EOSINOPHILLIA IN THE RETURNED TRAVELLER

 

            Eosinophilia may be due to a variety of causes and these need to be considered as well.

  1. Parasitic disease
  2. Allergic states
  3. Collagen vascular disorders
  4. Malignancy

This review will only focus on the parasitic causes:

 

      Travellers may present in the following ways:

  1. Asymptomatic – found on post travel screening
  2. Symptomatic – due to either transient migration of human intestinal parasites or prolonged retention of parasites in extraintestinal sites. This includes both human and animal paraites

The reaction is the result of a Type 2 T cell mediated delayed type hypersensitivity that increases IgE.

 

Diagnosis.

      In diagnosis the absolute eosinophil count is the most reliable.

Key points in the history are:

  1. Geographic and travel history
  2. Immunocompromised  - Strongiloides needs to be considered.
  3. History of eating raw/ undercooked food – meat/fish
  4. Exposure to pets/livestock/wild animals/mosquitoes

 

Why investigate?

  1. Specific treatment may be available
  2. Potential of longterm morbitiy
  3. May be non infectious cause

 

Investigation

Stool O and P up to 3x

Serology

Biopsy

 

NEMATODES

 

 

 

 

Name

Eosinophilia

Diagnosis Stool

Diagnosis Serology

Extra GI

Transmission

Host

 

Drug Rx

 

 

Ascaris

N/E

Y

N

N

RFV

Human

A

Necator

N/E

Y

N

N

Soil

Human

A

Ancyclostoma

N/E

Y

N

N

Soil

Human

A

 

Strongyloides

N/E

Often N

Y

Y

Soil

Human

I

Enterobius

N/E

Often N

N

N

RFV

Human

A

 

Trichuris

N/E

Y

N

N

RFV

Human

A/M

 

Anisakis

50% E

N

Y

Y

Raw fish

Fish

---

Gnathostomiasis

E  UP TO 90%

Biopsy

Y

Y

FWF

Dogs cats etc

A

Filarial Worms

 

 

 

 

 

 

 

Brugia malayi

Y

Microfilaria

Y PCR

Y

Mosquito

Human

DEC

W. bancrofti

Y

Microfilaria

Y PCR

Y

Mosquito

Human

DEC

Onchocera v.

Y

Skin snip

Y PCR

Y

Black fly

Human

I

Strepocerciasis

?

Skin snip

N

Y

Midge

Human

DEC

Loiasis

E +++

Blood/biopsy

N

Y

Deer fly

Human

DEC

Perstans filariasis

E often

Blood Microfilaria

N

Y

Midge

Human

DEC

Mansonella ozzardi

E

Blood Microfilaria

N

Y

Midge/ black fly

Human

I

 

 

 

 

 

 

 

 

TREMATODES

 

 

 

 

 

 

 

Blood flukes

 

 

 

 

 

 

 

Schistosoma

Y initially

Stool/urine

Y

Y

Cercariae

Snail

P

 

 

 

 

 

 

 

 

Hepatobilary Flukes

 

 

 

 

 

 

 

Clonorchis

?

Stool

N

Y

Raw Fish

Fish

P

Opisthorchis

?

Stool

N

Y

Raw fish

Fish

P

Fasciola hepatica

?

Stool

Y

Y

RV

Sheep Cattle

B

 

 

 

 

 

 

 

 

Lung flukes

 

 

 

 

 

 

 

Paragonimias

Y

Sputum Stool

Y

Y

Crustaceans

Human Others

P

 

 

 

 

 

 

 

 

Intestinal Flukes

 

 

 

 

 

 

 

Metagonimus

?

Stool

N

N

FWF

Fish

P

Heterophyes

?

Stool

N

N

FWF

Fish

P

Fasciolopsis Buski

?

Stool

N

N

FWP

Animals

P

Echinostoma

?

Stool

N

N

Snails

 

P

 

 

 

 

 

 

 

 

CESTODES

 

 

 

 

 

 

 

T saginata

E chronic

Stool

N

N

RM

Beef

P

T solium

E chronic

Stool

N

Y

RM

Pork

P

Diphyllobothrium

E chronic

Stool

N

N

Raw fish

Fish

P

Hymenolepsis

E chronic

Stool

N

N

Rat/Mice feces

Rat Mice

P

Dipylidium caninum

E chronic

Stool

N

N

Infected Fleas

Dog

P

Echinococcal

Gen N

Biopsy Imaging

Y

Y

RM

Sheep dogs

P

Sparganosis

E

Biopsy

?

Y

Raw frogs birds

Dog cat

?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 
             

Notes  Tropical eosinophillic syndrome is due to occult filariasis

            Loefflers syndrome is due to migration of Ascaris, hookworm or strongiloides in lung

 

Key

Drugs A = Albendazole

            I = Ivernectin

            M = Mebendazole

            B =  Bithionol

            P =   Praziquantel

            DEC = Diethylcarbamazine

 

RM = Raw meat

RFV = Raw fruit and vegetables

RF = Raw fish

FWF = fresh water fish

FWP = fresh water plants

 

 

Reference:

Jong E , McMullen R eds

The Travel and Tropical Medicine Manual

Saunders 2003

Chapters 40-44