general infection Flashcards
what is the treatment of systemic fusariosis ?
amphotericin B iv and
Intravitreal ( or voriconazole intravitreal) if associated Endophthalmitis
Echthyma gangrenosum ?
PSA
What are the Poor prognostic factors in cryptococcal meningitis ?
- Cryptococcus spp isolated from blood or other extraneural site
- Low CSF white cell count (< 20 cells/mm3)
- High CSF antigen titre (>1:1024)
- Cryptococci seen in CSF microscopy
- Altered mental status.
- Raised opening pressure
Recommended diphtheria antitoxin
antibody levels are:
- 0.01 IU/mL for those in routine diagnostic laboratories
- 0.1 IU/mL for those handling or regularly exposed to toxigenic strains
C Diphtheriaea contacts management?
1-isolation
2-swabs
3- chemoprophylaxis: Clarithromycin
500mg twice a day 7
or : Azithromycin 500mg once a day 6
or: Alternative
Benzathine benzylpenicillin IM
Common effects of congenital rubella syndrome (CRS) before 16 w?
cataracts
congenital heart disease
hearing impairment
developmental delay
miscarriage if early infection
Single most common effect of congenital rubella Before 16w?
Bilateral SNHL
most common cause of congenital syndromes:
Fetal hydrops
Rhinitis
Limb hypoplasia
Microcephaly
Fetal hydrops : maternal parvovirus.
Rhinitis : congenital syphilis
Limb hypoplasia : congenital varicella
Microcephaly : Zika virus
what is the cause and the vector of African Tick-Bite Fever (ATBF) ?
Caused by Rickettsia africae.
Transmitted by Amblyomma hebraeum and Amblyomma variegatum.
What is the triad of African Tick-Bite Fever (ATBF) ?
1- multiple eschars and tick bites
2- regional LN
3- diffuse skin rash
very commonly associated: fever , headache and myalgia
Amplifying hosts for:
1- JEV
2- West Nile virus
3- Nipah virus
4- Ebola
5- Lassa
1- JEV: pigs and aquatic birds
2- WNV: birds e.g crows (transmits by Culex)
3- Nipah virus : fruit bats (but can transmits by contaminated date palm sap or infected pigs)
4- Ebola: fruit bats
5- Lassa: multi-mammals rats
Transmission of Hendra virus?
Usually found in fruit bats and horses
Transmits to humans by exposure to body fluids.
Symptoms of West Nile virus?
rash
arthralgia
lymphadenopathy
sever disease : hepatitis , myelitis , pancreatitis
Indications for HNIG as PEP for infants with measles contact ?
1- All infant contacts under 6 months
2- All household infant contacts under 9 months without any testing.
Infectious period?
1- measles
2- VZV
1- measles: four days before to four days after rash onset
2- 2 days before the onset of rash and until all rash has crusted over
Treatment of Cutaneous larva migrans
- Ivermectin single 12mg PO.
- Albendazole single 400mg PO
cause of vesceral larva migrans VLM?
Toxocara catis and cannis
Types of typhoid vaccines?
1- Vi vaccine- injectable purified capsular polysaccharide - one dose 2 weeks before travel and every 3 years
2- Ty21a oral vaccine - live attenuated : total 4 capsules to be taken on alternative days - should complete 7 days before travel.
Neisseria meningitidis vaccination timing in UK?
1- MenB vaccination at 2,4 and 12 months.
2- Hib/MenC at 12 months.
3- MenACWY at 14 years of age.
Treatment of strongyloidiasis
1- first line: Ivermectin 200 mcg/kg single oral dose
2-Albendazole 400 mg once daily for 7 days
Indication for Men ACWY in UK ?
1- part of the current routine vaccination at age of 14
2- patients with asplenia and splenic dysfunction
3- complement disorders
4- Travellers
Indications for Rabies vaccine in UK?
1- Handlers of high-risk animals - bats
2- travellers to high risk countries
Hepatitis A:
Indication of PEP Vaccination?
Vaccine only:
1- pregnant and BF if not immune
2- MSM
3- IVDU
4- Sewage workers
5- haemophilia
——–
HNIG(within 14 d) in addition to vaccine:
1- Aged 60 and over
2- HIV and a CD4 count of <200
3- Chronic hepatitis B or C infection
4- Chronic liver disease
5- Immunosuppressed
how to treat neonate with maternal chickenpox 5 days before delivery?
prophylactic VZIG for neonates whose mothers develop chickenpox in the period 7 days before to 7 days after delivery .
also: IV Acyclovir if maternal infection occurs 4 days pre and 2 days post delivery
Dosing of dexamethasone in CNS TB?
1- If No focal neurological deficit and GCS 15: 0.3mg/kg reducing to 1mg/day over 6 weeks
2- If focal neurology :
0.4mg/kg for 8 weeks.
Category A biological warfare agents?
Bacillus anthracis
Yersinia pestis
Variola major (smallpox)
Franciscella tularensis
Viral haemorrhagic fevers (e.g. Ebola)
C. botulinum toxin.
Classical presentation of Histoplasmosis?
1- Travel to the Mississippi 2- Pulmonary symptoms
3-Erythema nodosum
4 - lymphopenia
5- Hepatosplenomegaly
6- LN
what are the types of pneumococcal vaccines in UK?
1- 23 valent polysaccharide vaccine - Pneumovax
- Not effective <2 years old
- No immune memory
- No protection against non-invasive disease
- No reduction in pharyngeal carriage
2- 13 valent conjugate vaccine - Prevenar13:
- effective from 2 m age
- part of UK routine V
- long term memory
- protect against non-invasive disease
- reduce carriage
- induce herd immunity
- indicated for HIV regardless CD4
What vaccine should be given to pt with new diagnosis of asplenia ?
(adults and children >10y age )
1 X PPV23
1x MenACWY
2x MenB
yearly influenza vaccine
indications of Chemoprophylaxis for iGAS close contacts ?
1- mother and baby if either develops iGAS in the first 28 days of life
2- for close contacts if developed symptoms of localised Group A streptococcal infection i.e. sore throat, fever, skin infection
3- he entire household if 2 or more cases of iGAS within a 30-day
what is the recommended chemoprophylaxis for iGAS?
Oral penicillin V 500mg QDS x 10 days or azithromycin 500 mg od for 5 days
First line to treat uncomplicated malaria in pregnancy ?
1- 1st trimester: quinine and clindamycin for 7 day
2- 2nd and 3rd trimester: artemether-lumefantrine
Unwell pt with sever neutropenia , multiple ulcerative skin lesions and endophthalmitis . what organism and how to treat?
1-Fusarium salonii
2- high dose IV and intravitreal amphotericin B
What is the mechanism of action of azole antifungals ?
inhibit cytochrome P450 and 14a demethylase in the ergosterol synthesis process
Griseofulvin
interferes with mitosis by disrupting microtubules.
Flucytosine
It is a precursor of cytotoxic drug 5-fluorouracil, but is converted to the active agent selectively in fungal cells( inhibit DNA synthesis)
Echinocandins (e.g. caspofungin)
prevent synthesis of the fungal cell wall agent β1-3 D-glucan
Terbinafine
inhibits squalene epoxidase
Mechanism of Amphotericin B?
binds to ergosterol containing membranes and disrupts them by forming pores
What is the recommended HBV Vaccine schedule for high risk ppl?
HBV Vaccine (Engerix B®) can be given at 0, 7
and 21 with a fourth dose at 12 months for longer term protection.
Any adults over 18 years of age at immediate risk e.g:
1- travellers to high endemicity
2- PWIDs
3- prisoners
What is the recommended PEP for HBV for sexual partner with acute Hepatitis B or new chronic HepB ?
1- accelerated vaccine
2- HBIG if within 7 days
What isPEP plan for HBV after needle stick and eye splash from Known HBV infected person (both in healthcare or community)?
1- hep B vaccine given at zero, one and two months.
No need for reinforcing dose at 12 m unless continues risk (e,g: HCW or renal dialysis )
2- HBIG If within 7 days
ideally within 24 hours of the first dose of vaccine
what is the recommended plan for hep B vaccine non responder ( An antibody level below 10mIU/ml 2 months after 1ry vaccination) ?
1- check for markers of current or past infection.
2- repeat course of vaccine followed by retesting 1-2 months later
3- if still have anti-HBs < 10 mIU/ml: HBIG if exposed to the virus
What are the poor prognostic factors for JC infection and PML ?
1- longer duration of treatment with natalizumab
2- peripheral JCV IgG positive
3- previous exposure to immunosuppressants
What is the commonest cause of dermatophyte scalp infection in UK?
Trichophyton tonsurans
what are the commonest cause endothrix and exothrix tinea capitis ?
1- Both Trichophyton tonsurans and Trichophyton violaceum cause endothrix infections
2- Microsporum canis causes ectothrix infections.
3- Trichophyton rubrum is rarely associated with cases of tinea capitis and normally only the skin is infected.
————
oral griseofulvin and terbinafine
what is current recommendation for secondary prophylaxis of
SBP ??
oral norfloxacin or ciprofloxacin prophylaxis
Invasive aspergillosis
what is first line in primary infection ? secondary infection (salvage therapy ) ? prophylaxis?
1- Voriconazole 6 mg /kg bd iv for 6-12weeks
2- caspofungin 70mg/day
3-Posaconazole 200 mg 3 times per day with food during neutropenia until Neutrophils> 500
What is the first line treatment for uncomplicated malaria in UK ?
1- Artemether + lumefantrine (Coartem)
2- Atovaquone proguanil: (malarone)
First line treatment for uncomplicated malaria in pregnancy?
1-In 1st trimester: Oral quinine 600 mg Q8h for 5 - 7d + clindamycin 450 mg
8 h for 7 days.
2- Artemether-lumefantrine is the treatment of choice in the 2nd and 3rd trimester
Severe / complicated malaria in pregnancy ?
1- artesunate is
preferred first option
2- IV quinine (with clindamycin) is an alternative.
Treatment of non-falciparum malaria?
1- Chloroquine for vivax, ovale, malariae and knowlesi malaria in adult and children
2- Artemether-lumefantrine
3- Parenteral artesunate
(or quinine)
Meningococcal Chemoprophylaxis for close contact??
1- single dose azithromycin
2- rifampicin is alternative 600 mg bd for 2 days
—-
should be given with in 7 days of contact regardless of vaccination status
invasive meningococcal disease : vaccination of index case ?
1- Fully immunised cases do not require additional
vaccination.
if not should complete appropriate vaccination
——–
2- At-risk index cases (e.g. asplenia, complement-deficiency) if unimmunised or partially immunised:
- MenACWY conjugate vaccine (2 doses one month apart if aged <1 year; 1 dose after first birthday)
- MenB vaccine (2 doses two months apart with a booster at
12 months for <1 year-olds, 2 doses 2 months apart for 1-10 year-olds and 2 doses 1
month apart for older children and adults)
Meningococcal disease
Vaccination of close contacts??
for confirmed MenACWY and MenB ?
1- MenACWY
contacts should receive MenACWY conjugate vaccine, unless immunised within the last 12 months (2 doses one month
apart if aged <1 year; 1 dose after first birthday). For MenC : another
MenC-containing conjugate vaccine should be given
—-
Men B contact :
vaccination is not recommended unless at risk group
treatment of african trypanosomiasis?
Suramin for first stage Melarsoprol for 2nd stage
treatment of paragonimiasis, - P. westermani??
triclabendazole or praziquantel
what are the commonest Sandfly viruses?
1- Toscana : Southern Europe and the Mediterranean - mainly in summer months
2- Naples virus.in Italy , Serbia and Egypt
3- Siciliana virus in the Mediterranean through to central Asia.
PVL toxin mechanism of action
pore-forming toxin
induces polymorphonuclear cell death by necrosis or by apoptosis by disruption of mitochondrial homeostasis and activation of caspase-9 and caspase-3
VZV Contact PEP in immunocompromised pt ?
Oral aciclovir (or valaciclovir) is first choice of PEP for susceptible immunosuppressed
individuals, all susceptible pregnant women ‘
start from day 7 until day 14
Cidofovir mechanism of action and resistance ??
Cidofovir: inhibits viral DNA polymerase pUL54 and incorporates itself into the viral DNA which interrupts further elongation of the virus
Cidofovir resistance is caused only by DNA polymerase mutations, mainly by a UL54 mutation which also results in cross-resistance to ganciclovir.
What is mutation H275Y has been detected in influenza A/H1N1?
-Is a single base pair change in the influenza neuraminidase
- it result in oseltamivir and peramivir resistance.
- It does not affect zanamivir and laninamivir both remain active.
T/F Amantadine act by binding the viral M2 ion channel and disrupting viral uncoating. Influenza B viruses are intrinsically resistant to amantadine
T
if HBsAg positive HCW ? what advice to give re EPP?
restart EPPs if their VL is adequately suppressed <200 (on 2 tests, at least 4 weeks apart). They would require retesting every 6 months while on treatment.
Mother with VZV symptoms 5 days before to 2 days after birth:
???
Keep mother and infant hospitalised and isolated for at least 3 days
Treat newborn with either VZIG or, if unavailable, IVIG 400 mg/kg as soon as possible within the first 48 - 96 hours after birth.
————-
If the newborn does not have any other comorbidity, mother and baby can leave the hospital between administration of immune globulins and start of acyclovir therapy.
———
intravenous acyclovir from day 7 after the onset of maternal rash and administer for 10 days. Alternatively, give oral acyclovir in case of no peripheral venous access
What is the cause and treatment of rhino-orbital-cerebral mucormycosis?
Mucorales:
Rhizopus, Mucor, Lichtheimia spp
—-
Tx:
Liposomal amphotericin B (AmBisome) given at high dose (10 mg/kg) is the preferred first-line agent, isavuconazole and posaconazole are secondary options
what is the Sterilization ? antisepsis ? Cleaning ?
Disinfection?
Sterilization: complete destruction of all microorganisms present including bacterial spores.
An antiseptic agent which safely disinfects skin or living tissues.
Cleaning is the physical removal of microorganisms and debris
Disinfection is a process which destroys microorganisms by chemical or heat methods and reduces them to a level not harmful to health.
