Fever of traveler return from tropical area (2)

Author

Dr Poon Kin Ming

Oct 2013

HKCEM College Tutorial

What is tropical region?

Patient with fever after return from tropical region

What are your differential diagnoses ?

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

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

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

What would you ask in the history ?

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 ?

Situation 1

▪ Fever + Maculopapular skin rash over the body

▪ What would you think of ?

▪ Dengue, Rickettsial infection, Leptospirosis and HIV seroconversion

IF YOU SEE ROSE SPOT IN PATIENT’S BODY,

WHAT DO YOU THINK OF ?

▪ If you see Rose spot in patient’s body, what do you think of ?

▪Typhoid fever !

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 ?

Situation 2

▪ Fever + lymphadenopathy ?

▪ Dengue fever, Rickettsial infection, Rubella infection, & HIV seroconversion

- Not a feature of malaria & typhoid fever !

Situation 3

▪Fever + splenomegaly + hepatomegaly ?

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 + haemorrhage ?

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

Some important tropical diseases

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

Anopheles 瘧蚊

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

Aedes Aegypti 埃及伊蚊

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

Ankle bends and skin rash

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

Red spots in typhoid fever

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

Eschar

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

Leptospirosis electron micrograph

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.

Thank You