1. Fever of traveler return from tropical area (2) Author Dr Poon Kin Ming Oct 2013 HKCEM College Tutorial

2. What is tropical region?

3. Patient with fever after return from tropical region What are your differential diagnoses ?

4. Diagnosis ▪ Infectious diseases esp. tropical illness ▪ Autoimmune diseases ▪ Malignancy

5. Infectious diseases that should not be missed Protozoal Malaria 瘧疾 Virus Dengue fever 登革熱 Chikungunya fever 基孔肯雅熱 Yellow fever 黃熱病 Rickettsial diseases 立克次氏體病 Bacterial Typhoid & Paratyphoid 傷寒及副傷寒 Leptospirosis 鈎端螺旋體病 Brucellosis 布魯氏桿菌病 Relapsing fever 回歸熱

6. How are you going to approach to a patient with fever after travelling back from tropical region?

7. Approach to patients with fever after return from tropical area ▪ If patient’s condition not stable, proceed to resuscitation ▪ If stable, proceed to history, physical examination, investigation & treatment

8. What would you ask in the history ?

9. History ▪ Approach to fever : TOCC What does it stand for ? -Continent visited -Chemoprophylaxis or vaccination -Mosquito bite / insect bite -Onset of fever : Incubation period -Fever pattern

10. Continent visited DestinationCommonOccasional Sub Saharan AfricaMalaria, Rickettsial dis. Dengue, Enteric fever, brucellosis South East AsiaMalaria,Dengue, Enteric fever Leptospirosis, Chikungunya South & central AsiaMalaria,Dengue, Enteric fever Chikungunya Latin American & Caribbean Malaria,Dengue, Enteric fever Leptospirosis, Histoplasmosis

11. Incubation periods Short (<10days) Acute gastroenteritis, Respiratory tract infection, Dengue, Chikungunya, Relapsing fever, Rickettsial infection Medium (10-21days) Malaria, Enteric fever, Brucellosis, Leptospirosis, Q fever, viral hemorrhagic fever Long (> 3 weeks) Malaria, Brucellosis, Schistosomiasis, Tuberculosis, amoebic liver abscess

12. Fever pattern PatternDescriptionDiseases Continuous Constant fever with variation <1 °C Typhoid fever, Rickettsial infection, encephalitis Intermittent Temperature returns to normal at least once during the day Malaria, Dengue fever, Leptospirosis, many viral illness, abscess Remittent Fever does not return to normal each day Typhoid fever, Tuberculosis, endocarditis Relapsing Recurrent over days & weeks Relapsing fever, brucellosis, malaria, lymphoma

13. Physical exam ▪ General appearance & vital signs ▪ Jaundice & skin rash ▪ Lung & heart signs e.g. crepitation & murmur ▪ Neurological sign e.g. meningism ▪ Lymphadenopathy, hepatomegaly or splenomegaly ▪ Joint or calf tenderness

14. Physical signs Maculopapular rash Dengue, rickettsial infection, leptospirosis (Rose spot in typhoid fever, Splinter hemorrhage in infective endocarditis, Eschar in scrub typhus) Lymphadenopathy Dengue fever, rickettsial infection, rubella infection Splenomegaly Malaria, dengue fever, typhoid fever, rickettsial infection, relapsing fever, brucellosis Hepatomegaly Viral hepatitis, malaria, typhoid fever, leptospirosis Haemorrhage Dengue fever, dengue hemorrhagic fever, meningococcal septicaemia

15. Investigation ▪ CBC with D/C - PMN leucocytosis: bacterial e.g. leptospirosis, relapsing fever, abscess - Neutropenia : Arbovirus infection (include dengue), malaria, typhoid, brucellosis, AIDS - Lymphocytosis: viral infection - Atypical lymphocyte: infectious mononucleosis - Thrombocytopenia : malaria, viral infection (including rickettsial infection) - thin & thick blood smear for malaria ▪ L/RFT ▪ Urine multistix & CXR

16. Investigation ▪ Specific tests: ▪ Immunodiagnosis including serology test and antigen detection like ELISA, RIA & immunofluorescene test. ▪ Helpful in diagnosing hepatitis, dengue fever, rickettsial infection, yellow fever, brucellosis.

17. Situation 1 ▪ Fever + Maculopapular skin rash over the body ▪ What would you think of ?

18. Situation 1 ▪ Fever + Maculopapular skin rash over the body ▪ What would you think of ? ▪ Dengue, Rickettsial infection, Leptospirosis and HIV seroconversion

19. IF YOU SEE ROSE SPOT IN PATIENT’S BODY, WHAT DO YOU THINK OF ?

20. ▪ If you see Rose spot in patient’s body, what do you think of ? ▪ Typhoid fever !

21. Have you heard of ? ▪ Very Sick People Must Take No Exercise - Temporal relationship between the onset of fever and skin rash ( from D1 to D7)

22. Have you heard of ? ▪ Very Sick People Must Take No Exercise -V – Varicella (chickenpox) (Day 1) -S – Scarlet fever -P – Smallpox -M – Measles (Day 4) -T – Typhus -N – Non specific -E – Enteric fever (Day 7)

23. Situation 2 ▪ Fever + lymphadenopathy ?

24. Situation 2 ▪ Fever + lymphadenopathy ? ▪ Dengue fever, Rickettsial infection, Rubella infection, & HIV seroconversion - Not a feature of malaria & typhoid fever !

25. Situation 3 ▪ Fever + splenomegaly + hepatomegaly ?

26. Situation 3 ▪ Fever + splenomegaly + hepatomegaly ? ▪ Malaria, typhoid fever If fever + splenomegaly, think of dengue fever, Riskettsial infection, relapsing fever & Brucellosis If Fever + hepatomegaly, think of viral hepatitis & leptospirosis

27. Situation 4 ▪ Fever + haemorrhage ?

28. Situation 4 ▪ Fever + hemorrhage ? ▪ Dengue fever, Dengue Hemorrhagic fever, yellow fever, other viral hemorrhagic fever, meningococcal septicemia

29. Physical signs (summary) Maculopapular rash Dengue, rickettsial infection, leptospirosis (Rose spot in typhoid fever, Splinter hemorrhage in infective endocarditis, Eschar in scrub typhus) Lymphadenopathy Dengue fever, rickettsial infection, rubella infection Splenomegaly Malaria, dengue fever, typhoid fever, rickettsial infection, relapsing fever, brucellosis Hepatomegaly Viral hepatitis, malaria, typhoid fever, leptospirosis Haemorrhage Dengue fever, dengue hemorrhagic fever, meningococcal septicaemia

30. Some important tropical diseases

31. Malaria 瘧疾 ▪ Protozoal parasite ▪ 4 species : - Plasmodium falciparum (most lethal) - P. vivax - P. ovale - P. malariae - Vector : Mosquitoes Anopheles, which bite mainly between sunset and sunrise

32. Anopheles 瘧蚊

33. Blood smear from a patient with malaria; microscopic examination shows Plasmodium falciparum parasites (arrows) infecting some of the patient's red blood cells.

34. Management - Rapid fluid replacement for dehydrated patients - Parenteral infusion of quinine or artesunate. -(Chloroquine is longer recommended due to its widespread resistance) Prevention : Protection from vectors -Insect repellents, mosquito coils, protective clothes Chemoprophylaxis : - Weekly chloroquine/mefloquine at least 1 week before departure and continued for 4 weeks after the last possible exposure to infection

35. Dengue fever 登革熱 ▪ Caused by Dengue virus, transmitted by the mosquito Aedes aegypti ▪ Dengue hemorrhagic fever (DHF) : Dengue fever + Hemorrhagic tendency + Plasma leakage -Dengue shock syndrome : (DSS) DHF + shock + rapid pulse with narrow pulse pressure < 20mmHg

36. Aedes Aegypti 埃及伊蚊

37. Treatment ▪ Supportive ▪ Correct hypovolaemia in patietns with DHF & DSS, which lasts or 24 - 48 hrs ▪ Monitor BP, haematocrit, platelet count, R/LFT, signs of bleeding ▪ Blood product transfusion maybe required

38. Chikungunya fever 屈公病 ▪ Caused by Chikungunya virus, transmitted by Aedes mosquitoes ▪ African language : that blends up ▪ An acute febrile mosquito borne illness characterized by prolonged arthralgia (over wrist, ankle & knee) and rash ▪ Symptomatic tx ▪ No vaccine available

39. Ankle bends and skin rash

40. Yellow fever 黃熱病 A mosquito (Aedes) -borne viral illness characterized by acute onset of brief & recurrence of fever, hepatitis, jaundice, albuminuria, renal failure, shock & generalized hemorrhage

41. Typhoid & paratyphoid 傷寒及副傷寒 ▪ Bacterial infection: Salmonella Typhi or Paratyphi ▪ An illness characterized by fever, headache, bradycardia, splenomegaly, rose spots on the trunk +/ - GI symptoms ▪ Treatment: rehydration + antibiotics of fluoroquinolone such as ciprofloxacin

42. Red spots in typhoid fever

43. Rickettsial Disease 立克次氏體病 ▪ An arthropod-borne viral infection characterized by fever, chills, muscle pain and body rash. ▪ Scrub typhus 叢林 / 鼠蝨斑疹傷寒 : a large punch out skin ulcer at the site of bite of an infected mite. ▪ Spotted fever 斑疹熱 : an eschar 焦痂 at the site of the arthropod bite, with nearby painful & swollen lymph node ▪ Q fever : endemic in area with sheep, cattle and goat industry 人畜共染

44. Eschar

45. Leptospirosis 鈎端螺旋體病 ▪ An acute febrile bacterial infection with Leptospira after exposure to environmental water contaminated by urine of domestic or wild animals. ▪ Characterized with headache, myalgia, meningeal irritation, abdominal pain, nausea, oliguria, skin rash ▪ Effective antibiotics include cefotaxime, doxycycline, penicillin, ampicillin, and amoxicillin

46. Leptospirosis electron micrograph

47. Relapsing fever 回歸熱 ▪ An arthropod – borne bacterial infection (Borrelia) with alternating febrile period & petechial rashes. ▪ Fever lasting for 2-9 days alternate with afebrile periods of 2-4 days ▪ Tetracycline-class antibiotics are most effective

48. Brucellosis 布魯氏桿菌病 ▪ is a highly contagious disease caused by ingestion of unsterilized milk or meat from infected animals or close contact with their secretions ▪ Antibiotics like tetracyclines, rifampicin, and the aminoglycosides are effective

49. In summary ▪ Detail history and physical examination ▪ Exclusion of life threatening infection or diseases with public health risk (e.g. measles, rubella) is the priority ▪ Don’t miss those life threatening infections include Falciparum malaria, dengue haemorrhagic fever/ dengue shock syndrome, leptospirosis, infective endocarditis and meningoccocaemia.

50. Thank You