UNUSUAL BUT SERIOUS INFECTIONS Flashcards
ZOONOTIC INFECTIONS TRAVEL RELATED INFECTIONS WORMS & MITE
Clostridium tetani
- Found in ___ (2)
- Causes: (3)
* Descending involvement of the nervous system –toxin causes sustained excitation of motor neurons, causing ___ + 4 features
~opp of botulism
- Found in animal faeces, contaminated soil
- Cause of tetanus: Superficial cut, contaminated splinter, thorn prick in gardeners….
- Descending involvement of the nervous system –toxin causes sustained excitation of motor neurons, causing motor spasms + Stiffness, Lockjaw, sardonic grin (a sneering grin), Opisthotonos (extreme arching of the back)
BOTULISM– CLINICAL FEATURES
opp of clostridium tetani
*Eyes affected first (double vision, drooping eyelids)
*Descending motor loss with flaccid paralysis
*Speech and swallowing difficulty
*Breathing difficulty
*Death from cardiac or respiratory failure
Burkholderia pseudomallei
- gram __ bacillus
- present in ___
- more cases during __ __ season (SEA, India)
- Incubation period: ___ to ___ days
- Significance in 2 countries
*A gram negative bacillus
*Present in soil and water in endemic regions
*More cases during monsoon rainy season: Thailand, Northern Australia, Singapore, Malaysia, Vietnam, Cambodia, India, Indonesia
Significance
*Thailand - 20% of community related
sepsis, 39% fatality
*Northern Australia – most common cause
of fatal community acquired
bacteraemia related pneumonia
*Incubation period – as short as 1 day, up to 21 days
What is vietnamese time bomb? 3 features
Meliodosis
*Latency
*Intracellular organism
*Reported cases of melioidosis in American soldiers who fought in the Vietnam war (onset of infection 62 years later)
*Reactivation remains rare (4% cases in Northern Australia)
Listeria monocytogenes – symptoms in normal, pregnant, immunocompromised ppl
Immunocompetent: fever, gastroenteritis, asymptomatic
Pregnant women: fever and other non-specific symptoms, such as fatigue and aches.
However, infections during pregnancy can lead to miscarriage, stillbirth, premature delivery, or life-threatening infection of the newborn.
Immunocompromised: septicaemia, meningitis
Listeria monocytogenes
Diagnosis and treatment
blood culture and CSF
avoid unpasteurised milk & dairy product / separate uncooked meat from other ready-to-eat item
Leptospirosis – Leptospira interrogans (Bacteria – spiral, fine coils with hooked ends)
*Spread through the ___ of infected animals, which can get into ___ or ___ and can survive for weeks to months.
*Wild & domestic animals carry the bacterium: (4)
When these animals are infected, they may have no symptoms of the disease.
*Spread through the urine of infected animals, which can get into water or soil and can survive for weeks to months.
*Wild & domestic animals carry the bacterium: Cattle, Pigs, Horses, Dogs, Rodents
When these animals are infected, they may have no symptoms of the disease.
Leptospirosis – how do humans get infected?
Humans can become infected through:
*Contact with ___ (2) from infected animals.
*Contact with ___ (3) contaminated with the urine of infected animals.
- Bacteria -> through skin or mucous membranes (eyes, nose, mouth), especially if the
skin is broken from a cut or scratch.
- ___ can also cause infection.
- Person to person transmission is ___.
Humans can become infected through:
*Contact with urine / body fluids from infected animals.
*Contact with water, soil, or food contaminated with the urine of infected animals.
- Bacteria -> through skin or mucous membranes (eyes, nose, mouth), especially if the
skin is broken from a cut or scratch.
- Drinking contaminated water can also cause infection.
- Person to person transmission is rare.
Leptospirosis – risk factors
swimming, wading, kayaking, and rafting in
contaminated lakes and rivers + farming
Leptospirosis – clinical features (2) + what if it gets worse?
-Jaundice
- red eyes
*If a second phase occurs, it is more severe; the person may have hepatorenal failure (Weil’s disease), meningitis, bleeding, haemoptysis. may die
Toxoplasmosis (cats): Toxoplasma gondii (single cell parasite)
- who is prone?
However, serious health implication in:
*pregnant women
and
*individuals who are immunocompromised eg. HIV
Toxoplasmosis – life cycle
- eating ___ ___of animals harboring tissue cysts
- food or water contaminated with CAT ___ or contaminated environmental samples (such as fecal-contaminated soil or changing the litter box of a pet cat)
- blood ___ or organ ___
- ___ from mother to fetus
- eating undercooked meat of animals harboring tissue cysts
- consuming food or water contaminated with cat feces or by contaminated environmental samples (such as fecal-contaminated soil or changing the litter box of a pet cat)
- blood transfusion or organ transplantation
- transplacentally from mother to fetus
In the human host, the parasites form tissue cysts, most commonly in skeletal muscle, myocardium, brain, and eyes; these cysts may remain throughout the life of the host. Diagnosis is usually achieved by serology, although tissue cysts may be observed in stained biopsy specimens. Diagnosis of congenital infections can be achieved by detecting T. gondii DNA in amniotic fluid using molecular methods such as PCR.
Toxoplasmosis signs
Generally, asymptomatic or mild, self-limiting illness in
the immunocompetent.
Malaria where?
Transmitted in tropical & subtropical areas, near equator
Malaria – symptoms
Physical findings may include:
*Fever
*Sweating
*Weakness
*Splenomegaly
Mild jaundice**
**Hepatomegaly
*Increased respiratory rate
Uncomplicated Malaria
The classical (but rarely observed) malaria attack lasts 6-10 hours. It consists of :
*a cold stage (sensation of cold, shivering)
*a hot stage (fever, headaches, vomiting; seizures in young children)
*and finally a sweating stage (sweats, return to normal temperature, tiredness).
Classically (but infrequently observed) the attacks occur every second day with the “tertian”
parasites (P. falciparum, P. vivax, and P. ovale) and every third day with the “quartan” parasite
(P. malariae).
More commonly, the patient presents with a combination of the following symptoms:
*Fever
*Chills
*Sweats
*Headaches
*Nausea and vomiting
*Myalgia
*General malaise
