Travel conditions

Question 1

Tests used in HIV diagnosis

Answer 1

A) Antibody test: antibodies against HIV

B) Antibody/antigen test: antibodies against HIV and HIV antigen (virus itself)

C) RNA/DNA test: screen for viral RNA -> detects virus directly & DNA -> copies of viral

RNA

• Antibody/antigen test is recommended for screening purposes -> better for identifying

early infection

• The other tests are recommended as confirmatory tests (as follow up after positive result

of antibody/antigen test)

Question 2

HIV diagnostic workout

Answer 2

Question 3

Aims of HIV management with anti-retroviral therapy

Answer 3

Question 4

What tests are involved in Dx of Malaria?

Answer 4

Question 5

Why it’s important to know % of RBCs infected by parasite? (in malaria)

Answer 5

% of RBCs infected by parasites is
important -> patients with >5% parasitemia can have worse outcome

Question 6

Common lab findings in malaria

Answer 6

Common lab findings:

• thrombocytopenia -> low platelet count
• elevated lactate levels -> due to hemolysis
• anaemia: normochromic (normal colour) and normocytic (normal size) BUT anaemia = low RBCs number

Question 7

Management algorithm in ‘suspected’ malaria case

Answer 7

Question 8

Types of malaria treatment (4)

Answer 8

• Suppressive treatment = Chemoprophylaxis is aimed to kill sporozoites before they infect hepatocytes -> given to travellers that go to endemic malaria countries

• Therapeutic treatment: to eliminate merozoites that are in erythrocytic phase -> given during active infection

• Gametocidal treatment - to kill gametocytes -> prevent spread of diseases

• Radical treatment - to kill hypnozoites in the liver (P. Vivax and P . Ovale infections)

Question 9

Name (2) agents used to treat malaria

Answer 9

chloroquine, quinine

Question 10

(2) options for malaria prevention - environmental

Answer 10

• to prevent mosquitoes from biting -> sprays, full body clothing, sleeping in the nets
• to remove containers with water -> as mosquitoes like to lay their eggs there (to control

mosquitoes population)

Question 11

What virus family causes Viral Haemorrhagic Fever?

Answer 11

Flaviviridae virus family

Question 12

What is the danger of viral haemorrhagic fever?

Answer 12

They can cause fever and bleeding disorders -> possible progression into shock and deaths

Question 13

Pathogenesis of viral haemorrhagic fever

Answer 13

Question 14

Symptoms of viral haemorrhagic fever

Answer 14

Question 15

What are general blood test findings in a person with viral hemorrhagic fever?

Answer 15

• decrease in total WBC (particularly in the lymphocytes)
• decrease in platelet count
• increase in blood serum liver enzymes
• reduced clotting ability -> measured as increased PT and PTT times
• hematocrit may be elevated
• urea and creatinine may be raised (depends on hydration status of the patient)
• prolonged bleeding time

Question 16

What is hematocrit?

Answer 16

*hematocrit - volume in % of RBCs; normally is around 47% (+/-5%) for men & 42% (+/- 5%) for women)

Question 17

management of viral hemorrhagic fever

Answer 17

• may require intensive support care
• antiviral therapy -> IV ribavirin (useful in some cases of VHF)

Question 18

Why do deaths usually occur in Ebola?

Answer 18

death occurs usually from low BP from fluid loss

• usually 6-16 days after the symptoms appear
• 50% of infected people die

Question 19

Simple pathology of Ebola

Answer 19

• Ebola virus enters the immune cells -> infects it -> inflammatory molecules are secreted from an infected cell -> inflammatory process starts; also virus replicated within the cell (as per normal viral mechanism -> hijacking the cell to make new viruses)
• inflammatory molecules -> damage to vascular integrity -> hemorrhagic fever

Question 20

Signs and symptoms of Ebola

Answer 20

Start usually 2 days - 3 weeks after contracting the virus

A. Early: fever, headache, muscle pain, sore throat (initially remains of a flu-like illness)

B. Later: vomiting, diarrhoea, rash and decreased renal and liver function *

* at later stage -> possible internal and external bleeding

Question 21

Complications of Ebola

Answer 21

• progression into disseminated intravascular coagulation (DIC) -> presents as low platelet count and elevated D-dimer
• diffuse /rozproszony/ haemorrhage -> shock
• multi-organ dysfunction
• renal and hepatic dysfunction -> elevated creatinie and liver enzymes

Question 22

How to make a diagnosis of Ebola from the results?

Answer 22

A. History, S&S
B. Decreased WBC -> then elevated WBC
C. D-Dimer -> elevated
D. platelet count decreased (DIC)
E. Prolonged PT and PTT (due DIC)
F. Liver enzymes -> elevated (hepatic dysfunction)
G. Urea and creatinine -> elevated (renal dysfunction)
E.ELISA (antigen recognition test) and PCR

Question 23

IgM and IgG detection in Ebola (timeframes)

Answer 23

• IgM detected 2 days after symptom onset
• IgG antibodies 6- 18 days after symptom onset

Question 24

Management of a patient with Ebola

Answer 24

* prevention measures (washes,disinfection, contact tracing, isolation, protective equipment, safe disposal, safe burial etc.)

• Supportive care as no specific treatments are available
• No licensed vaccine or anti-Ebola products developed

Supportive:

• Rehydration via oral or IV route
• analgesia
• nausea, fever and anxiety treatments
• blood products (fresh frozen plasma, RBCs, platelets)
• Heparin -> in effort to prevent DIC
• Clotting factors -> to decrease haemorrhage

Intensive care in developed worlds: maintaining blood volume and electrolytes (salt) balance, treating any bacterial infections that may develop

Question 25

What meds and why to avoid in Ebola

Answer 25

\*avoid ***ibuprofen*** or ***aspirin*** -\> as risk of bleeding

Question 26

How to distinguish Dengue from Ebola?

Answer 26

They are both types of viral haemorrhagic fever distinction from Ebola: no renal/hepatic failure, no DIC

Question 27

WHat virus causes Dengue?

Answer 27

mosquito-borne, tropical disease -\> caused by ***dengue virus*** (enveloped, single stranded, positive sense, RNA virus)

Question 28

Symptoms of Dengue infection

Answer 28

\*start 3 - 14 days after infection High fever, headache, vomiting, muscle and joint pain, characteristic skin rash

Question 29

What's prognosis in Dengue?

Answer 29

* Recovery usually takes \<2 - 7 days * Complication (in small proportion of cases), potentially fatal: A. Dengue hemorrhagic fever -\> bleeding, low platelet count, blood plasma leakage B. Dengue shock -\> extremely low BP

Question 30

Diagnosis of Dengue

Answer 30

Diagnosis made on basis of S&S and physical examination -\> however early manifestationsare difficult to be differentiated from other viral diseases/infections Number of different tests available for diagnosis: - detection of antibodies to the virus - detection of viral RNA

Question 31

Management of Dengue

Answer 31

No specific anti-viral drug is available Rx depends on a status of a person: * those whose hydration status is OK (drinking and passing urine) and are otherwise healthy (no warning signs) -\> can be managed at home with daily follow-up and oral rehydration therapy * patients with hydration and other health problems -\> need to be hospitalised for a regular follow up A. Preventative: vaccine available, reduction mosquito habitat, limitation of exposure to bites B. Acute dengue fever -\> supportive treatment: - fluids (oral or IV) - mild to moderate disease - blood transfusion - for severe forms of disease (if haematocrit is decreasing and vital signs are unstable)

Question 32

What to avoid in pt with Dengue?

Answer 32

To avoid: - invasive medical procedures e.g. NG tube, IM injections etc -\> as risk of bleeding - Do not use NSAIDs as they may increase risk of bleeding \*use Paracetamol (acetaminophren) instead (for fever and pain relief)

Question 33

What's atypical pneumonia?

Answer 33

***Atypical pneumonia*** aka *walking pneumonia* - pneumonia that is not caused by one of commonly pneumonia causing organisms - different clinical presentation to that of a typical pneumonia

Question 34

Difference between typical vs atypical pneumonia - antibiotics used to Rx - appearance on X ray

Answer 34

Question 35

Difference between typical vs atypical pneumonia - clinical presentation

Answer 35

Question 36

Cause of ***Ameobic Abscess***

Answer 36

* liver abscess caused by amebiasis -\> as liver tissue is involved in the infection by thropozoites of ***Entamoeb histolytica*** -\> abscess due to necrosis

Question 37

Symptoms and signs of amoebic abscess

Answer 37

_Symptoms:_ - pain in R hypochondriac area (referred to R shoulder) - pyrexia - sweating and rigors - loss of weight - earthy complexion - patchy pigmentation of the face _Signs:_ - pallor - tenderness in R hypochondriac area - palpable liver - intercostal tenderness - basal lung signs

Question 38

Management of amoebic abscess

Answer 38

A.Abscess aspiration B.Repeated liver imaging C.***Metronidazole*** - antibiotic and antiprotozoal medication

Question 39

What is the cause of ***Leptospirosis***? - how is it spread - who is at risk

Answer 39

Caused by a bacteria called ***Leptospira*** - spread by wild and domestic animals (rodents e.g. rats, mice, hamsters, squirrels) \*in developing world - farmers and low-income people living in the cities and slums \* in the developed world - outdoor activities in warm and wet areas

Question 40

Signs and symptoms of ***leptospirosis***

Answer 40

_S&S may range from:_ A) none to mild: headaches, muscle pains, fevers B) severe: bleeding from the lungs or meningitis

Question 41

(2) serious complications of Leptospirosis

Answer 41

* Weil’s disease -\> when a person infected with leptospira turns yellow, have kidney failure and bleeding (death rate \>10%) * Severe pulmonary haemorrhage syndrome -\> bleeding into the lungs (death rate \>50%)

Question 42

Diagnosis/Ix of *Leptospirosis*

Answer 42

Early diagnosis - test blood and urine: - blood and CSF -\> infection can be found within first 10 days - after 10 days -\> infection moves to kidney -\> can be found in fresh urine - U&Es and LFTs, creatinine and nitrogen - enzyme- linked immunosorbent assay (ELISA) and PCR -\> confirm diagnosis - MAT (microscopic agglutination test) -\> gold standard in diagnosis of leptospirosis

Question 43

Occupations at risk of Leptospirosis

Answer 43

_Occupations at risk_: vets, slaughterhouse workers, farmers, sailors, waste disposal workers _Adventure tourism_: kayakers, rowers, canoeists

Question 44

Treatment of Leptospirosis

Answer 44

A. Usually effective antibiotics - *Penicillin G, ampicillin, amoxicillin, deoxycline* B. More severe cases: cefotaxime or ceftriaxone C. Glucose and salt infusions D. Dialysis - if kidney affected severly E. Measure potassium (as elevation is common)

Question 45

Cause of *Schistosomiasis*

Answer 45

*Schistosomiasis* aka ‘snail fever’ * disease caused by parasitc flatworms (schistosomes) * Parasites infect fresh water snails

Question 46

***Schistosomiasis*** - site of infection - long- term complications

Answer 46

* Sites of infection: urinary tract or intestine * long time infection may result in: liver damage, kidney failure, bladder cancer, infertility

Question 47

Risk groups of schistosomiasis

Answer 47

* Disease is particularly common among children in developing countries -\> as they play a lot in fresh water (water is contaminated with shistosomes) * farmers, fishermen, people using unclean water

Question 48

Symptoms of ***schistosomiasis***

Answer 48

**Symptoms**: abdominal pain, diarrhoea, bloody stool, blood in the urine **Children**: poor growth and learning difficulties

Question 49

Dx / Ix of schistosomiasis

Answer 49

- finding eggs of the parasite in a person’s urine or stool - finding antibodies against the disease in the blood

Question 50

Prevention of Schistosomiasis

Answer 50

- improving access to clean water - reduction of water snail population - meds ***Praziquantel*** (drug against some parasites) given once yearly to the populations at risk

Question 51

Treatment of *Schistosomiasis*

Answer 51

All cases of schistosomiasis should be treated regardless of presentation -\> as parasite can live in host for years Preferably use ***Praziquantel*** (drug against some parasites) and combination of other drugs (mostly these used to treat malaria as anti-parasitic activity)

Question 52

**Exotoxin** mechanism of diarrhoea + bacteria causing it

Answer 52

* ***exotoxins*** -\> effect on the stomach, small bowel -\> mucosal inflammation symptoms of food poisoning (*Bacillus Cereus* and *Staphylococus Aureus*)

Question 53

***Enterotoxin*** mechanism of diarrhoea + bacteria causing it

Answer 53

**enterotoxins** -\> watery diarrhoea without fever *(E. Coli*) - usually no blood or mucous

Question 54

***Enteroinvasive*** mechanism of diarrhoea + bacteria causing it

Answer 54

***enteroinvasive*** -\> invade intestinal mucosa (*Enteroinvasive E. Coli, Shigella and Campylobacter*) -\> fewer, lower abdominal pain, bleeding diarrhoea + fever (dysentery)

Question 55

Possible complications of diarrhoea

Answer 55

electrolyte imbalances, renal impairment, dehydration, defective immune responses, inefficiency of administrated drug -\> as medication travels too quickly through digestive tract

Question 56

Medical management of diarrhoea

Answer 56

* Oral rehydration therapy -\> slightly sweetened and salty water -\> used to prevent dehydration; it can be given via NG tube; usually include zinc supplementation * Medication: antibiotics used only in certain cases of diarrhoea (bacterial) - \> beneficial in resource poor countries; antibiotics may contribute to diarrhoea **Other medications** (used only if the bloody diarrhoea is not present): * ***Bismuth compounds*** (Pepto-Bismol) -\> decreases number of bowel movements in traveler’s diarrhoea but do not decrease length of illness * ***Loperamide*** -\> anti motility agent -\> to reduce number of stools but again, not the illness duration * **Bile acid sequestrants** (bile reabsorption prevented from the gut) -\> for those with chronic diarrhoea due to bile acid malabsorption * **Zinc supplementation** -\> beneficial for children over 6 months old * **Probiotics** -\> reduce duration of symptoms by one day + reduce chance of symptoms lasting longer than 4 days (by 60%)

Question 57

Diet recommendation in diarrhoea

Answer 57

* Fluid and food: Replacing lost fluids (usually by oral rehydration therapy), in severe cases IV * diet restrictions are not recommended (even for babies and children; including those breast fed) -\> as nutrient is usually still absorbed and support children with growth and also eating as usual has an effect on speed up of recovery as support normal intestinal functioning; limitation of food has no effect on duration of diarrhoea

Question 58

**Antibiotic-associated diarrhoea** - common bacteria - severe form (names ) - age groups at risk - when develops

Answer 58

* bacterial overgrowth with ***C. Difficile*** * severe -\> can lead to ***acute colitis/ pseudomembranous colitis*** * common in young and elderly * diarrhoea develops 2 days - 4 weeks after taking antibiotics

Question 59

Risk factors for C Diff infection

Answer 59

_Risk factors:_ Prolonged hospital stay, multiple or prolonged antibiotic therapy, GI surgery, proton pump inhibitor use

Question 60

Ix and what can be seen in ***C Diff***

Answer 60

* detection of C.Diff toxins (in stool by enzyme-linked immunosorbent assay ELISA) * stool culture -\> C diff isolation (in 30%) * sigmoidoscopy -\> ulceration and a white pseudomembrane

Question 61

Management of C Diff infection

Answer 61

- antibiotics should be stopped - to treat dehydration (oral, IV fluids) - infection control measures) -\> barrier nursing and hand washing - antibiotics against C.Diff (***metronizadole*** or oral vancomycin) should be started following a diagnosis - more severe in the elderly -\> colectomy may be required for toxic megacolon