Treatment of traveller's diarrhoea

Despite preventive measures, traveller's diarrhoea is very common. Therefore, travellers should always be prepared to manage its symptoms.

Rehydration 

Replacement of fluid losses is the primary and most important part of treating traveller's diarrhoea. This is especially important for young children, elderly travellers and adults with chronic medical conditions who are are at higher risk for dehydration. In mild cases, rehydration can be maintained with any preferred liquid (including sports drinks), although overly sweet drinks (e.g., soda) can cause osmotic diarrhoea if consumed in large quantities.

Oral rehydration solution (ORS)

For severe fluid loss, oral rehydration solution (ORS) is the best replacement. ORS is widely available in most low- and middle-income countries and is prepared by adding 1 package to the indicated volume of boiled or treated water. For children, only commercial packages should be used since the risk of dosing errors in self-made formulations.

ORS can also be made by adding salt and sugar to water in the following quantity:

• 5 level teaspoons (25ml) of sugar
• ½ teaspoon (2.5ml) of salt
• Add to one liter of clean water

In the absence of vomiting it’s advised to continue a normal diet with smaller portions more frequently. Breastfed infants should continue to nurse on demand, and bottle- fed infants should continue to drink formula.

For travellers taking certain drugs, such as diuretics or metformin, it is advised to temporary interrupt or reduce the dose of the medication, preferably in consultation with a doctor.

Antidiarrheal agents

Loperamide (Imodium®)

It can reduce the frequency of bowel movements. Travellers should take one capsule or instant tablet of loperamide 2mg after each loose bowel movement, up to a maximum of four times a day (this is more restrictive than the package leaflet). To avoid constipation, loperamide should not be taken for more than three days in a row, and should be discontinued as soon as stools become more solid.
Loperamide alone is not recommended for patients with bloody diarrhoea or those who have diarrhoea and fever. It should not be used in children younger than 6 years of age and pregnant or breastfeeding women. The safety of loperamide when used alongside antibiotics has been well established, even in cases of invasive pathogens, however the acquisition of multidrug resistant microorganisms might be more common with coadministration.

Racecadotril (Tiorfix®)

It is a secretion inhibitor that can prevent fluid and electrolyte depletion from the bowel due to acute diarrhoea without affecting intestinal motility. It appears to be safe and well tolerated, but findings related to its benefit are inconsistent. There is some evidence that racecadotril is more effective than placebo or no intervention in reducing the duration of illness and stool output in children with acute diarrhoea, however, the overall quality of the evidence is limited due to sparse data, heterogenicity and risk of bias. Therefore ORS remains the corner stone in the treatment of diarrhoea in children.
Racecadortril is licensed from the age of 3 months or older. Adult dosing is 100mg three times a day, and dosing in children more than 3 months is 1.5mg/kg three times a day.

Stand- by antibiotics

Antibiotics are generally not required for treating traveller's diarrhoea and therefor prescribing stand-by antibiotics is not routinely recommended for all travellers.
‘Ordinary’ watery traveller's diarrhoea is generally self-limited and the effect of antibiotics is frequently overvalued by health care workers. There are no studies that prove that antibiotics are clinically superior to loperamide alone in treatment of mild or moderate traveller's diarrhoea. Advice on antibiotic use is mostly based on the reduction of duration of symptoms with one to two days and a potential theoretical reduction of postinfectious inflammatory bowel syndrome (IBS). Compliance with, even written, advice on the use of on demand antibiotics for traveller's diarrhoea is relatively poor and reduction of health care visits abroad with on demand antibiotics is not shown. In children, the main risk for hospitalisation is dehydration.
A study in a Finish cohort and the Dutch COMBAT study show that travellers who have taken antibiotics during their travel are more likely to be colonized with multi-resistant bacteria upon their return and are able to transmit these bacteria within their households suggesting that use of antibiotics by international travellers plays a role in the global spread of antimicrobial resistance. The cost and potential adverse effects largely outweigh the modest benefits of antibiotic treatment for a self-limited condition. 

Prescribing stand-by antibiotics

While it was previously thought that stand-by antibiotics should be prescribed for certain travellers (very young children, remote locations, high risk countries,…) indications nowadays have become stricter due to the lack of benefit and the increased risk of antimicrobial resistance. Certain case reports show that complications of traveller's diarrhoea (e.g., bacteraemia, metastatic infections) are more common in immunocompromised patients but whether antibiotics prevent these complications is not known.  

Indications for prescribing stand- by antibiotics:

• immunocompromised travellers:
  • post-transplant (organ- or stem cell)
  • HIV with CD4< 200/µl
  • severe immune modulating therapy
• travellers at higher risk of deterioration due to severe diarrhoea:
  • severe/insulin dependent diabetes mellitus
  • severe chronic kidney disease
  • severe heart failure
  • patients on medications with small therapeutic window,…
• it should not be prescribed for:
  • healthy travellers, regardless of the travellers destination
  • travellers only on proton pump inhibitors
  • inflammatory bowel disease (IBD) only using mesalazine (Pentasa®)
  • diabetes mellitus only on oral therapy

Preferred stand-by antibiotics

In prescribed, azithromycin is the preferred therapy:

• adults: azithromycin 1000mg single dose
• children: azithromycin 10mg/kg OD for three days

Increasing resistance to quinolones among diarrheal pathogens worldwide means fluoroquinolones are no longer indicated as stand-by antibiotics. 

Treatment with stand-by antibiotics

Travellers should be educated on when to take stand-by antibiotics. It can be challenging for even experienced travelers to make an informed decision about their health when symptoms arise in unfamiliar settings, so seeking medical assistance early is preferable.

Indications to start stand-by antibiotics:

• severe diarrhoea with fever: incapacitating diarrhoea or completely preventing planned activities accompanied with fever (>38.5°C)
• dysentery: passage of stools that contains gross blood admixed with stool and often accompanied by more severe constitutional symptoms including fever

Always advise to continue seeking medical assistance.