General trop dis Flashcards
Parasitic causes of moderate eosinophilia
Fasciola hepatica / gigantica Paragonimus westermani Clonorchis Opisthorchis Hookworm
Features of chronic paragonimus
Chronic cough
Blood- streaked sputum
Unimpaired general condition
Marked eosinophilia
ectoparasites features
- live on or in host skin
- feed on host blood / keratin
- go thru entire life cycle or part of it in host
Chagas organism
Trypanosoma cruzi
Chagas vector
triatomine insect
Typhoid relapse rate
5-10% relapse rate
Probs with chloramphenicol in Rx typhoid
Does not prevent chronic carriage, transitory carrier state, or relapse rate
Haematologic SEs (anaemia, leukopenia, BM aplasia)
some resistance
Benefits of quinolones in typhoid
Decrease chronic carriage (decrease GB Ca) Decrease spread Decrease relapse Decrease time of Rx Few SEs, good tolerance
Plague organism
Yersinia pestis
Rx plague
Streptomycin 10d
tetracyclin, chloramphen, gent, 3rd gen ceph, fluoroquin
Pathognomonic signs of cutaneous anthrax
black eschar
malignant oedema
Definition of biological warfare (BW) or biological terrorism (BT)
intentional use/attempted of viruses, bacteria, fungi or toxins derived from live orgs to cause death/disease among humans, animals or plants
Examples of BT/BW agents
anthrax botulism plague tularaemia haemorrhaged fever smallpox brucellosis
Causes of haemoptysis
Tropical - TB - bronchiectasis -paragonimiasis - melioidosis - leptospirosis - hydatid disease - endemic mycosis General - Ca - Chronic bronchitis - CHF - blood disease
Tropical pulmonary eosinophilia
- immunologic hyper responsiveness to microfilariae
- cough, wheeze, fever, LOW
- CXR diffuse interstitial miliary infiltrates
Pleural effusion common causes
Tropical - TB - paragonimiasis - cryptococcosis - histoplasmosis - LCa Other - CHF - Ca - PE - cirrhosisw
What is the most contagious virus known?
Measles
Most common cause of preventable death in refugee/IDP populations
Measles
Factors to consider when considering empiric diarrhoea Rx
Clinical syndrome Most likely etiological agents Age of pt Seasonality Location Local susceptibility data
Characteristics of an insect vector
Anthropophilic (feed on human blood)
Coincides in time and place with infected reservoirs and humans
Found naturally infected with given pathogen
Supports life cycle of pathogen w/i its organism
Carries out transmission event
Parasites of importance to consider before giving CCS Rx
strongyloides
entamoeba histolytica
ballantidium coli
Commonest STD worldwide
HPV
Commonest symptomatic STD worldwide
trichomonis
The two medically important clinical syndromes resulting from spider bites
Loxoscelism / Necrotizing arachnoidism (esp by loxosceles spp)
Latrodectism / Neurotoxic arachnidism (esp by lactrodectus spp)
Diseases transmitted by culex mosquitoes
Filiarisis
Viral - JE, West Nile
Culex mosquito features
Larvae - lie oblique to water surface to get air
- long siphon
Adult - short palps F, wings with uniform scales, rests with body & wings parallel to surface
- diverse larval habitats / polluted water
- active thru night
Anopheles mosquito features
Larvae - attached horizontal to water surface
Adult - palps as long as probiscus, spotted wings with dark/pale bands, rests perpendicular to surface
- oviposite in unpolluted water
- malaria vectors
- active sunset-sunrise
Aedes moquito features
Larvae - short siphon, otherwise like culex;
Adults - short palps F, wings uniform scales, rest parallel to surface
- active during day (esp morning/evening)
A aegypti - single eggs above waterline on artificial container
A albopticus - natural water containers, tree holes, ground pools etc
Diseases transmitted by Aedes aegypti
YF
Dengue
(filiarisis - other aedes)
RFs for aedes aegypti mosquitos
deficient basic sanitation lack of drinking water deficient conditions of water storage migration from country to city overcrowding
Sand flies (lutzomyia New World, Sergentomyia Old World) features
active at night
habitats semi desert, tropical rainforest, highlands
oviposition in humid places rich in plant debris
Peru - lutzomyia verrucarum
Vector of African Trypanosomiasis
Glossina palpalis (looks like house fly)
- long morsitans
- daylight hours
- one offspring every 10d, laid as mature larva
Cause of myasis
dermatobia hominis
Screw worm name
Cochliomyia homnivorax
Body lice - name and diseases for which vector
Pediculus humanus var corporis
Vectors of typhus (rickettsia prowazeki), trench fever (bartonella quintana), relapsing fever (borrelia recurrentis)
- entire life cycle occurs in close contact with human body
Diagnosis of toxocariasis
Clinical = fever + HMy + eosinophilia in a child
EPI vaccines
Measles DPT (and TT adult) Polio BCG Hep B Hib YF
Why isn’t rubella among EPI in many parts of world?
In areas with sustained vax coverage <90-95%, addition of rubella vax would cause paradoxical increase in congenital rubella synd.Vax introduction causes increased inter-epidemic period.
Dehydration effect on thermoregulation
After 2% loss of mass, 0.4 degrees temp increase for each additional 1% mass lost
Heat stroke
T40-47
CNS dysftn, TC, inc RR, HoT
Residual brain damage 20%
Dehydration - 3 critical signs / 3 important signs
3 critical signs: - thirst - sensorium: irritable or comatose - skin turgor: slow, very slow 3 important signs: - sunken eyes - dry MMs - absent tears
Diarrhoea incidence per child in limited resource situations
3 episodes/child/yr
Summary of mgt of diarrhoea in children
Oral rehydration Continue BF Early feeding restoration Zinc supplementation Most cases viral Consider ABx for dysentary & WD with fever and faecal leucs (>50)
Meliodosis organism
Burkholderia pseudomalli
Hypothermia cold and wet phases
- Cold shock (gasp, vasoconstr, TC, asystole)
- Rapid cooling of periphery (decreased coordination, strength)
- Cooling of core (mental status changes)
- cannot maintain core temp with muscle activity <25 degrees C
Frostbite key features
- duration more important than temperature (can occur > 0 degrees)
- injury - reward, hyperemia, sequellae
Commonest cause of FUO worldwide
TB
Acute mononucleus-like syndrome + leukopenia
HIV
Causes of granulomatous amebic encephalitis (GAE)
Balamuthia mandrillaris
Acanthamoeba spp
Pathogens from unpasteurized milk (EXAM)
Tick-borne encephalitis virus
Brucella
Listeria
TB
Modes of infection of tick-borne encephalitis virus (?exam)
Ixodes tick Unpasteurized tick BF Blood donation Lab accidents
Causes of biliary obstruction
- rare parasitic disease presentation:
Nematodes - ascaris
Trematodes - clonorchis sinensis, opistorchis viverrini, O felinieus, fasciola hepatica
Cestodes - E granulsosus (v rare)
Protozoans - cryptosporidium in AIDS - cholangiocarcinoma with Asian trematodes
,
Causes of intrahepatic cholestasis
Rare in bact disease, mostly bacterial: - lepto** - brucellosis - typhoid - TB (miliary dissemination) - pyogenic abscess - amoebic abscess (v rare) Cholestatic presentation HAV (CMV, EBV) Drugs - chlorpomazine, others
Treatment for fish toxins
Heat (hot water)
Antivenoms exist for which marine animal injuries?
Stonefish and jellyfish stings
What treatment for vinegar?
vinegar
Management coral and sea urchins
first aid
Management of octopus and cone snail stings
Pressure immobilisation
Shellfish and ciguatera management
supportive
Scombroid treatment
antihistamines
Cardiac glycosides - source, management
Oleander (contain compounds similar to dig) - Rx ovine antibodies (digibind/digifab)
Cyanide toxicity plant source, Sx, Rx
Yuca, sassava, allamanda
Prevent by correct trimming / soaking
Sx tropical ataxic neuropathy, epidemic spastic paraparesis
Rx limited
Amanita phalloides - source, sx, Rx
Death cap mushroom
Heptarenal failure - 20-30% mortality
Rx benzylpen, N-acetyl cysteine, haemodialysis, liver Tx
Causes of intestinal perforation
Balantidium coli
Salmonella typhi
Entamoeba histolytica
TB
Parasitic causes of massive eosinophilia (>5000)
Toxocara
Trichinosis
Lymphatic filariasis - TPE
Other parasitic causes of eosinophilia
ascaris (migratory phase) lymphatic filariasis non-lymphatic filariasis schisto taenia - cysticercosis echinococcus - cyst rupture trichuris aberrant animal helminths angiostrongylus gnathostoma capillaria trichostrongylus
Snakes
- Vipers
a) Bothrops - proteolytic + thrombin-like (oedema + bleeding); coast/Andes/jungle
b) Lachesis - same; Amazon
(aka mutamuta / shushupe /bushmaster)
c) Crotalus - neurotoxic + myonecrotic (dark urine, nephrotoxic); Puno - Elapidae
a) Microcurus (coral snakes) - neurotoxin
b) Ophiophagus (cobra)
Spiders
- Loxosceles species - violin-shaped marking, 6 eyes in 3 diads, eg L recluse
- Lactrodectus (black widow) - neurotoxic
