fever of traveler return from tropical area (2) author dr poon kin ming oct 2013 hkcem college...
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Fever of traveler return from tropical area (2)
Author
Dr Poon Kin Ming
Oct 2013
HKCEM College Tutorial
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
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
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
Continent visited
Destination Common Occasional
Sub Saharan Africa Malaria, Rickettsial dis.
Dengue, Enteric fever,
brucellosis
South East Asia Malaria,Dengue,
Enteric fever
Leptospirosis,
Chikungunya
South & central Asia Malaria,Dengue,
Enteric fever
Chikungunya
Latin American & Caribbean
Malaria,Dengue,
Enteric fever
Leptospirosis, Histoplasmosis
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
Fever pattern
Pattern Description Diseases
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
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
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
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
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.
Situation 1
▪ Fever + Maculopapular skin rash over the body
▪ What would you think of ?
▪ Dengue, Rickettsial infection, Leptospirosis and HIV seroconversion
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)
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)
Situation 2
▪ Fever + lymphadenopathy ?
▪ Dengue fever, Rickettsial infection, Rubella infection, & HIV seroconversion
- Not a feature of malaria & typhoid fever !
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
Situation 4
▪Fever + hemorrhage ?
▪Dengue fever, Dengue Hemorrhagic fever, yellow fever, other viral hemorrhagic fever, meningococcal septicemia
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
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
Blood smear from a patient with malaria; microscopic examination shows Plasmodium falciparum parasites (arrows) infecting some of the patient's
red blood cells.
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
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
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
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
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
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
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
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
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
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
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.
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