Good luck tomorrow!

Good luck everyone!

I hope this blog and the spots helped out some with studying.

Everyone has already put in a huge amount of work, and tomorrow is the chance to finish it all off.  Best of luck to all, and I will see you on the other side!

Preventive Medicine Paper Model Answers

One of the big 3: TB, malaria, HIV will be on there

Only 70% is infectious disease– 30% will be NCDs, refugee camps

  • WHO and CDC guidelines are where many of the examiners turn for their questions

Preventive Medicine Paper

1. GIS Question:

  • What is the role in public health?
    • GIS is computer aided database managemnt and mapping
    • GIS adds dimension of demographic analysis to IT linking data to map
    • Determining geographic distribution
    • Analysing spatial and temporal trends
    • Mapping populations at risk
    • Stratifying risk factors
    • Assessing resource allocation
    • Planning and targeting interventions
    • Monitoring diseases and interventions over time
  • Guinea worm
    • Maps drawn showing regional occurrence
    • Unsafe groundwater sources
    • Filters
    • Temephos – biodegradable larvacide
    • Systematically track all villages
    • Identify infected and reinfected
    • Detect target resoures
    • Monitor process towards eradication
    • Still in Southern Sudan and Chad
    • Community based surveillance – look for painful blister relieved by dipping in water

2. Polio eradication what is required (10 marks) and what are the obstacles (10 marks)?

  • Required
    • Surveillance of AFP with virology stool samples
    • Routine vaccination
    • Catch-up vaccinations/ mass vaccinations
    • Targeted mop-up campaigns
    • Other causes AFP: Guillan-barre, WNV, novel eneterovirus
  • Obstacles
    • Political will
    • Sanitation
    • Vaccine refusal
    • Increased costs as cases reduced
    • Violence against owkers
    • Vaccine-associated polio strains
    • Transition from IPV to OPV
    • Financing
    • Vaccine Supply
    • Trouble countries: India, Syria, Pakistan, Nigeria, South Sudan
    • Infrastructure
    • Cultural/religious beliefs

3. NCDs.  Using either Type 2 DM or epilepsy describe how you would organize delievery of care to a rural community in central Africa (20 marks)

  • Diagnosis
    • Diagnose with fasting or glucose challenge
    • Establish system to diagnose problem
  • Treatment
    • Essential medicine list, ensure no stockouts
    • Move care to Primary Health Centre
    • Set targets
    • Use simple regimens of cheap, effective drugs
    • Nurse-led clinical algorithms
  • Follow-up
    • Encourage and check compliance
  • Access to Care
  • Education
    • Educate patients and carers
    • Educate health care staff

4. HIV. Why is HAART important to take on time (5 marks)? In setting of Africa, describe strategies to ensure compliance (15 marks)?

  • Take all drugs on time to ensure ideal drug level.  Sub-optimal drug levels may provide pressure to select for resistant strains/mutations.  HIV has a rapid mutation rate and is highly prone to developing resistance so having 3 drugs at active levels at all times is critically important.
  • Strategies
    • Avoid stockouts
    • Treatment buddies (relatives)
    • Educate patients
    • Educate health care workers
    • Mobile phones/SMS
    • Simplified regimens
    • DOTs if needed
    • Adeherence counselling
    • Standardized adherence measures
    • Free drugs
    • Recall systems to prevent loss to follow up
    • Expert patients

5. HPV: Should you accept a donation of Cervarix or Garasil for three years

  • Vaccine basics
    • Highly effective
    • Expensive
  • Cost
  • Sustainability
  • Are there other health/social interventions to be given alongside?
  • Studies needed for acceptability, proportion of disease from 16/18
  • How do you market? Cancer prevention or STIs
  • Outside of typical vaccine target ages, how to be done?

6. Discuss 4 key messages that you would put into an information leaflet for men considering being circumcised (20 marks)?

  • Interventions: condoms, syndromic management, ART, cirucmcision
  • Shown repeatedly to prevent men acquiring HIV by almost half
  • Will not protect you from other means of infection
  • Keep using condoms
  • Don’t have sex for 6 weeks until wound is healed because it increases chance until then

7. 6 critical public health measures for diarrhoeal prevention

  • Clean water
  • Nutritional supplementation: vitamin A, zinc
  • Rotavirus immunization
  • Exclusive breastfeeding
  • Wat/san
  • Hand hygiene
  • Hygienic nutritious weaning foods (not just rice)
  • ? Anti-helminthic
  • Main causes (GEMS Trial): Rotavirus, Cryptosporidium, Shigella, Enterotoxigenic E. Coli

Trachoma

  • Wat/san
  • Latrines
  • Access to safe water

 

Killer B’s

In a fit of homonym frustration, I have finally decided to write down every “B” infection on one page so I can hopefully stop confusing them.

Borreliosis: tick and louse-borne relapsing fever

  • Tick-borne:
    • Vector: Ornithodoros (soft tick)
    • 14d incubation
    • 3-6 attacks of sudden onset headache and fever lasting 2-3 days
    • Hepatosplenomegaly 30%
    • CNS involvement w facial nerve palsy and lymphocytic meningitis
  • Louse-borne
    • Vector: Pediculus humanus
    • Wide clinical variety: self-limiting to 70% fatal
    • Incubation 4-8 days
    • Abrupt onset febrile illness
    • Myalgia, headache, cough, jaundice
    • Rash
    • Hepatosplenomegaly is typical
    • Complications: hepatic +/- cardiac +/- DIC
    • Relapse 1 week later 60-70% of the time
  • Treatment: doxycycline
    • Jarisch-Herxheimer reactions common

Brucellosis: bacterial infection associated with livestock

Babesiosis: tick-bonre intra-erythrocytic infection

  • Ixodes (hard tick)

Burkholderia pseudomallei: causitive agent of melioidosis

Bartonella:

Honorable mention:Burkitt’s lymphoma, buruli ulcer

Preventive Medicine paper

So, the exam is coming up and one of the major sections is the preventive medicine paper.  Listed below are two exams worth of questions.

Tragically, I have no answers to accompany them, but hopefully it will help guide people’s studying.

Old Style Questions (no longer this vague)

  1. What are the health effects of urbanization in tropical countries?
  2. What are the main features of the African Programme for Onchocerciasis Control?
  3. What is an Essential Medicine List is a resource poor country? What factors affect drug choice?
  4. What are the barriers to the elimination of malaria in Asia?
  5. Write short notes on the control of an outbreak of cholera in a refugee camp
  6. Outline the principles of tuberculosis control in sub-Saharan Africa.
  7. Why has polio not been globally eradicated?
  8. What may help to prevent blindness in tropical countries?
  9. Write short notes on the cause and prevention of two common malignancies in Africa

New-fangled Questions (this is what we can expect this year)

  1. The WHO three I’s strategy to improve TB control in HIV. The three related interventions are “Intensified case finding, Isoniazid preventive therapy and Infection control”. For each of these three, explain rationale behind them and how they might benefit HIV infected people in resource poor settings (20 marks).
  2. Outbreak of anthrax is suspected in rural Ethiopia: how do you confirm that anthrax is the cause of the illness and assess the extent of the problem(6 marks)?  What control measures need to be put into place if anthrax is confirmed (14 marks)?
  3. What are the factors contributing to poor mental health care in resource limited tropical countries (10 marks), and how can they be overcome (10 marks)?
  4. Health threats in a refugee camp in a developing country (10 marks)? How would you go about managing these (10 marks)?
  5. You are asked by the minister of health of a South Asian country where low incidence of which is 70% is vivax to give advice about eliminating malaria.  Neighboring countries have similar epidemiology.  Local mosquitoes are outdoor biters and there is evidence of artemesin resistance.  What are the arguments for (10 marks) and against (10 marks) trying to eliminate malaria?
  6. You are in charge of the national STD control program in African country.  State the aims of the programme and describe how you will achieve them (20 marks)
  7. What are the causes of vitamin A deficiency (10 marks)? What are the effects of vitamin A deficiency in pregnant women and how should a woman with vitamin A deficiency be treated (10 marks)?
  8. Pneumonia kills more children under five than anything else in every region in the world. What factors contribute to high morbidity and mortality in developing world (10 marks)? Describe the interventions that would reduce mortality from childhood pneumonia (10 marks)?
  9. A 43 year-old woman has troublesome asthma is Angola requiring frequent courses of prednisolone.  What are the potential risks of this treatment (10 marks) and how might you be able to prevent such problems (10 marks)?
  10. Different types of trypanosomiass.  Trypanosoma brucei gambiense and T. b rhodesiense exist in the different parts of Uganda.  How do the two infections differ in clinical presentation (5 marks) and treatment (5 marks)?  What are the barriers to controlling trypanosomiasis in that country (10 marks)?

Malaria Treatment

Treatment of non-falciparum (P. vivax/ovale/malariae)- chloroquine, followed by primaquine (gametocide) for P. vivax

Falciparum: quinine or ACT

– iv treatment required for hyperparasetemia or e/o schizonts (need blood film) and/or complications (anemia (kids), coma/stupor, liver/renal failure, ARDS, hypoglycemia, bleeding, DIC)

– in UK, quinine po followed w second agent (doxy or fansidar)

 

Malaria (from an epi point of view)

Ro  α  p^n (survival)

Ro  α  a^2 (man-biting habit)

Stable malaria
–Transmission intensity sufficient to generate collective immunity
–Seasonal variation, no epidemics, children affected

 

Unstable malaria
–Insufficient exposure to build collective immunity
–High risk of epidemics, affects all ages
Control: ITN, IRS, ivermectin (reduces seurvival, delays sporogony, delays times to re-feed), IPT
Overprescribing and access to diagnostics an issue

Influenza

Clinical: sudden onset fevers, sore throat, cough, myalgia

Type A, B, C

  • But only Type A (esp. subtypes H1-H3) associated with epidemics

Details:

  • Incubation: 1-3d
  • Symptomatic: 2-7d
  • Infectious: 3-5d after clinical onset adults, up to 7 in children
  • Transmission: via resp secretions (airborne and droplet), contaminated surfaces
  • Ages most affected: very young and very old
  • Duration of activity: usu. 8-10 weeks during winter
  • Complications: secondary bacterial, exacerbate underlying comorbidities
  • Mortality:3,000-4,000/annum up to 20,000+ in epidemics

Antigenic drift: small change in structure vs. Antigenic shift: producing new “subtype”

Unclear efficacy of Tamiflu for treatment or prevention

Pandemic Trends

  • Young children (under 5’s) have highest attack rates
  • Seasonal flu features/activity change with pandemic shifts

Avian influenza

  • Migratory wild fowl harbor all strains of Influenza Type A and are reservoir for disease -> mix w/ domestic fowl
  • H5N1 causes severe illness in poultry -> transmits disease (often severe) to humans
    • Limited human-to-human spread
  • H7N9 is mostly asymptomatic in poultry->transmitted to humans (often very severe disease)
    • Almost zero human-to-human spread

Currently only in China

Snake bite

(With thanks to the AFEM chapter on snakebites)

Proteolytic (cytotoxic) venom: (usually viper bites):

  • Local oedema, blistering, necrosis, evidence of compartment syndrome
  • Haemorrhage or ecchymosis
  • Myalgia, myoglobinuria (black urine) (evidence of rhabdomyolysis),
  • decreased urine output (renal failure)
  • Hypotension or arrhythmias

Neurotoxic venom (usually elapid bites – often no to minimal local symptoms
and delayed presentation):

Elapidae

  • Descending paralysis that can impede bulbar and respiratory function
  • Tremors, salivation, dysarthria, diplopia, ptosis, fixed myosis, seizures

Some cobras ‘spit’ venom at their victims, who may complain of eye pain,
tearing, and impaired vision

Haemotoxic venom: ‘Boomslang’ – slow acting haemotoxic venom that
affects blood clotting and requires specific antivenom

WHO Guide to snakes and antivenoms: http://apps.who.int/bloodproducts/snakeantivenoms/database/snakeframeset.html

DTM and H Exam Info

From Dr. Gary Brook (Chairman of Examiners)

Talk about exam:

  • 2/3 not from LSHTM, public exam open to public (Glasgow and Liverpool), but aligned very closely by DTM&H course (like an exit exam)
  • Very broad: need to know a little bit about everything
  • 4 Parts:
    • 70 Best of Five questions, lasts 2 hours
    • Short notes exam. 5 questions out of 10, lasts 1 hours
    • Clinical exam: 30 Best of Five questions, 16 based on pictures, lasts 1 hour
    • Practical exam in parasitology and entomology, lasts 2hrs and 30 min
  • No viva voce
  • RCP website has example questions: liver (fasciola, hydatid, amoebic, HCC, cholangiocarcinoma), ITNs (stats/clinical trials questions)
  • Shorts notes/preventative medicine: don’t need discursive essay- only bullet points, look at marks for idea of how much/how many to write, can pass with a single side side of a piece of paper
  • Practical Exam: mixture of seated and steeplechase
  • Who passes? Rate 90-95%, London School less likely to fail
  • Topic breakdown: Infectious diseases 60%, Public Health 25%, NCD 15%

Clinical Slide Session

  • Indian- maculopapular rash, low grade fever, posterior auricular LN, arthralgia vs. Thailand (thrombocytopenia, muscle pain, similar rash, headache)
    • India=rubella vs. Thailand=dengue (maculopapular then confluent, saddleback fever [Parvoviremic then immune complex fever])
  •  Parvovirus- reticular rash on lower limbs, can cause hydrops faetalis, sickle cell crisis
  • Transient swelling of wrist:
    • West Africa= Calabar swelling with loa loa + eosinophilia, tx: DEC;
    • Thailand= gnithostomiasis, accidental host, wanders and dies to form inflammatory mass
  • Transient linear lesion on trunk: eos and itch= larva currens (12 hrs, indicative of strongyloides, not necessarily recent), cutaneous larva migrans (lasts longer, spontaneously resolves, dog hookworm, tx topical thiabendazone)
    • Strongyloides: when immune compromised later in life-> strongyloides hyperinfection syndrome, lungs fill w larvae, adults live in upper gut (duodenum, jejunum), repenetrate self if eggs hatch before leave body), tx: ivermectin
  • Slowly increasing lesions on skin over weeks
    • Israel: cutaneous leish, can do slit skin smear for amastigotes, tx:
    • India: itchy papule scratched-> Staph aureus
  • skin “boils”
    • West Africa- cutaneous myiasis, tx w petroleum jelly and elastoplast, prevent by ironing your clothing
    • South American – cutaneous myiasis from fly that lays eggs on mosquitos which then deposits on people, remove w/ needle or liquid nitrogen
    • East Africa- eschar of tick typhus (maculopapular rash, fever, tx:doxycycline)
  • Sore throat
    • Gelatinous exudate with hemorrhage: diptheria (treatment: airway(trach), antitoxin, antibiotics), partly occlusion and partly toxin mediated (cardio and neuro toxin that can cause palatal paralysis)
    • Cheesy confluent exudate: EBV, minimally tender LAD, leads to Burkitt’s lymphoma (malarial [low-land] children
  • Headache, fever, neck stiffness
    • Meningococcemia- subconjunctival petechiae, not as bad prognosis as pneumococcal meningitis, meningitis belt, vaccine preventable
  • Babesiosis (PUO and abnormal blood film, traveled to cattle ranch in USA)
    • 3 intra erythrocytic infections: Oroyo fever (bartonellosis), babesiosis, malaria
    • If malarial parasitemia > 2% then treat iv
  • Smelly liquid stool for weeks: malabsorption stool (usually giardia or tropical sprue)
  • Dyseneteric: sm amounts stool, blood mixed with mucous, shigella/amoeba (less likely campylobacter, salmonella)
  • String test: diagnose giardia and strongyloides
  • Amoebic liver abscess: fever, TTP, can present 6 months or year after visit, dx: sigmoidoscopy (usually see amoebic ulcers in rectum, darkfield shows trophozoites with digested erythrocytes)
  • Visceral leishmaniasis: hepatosplenomegaly, fever, assoc w HIV in southern Mediterranean, transmitted by Phlebotamine bite, dx: serology, splenic aspirate, tx: liposomal amphotericin B
    • India: L. donovani, Rest of World: L. infantum
  • Hydatid cyst: diagnose: ultrasound, treatment: albendazole, can ? aspirate (Percutaneous Aspiration, Injection and Reaspiration) if failed medical treatment and only 1-2 locules, if spill during surgery can get anaphylaxis and dissemination throughout body
  • Papules-> nodules on , then disappear and reappear
  • Front of legs: erythema nodosum (TB, IBD, others)
  • Back of legs: Basin’s disease (EN on back of legs-> they have TB 50% pulmonary)
  • Two lesions: one on penis and one on pubic area, deep and indurated with inguinal LAD
    • Syphilis: dx with darkfield microscopy
    • LGV: tiny painless ulcers with large LAD
    • Herpes: painful, small LAD
    • Bechet’s: Turkey
    • Swollen joint in youngsters: reactive arthritis (Chlamydia) vs Gonococcemia (infectious)

    Morbiliform rash + white spots on buccal mucosa (Koplik spots)= measles

  • Amoxicillin + EBV – rash all over