fever of traveler return from tropical area (1) author dr. poon kin ming oct, 2013 hkcem college...
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Fever of traveler return from tropical area (1)
Author
Dr. Poon Kin Ming
Oct, 2013
HKCEM College Tutorial
A case
▪ 50/M, smoker, GPH ▪ C/O fever for 5 days ▪ Also has sore throat,
cough, myalgia, poor appetite, chills, headache
▪ SOB, chest pain –ve ▪ Seen GP once and just
partial improvement ▪ Recalled travel history to
Thailand 10 days ago for a trip
▪ Vitals stable
▪What would you like to ask more in the history ?
History
▪ TOCC
What does it stand for ?
- Others symptoms ?
- Chemoprophylaxis or vaccination before the trip
- Mosquito bite / insect bite /animal contact
- Onset of fever : Incubation period
- Fever pattern
On further history
▪Travel : Thailand for 4 days, noted fever 2 days after back to HK
▪Occupation : teacher
▪Contact / cluster –ve
▪No chemoprophylaxis or vaccination before the trip
▪Mosquito bite +
Physical exam:
▪ Alert, responsive ▪ Temp 38.1C, Jaundice
& pallor –ve ▪ BP118/55mmHg, Pulse
88/min ▪ RR 16/min , SpO2 98%
on RA ▪ Chest clear & no heart
murmur ▪ Pharynx congested +
▪ A 1cm lymph node over L side of the neck
▪ Maculopapular skin rash over the body, petechiae –ve
▪ Neck stiffness –ve
▪ Liver & spleen not palpable
▪ Multiple joints pain but calf soft
Measles-like skin rash
▪ The rash consists of macular lesions that are red and usually 2–10 mm in diameter but may be confluent in places
▪ Morbilliform refers to a rash that looks like measles
http://upload.wikimedia.org/wikipedia/commons/9/91/Denguerash.JPG
Patient with fever after return from tropical region
▪What is your differential diagnosis in general ?
Diagnosis
▪Infectious diseases esp. tropical illness
▪Autoimmune diseases▪Malignancy
Infectious diseases that should not be missed
Protozoal Malaria瘧疾
Virus Dengue fever登革熱Rickettsial diseases 立克次氏體病Chikungunya fever 基孔肯雅熱Yellow fever 黃熱病
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
What is tropical region?
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 °CTyphoid 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 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
Clinical diagnosis
▪ Dengue fever,
▪ Infectious mononucleosis,
▪ Influenza,
▪ Rickettial infection,
▪ Malaria,
▪ Typhoid fever
▪ Other non-infectious causes e.g. malignancy, auto-immune
Patient’s progress – fever pattern
Investigation
▪ WCC : 3.9 (N : 4.5 -11x 10 9 /L)
Differential count : neutropenia & lymphopenia
▪ HGB :14.9 (N : 14 – 17.5 x 10 9/ L )
▪ Platelet : 100 (N: 150 – 450 x 10 9/ L)
▪ INR normal
▪ APTT prolonged to 42.1 sec
▪ R/LFT normal
▪ Malaria parasite –ve
Progress – lab. result
Day 1 2 4 8
WCC 3.9 2.5 1.9 4.2
HGB 14.9 15.1 16.8 13.8
Platelet 100 78 49 128
Haematocrit
43% 46% 49% 41%
APTT 28 33 42.1 26
ALT 20 134 305 42
BP 115/50 108/52 95/45 128/62
Day 1 Admission to Medical
D 2 Remained fever. Clotting profile & LFT impaired.
Influenza –ve
D 3 Monospot test –ve
Doxycycline was added to cover rickettial infection
D 4 Fever down. Appetite improved
Blood culture – ve
D 5 Dept of Health : PCR +ve for Dengue fever serotype 1. Doxcycline stopped
D 8 WCC, ALT & platelet returned to normal
D 9 Discharge
Dengue fever 登革熱
▪ A viral disease transmitted by the infected mosquito, Aedes aegypti ( 埃及伊蚊 )
▪ In HK, most abundant species is Aedes albopictus ( 白紋伊蚊 )
▪ 4 dengue virus serotypes
▪ Most common serotype in HK is type 1
▪ A statutory notifiable diseases in HK
▪ About 3-17 cases per year
Aedes Aegypti 埃及伊蚊
www.giron.co.cu/es/noticia/social/lucha-contra-el-aedes-aegypti-alertas-en-todo-momento
Dengue fever
▪ Incubation period of dengue infection is 4 to 7 days
▪ Fever usually lasts for 5 to 7 days
▪ Another name : break bone fever
▪ Clinical presentation ranges from non- specific febrile illness to severe life threatening conditions such as dengue hemorrhagic fever (DHF) & dengue shock syndrome (DSS)
http://www.niaid.nih.gov/SiteCollectionImages/topics/denguefever/michaelRossmannStory.JPG
Dengue Hemorrhagic fever
Dengue fever 登革熱
▪ Dengue hemorrhagic fever (DHF) :
Dengue fever + Hemorrhagic tendency + Plasma leakage (>20%)
- Dengue shock syndrome : (DSS)
DHF + shock + rapid pulse with narrow pulse pressure < 20mmHg
Pathophysiology of DHF & DSS
▪ Rarely occurs in primary infection as host develops life long immunity only against specific serotype
▪ In secondary infection with another serotype, the a/b at primary infection cross reacts & forms complexes with viral antigen, which enhances the phagocytosis by mononuclear cells.
▪ The virus replicates inside the cells, which release the vasoactive immune mediators causing DHF & DSS
http://mednews.com/wp-content/uploads/dengue-virus-296x300.jpg
Treatment
▪Mainly supportive
▪Steroid & antiviral agents not effective
▪Paracetamol as antipyretic agent
▪Avoid aspirin as worry of Rye’s syndrome
▪No vaccine available
▪Vector (mosquito) control
Summary
▪ Tropical infection, especially the Dengue fever, Malaria, Rickettsial diseases & Typhoid & Paratyphoid
▪ Protection against the vector (mosquito)
▪ Chemoprophylaxis against malaria before the trip
Summary
▪ Exclusion of life threatening infection or diseases with public health risk (e.g. measles, rubella) is the priority
▪ Life threatening infections include Falciparum malaria, dengue haemorrhagic fever/ dengue shock syndrome, leptospirosis, infective endocarditis and meningoccocaemia.
ANY QUESTIONS ?