Tetanus, Brucellosis, Melioidosis, Bartonella, Anthrax Flashcards
What is tetanus?
Clostridium tetani - gram positive anaerobe
2 toxins released by tetanus
Tetansopasmin - enters nerves and CNS (inhibits GABA) -> spasms
Tetanolysin
What is cause of death in tetanus?
Autonomic or respiratory involvement
Who gets neonatal tetanus
Babies of non-immune mothers
Tetanus Ix? dx? In ICU they should all get?
Clinical diagnosis
Tetanus Ig
Wound debridement
Metronidazole
benzos
May need rx of autonomic sx eg Labetalol for HTN / Atropine for bradys
May need paralysis
-Should all get magnesium
Tetanus control
Vaccines
Brucellae are? How do you get infected? Key at risk group?
gram negative coccobacilli
-Brucella melitensis
Consuming milk / unpasteurised cheese from affected animals
-Farmers/vets at high risk as aerosol infection from the placenta is very infectious
Brucellosis sx?
Has relapsing and remitting fever over several months
Often cough and low mood / anorexis
Key feature is focal MSK typically vertebrae, hip or knee
Brucellosis bloods
lymphopenia and thrombocytopenia
Often mild rises LFTs
Brucellosis rx without bone / localising disease? with bone/localising?
if kids?
Doxy + gent
Doxy+gent+rifampin - if bone/localising
Young kids / pregnant - co-trimox + rifampin
Neurobrucellosis rx
Doxy+rifampin+ceftriaxone
Brucellosis control
Pasteurize milk / cheese
Can vaccinate animal herds
Slaughter herds which have any positive tests (need to financially compensate)
What causes melioidosis? Found where? Pathogenesis
Gram negative bacilli - Burkholderia pseudomallei
Rice paddys in south east asia
Innoculation of contaminated soil/water
cause multiple abscesses or remain latent for years
melioidosis dx? rx?
Culture/gram stain blood/pus
Now has lateral flow assay / other RDTs
Requires expensive Abx
-ceftazidime or a carbapenem
-followed by prolonged co-trimox [doxy/co-amox options]
-Mortality remains 20% despite this rx
Malodorous sweat =
brucellosis
brucellosis ix?
Rose-bengal agglutination test
PCR / serology - best but less good in relapse
Brucellosis most common bug?
Brucella melitensis - Goats/sheep reservoir
[Brucella abortus second most]
What global region has highest rates of brucella
Mongolia > Middle east
Leading cause of laboratory transmitted infection worldwide
Brucella (especially Brucella melitensis)
Presents with:
Night sweats, weight loss
Constipation
Back pain
Key Dx? Other key Sx?
Brucella
[Extensive sweating
Back pain]
Brucella vertebrae features Vs TB
Age? sex? where? multiple vertebrae? abscess? type of lesion?
Brucella in kids presents different in what way?
<15 - often presents with peripheral arthritis
Spondylitis very rare
Which deficiency does Brucella cause worse Sx? who does this affect?
Iron deficiency - More common in women
Severe thrombocytopenia
Arthritis
Clinical severity
Blood finding in severe brucella =
Thrombocytopenia
Brucellosis bug
Brucella melitensis
When do you get outbreaks of melioidosis? Method of inoculation
Rainy seasons
-lives in water and soil
Usually percutaneous
-Can be respiratory / GI
Risk factors for severe burkholderia pseudomallei?
Most people who get melioidosis are ASx
diabetes
excessive alcohol use
chronic renal/lung disease
[All associated with neutrophil dysfunction]
Most common manifestation of melioidosis?
Pneumonia most 50%
Skin [ulcers/abscesses] 13%
GU 12%
No focus 11%
[visceral Abscess/bone/joint]
Chonic melioid resembles?
TB - often upper lobe cavitary lesion
Fever
Wt loss
Cough (hemoptysis)
Most common location for visceral melioidosis abscess
Prostate
Scratched by cat - has this lesion
then develops painful lymphadenopathy =
Bartonella Henselae - cat scratch disease
Cause of this neuroretinitis
Bartonella Henselae - Macular star
Some patients develop a star shaped macular exudate
(“macular star”).
Vector for carrions disease? cause?
Lutzomya. verrucarum
Bartonella bacilliformis
What is this lesion on the back of a calf? Geography
Mular lesions (carrions disease - Bartonella bacilliformis )
Peru, equador, columbia
Bartonella type of bacteria? stain?
Gram negative bacilli - giemsa stain
Grows at 27 degrees
Anaemia, Hepatomegaly, fever, Cardiac murmur, Jaundice, Visit jungle in peru
Bartonella Baciliformis (carions disease)
Why anaemia in Bartonella Baciliformis infection?
Infect RBCs
Bartonella endocarditis Rx
Doxy + gent
Oroya fever Rx
Bartonella Bacilliformis
Cipro + ceftriaxone if severe
Co-amox if <14
Chronic Bartonella bacilliforms causes multiple eruptions rx?
Azithromycin
Anthrax bug
Bacillus anthracis
- Encapsulated gram-positive rods
Different forms of anthrax, associated mortality?
Skin - 1% mortality
GI - 50% mortality
Pulmonary - inhalation = dead
Meningitis -> dead
IV - in IVDU forms a black eschlar
=? history?
Papule which ulcerates -> dark eschar
-> oedema -> tender proximal lymphadenopathy
PAINLESS at the site of lesion - look at oedema surrounding
Compare anthrax and spider bite
Anthrax - painless lesion + oedema with painful lymph node
Loxosceles - Painful lesion without oedema
Uncooked meat -> oral pharyngeal ulcerations + significant cervical lymphadenopathy
Gastroenteritis + bloody diarrhoea
GI anthrax
pt develops rapid appearance of pulm sepsis
Hemorrhagic mediastinitis (pleuritis or myocarditis)
No pneumonia (increased Mediastinal ganglia).
Then develops stridor.
Pulm anthrax
IVDU with apparent Bacillus cereus bacteraemia ….
Gram-positive in chains
Anthrax
Anthrax Ix
Gram stain - blood, CSF, skin lesion (eschar), or oropharyngeal ulcer
PCR / other serology
cutaenous Anthrax Rx
Penicillin
Or Cipro
Anthrax post-exposure prophylaxis
Cipro for 60 days
Anthrax vaccine over 4 weeks (3 doses)
3 main species of Bartonella and 1 things they cause each
Bartonella henselae - cat scratch CSD, BA, peliosis hepatis, endocarditis, bacteremia, neuroretinitis
Bartonella bacilliformis - Carrion’s disease
B Quintana - BA, endocarditis, trench fever, chronic bacteremia
Which bartonella seen in HIV commonly
Bacillary angiomatosis (B hensalae/quintana)
Bartonella henselae Rx If visceral involvemetn
Doxy + rifampicin/gent if visceral
Azithro for CSD
GI/inhalation anthrax rx
cipro + linezolid [+antitoxin]
[If ANY possibility of meningitis - meropenem too]
then 2 months of cipro/doxy as post exposure
CNS anthrax Rx
cipro + linezolid + mero [+antitoxin]
[Gram positive smash linez/mero]
then 2 months of cipro/doxy as post exposure
49M poor controlled t2dm ->amputation 1 week ago
Breathing difficulty. Not eating. Difficulty
swallowing. Spasms = ? name 2 ddx?
Tetanus
Strychnine poisoning
HypoCa
Neuroleptic malignant syndrome
rabies
Epilepsy
What is trismus? Risus sardonicus? Opisthotonus?
Trismus - lock jaw
Risus sardonicus - spasmed smile
Opisthotonus - extensive spasm -> arched back
Diagnosis of tetanus
- Trismus (inability to open the mouth)
or - Risus sardonicus (sustained spasm of the facial
muscles)
or - Painful muscular contractions.
CLINICAL not via tests
Injury to face
* Lower cranial nerve muscles
* Facial palsy/stiffness
* Trismus
* Pharyngeal spasms
* Laryngeal spasms, dysphagia, neckstiffness
* Paresis of IX/X/III
Cephalic tetanus
Wound on limb
then spasms of muscles around wound
* Pain
* Weakness
* Increased deep tendon
reflexes
Localised tetanus
Tetanus Rx name 5 parts
Minimise stimuli - light/sound
Benzodiazepines IV
Magnesium
Ventilate
Surgical debridement
Metronidazole
Tetanus Ig (Human vs equine antitoxin are equal)
Autonomic sx rx - eg labetalol / clonidine
Management of autonomic dysfunction in tetanus
Hypertension - Labetaol (short-acting)
Suppression of catecholamine release- clonidine/morphine
Management of autonomic dysfunction in tetanus
Hypertension - Labetaol (short-acting)
Suppression of catecholamine release- clonidine/morphine
Do you need a tetanus vaccine if you’ve already had tetanus?
YES
There is no naturally-acquired immunity to tetanus. Immunity
It can only be acquired only by active or passive immunisation.
3 doses -> boosters every 10 years
7d baby
Born at full term now refusing to feed.
Fever, breath holding, clenched hands, facial muscle spasm, arching back. Umbilical cord necrosis.
dx?
prevention?
Neonatal tetanus
Vaccination of mothers
clean delivery practice
types of tetanus
localised, neonatal, cephalic
generalized present in (80%)
Define neonatal tetanus elimination
<1 per 1000 live births in every district each year
South/SE Asia - Without local evidence of snakebite
sleeping on floor Nocturnal onset of chest discomfort, breathlessness, abdominal pain=? Key Sx?
Elapid - c krait (Bungarus) bites
“early morning paralysis”
2 main snake families
Viperidae - short thick bodies and tails. Long retractable fangs
-vipers, adders, pit-vipers, moccasins, rattlesnakes
Elapidae - Long thin bodies, short ‘fixed’ fangs
- cobras, kraits, mambas, coral snakes, Oceanian venomous snakes, sea-snakes
What is this called in snake bite
Cyto-toxicity: local swelling, bruising, blistering, necrosis
Snake bite then this =? Test with?
Haemato-toxicity
(vipers, Oceanian elapids, a few colubrids)
WBC20 test
snake bite then - unable to protrude tongue + ptosis
Neuro toxicity
Elapids (and some vipers)
How do you check true ptosis
patient is asked to “look up at my finger”
Note raised eyebrows and puckered forehead from contraction of frontalis muscle, hooded pupils, and associated divergent gaze and dilated pupils
Bitten by snake -> hypovolaemic shock = which snake
Viper
Myocardial toxicity = what type of snake
Vipers (including European adder)
Generalised myotoxicity (rhabdomyolysis) = which snake?
Elapids - especially sea snakes
How often do you get ‘dry’ bites with snakes
About 50% - doesn’t actually inject venom
Pre-hospital Rx snakebite - name 3 aspects
Reassure the victim
* Immobilise whole body, especially bitten limb
* Remove tight rings, bracelets, anklets
* Apply pressure-pad-immobilisation
* Transport rapidly but safely and passively to medical care (recovery position)
pressure pads -> compresses veins / lymphatics
Snake bite in hospital -> give antivenom. What are some considerations?
1- administer antivenom intravenously
2- pre-treat with sub-cutaneous adrenaline (epinephrine)
3- monitor patient closely for signs of early antivenom
reaction over next 4 h
4- observe response to antivenom (improved signs, restored
blood coagulability, or consider repeat dose)
5 - Tetanus booster
Name 3 indications for antivenom
Shock
Spontaneous systemic bleeding +/-
Incoagulable blood (+ve 20WBCT, INR>1.3)
Neurotoxicity
Black urine (haemoglobin or myoglobin)
Rapidly-progressive local swelling (especially bites on digits)
Snakebite -> given antivenom and returns a week later like this? rx?
late serum-sickness type reactions
Develop 5-15 days post-antivenom – Treat with histamine H1 blockers (e.g. chlorphenamine) or prednisolone
Melioid appearance
Gram -ve rod
