused by the bacteria Bacillus anthracis. People may become sick with anthrax if they come in contact with infected animals or contaminated animal products.

Symptoms:

  • Skin infection:
    • formation of dark ulcers at point of infection
  • Inhalation
    • Fever
    • Shortness of breath

Intestinal or injection infection are rarer, but the prognosis for all infections are generally considered poor. Anthrax toxin is one of the most lethal toxins known. To make matters worse, anthrax endospores are notoriously hard to sterilize, resulting autoclaving for smaller heat-resistant equipment, irradiation for items such as letters or packages, and gas treatment for infected buildings.

Anthrax has gained notoriety because it is a very good bioweapon with low median lethal dose and quick infection periods, as well as the ability to form endospores. These spores may persist in soil for years, making it easily spread among livestock. In 2001, a terrorist plot involving anthrax spore-seeded letters mailed to US Senators killed postal workers and led to a complete cleanup of several facilities. In addition, it is known that the Soviet Union's bioweapons program developed many highly contagious strains of anthrax and other infectious diseases.

A vaccine exists, but has dangerous side effects that limit its use in civilian populations. Antibiotics and antitoxins are generally used for treatment.

Botulism

Botulism is a serious food borne illness caused by Clostridium botulinum. It is found in canned foods and the spores can be found in honey, but the pores do not pose a threat to anyone with a developed immune system.

Symptoms:

  • Muscle paralysis
  • Breathing problems
  • Nausea

Botulinum toxin is the most acutely lethal toxin known. By preventing the release of acetylcholine, it makes muscles relax (as opposed to tetanospasmin, which makes muscles permanently contract). All Clostridium bacteria are obligate anaerobes - oxygen kills them, but not the endospores, so improperly canned food will sometimes provide an ideal anaerobic environment. The immune system neutralizes the bacteria effectively, but the disease is primarily caused by the toxin, which can persist even if the bacteria do not. As a result, newborns, elderly, and immunocompromised individuals are at risk.

Prevention of botulism involves properly preparing canned food, avoiding canned food with bulging containers (a sign that bacteria have colonized it and are actively producing gas), not feeding honey to infants under the age of one, and heating food at 85 degrees Celsius for at least five minutes. Sodium nitrite preservatives also protect against botulism.

There are seven types of botulinum toxin, two of which are utilized in cosmetics/plastic surgery as the ingredients of Botox.

Cholera

Cholera is a bacterial infection spread in contaminated water. It can be very severe and dangerous if untreated. Cholera is caused by two serotypes of Vibrio cholerae, O1 and O139. Noninfectious bacteria may be made infectious by viral transduction.

Symptoms:

  • Vomiting
  • Rice-water diarrhea (the name is self-explanatory: please don't make me describe it)

Once widespread in major cities, proper sanitation has generally banished it to developing nations, without proper sanitation/sewage systems in place. It is spread by the fecal-oral route. In addition, unprepared seafood may also contain an infectious dose of V. cholerae.

Vaccines generally have a short effective period (6 months). Treatment involves replenishing water and electrolytes via rehydration therapy or by intravenous injection. Although antibiotics may be used, erythromycin- and amoxicillin-resistant strains have appeared in Bangladesh, limiting the effectiveness of these drugs.

Chlamydiasis

Clamydiasis is caused by the bacterium Chlamydia trachomatis. It is most infamously known as an STI, but can also be spread by a fly vector.

Symptoms:

  • Abnormal genital discharge
  • Burning sensation during urination
  • Conjunctivitis (for eye infections)

There are no vaccines for chlamydiasis. Generally, antibiotics such as erythromycin, doxycycline, fluoroquinalone, and amoxicillin (during pregnancy) are used to treat infections. It is advisable to also test for other common STIs such as AIDS and syphilis in conjunction. Prevention of sexually transmitted chlamydiasis is standard for all STIs - abstinence or usage of condoms.

Dental Caries

Dental Caries, more commonly known as cavities, are most commonly caused by two Streptococcus bacteria, S. mutans and S. sobrinus.

Symptoms:

  • Excessive plaque
  • Formation of caries (cavities)

This is the most common bacterial disease. The bacteria involved form a biofilm naturally on teeth, which is known as dental plaque. It causes tooth decay and the demineralization of hydroxyapatite, the constituent of dental enamel. Fortunately, it is easily prevented by avoiding high sucrose/glucose food, brushing and flossing, and fluoridation of tap water.

Legionnaire's Disease

Legionnaire's Disease is an infection of the lungs caused by the bacteria Legionnella pneumophila. The bacteria is known to contaminate water, and is usually spread through mist containing the bacteria. The disease is named for the outbreak where it was first identified, the 1976 American Legion convention.

Symptoms:

  • Pneumonia
  • Nausea
  • Vomiting
  • Diarrhea

L. pneumophila spreads extremely well in aerosols and mists. For this reason, it is most common during the summer and fall, when air conditioning systems with contaminated water can spread the droplets indoors. A mostly opportunistic disease, it affects elderly, young, and immunocompromised individuals the most.

Prevention involves avoiding contaminated water and biofilms, as well as inspecting any cooling systems for colonization/contamination. Antibiotics have proven effective against the disease, specifically doxycycline and azithromycin.

Lyme Disease

A rash caused by Lyme Disease

Lyme Disease is a bacterial infection spread by ticks carrying the pathogen Borrelia burgdorferi. The disease is named for the place where it originates: Lyme, Connecticut. The most common symptom is a rash originating from the tick bite that slowly spreads across the body. Other symptoms include fatigue, headache, and fever. Lyme Disease can be prevented by staying on trails when hiking, avoiding brushing against bushes and trees, and wearing long-sleeved shirts. Lyme Disease can be treated by taking antibiotics for one to four weeks.

MRSA

MRSA, or Methicillin-resistant Staphylococcus aureus, is a type of bacteria that is resistant to many types of antibiotics. This infection is often healthcare-associated, so proper sanitation measures should be taken in hospitals. The first symptom is usually a small red bump on the skin that grows larger and more painful. A rash and fever may also be present. MRSA can be treated by antibiotics, such as doxycycline and ciprofloxacin.

Peptic Ulcer Disease

The most common causative agent of peptic ulcer disease is Helicobacter pylori. These bacteria are able to resist the antimicrobial effects of stomach acid and colonize the stomach mucosa, resulting in the formation of ulcers. H. pylori is a risk factor for stomach cancer.

Pertussis

Pertussis, also known as the whooping cough, is a disease caused by the bacteria Bordetella pertussis. Pertussis most commonly affects children, and spreads easily through the coughs and sneezes of an infected person. Pertussis typically lasts around 10 weeks. It can be treated using antibiotics, such as erythromycin and azithromycin.

Pseudomonas aeruginosa (Nationals Only)

The pathogen is in the name of the disease, for starters. It mainly affects weak people. Furthermore, it is almost always a nosocomial infection, meaning that outbreaks originate in a hospital. There is no definitive mode of transmission, but airborne infection is a possibility. The symptoms are chills, fever, and abnormal sensations in organs. Many antibiotics can be used to treat this illness.

Rocky Mountain Spotted Fever

Rocky Mountain Spotted Fever (RMSF) is a bacterial infection spread through ticks carrying the bacteria Rickettsia rickettsii. The most common symptoms are fever, headache, and muscle pain, followed by rashes all over the body. The disease originated in the 1930's in the Rocky Mountains, hence the name. The disease has since spread all over the United States, and from Canada to Central America. RMSF can be fatal if not treated promptly. The most common antibiotic used in treating RMSF is doxycycline.

Strep Throat

Strep throat is caused by streptococcus bacteria, namely Streptococcus pyogenes. Hence the name, strep throat's most common symptom is... you guessed it! A sore throat. The most effective treatment for strep throat is oral antibiotics.

Syphilis

Syphilis is a sexually-transmitted disease spread by the bacteria Treponema pallidum. Common symptoms include rashes, fever, sore throat, malaise, weight loss, hair loss, and headache. Syphilis can be fatal if not treated, and can be prevented by blood test. The most common antibiotics used in treating Syphilis are penicillin and doxycycline.

Tetanus

Tetanus is an infection that affects the muscles and nervous system, causing them to spasm. It is caused by the bacteria Clostridium tetani. The most common symptom is "lockjaw", a painful muscle spasm in the jaw. The bacteria enters the body through a cut or contact of a cut with an infect surface. It is preventable by vaccine.

Tuberculosis

Tuberculosis (TB) is an infectious disease caused by the bacteria Mycobacterium tuberculosis. Roughly one-third of the world's population is thought to have TB, of which about 10% develop the disease. People with HIV/AIDS and those who smoke are more likely to develop TB. Common symptoms include fever, chills, sweating, loss of appetite, and fatigue. TB generally affects the lungs, but occasionally affects other organs. TB can be treated by antibiotics, such as isoniazid and ethambutol.

Wolbachia (Nationals Only)

Bacteria of the Wolbachia genus only affect insects (lucky for us, because they are called "gonad-chomping parasites"). These bacteria are vertically transmitted from an infected mother to her offspring (yes, males are useless once again). The main symptom is infertility, but this illness can be treated with doxycycline, but don't ask how it's administered because I don't have the answer.

Fungal Diseases

Athlete's Foot

Athlete's foot is an infection caused by Tinea pedis, a dermatophyte fungus. Unlucky individuals can get this illness by walking barefoot. The symptoms are minor, them being a scaly rash, irritation, itching, or burning, and can be treated with most types of antifungal creams.

Dutch Elm Disease

Dutch elm disease only affects dutch elm trees. The fungus is transmitted through bark beetles that attack the trees. Infected trees have branches that either wither or turn yellow, and roots that die. Pesticides or pruning can be used to combat the infection.

Early Potato Blight

Early potato blight was a major factor of the Great Famine in Ireland. From 1845 to 1849, potato blight ruined entire fields of crops. Of course, however, it only affects potatoes. The primary symptom is the watery rot of leaves. To treat potato blight, burn infected foliage after removing it from the plant.

Histoplasmosis

Histoplasmosis is a disease caused by the fungus Histoplasma capsulatum. The disease typically affects the lungs, but occasionally can affect other organs. The most common symptoms include coughing and flu-like symptoms. The disease can be fatal if left untreated. Treatment includes antifungal medications, with the most effective being itraconazole.

Ringworm

Although it sounds like a parasitic worm, ringworm is caused by the fungus Trichophyton rubrum. It can be transmitted through direct skin-to-skin contact or through objects that an infected person has touched. The name ringworm comes from the ring-shaped rash that is characteristic of this infection.

Thrush

Thrush is caused by the buildup of Candida albicans in the mouth. The most distinguishing symptom is a white tongue accompanied with white inner cheeks. Other symptoms include abnormal taste, bad breath, and difficulty swallowing. Antifungals can be used to treat thrush.

White Nose Syndrome

White Nose Syndrome (WNS) is an infection of bats caused by the fungus Pseudogymnoascus destructans. WNS is named for the white fungus that typically appears on a bat's nose. Other symptoms include flying, loss of body fat, damage to the wing membranes, and death. By 2012 WNS had been associated with at least 5-7 million bat deaths.

Protozoan & Algal Diseases

Cryptosporidiosis

Cryptosporidiosis or "crypto" is caused by the Cryptosporidium parasite. It can be transmitted through contaminated food and water. Dehydration caused by watery diarrhea is a typical symptom of crypto. To treat it, alleviating symptoms is recommended.

Giardiasis

Giardiasis is a foodborne intestinal infection caused by the Giardia parasite. Aside from contaminated food and water, giardiasis can also be transmitted through touching contaminated objects. Watery diarrhea is amongst the common symptoms, others being fatigues and cramps. Some of the infected individuals may be asymptomatic. Cases usually require no treatment as the illness passes within a few weeks.

Malaria

Malaria is a disease caused by multiple parasites. They are all spread by mosquitoes. It can cause flu-like symptoms in addition to vomiting, yellow skin, comas, seizures, and death. It can be treated with antimalarial drugs like quinine and artemisinins. It can be prevented by avoiding mosquito bites with nets, sprays, not going outside during dusk and dawn, etc.

Naegleria

Naegleria is a freshwater illness caused by protozoa. This illness is extremely rare, and to get this illness, you must nasally inhale contaminated freshwater (can't get illness by drinking). The illness has two stages: the first with very basic and harmless symptoms, and the second ending in a coma. Naegleria is fatal and only five survivals have been recorded.

Paralytic Shellfish Poisoning

Paralytic Shellfish Poisoning (PSP) is an algal infection caused by eating contaminated shellfish. PSP is caused by dinoflagellates and is commonly associated with algal blooms. Symptoms include nausea, vomiting, diarrhea, abdominal pain, and numbness, especially around the mouth. There is no specific treatment for PSP, except avoiding raw shellfish.

Prionic Diseases

Prions are one of the two classes of nonliving pathogens. Commonly found in animal neural tissues, proteinaceous infectious agents (prions) are misfolded proteins that induce misfolding in other normal versions of itself into the prion form. Because of the subtle differences between homologous proteins of different species, prionic diseases are usually species specific, with the exception of bovine spongiform encephalopathy (BSE), which is able to spread from cattle to humans, causing Creutzfeldt-Jakob Disease (CJD). The function of normal prions are not completely understood, but it is believed they play a role in nerve bundle myelinization. Prions are especially dangerous because they are heat-stable, meaning sterilization requires extensive autoclaving and chemical degredation, which may be hard to achieve in the field. Prion diseases are fairly rare in humans, mainly passed on by genetic disorders. Prion diseases are progressively fatal, causing brain plaques that resemble Alzheimer's in postmortem autopsies. Treatment is limited, but several drugs and genetic treatments are being research.

Chronic Wasting Disease

Chronic wasting disease (CWD) exclusively affects deer, elk, reindeer, moose, and similar animals, and it might be the origin of scrapie. Possible modes of transmission are contaminated soil, water and food, as well as infected urine, saliva, or feces. The infected organisms often show progressive weight loss. This leads to excessive urination and/or salivation. They may also display behavioral changes, such as hyper-excitability. But, with prionic diseases, all infected specimens eventually die, and CWD is no exception. The incubation period is over a year, so it may be hard to trace the origin of contamination.

Kuru

This is a unique prion disease that occurs in humans, spread by cannibalism. In the past, the Fore tribes in Papua New Guinea engaged in funerary cannibalism as part of their culture. The body is allowed to partially decompose, and then be consumed. The brain was most commonly consumed by women, resulting in a higher mortality rate among females. Funerary cannibalism is no longer performed among the Fore, but it is hard to determine whether the disease has truly been eradicated due to the long incubation period, up to 50 years. There are three stages of the disease, initially causing tremors but eventually causing loss of motor abilities and eventually death.

Parasitic Worms

Parasitic worms, known as helminths, are multicellular eukaryotes. They are split into several classes: nematodes (roundworms), platyhelminthes (flatworms), cestodes (tapeworms), and trematodes (flukes). Most helminth infections are spread by the fecal-oral route, where contaminated water containing worm spores is consumed. The worms hatch and grow in the lower GI tract, where they lay their eggs and spores. Many worms cause Neglected Tropical Diseases (NTDs), due to poor sanitation in tropical developing nations.

Anthelmintics are drugs with action against helminths. They include mebendazole, albendazole, and pyrantel palmoate. They work either by killing the worms, or paralyzing the worms, so that they drop out of the intestine in the stool. Many herbal remedies also show efficacy against helminths.

Hookworm

Hookworm is an intestinal parasite that affects humans and other animals. The worm can be acquired through either ingestion or fecal transmission. Although usually asymptomatic, individuals with a hookworm infection may display fatigue, diarrhea, abdominal pain, or loss of appetite. The treatment for hookworm is antiparasitic drugs.

Pinworm

Pinworms are intestinal parasitic worms. After infection, the worm lays ten to fifteen thousand eggs around the anus of the infected individual. The transmission of pinworms is usually as follows: the infected person scratches their anus and the eggs somehow get into their mouth or someone else's mouth, then the cycle restarts. It's best not to think about it. Given that, anal discomfort is a common sign of a pinworm infection.

Schistosomiasis

Schistosomiasis or bilharzia is a freshwater illness most common in the subtropics. It is caused by parasitic flatworms. Symptoms develop months after infection and include rash, itching, fever, and chills. Eventually, the flatworms can damage vital organs. Praziquantel can be used to treat bilharzia.

Tapeworm

Tapeworm infections are usually caused by two tapeworms of the Taenia genus. In order to get an infection, you must consume the larvae, which are found in infected animal meat. At a whopping length of 8-11 ft, tapeworms can wreak havoc on the body, causing symptoms such as seizures, headaches, and salt cravings. The treatment is anthelmintics.

Trichinosis

Trichinosis, also known as trichinellosis, is an infection caused by the parasitic roundworms of the Trichinella genus. The primary mode of transmission is through raw or undercooked pork. Trichinosis results in the common foodborne symptoms, such as nausea, diarrhea, and vomiting. It can be treated with antiparasitic drugs.

Archaea

Archaeans are not known to cause any human diseases, but because they are mentioned in most Microbe Mission tests, an introduction will be given here.

Archaea comprise of the most ancient domain of life. They are prokaryotes with distinct eukaryotic traits. Archaeans are most known for certain extremophilic members, although most archaeans are mesophilic. They have no membrane-bound organelles, being prokaryotes, but certain aspects of their genetic material replication and translation are more eukaryotic.

A more detailed description can be found in the event page: Microbe Mission

Diseases from Past Years

Information about diseases that were on previous years' lists but have since been removed. Occasionally these are tested on by inexperienced or less dedicated event supervisors who mistakenly use past lists or reuse old questions indiscriminately.

Previously Listed Diseases

Viral Diseases

Herpes
Smallpox

Eradicated in 1980, smallpox was an extremely infectious disease that caused a rash along the body. Although it was preventable with a vaccine, the vaccine had risky side effects which made it dangerous to use.

Viral Encephalitis
Viral Pneumonia
West Nile Fever

The West Nile Virus is a mosquito borne virus which causes no symptoms in the majority of cases. Less than 1% of cases are serious or fatal. The most common form of prevention is to prevent mosquito bites themselves.

Bacterial Diseases

Bacterial Meningitis
Bacterial Pneumonia
Crown Gall Disease (Nationals Only)
Gonorrhea
Toxic Shock Syndrome
Typhus

Fungal Diseases

Batrachochytrium (Nationals Only)
Ergotism

Ergotism is caused by eating the Claviceps purpurea fungus, which grows on rye and other wheats. It causes diarrhea, nausea, and vomiting followed by neurological symptoms such as seizures, mania, convulsions, and itching. It can also cause gangrene. It can be prevented by avoiding ergot infections in grains with methods like checking grains for ergot, preventing the fungus from germinating, and chemicals.

Protozoan & Algal Diseases

Estuary Associated Syndrome

Prionic Diseases

Scrapie

This is a spongiform encephalopathy that occurs in sheep. It is so named because one of the symptoms is affected sheep scraping their fleece on rocks. Another symptom is excessive lip smacking. Because the prions don't degrade, they can easily infect other sheep. There are no cases of scrapie infecting humans, however.

Mad Cow Disease

Resources

2017 list
2012 list
2011 list