Microbiology Chapter 18

What suffix is used for medical conditions involving the blood?

-emia

What is viremia?

The presence of viruses in the blood.

What does bacteremia refer to?

The presence of bacteria in the blood.

What is septicemia?

Bacteria growing and flourishing in the blood.

What is septic shock?

Cascading immune responses to septicemia, resulting in decreased blood pressure.

What is the normal biota of the cardiovascular and lymphatic systems?

In a healthy state, no microorganisms colonize these systems.

What recent studies suggest about the bloodstream?

It is not completely sterile, even in periods of apparent health.

What caused the COVID-19 pandemic?

Severe acute respiratory syndrome coronavirus #2 (SARS-CoV-2).

What are common symptoms of COVID-19?

Acute respiratory symptoms, vomiting, diarrhea, and a cytokine storm.

What is a cytokine storm?

A hyperinflammatory response in the lungs and other organs.

What neurological issues can COVID-19 cause?

Loss of taste and smell, and dementia.

What are the variants of SARS-CoV-2?

Mutations in the virus's genome that arise as it remains in the population.

What role do spike proteins play in COVID-19?

They attach to host cell ACE-2 receptors to enter cells.

What is the significance of ACE-2 receptors in COVID-19?

They help dampen the inflammatory response, which is blocked by the virus.

What types of tests were developed for COVID-19?

RT-PCR and immunological tests measuring antigens and antibodies.

What is the key preventative measure against COVID-19?

Vaccines that trigger the immune system to recognize and eliminate the virus.

What is malaria?

A dominant protozoan disease threatening 40% of the world's population annually.

What are the first symptoms of malaria?

Malaise, fatigue, vague aches, nausea, followed by chills, fever, and sweating.

What causes the cyclic pattern of symptoms in malaria?

Synchronous red-blood-cell rupture.

What is cerebral malaria?

A serious complication where small blood vessels in the brain become obstructed.

What are the five Plasmodium species that infect humans?

P. malariae, P. vivax, P. knowlesi, P. ovale, and P. falciparum.

How is malaria primarily transmitted?

By the female Anopheles mosquito.

What is the definitive diagnosis for malaria?

Discovery of a typical stage of Plasmodium in stained blood smears.

What is the annual global case rate of malaria?

200 million new cases reported each year.

What are some complications of malaria?

Hemolytic anemia, organ enlargement, and rupture due to cellular debris.

What is the incubation period for malaria?

10 to 16 days.

What is the mortality rate of malaria in children?

Malaria has the highest death rate in the acute phase, especially in children.

What is the role of convalescent plasma in COVID-19 treatment?

It contains active anti-viral antibodies from recovered patients.

What is the primary method of malaria prevention?

Long-term mosquito abatement and human chemoprophylaxis.

What innovative method are scientists exploring for malaria abatement?

Introducing sterile male mosquitoes into endemic areas.

What are some ways humans can reduce their risk of malaria?

Using netting, screens, repellants, remaining indoors at night, and taking weekly doses of antimalarial drugs.

What is the mainstay treatment for malaria?

Quinine.

Which drug is used for nonresistant forms of malaria?

Chloroquine.

What plant compound has been most effective in treating malaria?

Artemisinin.

What factors are symptoms of HIV tied to?

The level of virus in the blood and the level of T cells in the blood.

What are initial symptoms of HIV infection?

Fatigue, diarrhea, weight loss, and neurological changes.

What is the progression of HIV in the absence of treatment?

Initial high levels of virus, few antibodies, vague symptoms, followed by a drop in blood virus levels and a decrease in CD4 T cell numbers.

What is the primary mode of HIV transmission?

Sexual intercourse or transfer of blood or blood products.

How can babies be infected with HIV?

Before or during birth, or through breastfeeding.

What is the causative agent of HIV?

HIV is a retrovirus.

What is a significant characteristic of retroviruses like HIV?

They can permanently integrate viral genes into the host genome.

What is the mortality rate of bubonic plague even with treatment?

Can reach up to 15%.

What bacterium causes bubonic plague?

Yersinia pestis.

What are the acute symptoms of tularemia?

Headache, backache, fever, chills, coughing, and weakness.

What is the causative agent of tularemia?

Francisella tularensis.

What is endocarditis?

Inflammation of the endocardium, often referring to infection of the heart valves.

What are the two variations of endocarditis?

Acute and subacute.

What is the significance of CD4 T cell count in HIV infection?

A count below 200 cells/µl indicates AIDS.

What is the role of reverse transcriptase in HIV?

It catalyzes the replication of double-stranded DNA from single-stranded RNA.

What is the recommended prevention method for HIV?

Avoidance of sexual contact with infected persons and using barrier protection.

What is the significance of the term 'nonprogressor' in HIV infection?

About 1% of people who are antibody-positive remain free of AIDS.

What is a common misconception about HIV transmission?

HIV is not transmitted through saliva.

What is the treatment approach for HIV?

Combination of three drugs from two different classes, starting soon after diagnosis.

What challenges exist in HIV treatment globally?

Making drugs widely available and developing affordable treatment options.

What is the role of opportunistic infections in AIDS?

AIDS patients often receive a wide array of drugs to prevent or treat these infections.

What is the primary mode of HIV transmission in most parts of the world?

Heterosexual intercourse.

What is the importance of testing for HIV?

Diagnosis is based on testing positive for the virus, which is not the same as having AIDS.

What is a major risk factor for developing endocarditis after surgery?

Bacteria introduced during the surgical procedure.

What are common signs and symptoms of endocarditis?

Fever, fatigue, joint pain, edema, weakness, anemia, abnormal heartbeat, and petechiae.

What distinguishes acute endocarditis from subacute endocarditis?

Acute endocarditis symptoms develop rapidly and are more severe, while subacute symptoms develop slowly and are less pronounced.

What is a common causative agent of acute endocarditis?

Staphylococcus aureus.

What are Janeway lesions?

Red, painless skin spots on the palms and soles associated with endocarditis.

What is the primary transmission route for subacute endocarditis?

Minor disruptions of skin or mucous membranes introducing bacteria into the bloodstream.

What bacteria commonly cause subacute endocarditis?

Streptococcus sanguis, S. oralis, or S. mutans.

What are early signs of sepsis?

Fever, fast heart rate (tachycardia), and rapid breathing (tachypnea).

What is a hallmark sign of septicemia?

Low blood pressure caused by the inflammatory response to infectious agents.

What is the primary causative agent of septicemia?

Bacteria, with a significant number being gram-positive and gram-negative.

What is endotoxic shock?

A drastic drop in blood pressure due to the release of endotoxins from gram-negative bacteria.

What is the role of blood culture in septicemia diagnosis?

It is the primary method for diagnosing infections in the bloodstream.

What are the common symptoms of Lyme disease?

Erythema migrans, fever, headache, stiff neck, and dizziness.

What is the causative agent of Lyme disease?

Borrelia burgdorferi.

How is Lyme disease primarily transmitted?

By hard ticks of the genus Ixodes.

What is the characteristic rash associated with Lyme disease?

Erythema migrans, resembling a bull's-eye.

What is the recommended treatment for early Lyme disease?

Prolonged treatment with doxycycline or amoxicillin.

What does septic shock indicate?

Severe sepsis with very low blood pressure.

What are Osler's nodes?

Small, painful nodes on the pads of fingers and toes associated with endocarditis.

What can happen if subacute endocarditis is untreated?

It can lead to clubbed fingers and toes due to prolonged lack of oxygen in the blood.

What is the significance of prophylactic antibiotic therapy?

It is used to prevent endocarditis in patients with underlying valve irregularities before surgical and dental procedures.

What is a common complication of septicemia?

Organ damage due to the inflammatory response.

What are the long-term complications of untreated Lyme disease?

Chronic neurological complications and crippling arthritis.

What is the importance of early diagnosis in Lyme disease?

It allows for effective treatment and prevents progression to severe stages.

What is a common risk group for septicemia?

Intravenous and subcutaneous drug users.

What is the role of deep sequencing techniques in septicemia?

To provide faster and more appropriate treatment.

What factors contribute to the virulence of Borrelia burgdorferi?

Its ability to change surface antigens for immune evasion.

What are the dimensions of large spirochetes?

0.2 to 0.5 micrometers in width and 10 to 20 micrometers in length.

How does the bacterium causing Lyme disease evade the immune system?

It changes its surface antigens while in the tick and again after transmission to the mammalian host.

What is the primary vector for Lyme disease?

Hard ticks of the genus Ixodes.

Which tick is known as the black-legged deer tick?

Ixodes scapularis.

What is the typical diagnosis method for early Lyme disease?

Based on symptoms and history of exposure to ticks.

What antibiotics are effective for treating early Lyme disease?

Doxycycline and amoxicillin.

What is the causative agent of Infectious Mononucleosis?

Epstein-Barr virus (EBV).

What are common symptoms of Infectious Mononucleosis?

Sore throat, high fever, cervical lymphadenopathy, gray-white exudate in the throat, and fatigue.

What is a notable sign of Infectious Mononucleosis?

Sudden leukocytosis initially consisting of infected B cells.

How is Infectious Mononucleosis primarily transmitted?

Through direct oral contact and contamination with saliva.

What is the main treatment for Infectious Mononucleosis?

Symptomatic relief of fever and sore throat.

What are Hemorrhagic Fever Diseases characterized by?

Extreme fevers and potential internal hemorrhaging.

What is the causative agent of Chagas Disease?

Trypanosoma cruzi.

What is a common symptom of Chagas Disease during the acute phase?

Mild to severe fever and the appearance of a 'Chagoma' at the site of the bug bite.

What is the primary vector for Chagas Disease?

Triatomine insects.

What is the causative agent of Anthrax?

Bacillus anthracis.