Week 12 Diseases of cardiovascular and lymphatic symptoms Flashcards
Septicaemia definition
proliferation of microbes in
the blood
Characteristics of septicaemia (2)
Lyses of red blood cells through haemolysin (containing
haemoglobin) releases iron accelerate growth
Clinical sign = lymphangitis (inflamed lymph
vessels visible as red streaks under the skin)
Sepsis definition
Toxic condition resulting from septicaemia; bacteria (Mainly G-ve rods) enter the blood from focus of infection.
Septic shock definition
Lyses of G-ve bacteria releases endotoxin, drop of
blood pressure (hypotension)
Puerperal sepsis cause
Caused mostly by S.pyogenes (group A, beta haemolytic)
Puerperal sepsis progression
A nosocomial infection -> infection of uterus ->
infection of abdominal cavity (peritonitis) and septicaemia, also child birth fever or abortion.
Puerperal sepsis transmission
contaminated hands and instruments used during delivery of baby
Endocarditis affects what part of the heart
Infection of the inner layer of the
heart (endocardium)
Cause and progression of subacute endocarditis
Microbes (e.g. streptococci) from teeth or tonsils enter
blood (dental extraction) and colonise heart (in patient with abnormal heart valves).
Acute endocarditis cause and pathology
S. aureus, rapid destruction of heart valves.
Rheumatic fever cause
S. pyogenes
Age group affected by rheumatic fever
4-18
Rheumatic fever pathology
Short period of arthritis and fever.
Subcutaneous nodules at joints, inflammation of heart (misdirection of the immune reaction against M protein of Streptococci), damage to heart valve.
Tularaemia cause and characteristics
Francisella tularensis: a small, G-ve rod, facultative-
anaerobe.
Infection mechanism and symptoms in tularaemia
❖ Infection due to inhalation, ingestion, bites (e.g. rabbits) arthropods (e.g. ticks), contact through skin breaks.
❖ Clinical syndrome: ulceroglandular tularaemia (Lymph nodes are swollen, no visible ulcer)
Brucellosis cause (3)
Brucella abortus, B. suis and B. melitensis
Reservoirs for brucella species
Abortus: infects livestock
Suis: infects swine and cattle
Melitensis: reservoir in sheep
How is brucellosis transmitted, what symptoms occur
Transmission through milk and dairy products
Causing chills, fever (40oC, wavelike fever)
Anthrax cause
bacillus anthracis
Bacillus anthracis characteristics
G+ve, long chain, central spore
Short chain in infected tissue
Non motile and non haemolytic
Capsule, (D-glutamic acid polypeptide), with a high anti-phagocytic effect
How is anthrax spread
Disease of sheep and cattle
Diseased animal spread spores in soil, skin contact ->disease
Respiratory disease of wool-sorting workers (respiratory anthrax)
Anthrax infection of skin MOA and symptoms
Cutaneous anthrax: “malignant pustule”
❖Cut on skin
❖lesion on site black necrotic area
❖regional lymph nodes, blood, death (5-6
days)
Cutaneous anthrax treatment
Penicillin, sulphonamide
Anthrax prevention
❖Live attenuated vaccine for sheep and cattle
Gangrene cause and pathology
Clostridium perfringens
Necrosis specially in muscle tissues will lead to gas gangrene
❖ alpha-toxin:sub-cutaneous, causes muscle necrosis Ischemia: interruption of blood supply ->, wound becomes anaerobic and ischemia will lead to necrosis (death of tissue; gangrene)
Treatment for gangrene
Surgical removal of necrotic
tissue , if in abdominal cavity, treatment in hyperbaric chamber
Plague causes (3) and characteristics
Yersinia pestis: plague
Yersinia enterocolitica: enterocolitis
Yersinia pseudotuberculosis: local and systemic necrosis
Non motile, non spore forming
Invasive, produce enterotoxin and endotoxin
Yersinia pestis major disease and transmission
Black death (pandemic plague/ bubonic plague)
Disease of rats transmitted by rat flea xenopsylla cheopis
Plague progression
Bacterial growth blocks flea’s digestive tract
(blood is not digested).
Bacteria enter human blood, propagate in
lymph nodes & blood -> systemic infection &
fever (septicaemic plague).
Pulmonary spread, produces a fatal
necrotizing haemorrhagic pneumonia:
Pneumonic plague
Y. pestis symptoms
Enlarged lymph nodes in groin and armpit
Swelling associated with haemorrhage called bubo (bubonic plague)
Mortality 50-70%, a week after symptoms appear
Gastrointestinal anthrax cause
Potent exotoxin from bacillus anthracis that cause extensive oedema (Oedema factor), spread by eating meat
relapsing fever cause and transmission
Borrelia (a spirochete)
Transmission by soft ticks that feeds on
rodents
Relapsing fever symptoms
Fever (40.5oC), jaundice, skin spots (3-5 days)
❖ Relapses occur (3-4 times) by antigenically different serotypes of Borrelia
Lyme disease cause and transmission
tick-borne disease caused by B. burgdorferi
Is lyme disease transmissable between humans
No
Lyme disease symptoms
Rash at bite site
red area that clear in the centre and expands
(15 cm)
Flu-like symptoms 2 weeks
Rash fades
Heart becomes infected
Neurological symptoms (e.g. Facial paralysis, meningitis and encephalitis)
Cat scratch disease cause
G-ve rod, Bartonella benselae
Cat scratch disease transmission and symptoms
Part of the oral flora of cats and dogs
❖ From scratch, or bite, the bacterium enters lymph nodes and
multiplies
❖ Extremely swollen nodes
Cat scratch disease treatment
❖ The infection will resolve by its own
❖ Treatment: rifampicin, ciprofloxacin
Rocky mountain spotted fever cause and characteristics
Rickettsia rickettsii (an
obligate intracellular bacterium), G-ve rod
Rocky mountain spotted fever transmission and progression
Transmitted by arthropods (ticks, lice, fleas
etc)
The bacterium multiplies in inner lining
of blood vessels. Damages capillaries in the skin,
causing spotty rash
Typhus types
Epidemic (louse borne) and murine (mouse)
Epidemic typhus cause and transmission
Rickettsiae prowazekii, transmitted by lice during a blood meal
Murine typhus cause and transmission
Rickettsiae typhi, lice on mice and rats, less severe than epidemic typhus
Typhus symptoms
high headache, shaking chill, fever, muscle ache
Infectious mononucleosis cause and characteristics
Epstein barr virus a DNA herpes virus with
a lipid envelope
Infectious mononucleosis symptoms
fatigue, sore throat, swollen lymph nodes
❖ High number of enlarged lymphocytes
❖ Recovery after 4-6 weeks
Chagas disease (american trypanosomiasis) cause and vector
Trypanosoma cruzi, reduviid bug (kissing bug)
Toxoplasmosis cause
Toxoplasma gondii (protozoan parasite) ingested in cyst form
Toxoplasmosis infects what species
Cat, mice/rat, human
Complication of toxoplasmosis
Threaten health of unborn child
Toxoplasmosis diagnosis
PCR and serological test
Toxoplasmosis treatment
Combination of sulfadiazine and folic acid
5 causes of malaria in humans, which two cause majority of deaths? What vector
➢ Plasmodium. Falciparum
➢ Plasmodium. vivax
➢ Plasmodium. malaria
➢ Plasmodium. ovale
➢ Plasmodium. knowlesis
Falciparum then vivax
Female anopheles mosquito
WHich is the intermediate and which is the definitive host of malaria
Mosquito is the definitive host and human is the intermediate host
Population at risk of malaria
tropical and subtropical
Population at risk: children, pregnant women and non-immune travellers/ immigrants
Malaria symptoms, when do they occur
severe anaemia,
respiratory distress in relation
to metabolic acidosis, or
cerebral malaria.
7 days or more after invasion
Prevention of malaria (2)
Vector control:
Insecticide-treatment mosquito nets: It is efficient,
long lasting and cost-effective.
Indoor residual spraying (IRS): Spraying with insecticide
is powerful way to rapidly reduce transmission. It is
effective for 3-6 months, depending on insecticide
formulation used.
Malaria treatment (2)
Chloroquine and primaquine
Leishmania causes (3)
L. donovani, that attacks
the internal organs e.g. visceral Leishmaniosis
L. Tropica and L. braziliensis attack skin
and mucous membrane e.g. cutaneous
leishmaniasis
Two types of leishmania
Cutaneous and visceral
Schistosomiasis causes and what they affect
1- Schistosoma haematobium (also know as urinary
schistosomiasis) effect urinary tract and bladder
2- S. japonicum: intestinal inflammation
3- S. mansoni : intestinal inflammation
Small fluke (protozoa)
