UNIT 4 STUDY GUIDE

how is neurocysticercosis treated

using antihelminthic drugs or surgery to remove the large cysts from the CNS

what is African trypanosomiasis

a serious but treatable disease endemic to 2 distinct regions in sub-Saharan Africa

what is African trypanosomiasis caused by

insect borne hemoflagellate trypanosoma brucei

The various forms of ameobic encephalitis caused by the different amoebic infections are typically

fatal even with treatment, but they are rare.

Some protist infections of the nervous systems are fatal if not treated, including

primary amoebic meningitis, granulomatous amoebic encephalitis, human African trypanosomiasis, and neurotoxoplasmosis

Neuromycoses are

uncommon in immunocompetent people, but immunocompromised individuals with fungal infections have high mortality rates.

what are treatments of neuromycoses

prolonged therapy with antifungal drugs at low dose

what are the 3 layers of the skin

epidermis, dermis, hypodermis

the skin is considered an effective ________ against microbial invasion

physical barrier

what characteristics of the skin discourage colonization by transient microbes

dry environment and normal microbiota

what is a frequent site for microbial infection in the eye

the conjuctiva

what is rabies

nearly always fatal when untreated and remains a significant problem worldwide

what is polio

typically a mild intestinal infection but can be damaging or fatal if it progresses to a neurological disease

what is zika virus

an emerging arboviral infection with generally mild symptoms in most individuals, but infections of pregnant people can cause the birth defect microcephaly

The nervous system consists of two subsystems called

central nervous system and peripheral nervous system

what are the meninges

dura mater, arachnoid mater, pia mater

Tissues of the PNS and CNS are formed of cells called 

glial cells and neurons

what is chagas disease

tropical disease transmitted by triatomine bugs. The trypanosome infects heart, neural tissues, monocytes, and phagocytes, often remaining latent for many years before causing serious and sometimes fatal damage to the digestive system and heart.

what is leishmaniasis

caused by the protozoan Leishmania and is transmitted by sand flies. Symptoms are generally mild, but serious cases may cause organ damage, anemia, and loss of immune competence

what is toxoplasmosis

widespread protozoal infection that can cause serious infections in the immunocompromised and in developing fetuses. Domestic cats are the definitive host.

what is bacterial vaginosis

caused by an imbalance in the vaginal microbiota, with a decrease in lactobacilli and an increase in vaginal pH

what is the most common cause of bacterial vaginosis

G. vaginalis

what are the symptoms ofd

what is gonorrhea caused by

N. gonorrhoeae

what is chlamydia

most commonly reported STI, most infections are asymptomatic

what is chlamydia caused by

C. trachomatis

what can happen if chlamydia goes untreated

can spread to involve the epididymis of males and cause salpingitis and pelvic inflammatory disease in females

what is syphilis caused by

T. pallidum

what is primary syphilis associated with

painless hard chancre lesion on genitalia

what is secondary syphilis associated with

skin and mucous membrane lesions

what is tertiary syphilis

most serious and life-threatening, and can involve serious nervous system damage

what is a chancroid

infection of the reproductive tract that results in the development of characteristic soft chancres

what are chancroids caused by

H. ducreyi

what is genital herpes

is usually caused by HSV-2 (although HSV-1 can also be responsible) and may cause the development of infectious, potentially recurrent vesicles

what is neonatal herpes

can occur in babies born to infected people and can cause symptoms that range from relatively mild (more common) to severe

what is human papillomaviruses

most common sexually transmitted viruses and include strains that cause genital warts as well as strains that cause cervical cancer

where is Candida spp. typically present

normal microbiota in the body, including the skin, respiratory tract, gastrointestinal tract, and female urogenital system

Disruptions in the normal vaginal microbiota can lead to an overgrowth of Candida, causing…

vaginal candidiasis.

how can vaginal candidiasis be treated

topical or oral fungicides. Prevention is difficult

what is trichomoniasis

common STI caused by Trichomonas vaginalis.

where is T. vaginalis is common at

low levels in the normal microbiota

how is trichomoniasis treated

antiflagellate drugs tinidazole and metronidazole

the digestive tract consists of…

oral cavity, pharynx, esophagus, stomach, small intestine, and large intestine

what does the digestive tract have that is important for health

normal microbiota

what helps prevent colonization by pathogens in the digestive tract

The constant movement of materials through the gastrointestinal canal, the protective layer of mucus, the normal microbiota, and the harsh chemical environment in the stomach and small intestine

Infections or microbial toxins in the oral cavity can cause what

tooth decay, periodontal disease, and various types of ulcers.

Infections and intoxications of the gastrointestinal tract can cause general symptoms such as

nausea, vomiting, diarrhea, and fever

Localized inflammation of the GI tract can result in

gastritis, enteritis, gastroenteritis, hepatitis, or colitis, and damage to epithelial cells of the colon can lead to dysentery.

what are foodborne illnesses

refers to infections or intoxications that originate with pathogens or toxins ingested in contaminated food or water

what is caused by overgrowth of oral bacteria, usually Streptococcus and Actinomyces species, as a result of insufficient dental hygiene

Dental caries, tartar, and gingivitis

what is oral thrush

a fungal infection caused by overgrowth of Candida yeast

what is mumps

a viral infection of the salivary glands caused by the mumps virus, a paramyxovirus

The herpes simplex virus type 1 can cause lesions of the mouth and throat called

herpetic gingivostomatitis

Major causes of gastrointestinal illness include

Salmonella spp., Staphylococcus spp., Helicobacter pylori, Clostridium perfringens, Clostridioides difficile, Bacillus cereus, and Yersinia bacteria.

what is an important cause of hospital acquired infection

C. difficile

what does Vibrio cholerae cause

cholera

what is cholera

a severe diarrheal illness

what is H. pylori associated with

peptic ulcers

what are the different strains of E. coli

ETEC, EPEC, EIEC, and EHEC

what do the different strains of E. coli cause

different illnesses with varying degrees of severity

Salmonella enterica serotypes can cause 

typhoid fever

what is typhoid fever

a more severe illness than salmonellosis

Careful antibiotic use is required to reduce the risk of causing what

C. difficile infections and when treating antibiotic-resistant infections

what are common viral causes of gastroenteritis

rotaviruses, noroviruses, and astroviruses

Hepatitis may be caused by several unrelated viruses such as

hepatitis viruses A, B, C, D, and E

how do hepatitis viruses differ from one another

modes of transmission, treatment, and potential for chronic infection

what are some intestinal infections caused by protozoans

Giardiasis, cryptosporidiosis, amoebiasis, and cyclosporiasis

how are protozoan intestinal infections commonly transmitted

through contaminated food and water.

how are protozoan infections of the GI tract treated

Treatment varies depending on the causative agent, so proper diagnosis is important.

what is often used to diagnose protozoan infections of the GI tract

Microscopic examination of stool or biopsy specimens, in combination with other approaches. Fecal float

what do helminth infections often cause

intestinal infections after transmission to humans through exposure to contaminated soil, water, or food

helminth infection signs and symptoms are often considered…

mild, but severe complications may develop in some cases.

what does the circulatory system do

moves blood throughout the body and has no normal microbiota

what does the lymphatic system do

moves fluids from the interstitial spaces of tissues toward the circulatory system and filters the lymph. It also has no normal microbiota.

The circulatory and lymphatic systems are home to many what

components of the host immune defenses.

how do infection of the circulatory system occur

a break in the skin barrier or they may enter the bloodstream at the site of a localized infection.

Pathogens or toxins in the bloodstream can spread rapidly throughout the body and can provoke systemic and sometimes fatal inflammatory responses such as

SIRS, sepsis, and endocarditis

Infections of the lymphatic system can cause…

lymphangitis and lymphadenitis

what are papillomas (warts) caused by

human papillomaviruses.

what does Herpes simplex virus (esp. HSV-1) mainly cause

oral herpes, but lesions can appear on other areas of the skin and mucous membranes.

what is viral conjunctivitis caused by

adenoviruses and may be associated with the common cold

what is herpes keratitis caused by

herpesviruses that spread to the eye

what is the urinary system responsible for

filtering the blood, excreting wastes, and helping to regulate electrolyte and water balance.

what are parts of the urinary system

kidneys, ureters, urinary bladder, and urethra

what are common sites of infections in the urinary system

bladder and urethra

what are common sites of infection in the male reproductive system

urethra, as well as the testes, prostate and epididymis.

what are the most common sites of infection in the female reproductive system

vulva, vagina, cervix, and fallopian tubes.

how do infections of the urogenital tract occur

colonization from the external environment, alterations in microbiota due to hormonal or other physiological and environmental changes, fecal contamination, and sexual transmission (STIs).

what is bacterial cystitis commonly caused by

fecal bacteria such as E. coli.

what is pyelonephritis

serious kidney infection that is often caused by bacteria that travel from infections elsewhere in the urinary tract and may cause systemic complications.

what is leptospirosis

a bacterial infection of the kidney that can be transmitted by exposure to infected animal urine, especially in contaminated water. It is more common in tropical than in temperate climates.

what is Nongonococcal urethritis (NGU) is commonly caused by

C. trachomatis, M. genitalium, Ureaplasma urealyticum, and M. hominis.

what is malaria

protozoan parasite that remains an important cause of death primarily in the tropics.

Plasmodium are responsible for malaria and all are transmitted by 

Anopheles mosquitoes

what does malaria (Plasmodium) do

infects and destroys human red blood cells, leading to organ damage, anemia, blood vessel necrosis, and death

how is malaria treated

various antimalarial drugs and prevented through vector control

what is babesiosis

generally asymptomatic infection of red blood cells that can causes malaria-like symptoms in elderly, immunocompromised, or asplenic patients

what excludes most microbes in the nervous system

blood-brain barrier