General Tropical Med (from revision session) Flashcards
Entamoeba Histolytica
Diagnosis?
Treatment?
If extrahepatic- Serology
If intrahepatic liver abscess - then aspirate (anchovy like non-odouress substance - positive for trophozoites)
Metrondiazole + amoebicide
Giardia treatment
metronidazole or tinidazole
Ascaris lumbricoides
disease it causes?
transmission?
why does it cause symptoms?
= Roundworm
faeco-oral
tends to create high volume of worms which can cause bowel obstruction
Hookworm
transmission?
Through skin penetration
Trichurius
disease?
Symptoms?
Whipworm
Particularly in children - UC like symptoms (incl bloody diarrhoea), anaemia, rectal prolapse, tenesmus, nocturnal soiling
Strongyloides
Transmission
Important relevance of this condition?
rash related to this?
Through skin
It can cause superinfection in immunosuppressed as its life cycle can occur solely in humans - autoinfection
Larva Currens
Cutaneous Larva Migrans related to?
dog/cat hookworm
Taenia Solium
disease?
important significance of this type?
Pork tapeworm
humans can be the intermediate hosts in this infection meaning that the cystercerci can cause cystercercosis (in brain, muscles, eye etc)
Echinococcus causes…
Hydatid disease
D. Latum = which disease?
associated with?
Fish tapeworm
associated with megaloblastic anaemia
Schistosomiasis transmission?
cercariae penetrate through skin in fresh water (after having developed from miricidae into cercaria in snails). Then they lose their tails and migrate through lymphatics to the hepatic portal system over 2-3 weeks maturing. Then male and female join (for life) and go to bowel or bladder.
Schistosomiasis initial reaction?
Immediately - urticarial rash where penetration is
at 21 days post infection = Katayama Syndrome (fever, rash, cough, abdo pain)
Schistosomiasis treatment?
Praziquantel (2 doses)
MDA with praziquantel also
Fasciola hepatic disease?
Transmission?
symptoms?
treatment?
Liver fluke
Eating watercress
fever, hepatomeghaly and liver dysfunction
Tx: triclabendazole
Paragonimus westermanni
disease?
transmission?
treatment?
Lung fluke
from eating Crabs/crustaceans
Praziquantel or triclabendazole
Lymphatic filariasis Parasite names?
Typical effect in the lungs?
Treatment?
Brugia Malayi, Wuchereria Bancrofti
- can cause pulmonary eosinophilia which is asthma-like (cough, wheeze, high eosinophils)
Tx: Inside Africa - Albendazole + Ivermectin
- Outside Africa - DEC + albendazole + ivermectin (as long as sure no Loa Loa)
Diseases that cause eosinophilia?
Schistosomiasis
Hookworm
Ascaris lumbricoides
Strongyloides
Lymphatic filiariasis
Lung fluke (Paragonimus Westermani)
Onchocerciasis
transmitted by?
where does it affect?
Black fly bites (simulium)
skin - nodules, ITCHING!! sowda (darkened skin), lizard skin and leopard skin and eyes - leading to blindness (optic nerve atrophy and keratitis)
onchocerciasis diagnosis?
Tx?
bloodless skin snip
tx: ivermectin (if confident it isn’t Loa Loa (i.e. if out of africa). Give Doxycycline (as this won’t affect LoaLoa and is safe)
Loa Loa
transmission?
Tx?
important consideration?
= Eye Worm
transmitted through chrysops fly bite
tx: DEC if low filariae, if high then give slow albendazole in hospital or over 21 days
NB: if have Oncho as well and you gave DEC then can cause Marzotti reaction - must rule this out first.
Guinea Worm features?
Tx?
fiery worm!
causes ulceration as adult worm comes out of skin
Treatment - gradually using a pencil to pull out the worm
HAT life cycle
what form of parasite enters humans?
metacyclic tryposmastigotes and turn into bloodstream trypomastigotes - these either become long, slender forms which are able to evade immune system with the VSGs (variable antigenic presentation) and multiply, and the short, stumpy forms which can be taken up blood meal of tsetse fly
HAT tx?
Rhodiense?
Gambiense?
For gambiense 1st and 2nd stage = fexinidazole
Rhodiense 1st stage = Suramin
2nd stage = Melarsoprol
Chaga’s disease
stage of entering human?
lifecyle in human
trypomastigotes enter human –> transform into intracellular amastigotes –> transform into trypomastigtes which burst out of the cell and into blood stream
Chagas treatment?
Important to remember regarding who needs treatment?
Benznidazole for 60 days (doesn’t change trajectory if already has chronic cardiomyopathy etc)
If in indeterminate phase (as proved by positive serology but asymptomatic) you need to treat if Children, pregnant, of childbearing age or immunosuppressed
Leprosy stages
- TL tuberculous Leprosy - good immune response - granulomas, paucibacillary
- BT borderline tuberculoid
- BB Borderline
- BL borderline lepromatous
- LL lepromatous Leprosy - poor immune response, high bacillary load
Cutaneous Leishmaniasis
Vector?
Diagnosis?
Vector - sandflies
- impression smear
- skin biopsy using microscopy, PCR, serology (DAT) or culture
Visceral Leishmaniasis
Onset?
Diagnosis?
Mainly Leishmania Donovani
Sub-acute - over months
Spleen/bone marrow/LN aspirate for microscopy, PCR, or serology/urinary antigen
Visceral Leishmaniasis tx:?
tx: miltefosine and liposomal amphotericin B
Vipers snakebite effects?
Swelling at bite site with necrosis sometimes. Then can lead to coagulopathy and haemorrhage.
Elapids snake bite effects?
Local effects minimal (unless cobras)
Neurotoxicity predominates
Useful test in snakebite assessment?
20 min whole blood clotting test (if not clotted after 20 minutes you know you’ve got serious problems!)
Sea snakebite effects?
No local effects. Leads to myotoxicity and paresis
Buruli ulcer
Bacteria?
Where might you see it?
Treatment:
Mycobacterium ulcerans
West Africa
Rifampicin + macrolide/streptomycin
Leprosy
1. paucibacillary
2. multibacillary
treatment?
- Dapsone, rifampicin and clofazimine for 12 months
- Dapsone and Rifampicin for 6 months
Reasons why someone might present with a fever VERY unwell in low resource setting?
later presentation
Anti-microbial resistance
poor fluid balance
poor diagnostics
Severe falciparum malaria treatment?
IV Artesunate (or IV quinine if don’t have artesunate)
Then oral stepdown to ACT after at least 24 hrs of IV
Role of Primaquine in Malaria treatment?
- Can give single dose of primaquine in low transmission areas (to clear gametocytes to prevent onward transmission)
- Or you give 14 days course of Primaquine for eradication of hypnozoites in liver for vivax or ovale
tx for non falciparum malaria?
if not chloroquine reistance then give that.
Otherwise give ACT
Malaria elimination efforts (list of five)
- vector control (ITN, IRS etc)
- Diagnosis and tx of cases
- IPT (in pregnancy, infants and seasonal)
- ?MDA in future
- Vaccine delivery
Typhoid fever Diagnosis?
via blood culture
Widal Test (serology)
Typhoid complications
shock
syndrome of confusion
encephalopathy
cholecystitis
bowel perforation
GI bleeding
Melioidosis bacteria?
Burkholderia pseudomallei
Risk factor for melioidosis?
diabetic
CKS
CLD
alcoholism
long term steroids
Melioidosis features?
Tx?
acute sepsis + abscess formation in skin and viscera + suppurative parotitis + multifocal pneumonia
Tx: Ceftazidime (resistant to ceftriaxone)
Leptospirosis complications?
Treatment?
ARDS (pulmonary haemorrhage), AKI and Transaminitis
Tx: Doxycycline or amox
If severe: penicillin IV
Bubonic plague symptoms?
Can become pneuomonic - significance?
Fever, headache chills and swollen LN (called buboes)
Once pneumonic then it can spread more easily - aerosol-borne/inhalation
Dengue Virus
transmitted by?
Aedes Aegyptii
Important monitoring and indications of worsening Dengue?
Abdo pain, fluid oedema, mucosal bleeding and hepatomegaly
Falling platelet count, rising haematocrit
Japanese Encephalitis
transmitted by?
Culex Mosquito
How to respond to possible VHF outbreak?
- waste management
- PPE supply
- washing of linen
- cleaning rota
- safe burials
- isolated triage area and barrier nursing
- donning and doffing area (observed)
- Inform country’s public health authorities - ask for support
- contact tracing
…
Risk factors for TB (i.e. increased chance of not clearing initial infection)
HIV, Vit D deficiency, Malnutrition and diabetes
Diagnosis of Pulmonary TB
Sputum smear - microscopy
TB culture
Gene Xpert (ultra) = gold standard
CXR and clinical symptoms
HIV test
TB tx priniciples
Intensive phase - 2RHZE
Continuation phase - 4RH
What to discuss before TB tx?
adherence
discuss SE
Advise about contraception
check visual acuity
Check LFTs
get baseline Weight (monitor this for sign of effective tx)
Investigations for extra-pulmonary TB
Urinary LAM for HIV+ve patients and GU EPTB
Culture of gastric aspirate/LN/pericardial aspirate/pleural aspirate/bone biopsy (dependant on where!)
- MDR drug resistance meaning?
- RR/MDR meaning?
- Pre-XDR meaning?
- XDR meaning?
- resistant to at least rifampicin and izoniazid
- rifampicin resistant
- Fluroquinolone, rifampicin and isoniazid resistance
- fluroquinolone, bedaquiline and or linezolid resistant as well as MDR
reasons for TB drug resistance?
poor adherence
No DOTS
Drug supply issues
malabsorption
didn’t complete course
HIV initial tx?
Two NRTIs and PI/INSTI/NNRTI
e.g. Tenofovir and Lamivudine and Doltegravir (or Efavirenz)
HIV counselling 5 key points to address
no cure
lifelong treatment
U=U
partner notification
adherence