infectious Disease, just diseases (General Pathology)

the gold standard for diagnosis of infections identification is from:

cultures

Serology

molecular techniques depending on the organsim

Nucleic acid amplification tests, such as ___, and transcription mediated amplification are common for rapid identification of microbes

PCR

Some infectious agents can be seen with routinely stained histologic slides, that produce characteristic viral cytopathic effect, such as:

CMV

HSV

These agents pose the highest risk and can be readily disseminated from person to person, cause high mortality. An example is small pox.

Category A

These agents are relatively easy to disseminate and produce moderate morbidity but low mortality and require special diagnostic and disease surveillance. Many are foodborne or waterborne, examples are Brucella species and vibrio cholera

Category B

These agents including pathogen that could be engineered for mass dissemination because of availably, ease of production, and dissemination potential for high morbidity and mortality. Examples are hantavirus and nipah virus.

Category C

Infectious causes of some diseases were not new but previously unrecognized because some of the infectious agents were difficult to culture, such as:

H. pylori

HPV

HCV

Legionella pneumophila

Some infectious diseases are new to humans such as:

HIV causing AIDS

B. burgdoferi causing Lyme disease

STI’s may become established in these areas of the body, then spread systemically through the circulation.

Urethra, vagina, cervix, rectum, oropharynx

Perinatally aqcuired C. trachomatis can cause:

conjunctivitis and neonatal HSV (visceral and CNS disease)

Lymphatic filariasis is transmitted by:

mosquitoes

Transmission of Lymphatic filariasis:

Infected larvae released by mosquitos into the tissues

Develop in the lymphatic channels

Immune responses to the filarial worms produce damage to the host

In chronic lymphatic filariasis, damage to the lymphatics is caused by the adult parasites and by a:

Th1-mediated immune response, stimulating the formation of granulomas around the adult parasites

Oncocerca volvulus (oncocerciasis) is a filarial nematode that is the leading cause of this in Africa

blindess

Oncocerciasis is transmitted via:

black flies and insects

Schistosoma Mansoni and S. Japonicum affect what organs?

Liver, gut

S. hematobium can cause:

chronic granulomatous bladder inflammation that may lead to hematuria, obstructive uropathy, squamous carcinoma of the bladder

How is schistosomiasis transmitted?

Released from snails, miracidum mature into infectious larvae (cercaiae) that can swim in fresh water, then penetrate human skin with the aid of of enzymes secreted by the larvae.

Schistosomes migrate through the skin and into the peripheral vasculature and lymphatics. They will mature and then settle into the venous system (portal or pelvic veins). The female will lay eggs that will elicit an inflammatory reaction. The inflammatory reaction will cause:

liver fibrosis and chronic active inflammation in the bladder, leading to cancer

Trichinella species are acquired by the ingestion of larva in undercooked meat from infected animals, such as:

pigs

After the ingestion of trichinella species, the larvae will disseminate hematogenously and penetrate muscle cells, causing:

fever, myalgias, marked with eosinophilia and periorbital edema

Trichinella species may also be found in the heart, lungs and brain, causing:

dyspnea, encephalitis, cardiac failure

Hydatid disease is caused by ingestion:

eggs of echinococcus species

Hydatid disease will cause the formation of cysts in:

organs where the parasite larvae are deposited

Humans are the incidental hosts of Hydatid disease, infected by ingestion of food contaminated with:

eggs shed by dogs or foxes

Hydatid disease infection in humans is usually asymptomatic but large cysts in the liver and lungs can cause:

pain or obstruction and pulmonary cysts can cause pain, cough and hemoptysis

Eggs from the echinococcus species can hatch in the duodenum and the larvae will invade the (Hydatid disease):

Liver, lungs or bones

Why is there caution when trying to surgically remove a cyst caused by Hydatid disease?

Anaphylaxis or dissemination of the organisms can result in spillage of the cyst contents

Cysticercosis and hydatid disease are caused by larvae that develop after ingestion of:

tapeworm eggs

Taenia solium and Echinococcus granulosus are cestode parasites (tape worms) that cause:

cysticercosis and hydatid disease

Tapeworms have a complex lifecycle, requiring a mammalian host and a definitive host, in which:

the worm reaches sexual maturity, and an intermediate host in which the worm does not reach sexual maturity

T. solium causes disease because of the deposition of:

cysts (cyticerci) in organs, RESULTING IN INFLAMMATORY RESPONSE

Tapeworms consists of a head (scolex) that has suckers and hooklets that attach to the:

intestinal wall, neck,

Tapeworms have many flat segments called ____, containing both male and female reproductive organs

Proglottids

New proglottids develop behind what portion of the tape worm?

Scolex

Most distal proglottids are mature and contain many eggs, detach and shed in the:

feces

T. solium can be transmitted to humans in 2 ways:

Larval cysts

Eggs

Larval cysts are called ____, ingested in undercooked pork and attach to the intestinal wall were they develop in the mature adult tape worms

Cysticerci

Tape worms can grow to :

2 mm in length

The parasite lifecycle is completed with this mode of infection in disseminated:

cystocercosis

When the intermediate host ingests eggs in food or water contaminated with human feces, the eggs become an:

oncosphere

the oncosphere will hatch and penetrate the gut wall, disseminating hematogenously, followed by the transition to:

a cysticercus, existing in many organs, giving rise to clinical symptoms of cysticercosis

Metazoa are:

multi-cellular, eucharyotic organisms with organ systems

Parasitic metazoal infections are contracted by consuming:

parasite ova in undercooked meat or direct invasion of the host through insect bites

Metazoa can dwell in many sites of the body, including the:

intestine, skin, lung, liver, muscle, blood vessels, and lymphatics

metazoal infections are diagnosed by:

microscopic identification of larvae or ova in excretions or tissues, serology

Strongyloides stercoralis worms can live in the:

soil

Strongyloides stercoralis infect humans when the larvae penetrate the skin, traveling to:

the circulation then to the lungs, then travel up to the trachea to be swallowed

Strongyloides stercoralis female worms reside in the mucosa of the:

small intestine

Strongyloides stercoralis larvae are passed in the stool, then may contaiminate the soil to:

continue the cycle of infectionallow re-infection or infection of new hosts.

Strongyloides stercoralis can also become infectious, leading to auto infection. In immunocompromised hosts, the auto infection can:

produce large amounts of the parasite, causing death

What are 3 types of nematode (roundworms) infections?

1. Strongilodiasis

2. Trichinosis

3. Lymphatic filariasis

What are 2 types of cestodes (hookworms) infections?

1. Hydatid disease

2. Cysisterocercosis

What is an example of a trematode infection (flukes)?

1. Schistomiasis

T. gondii causes:

Toxoplasmosis

T. gondii causes significant disease in what patients?

Immunocompromised and in pregnant women and their offspring

T. gondii infection occurs by:

eating undercooked meat, contaminated with tissue cysts or by acquiring the cysts through drinking contaminated water

accidental ingestion following cleaning the cat litter box

Another route of infection of T. gondii is this transmission during pregnancy:

Vertical transmission

T. gondii can be reactivated following:

immunosuppression

Trypanosoma cruzi is a kinetoplastid, which is a:

intracellular protozoan parasite, causing Chagas disease

Trypanosoma cruzi causes:

Chagas disease

T. cruzi parasites infect many animals such as:

dogs, cats, rodents

T. cruzi parasites are transmitted between animals into humans by what insects?

Triatomine or kissing bugs

Transmission of T. cruzi:

Infecitous parasites in the feces are transmitted to the host through damage to the skin or through mucous membranes

At the site of T. cruzi entry, there may be:

transient erythematous nodule

Chagas disease primarily effects the:

heart, cause of sudden death due to cardiac arrhythmia

Clinical issues causes by T. cruzi:

1. Inflammatory infiltration of the myocardium

2. Autoimmune responses, cross reacting with myocardial cells, nerve cells and extracellular proteins, leading to dysfunction of the heart

3. Damage to the myenteric plexus, dilation of the colon and esophagus

Kinetoplastic parasites contain:

a large massive DNA called a kinetoplast

African trypanosomiasis proliferate as extracellular forms in the blood, causing:

1. Intermittent fevers

2. Lymphadenopathy

3. Splenomegaly

4. Progressive brain dysfunction (sleeping sickness)

5. Cachexia

6. Death

Trypanosomes evade the immune detection by:

varying the variant surface glycoprotein (VSG)

When the immune system recognizes the VSG and mounts an immune response, a small number of trypanosomes evade detection by:

producing a different VSG on their surface

Waves of fever will continue to occur as a response to the trypanosomes, until they penetrate the:

CNS

Reservoirs of Leishmania:

Mammals (rodents, dogs, foxes)

This is a chronic inflammatory disease of the skin, mucous membranes, or viscera caused by obligate intracellular, kinetoplast containing protozoan parasites, transmitted through the bite of sand flies.

Leishmaniasis

Leishmaniasis is an endemic in:

tropical and subtropical regions, particularly in parts of South America, Asia, and Africa.

The lifecycle of Leishmaniasis species has 2 forms:

1. Promastigote, develop and lives extracellularly in the sandfly

2. Amastigote, multiply in intracellular host macrophages

Leishmania infections, like infections of other intracellular organisms, are exacerbated by conditions that interfere with:

T-cell function (AIDS)

Transmission of Leishmaniasis:

1. Bitten by the sandfly

2. Promastigotes are released to the host dermis, along with sand fly saliva, potentiates parasite infectivity

3. Promastigotes are phagocytosed by macrophages, acidity within the phagolysome induces them to transform

4. Amastigotes proliferate within the macrophages, dying macrophages release them and then they infect other macrophages.

Reservoir for B. microti:

white-footed mouse

Babesia species parasitize red blood cells, causing:

fever and hemolytic anemia

Babesiosis is caused by:

1. Babesia microti

2. Babesia divergens

This infection is caused by malaria like protozoans, transmitted in the same manner to lyme disease. The reservoir is the white footed mouse, parasitizing red blood cells.

Babesiosis

The lifecycle of Plasmodia involves only:

humans and mosquitoes, but has a complex development

These parasites cause low levels of parasitemia, mild anemia, and in rare instances splenic rupture and nephrotic syndrome.

1. P. vivax

2. P. ovale

3. P. knowlesi

4. P. malariae

The infectious stage of plasmodium, the sporozoite, is found in the:

salivary gland of mosquitos