LECOM Microbiology Lecture 7- blood borne infections

what is the vector and reservoir for Lyme disease

vector: hard ticks (Ixodes)

reservoir: white-tailed deer, white-footed mouse

what is the geographic location for Lyme disease

Northeast U.S.

what is the vector and reservoir for epidemic relapsing fever

o Vector

§ Body louse "lice"-borne relapsing fever

o Reservoir

§ Humans

what is the geographic location for Rocky Mountain spotted fever

southeast U.S.

what are special characteristics of Rickettsia akari

§ Requires outer membrane protein A (OmpA)

· Adheres to endothelial cells and enters.

what causes epidemic typhus and Brill-Zinsser disease

- Rickettsia prowazekii

what is the vector, reservoir, and geographic location for epidemic typhus

o Vector

§ Human body louse

o Reservoir

§ Humans

o Geographic distribution

§ Parts of Africa, Central and South America, and Asia

what are the clinical symptoms of epidemic typhus and Brill-Zinsser disease

§ Epidemic typhus

· Fever, headaches, chills, and myalgia

· Macular rash starts on chest and spreads outward

§ Brill-Zinsser Disease

· Can occur years after initial infection.

· Milder symptoms and absence of rash

§ Can be fatal in untreated patients.

what causes endemic typhus

Rickettsia typhi

what is the vector, reservoir, and geographic location for endemic typhus

o Vector

§ Rat flea

§ Cat flea

o Reservoir

§ Rodents, cats, racoons, and skunks

o Geographic distribution

§ Found worldwide in warmer climates.

what are the clinical symptoms of endemic typhus

· Fever, headache, myalgia

· Maculopapular rash

o Chest and abdomen

· Disease lasts about 3 weeks.

· Less severe than epidemic typhus

what bacteria causes scrub typhus

Orientia tsutsugamushi

what is the vector, reservoir, and geographic location for scrub typhus

o Vector

§ Mites

o Reservoir

§ Wild rodents

o Geographic distribution

§ Japan, Eastern Asia, Northern Australia, Western and Southwestern Pacific

what are the clinical symptoms of scrub typhi

§ Fever, headache, myalgias

§ Maculopapular rash

· Starts on trunk and spreads to extremities

§ Rare symptoms

· Lymphadenopathy, splenomegaly, CNS complications, heart failure

what parasite causes babesiosis

Babesia microti

what is the lifestyle for babesia microti

· Ixodes tick

o Transovarian transmission

· Forms a ring structure in RBCs

o Tetrad formation: "Maltese" cross

what are the initial and advanced symptoms of babesiosis

· Babesiosis

o Can be asymptomatic.

· Initial symptoms

o Malaise, fever headaches, chills, and fatigue

· Advanced symptoms

o Hemolytic anemia

o Renal failure

o Hepatomegaly and splenomegaly

o Acute respiratory distress syndrome (ARDS)

what are the lab tests and characterisitcs

§ Lab tests

· Blood smear

o Ring form and Maltese cross in RBCs

· PCR

§ Characteristics

· Intracellular sporozoan parasite

which two organisms can be a co-infection

The tick can pass on both Babesia microti and Borrelia burgdorferi.

Recognize the difference between an amastigote and trypomastigote

o Trypomastigotes enters the bloodstream.

o Amastigote gets into the tissue.

what causes American trypanosomiasis

Chaga's Disese

Trypanosoma cruzi

what is the lifestyle of Trypanosoma cruzi

o Trypomastigotes enters the bloodstream.

o Amastigote gets into the tissue.

Trypanosoma cruzi reservoir

rodents, opossums, armadillos

what is the vector for Trypanosoma cruzi

Reduviid bug (kissing bug)

what is the geographic distribution of Trypanosoma cruzi

south america

clinical symptoms of American trypanosomiasis (Chagas disease)

o Chagas disease

§ Chagoma

§ Acute phase

· Mostly asymptomatic

· Fever, chills, malaise, fatigue

§ Chronic phase (can be fatal)

· Myocarditis

· Megacolon

what are the lab tests for American trypanosomiasis

o Acute phase

§ Parasite in bloodstream

§ Blood smears

o Chronic phase

§ Parasite in tissues

§ IFA

o Xenodiagnoses (not done as much anymore)

what are the characteristics of Trypanosoma cruzi

o Transmitted through feces of Reduviid/Kissing bug

§ Congenital

§ Blood transfusion

§ Organ transplants

§ Contaminated food or drinks (rarely)

o Chagas- 3 Cs

§ Children, chagoma, cardiac

African sleeping sickness is caused by what parasite

Trypanosoma brucei gambiense/rhodesiense

what is the lifestyle of Trypanosoma brucei gambiense/rhodesiense

o Trypomastigote in blood

§ Lymph will enter the spinal fluid (CSF)

what is the vector, reservoir, and geographic location for Trypanosoma brucei gambiense/rhodesiense

· Vector

o Tsetse fly

· Reservoir

o Humans and wild animals

· Geographic distribution

o Africa

what are the First stage clinical symptoms of Trypanosoma brucei gambiense/rhodesiense

§ Hemo-lymphatic disease

· Painful chancre that can ulcerate

· Lymphadenopathy

· Winterbottom's sign

o Enlargement of posterior cervical lymph nodes

· Fever, headache, and muscle pain

what are the Second stage clinical symptoms of Trypanosoma brucei gambiense/rhodesiense

§ Meningo-encephalitis

· Headache, personality changes, and ataxia (loss of coordination)

· Sleep disorder

o Awake during night, sleeping during day

· Fatal if untreated

What are the lab tests and characteristics of Trypanosoma brucei gambiense/rhodesiense

· Lab tests

o Giemsa stain

§ Blood, aspiration from lymph nodes or spinal fluid (CFS)

o Second stage

§ CSF

· Characteristics

o Opposite sleeping conditions

o Can progress to meningitis and encephalitis type symptoms

what parasitic species is responsible for malaria

o Plasmodium species

§ P. falciparum (also P. vivax and P. ovale)

§ Protozoan parasite

what is the transmission of Plasmodium falciparum

Anopheles mosquito (night biting), blood transfusion, congenital

what is the life cycle of Plasmodium falciparum

· Mosquitos transmit into blood -> ring structures form in RBCs

o Crescent/sausage shape gametocytes

what is the geographic location for Plasmodium falciparum

Africa and parts of Asia

Uncomplicated Malaria

· Chills, fever, nausea, vomiting, and diarrhea

· Tertian cycle

o Due to lysing RBCs, RBC regeneration, and lysing occurs again

o Symptoms return every 48 hours

Severe malaria

· Anemia, altered mental status, seizures, coma, death

blackwater fever

different form of malaria

· Severe anemia, jaundice, dark urine

· Just know this exists

what is the diagnosis of Plasmodium falciparum

· Blood smears

o Ring form, crescent-shaped gametocyte

· Rapid tests

o Antigen detection (performed in 15-20 min)

· PCR

· IFA or ELISA

o Antibody detection

what bacterial strain causes Lyme disease and what is its morphology

borrelia burgdorferi, spirochete

what is the life cycle of borrelia burgdorferi

§ Borrelia burgdorferi is within the reservoir

· Tick acquires bacteria when feeding on reservoir

· Tick then feeds on humans and passes the borrelia burgdorferi

o Ticks cant pass the disease to their offspring

what are the clinical symptoms of early localized Lyme disease

§ Malaise, fever, lymphadenopathy (can last up to 4 weeks)

§ Erythema migrans- bullseye rash (70-80% patients)

what are the clinical symptoms of early disseminated Lyme disease

§ Untreated patients

· Arthritis, neurological manifestations (facial nerve palsy- drooping of one side of face)

· Cardiac complications (Atrioventricular block)

· Light-heatedness, shortness of breath, chest pain

what are the clinical symptoms of late (chronic) Lyme disease

§ Untreated patients- months to years later

· Chronic arthritis

· Encephalopathy

o Memory loss, sleep disturbance, fatigue, depression, irritability

· Peripheral nerve involvement

o Tingling sensation in extremities

what are the lab tests and characteristics for Lyme disease

§ Do not use microscopy or cultures

§ Mainly look at antibody detection

· Immunofluorescence assay (IFA)

· Enzyme Immunoassay (EIA)

o Positive result -> western blot (IgG and IgM)

what bacteria causes epidemic relapsing fever and what is it's morphology

Borrelia recurrentis, spirochete

§ Louse-borne relapsing fever

what is the geographic distribution for epidemic relapsing fever

Ethiopia, Eritrea, Somalia, Sudan

what are the clinical symptoms for epidemic relapsing fever

§ Abrupt onset

· Fever, chills, muscle aches, and headache

§ 1 week later

· Mild symptoms return

§ Splenomegaly, hepatomegaly, mortality (30-70%)

Cardiac failure, hepatic necrosis, or cerebral hemorrhage

what are the lab tests and characteristics for epidemic relapsing fever

o Lab tests

§ Detection: blood smear

· No serology due to antigenic variation

o Characteristics

§ Antigenic variation

· Changes of the outer proteins confuse the immune system.

o This also occurs in gonorrhea.

· Alters the outer surface gene (OspC- outer surface protein C)

what are the bacterial strains responsible for Rickettsiaceae and what are the lab tests

o Rickettsia and Orientia

o Lab tests

§ Microimmunofluorescence test

· Detects antibodies against outer membrane proteins and LPS.

§ Also based on geographic location

what is the bacteria strain and morphology for Rocky Mountain spotted fever

- Rickettsia rickettsii

· Obligate intracellular Gram-negative rods

Rickettsia rickettsii lifestyle

· Transovarian transmission- can pass to offspring

what are the clinical symptoms of Rocky Mountain spotted fever disease

· High fever, headache, malaise, nausea, vomiting.

· Rash- starting from palms/soles and spreads inward toward trunk.

· Encephalitis

· Pulmonary edema

· Cardiac arrhythmias

· Can be fatal if not treated

what is the bacteria that causes Rickettsialpox

Rickettsia akari

what is the vector, reservoir, and geographic location for Rickettsialpox

o Vector

§ Mites

o Reservoir

§ Wild rodents

o Geographic distribution

§ Cosmopolitan distribution

what are the clinical symptoms of Rickettsialpox

§ Biphasic

· First phase: papule at bite site= black eschar

· Second phase (systemic spread):

o 9-14 days later

o Fever, headache, and chills

o Papulovesicular rash

§ Vesicles form and crust over

· Resolves within 2-3 weeks.

what is the vector, reservoir, and geographic location for babesiosis

§ Vector

· Ixodes tick

§ Reservoir

· Small rodents

§ Geographic distribution

· Northeast