DIARRHOEA IN RETURNING TRAVELLERS

            One third of travellers on average get Travellers diarrhea. Approximately 3% will last more than 14 days and 1-2% will last greater than one month. This percentage is higher in travellers from Haiti, central and west Africa and Nepal. Persistent diarrhea was the second commonest cause of health impairment post travel that lead to inability to work (1)

            In the history important points are:

1.      Geographical region of travel e.g. Cyclospora in Nepal in the spring and summer.

2.      Immunocompromised or not  e.g. Cryptosporidium worse

3.      Medications already taken by the traveler for the diarrhea

4.      The characteristics of the diarrhea

                                                Bacterial                   Parasitic

Timing                          early                             late

Onset                           abrupt                          gradual

Duration                       short                             long

5.      Symptom Complex

E.g. for parasitic diarrhea:

Symptom          Giardia             E Histolytica           Cyclospora Crptosporidium

Onset               Gradual            Gradual                1/3 abrupt              Watery

Stool type        2-5 semi-          Alternating           Watery     

                         Formed/day      diarrhea/            

                                                  Formed 1-2d

Gas/bloating   Moderate            None                    Severe                   Moderate

Fatigue            Mild                   Moderate              Severe                   Mild

Anorexia         None                  Mild                      Severe                   Mild

Ref(2)

Diarrhea in returning travellers divides into three major groups

1. Undiagnosed infection
2. Malabsorption
3. Previously undiagnosed Gastrointestinal disease

Potential causes:

            Bacterial                                               Parasitic                                   Non infectious

            E coli ( ETEC/ EPEC)                          Giardia                                     Tropical sprue

            Campylobacteur                                   Entamoeba histolytica               Lactose intolerance species       Shigella                                     Cyclospora                               Post infectious

            Aeromonas                                           Dientamoeba fragilis                  irritable bowel

            C. dificile ( if prior antibiotic use)           Capillaria phillipensis                 Inflammatory

            Isospora belli                                        Fasciolopsis buski                     bowel disease

            Plesiomonas                                         Sarcocystis                               Small bowel

                                                                                                                        bacterial

                                                                                                                        overgrowth

                                                                                                                        Brainerd diarrhea

Investigation:

1. Stool smear ( using methylene blue )

Pus cells positive                       negative

Shigella                         E coli ETEC

Salmonella                                Vibrio cholers

E histolytica                              Giardia

Campylobacteur                       Cryptosporidium

2. Stool culture x1
3. Stool O and P x1   ---- A study showed that one sample picked up 90% cases (3)       

                                                If  first sample negative and still symptomatic repeat O and P x2

4. CBC for eosinophillia
5. Serology for amebiasis, strongyloides, schistosomiasis etc         

 Management Algorithm:

                                    Stool O and P,  Stool Culture ( if suspect Cyclospora/ Cryptosporidium  ask for supplemental testing)

If Positive:  Treat organism identified                 If Negative

For parasites:                                    

            Intestinal worms -Rx

            Intestinal protozoans – Rx if pathogenic          Antibacterial therapy x5 days ----  Cure

and symptoms

EXCEPT  filaform larva Strongyloides                     No Cure

                 Trohozoites E. histolytica                                                                

                                                                                    Antigiardial therapy x10 days --------  Cure

                                                                                                No cure

                                                                                    Gastrointestinal referral:

Endoscopy ---  Small bowel biopsy to r/o             

                                                                                                              Tropical Sprue

                                                                                    Colonoscopy – r/o inflammatory  disease

Notes.

1. Antibacterial Rx-    Ciprofloxacin 500mg bid

                                    Norfloxacin     400mg bid

                                    Orofloxacin     300mg bid etc

2. Antigiardial Rx -     Metronidazole 250mg qid

                                    Furazolidine  1.5gm stat (in USA )

3. E histolytica            Asymptomatic cyst passer probably has E dispar and does not need Rx

                                    Non-dysenteric illness/ amoebic dysentery

 Rx metronidazole 750mg tid x 10days then

Luminal amebicide e.g. paromomycin500mg tid x 10 days

                                    Or tindazole 2 gms od x 3 days

6. HIV positive: Consider Cryptosporidium ----  Rx Paromomycin 500mg qid x 14 days

   Isopera belli        ----  Rx Cotrimazole DS 1 qid x 10 days

7. Brainerd diarrhea --- watery diarrhea up to 36 months with no response to antibiotics

References:

Dupont HL, CapustoEG

Persistent diarrhea in travellers

 Clin Infect Dis 22: 124 1996

Steffen R et al

Health problems after travel to developing countries

J Infect Dis 156:84 1987

Taylor DN et al

Chronic diarrhea in the returned traveler

Med Clin N Am 83:1033 1999

Jong E, McMullen R eds

The Travel and Tropical Medicine Manual                                                                          

Saunders 2003

Chapter 25 Approach to Diarrhea in the Returned Traveler