Infectious Diseases Flashcards
measles
Notify department of health
– Take blood for measles serology-in Australia measles vaccine is given at the age of 12 months.
– Discuss the nasal swab PCR for measles with the department of health.
– Isolate her in the community from other contacts.
– There is no need to send the patient to the emergency department as it would risk the spread of measles to other susceptible patients in the hospital.
Zostavax
vaccine used to prevent herpes zoster infection
live attenuated vaccine
Zostavax contraindications
– Severely immunocompromised patients such as this patient who is on long term
steroids for his rheumatoid arthritis.
– Hematological malignancy.
– Recipients of haemopoietic stem cell transplantation.
-HIV infection and immunosuppression (below 15% CD4 lymphocytes).
Zostavax is a vaccine used to prevent shingles (herpes zoster) in older adults. However, it’s a live attenuated vaccine, meaning it contains a weakened form of the virus. Because it’s a live vaccine, there are certain groups of people for whom Zostavax is contraindicated, meaning they should not receive it.
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Severely Immunocompromised Patients:
- Why: These patients have weakened immune systems that can’t effectively control even the weakened virus in the vaccine. This includes people on long-term steroids (like the patient with rheumatoid arthritis), which suppress the immune system and make it risky to receive live vaccines. The weakened virus could potentially cause serious illness in these individuals.
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Hematological Malignancy (e.g., leukemia, lymphoma):
- Why: These cancers affect the blood and immune system, significantly impairing the body’s ability to fight infections. Receiving a live vaccine like Zostavax could lead to the reactivation of the virus, causing illness rather than preventing it.
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Recipients of Hematopoietic Stem Cell Transplantation:
- Why: After a stem cell transplant, the immune system is often extremely weakened and rebuilding. During this period, the body may not be able to handle a live vaccine, increasing the risk of complications from the vaccine itself.
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HIV Infection with Severe Immunosuppression (CD4 Count Below 15%):
- Why: In patients with HIV, especially when their CD4 count (a type of immune cell) is very low, their immune system is compromised. A CD4 count below 15% indicates severe immunosuppression, meaning the patient’s body would struggle to control the weakened virus in the vaccine. This could lead to an actual shingles infection, rather than protecting against it.
Zostavax is contraindicated in these groups because their weakened immune systems may not be able to handle the live virus in the vaccine. Instead of providing protection, it could potentially cause a serious infection.
Genital chlamydial infection
sexually transmitted
is commonly asymptomatic until severe salpingitis or urethritis occurs
common cause of infertility due to
tubal obstruction
cat scratch disease
- B.henselae from cats to humans through a contaminated
cat scratch wound or across a mucosal surface - Symptoms occurs 3 to 10 days after initial injury.
- papulopustular lesions at the bite site
- enlarged tender regional lymph nodes.
Axillary vein thrombosis
sportsmen
after strenuous exercise like wrestling.
oedema and redness
No tender lymphadenopathy
JE vaccination for shorter-term travellers, particularly if:
travel is during the wet season
travel may be repeated
the person will spend a lot of time outdoors
the person’s accommodation has no air-conditioning, screens or bed nets
Typhoid vaccine may be recommended for travellers ≥2 years of age travelling to
endemic regions, including:
the Indian subcontinent
most Southeast Asian countries
several South Pacific nations, including Papua New Guinea
cholera vaccine
Most travellers do not need
not officially recommended by WHO
if the traveller has never received a dose of traveller has never received a dose of dTpa.
offer dTpa vaccine
if the last dose was more than 10 years ago
Tetanus
Adults are recommended to receive a booster dose of tetanus-containing vaccine
Fever with rigors and chills
Biliary sepsis, lymphoma, pyelonephritis and pneumococcal pneumonia
Thailand + fever + rash + joint pain + low platelets + low WBC
Dengue fever
Dengue fever treatment
Suppurative treatment
Zika virus
microcephaly
- SEEN IN BABIES
Symptoms: • Many people infected with Zika virus are asymptomatic. • When symptoms do occur, they are generally mild and include fever, rash, conjunctivitis, muscle and joint pain, headache, and malaise. • Symptoms typically last for 2-7 days. 3. Complications: • Microcephaly: Zika virus infection during pregnancy can cause severe birth defects, including microcephaly, where babies are born with smaller heads due to abnormal brain development. • Guillain-Barré Syndrome: There is also an association between Zika virus and Guillain-Barré syndrome, a rare condition where the immune system attacks the nerves. 4. Diagnosis: • Diagnosed through laboratory tests like RT-PCR (Reverse Transcriptase Polymerase Chain Reaction) or serological tests to detect Zika virus RNA or antibodies.
shingles (herpes zoster infection)
- within 72 hours= famciclovir or acyclovir for
7-10 days after taking the viral swab.
after 72 hours since the onset of rash= no
benefit with antiviral treatment.
key serological feature of hepatitis D
Anti-LKM3 (liver, kidney microsomes)
autoimmune hepatitis.
anti-LKM1
outcome of liver transplantation
chronic hepatitis D is better than that for
chronic hepatitis B
When comparing the outcomes of liver transplantation for chronic hepatitis D versus chronic hepatitis B, the key point is:
- Hepatitis D: Patients with chronic hepatitis D generally have better outcomes after liver transplantation compared to those with chronic hepatitis B. This means they tend to have fewer complications and a higher chance of long-term survival.
- Hepatitis B: Although liver transplantation can be life-saving, patients with chronic hepatitis B are more likely to experience complications after the transplant, such as a recurrence of the virus in the new liver, which can affect their overall outcome.
In simple terms, liver transplant patients with chronic hepatitis D usually do better in the long run than those with chronic hepatitis B.
Chronic hepatitis D infection
increases the severity and progression of chronic hepatitis
if HDV infection occurs in acute hepatitis B
Chronic hepatitis D infection is unlikely
malaria incubation period
malaria prevention
- Doxycycline 100mg daily one day before the trip and continuing for four
weeks after leaving malaria zone. - Atovaquone/proguanil 250mg/100mg tablet started 1-2 days before travel and continued for
seven days after leaving malaria area
clinical diagnosis of herpes zoster infection
- maxillary nerve of the trigeminal nerve in this patient with a rash without an eruption.
Severe unilateral facial pain may be the first symptom of acute herpes zoster (shingles) and precedes the skin rash by a few days
Trigeminal neuralgia
sudden, brief and very severe paroxysms of
pain on one side of the face, in the distribution of one or more branches of the
trigeminal) nerve.
Definitive diagnosis of N. gonorrhoea infection
nucleic-acid amplification testing of a urethral or urine sample
Appropriate therapy for gonococcal urethritis
single dose of ceftriaxone 250 mg
intramuscularly plus a single dose of azithromycin 1 gram orally
Treatment of Chlamydia
- Single dose of 1-gram Azithromycin or Doxycycline for
seven days. - Should not have sex until at least a week has passed after the treatment.
- notifiable disease
Post-exposure prophylaxis for hepatitis B (hepatitis B vaccine and immunoglobulins)
recommended
– The exposed person has been vaccinated in the past and the post-vaccination antiHBs level is below 10 mIU/ml.
– Un-vaccinated exposed individuals.
– Unknown vaccination status of the exposed person.
previously vaccinated persons exposed + response to previous vaccination is unknown
the anti-HBs level should be
determined as quickly as possible
previously vaccinated persons exposed+
protective response anti-HBs level =10
mIU/mL at any time after previous vaccination
post-exposure prophylaxis is
not necessary
Live attenuated zoster vaccine is contraindicated in persons
– Chemotherapy.
– Radiation therapy.
– Oral corticosteroids (asthma, COPD, etc)
– Disease-modifying anti-rheumatic drugs (DMARDs).
– Malignant conditions of the reticuloendothelial system (such as lymphoma, leukaemia, Hodgkin’s disease).
– AIDS or symptomatic HIV infection.
positive HBsAg
positive HBcAb (IgM)
Acute infection
HBeAg positive
high infectivity in recent infection
influenza vaccine
- Protection for the mother and the
newborn baby for the first six months after birth - free to all pregnant woman in Australia.
- recommended for all pregnant women regardless of
gestation. - recommended for a woman planning a pregnancy.
- An unvaccinated pregnant woman should be immunised at any time during influenza season
unsafe sex + for HIV checkup
wait for 12 weeks before a test can
reliably confirm or rule out HIV infection
Contraindications for administering
pertussis-containing vaccinations
- severe allergic reaction to the vaccine (or
to one of its components) - encephalopathy not due to any other cause within 7
days of a prior vaccination. - Uncontrolled neurological disorders should prompt a
delay of the vaccination until the condition has been sufficiently assessed
Post sexual assault victim + STI prophylaxis
ceftriaxone 250 mg intramuscular as a single dose,
azithromycin 1 gram as a single dose and metronidazole 2 gram as a single
dose
to cover gonorrhoea, chlamydia species
and trichomonas vaginalis
most commonly seen symptom in botulism
Dysarthria
needle stick injury + exposure to an HIV positive person
PEP is recommended. ASAP
PEP should not be offered more than 72
hours after exposure.
health care worker should have
follow-up HIV-antibody testing at baseline, 6 weeks,
3months up to 6 months
medication of choice for prophylaxis
of malaria
Doxycyclin and atovaquone-proguanil
Current recommendations about chlamydia infection of urogenital tract
– Treat the patient with oral antibiotics.
– Do contact tracing and treat the patient’s all sexual contacts in last six months.
– Notify health department (GP responsibility).
– Repeat testing for chlamydia in 3-12 months for reinfection.
Most common pneumonia with HIV/AIDS
Pneumocystis Jiroveci (PJP)
dry cough + slow onset of pneumonia symptoms + CD4 < 200
Pneumocystis Jiroveci (PJP)
HIV + rapid onset acute pneumonia symptoms + lung consolidation
Organism
Streptococcus pneumoniae
hospital-acquired
pneumonia (HAP
Staphylococcus aureus
Streptococcus pneumoniae
community-acquired pneumonia
high grade fever + chills after recovering from pneumonia
IV cannula bacteraemia
copious yellow-green sputum + underlying condition (pneumonia)
Bronchiectasis
Bronchiectasis management
Ticarcillin-clavulanate.
foul-smelling productive cough + Fever + Weight loss + Malaise
lung abscess
high fever + respiratory symptoms precipitated from pneumonia treatment
Superinfection by a different type of bacteria.
fever + arthralgia/arthritis + skin rash precipitated by pneumonia treatment
Serum sickness (hypersensitivity reaction to penicillin)
lung abscess management protocol
- chest X-ray
- sputum stains and
cultures - Chest CT
Uncomplicated: IV antibiotics
Complicated: Transpleural drainage/lobectomy
eyebrow and eyelash loss with no loss of scalp hair; skin changes +
history of paresthesias
Hansens disease/ leprosy
Standard treatment for lepromatous leprosy
dapsone, rifampin, and clofazimine administered for 12 to 24 months.
Gonorrhea infection management
– Ceftriaxone 500mg IM in 2ml of 1% lignocaine Plus Azithromycin 1000mg stat
orally.
– Advise no sex even with condoms for 7 days and no sex with recent or previous
partners until they have been tested and treated.
– Contact tracing for gonorrhoea is recommended for the previous 2 months.
– Offer test of cure in 4 weeks.
patient on high-dose corticosteroids +
positive CSF India ink stain
Cryptococcal meningitis
patient with hemolytic uremic syndrome,
stool culture on sorbitol MacConkey will
help diagnose E coli O157:H7
Primary syphilis
-10-90 days after contact
- glans penis/vulva-cervix
Secondary syphilis
2-10 weeks
- headache, anorexia, vomiting, fever, neck stiffness
- non-pruritic bilateral maculopapular rash
- generalised non-tender lymphadenopathy
patchy alopecia/condylomata lata
Latent syphilis
Syphilis tests
dark field microscopy
rapid plasma reagin (RPR) test
fluorescent treponemal antibody absorption (FTA-ABS) tes
erythema nodosum + weight loss + productive cough/blood
Tuberculosis
Tuberculosis steps in investigation
- QuantiFERON-TB/Tuberculin test
- Chest X-ray
- 3 sputum (AFB)
history of pulmonary tuberculosis +
MRI shows a right frontal lesion +
biopsied which shows
Caseating granulomas
patients with HIV + CD4 below 50 cells/μ
prophylaxis?
prophylaxis against Mycobacterium Avium
Complex (MAC) should also be commenced, after exclusion of active MAC Complex (MAC) should also be commenced, after exclusion of active MAC
or Mycobacterium Tuberculosis (TB)
opportunistic infections in HIV infected patients
- Pneumocystis jiroveci: Trimethoprim-sulfamethoxazole
- Toxoplasmosis: Trimethoprim-sulfamethoxazole
- Mycobacterium avium: Azithromycin
80-year-old + 3-day history of a painful rash +
forehead and down to his left eyelid + weeping vesicular lesions
Herpes zoster
Giardia lamblia
bloating, loose stools and weight loss.
mainstay of Vibrio cholerae therapy
Oral glucoseelectrolyte solution rehydration
First-line treatment of PHN (Postherpetic neuralgia)
(TCAs)
Investigations for Men who have sex with Men (MSM)
– Pharyngeal swab for gonorrhoea
– Anal swab gonorrhoea and chlamydia PCR
– Urine PCR for chlamydia
– Serology for HIV, Syphilis, Hepatitis B and C.
– Vaccinate for hepatitis B if not immune
– Repeat test for HIV in 12 weeks (window period).
peripheral blood film in infectious mononucleosis (glandular fever)
lymphocytosis with >10% atypical/reactive
lymphocytes (Downey cells).
Elevated
aminotransferases + pharyngitis
possibility of IM.
Resuming activity in IM
resume non-contact sports after >3
weeks and contact sports >4 weeks after illness onset to prevent splenic rupture.
high grade fever+ swollen tonsils with exudate + rash precipitated by penicillin
Epstein-Barr infectious mononucleosis (EBV IM)
Epstein-Barr infectious mononucleosis (EBV IM) investigation
- Most appropriate: FBC to see lymphocytosis (>50% lymphocytes)
- Diagnostic: Paul-Bunnell test / Monospot test
EBV associated cancers
Burkitt lymphoma and nasopharyngeal CA.
Rocky Mountain spotted fever
tick bite
fever, headache, malaise, myalgia, nausea, vomiting,
and anorexia as the most common symptoms
Involvement of the palms and
soles is considered important for diagnosis of Rocky Mountain spotted fever.
Lyme
disease
Borrelia burgdorferi
erythema chronicum migrans, a target-shaped lesion
chronic
meningitis preceded by an arthralgia
Facial weakness may be the only neurologic sign of Lyme disease.
Optic neuritis
significantly decreased CSF glucose + high protein level + elevated CSF opening pressure
bacterial, TB, fungal and carcinomatosis meningitis,
bacterial meningitis treatment
- IV antibiotics
- Corticosteroids (dexamethasone)
- analgesics
bacterial meningitis + Listeria
monocytogenes
ampicillin plus gentamicin.
infant + drowsiness + fever + petechial rash
meningococcaemia (life threatening)
meningococcaemia treatment
IV fluids + supplemental oxygen
sleeping sickness + tsetse flies
Human African trypanosomiasis
Pentamidine is used in the treatment
investigations in female sexual health workers
To organize the screening and immunization protocol outlined, here’s a clear and structured approach:
- Frequency: Every 5 years.
- Action: Perform HPV testing unless there is a history of abnormal results.
- Initial Screening: If the HIV test is negative, proceed with HIV serology.
- Follow-up: Annual HIV serology testing.
- Urine Test: First-catch urine sample for Chlamydia and Gonorrhoea PCR.
-
Endocervical Swabs:
- Frequency: Every 3 months if 100% condom use; more frequently if less than 100% condom use.
- Frequency: Serology every 12 months.
- Initial Testing: Perform serology if hepatitis A and B status is unknown and the patient has not completed vaccination.
- Action: If there is no serological evidence of immunity (anti-HA negative and/or anti-HBs negative), offer the appropriate immunization.
- Follow-up: Only perform annual serology testing for hepatitis A and B if not immunized.
- Frequency: Serology every 12 months.
- Consideration: Perform if there is a history of oral sex without condoms.
This organized protocol ensures comprehensive screening and vaccination for sexually transmitted infections (STIs), tailored to individual risks and behaviors. Regular follow-ups and adherence to the recommended timelines are crucial for effective prevention and early detection.
– HPV test 5-yearly (unless abnormal)
– HIV screening (if negative, proceed with HIV serology), then perform serology test annually
– First-catch urine for chlamydia and gonorrhoea PCR
– Syphilis serology and 12-monthly
– Endocervical swabs for Chlamydia and gonorrhoea 3 monthly (if 100% condom
use, more frequently if <100% condom use)
-Hepatitis A and B serology, (if hep A and B status unknown and patient has not
completed a course of hep A and B vaccination, offer testing and if no serological
evidence of immunity (i.e., anti-HA negative and/or anti-HBs negative, offer
appropriate immunisation) –> only perform annual serology test for hepatitis A and
B if not immunised)
– Hepatitis C serology and 12-monthly
If there is a history of oral sex without condoms, consider doing throat swab for
gonorrhoea and chlamydia.
immunity status is unknown in measles
recommended that all
immunocompetent. non-pregnant patient receive MMR of vaccine with in 72 hours
of exposure. A second dose should then follow at least 4 weeks later.
head injury to the left temporal region + unresponsive after a lucid interval + progressive right-sided weakness
epidural hematoma
features Rapid expansion expansion of
the EH:
Increase intracranial pressure (eg, Cushing triad of hypertension, bradycardia, and bradypnea),
compress compress the temporal lobe leads to uncal herniation
(in epidural hematoma)uncal herniation in temporal lobe causes:
- Ipsilateral fixed and dilated pupil from compression of the ipsilateral
oculomotor nerve (CN III) - Contralateral hemiparesis Contralateral hemiparesis (compression of the ipsilateral cerebral peduncle)
-Contralateral homonymous hemianopsia with macular sparing from
compression of the ipsilateral posterior cerebral artery
worsening herniation = psilateral hemiparesis, a false localizing sign known as Kernohan phenomenon
Local tenderness + erythema + IV drug abuse
osteomyelitis
osteomyelitis investigation
MRI
acute dacryocystitis treatment
oral di/flucloxacillin, amoxicillin-clavulanate, or cephalexin
-IV if severe cellulitis,
orbital involvement (orbital cellulitis) or severe adjacent facial/periseptal cellulitis.
UTI treatment in renal impairment
Trimethoprim
HACEK
H Hemophilus,
A Aggregatibacter actinomycetmcomitans,
C Cardiobacterium hominis,
E Eikenella corrodens
K Kingella kingae.
HACEK in infective endocarditis complications
mycotic (infective) aneurysms
HACEK investigation
CT angiography
most common cause of epididymoorchitis
<35: Chlamydia
>35: E.coli
inflammation of meibomian glands
Internal hordeolum (meibomian
abscess).
Internal hordeolum infection pathogen
Staphylococcus aureus)
