Infectious Diarrhea Treatment Guidelines PDF

# Causes of acute infectious diarrhoea Acute gastrointestinal infections often present with diarrhoea, but in some cases upper gastrointestinal symptoms such as nausea and vomiting are prominent. Acute diarrhoea is defined by an increase in the frequency of stools or decrease in stool form that la...

# Causes of acute infectious diarrhoea Acute gastrointestinal infections often present with diarrhoea, but in some cases upper gastrointestinal symptoms such as nausea and vomiting are prominent. Acute diarrhoea is defined by an increase in the frequency of stools or decrease in stool form that lasts less than 14 days. Most cases of acute infectious diarrhoea are viral, self-limiting and resolve without specific treatment. ## Clinical Clues that may help differentiate between viral, bacterial and toxin-mediated diarrhoea * **Viral:** history of contact with a person who has acute infectious diarrhoea, outbreak with secondary cases, or prominent upper gastrointestinal symptoms such as vomiting and nausea. Fever, tenesmus and bloody stool. * **Bacterial:** fever, tenesmus and bloody stool. Returned travellers and immunocompromised patients at greater risk. * **Toxin-mediated:** Vomiting, nausea and abdominal pain are usually prominent symptoms, diarrhoea if present, occurs later in the course of illness. Short incubation period. Closely clustered cases. ## Severity of acute infectious diarrhoea * **Mild:** the patient is able to undertake normal activities * **Moderate:** the patient is able to function but needs to modify normal activities * **Severe:** the patient is incapacitated and may require admission to hospital. ## Faecal testing in acute infectious diarrhea Faecal testing in patients with acute diarrhoea is only appropriate when the results will inform management. Faecal testing, including for Clostridioides difficile, is recommended in: * Patients presenting with bloody stools, moderate to severe disease, or with prolonged symptoms * Immunocompromised patients - in addition to faecal microbiological testing for routine pathogens, request tests for parasites and viral pathogens * Situations of public health importance (eg an outbreak, in residential aged-care facilities, food handlers) - perform testing as directed by the local public health authority ## Empirical Antibiotic Therapy of Acute Infectious Diarrhea **Rehydration and other supportive measures** The principal aim of treatment of acute diarrhoea is to achieve and maintain adequate hydration. All patients with diarrhoea should have their hydration status assessed so that appropriate rehydration can be given. In adults and children, oral rehydration is indicated unless there is evidence of severe dehydration, when intravenous therapy is necessary. **Empirical antibiotic therapy** * **Rehydration** is the mainstay of therapy for acute infectious diarrhoea * Empirical antibiotics are usually not indicated for community-acquired infectious diarrhoea. * In children with bloody diarrhoea without fever or sepsis, empirical antibiotic therapy is not recommended * Empirical antibiotic therapy is indicated or should be considered in some groups. ## Treatment for the first episode **In addition to antibiotic therapy, rehydration is important when treating *C. difficile* infection.** * Seek expert advice for all patients with severe disease. * Stop any implicated antibiotics unless there is a strong rationale for continuing them. * For the first episode of mild to moderate *C. difficile* disease: * **Metronidazole** 400 mg (child: 10 mg/kg up to 400 mg) orally or enterally, 8-hourly for 10 days * **Vancomycin** 125 mg (child: 10 mg/kg up to 125 mg) orally or enterally, 6-hourly for 10 days * **Metronidazole** can be given intravenously in patients who cannot tolerate the oral formulation * **There is evidence that vancomycin has similar efficacy to metronidazole in this setting; however, for antimicrobial stewardship reasons, it is not the preferred drug.** ## Treatment for first recurrence or refractory disease **Recurrence of *C. difficile* infection is common. Recurrent disease is defined as *C. difficile* infection occurring within 2 months of the previous episode, after resolution of symptoms. Refractory disease is defined as lack of clinical improvement following 3 to 4 days of recommended therapy.** * Seek expert advice for all patients with severe disease. * In adults and children with a first recurrence of *C. difficile* infection, or with refractory disease, use: * **Vancomycin** 125 mg (child: 10 mg/kg up to 125 mg) orally or enterally, 6-hourly for 10 days * **Fidaxomicin** 200 mg orally, 12-hourly for 10 days ## Treatment for second and subsequent recurrences or ongoing refractory disease * **Faecal microbiota transplantation (FMT) or 'stool transplant' is an effective therapy for *C. difficile* infection, and is the preferred treatment for adults with second and subsequent recurrences or ongoing refractory *C. difficile* disease.** * **In adults, faecal microbiota transplantation is the preferred treatment for second and subsequent recurrences of *C. difficile* infection or ongoing refractory disease. If faecal microbiota transplantation is not available, use:** * **Vancomycin** 125 mg orally or enterally, 6-hourly for 14 days * **Fidaxomicin** 200 mg orally, 12-hourly for 10 days * **In children with second and subsequent recurrences of *C. difficile* infection, or ongoing refractory disease, use:** * **Vancomycin** 10 mg/kg up to 125 mg orally or enterally, 6-hourly for 14 days * **Nitazoxanide** (child 1 to 3 years: 100 mg orally, 12-hourly for 10 days) * **Nitazoxanide** (child 4 to 11 years: 200 mg orally, 12-hourly for 10 days) * **Nitazoxanide** (child 12 years or older: 500 mg orally, 12-hourly for 10 days) ## Severe *Clostridioides difficile* infection * **Seek expert advice for all patients with severe disease.** * **For severe *Clostridioides difficile* infection, use:** * **Vancomycin** 125 mg (child: 10 mg/kg up to 125 mg) orally or enterally, 6-hourly for 10 days * **Intravenous vancomycin is not effective against *C. difficile* infection due to inadequate penetration of the drug into the lumen of the colon.** * **In complicated cases (eg hypotension or shock, ileus, megacolon), in addition to oral or enteral vancomycin, use:** * **Metronidazole** 500 mg (child: 12.5 mg/kg up to 500 mg) intravenously, 8-hourly for 10 days * **Consider adding intracolonic vancomycin, particularly in the presence of ileus. Use:** * **Vancomycin** 500 mg in 100 mL sodium chloride 0.9% rectally (via rectal tube), administered as a retention enema, 6-hourly ## Enterohaemorrhagic *Escherichia coli* enteritis Infection with Shiga toxin-producing strains of Escherichia coli (eg 0157:H7 or 0111:H8) may cause bloody diarrhoea and lead to the development of haemolytic uraemic syndrome (HUS) or thrombotic thrombocytopenic purpura, particularly in children. Antibiotic therapy should not be given to children with enterohaemorrhagic *E. coli* who do not have fever or sepsis, because antibiotics increase toxin release and therefore the risk of developing haemolytic uraemic syndrome. **Rehydration** is the mainstay of therapy. ## *Salmonella* enteritis In otherwise healthy patients without risk factors for complications, nontyphoidal *Salmonella* enteritis is usually self-limited. Antibiotic treatment is not indicated in these patients because it does not shorten duration of illness, is associated with a higher rate of adverse events, and can prolong excretion of pathogens. Antibiotic treatment of nontyphoidal *Salmonella* enteritis is not indicated for otherwise healthy patients without risk factors for complications. * **Neonates and children younger than 3 months.** Before administering antibiotics, collect blood samples for culture and, when relevant, cerebrospinal fluid samples for microscopy and culture, to exclude systemic infection. For antibiotic choice and dosing in neonates, seek expert advice. * **Patients of any age with severe diarrhoea** * **Patients with invasive disease, sepsis or bacteraemia** * **Patients with prosthetic vascular grafts or haemoglobinopathies** * **Immunocompromised patients.** * **Rehydration** is the mainstay of therapy. * If antibiotic therapy is indicated for *Salmonella* enteritis, use: * **Azithromycin** 1 g (child: 20 mg/kg up to 1 g) orally on the first day, then 500 mg (child: 10 mg/kg up to 500 mg) orally, daily for a further 4 days * **Ciprofloxacin** 500 mg (child: 12.5 mg/kg up to 500 mg) orally, 12-hourly for 5 days * **Amoxicillin** 1 g (child: 30 mg/kg up to 1 g) orally, 8-hourly for 5 days. * **Initial intravenous therapy is recommended in the following situations:** * When oral therapy is not possible * In children aged 1 to 3 months * In patients with bacteraemia, endovascular infection or osteoarticular infection. * **For initial intravenous therapy, use:** * **Ceftriaxone** 2 g (child 1 month or older: 100 mg/kg up to 2 g) intravenously, daily - for patients with septic shock or requiring intensive care support, use 1 g (child 1 month or older: 50 mg/kg up to 1 g) intravenously, 12-hourly * **Ciprofloxacin** 400 mg (child: 10 mg/kg up to 400 mg) intravenously, 12-hourly ## *Shigella enteritis (shigellosis)* * *Shigella* is easily transmitted person-to-person. * Send faecal samples for culture and susceptibility testing for cases of suspected *Shigella* enteritis. ## *Vibrio cholerae* (cholera) * Cholera is caused by *Vibrio cholerae* serotypes O1 and O139. It is rarely seen in Australia. * **Rehydration** is the mainstay of treatment. Antibiotic therapy reduces the volume and duration of diarrhoea. * **Consider:** * **Azithromycin** 1 g (child: 20 mg/kg up to 1 g) orally, as a single dose * **Ciprofloxacin** 1 g (child: 20 mg/kg up to 1 g) orally, as a single dose ## *Vibrio: noncholera* species causing enteritis * Enteritis caused by *Vibrio parahaemolyticus* and other noncholera vibrios occasionally occurs following ingestion of contaminated shellfish. * The disease is usually self-limiting. **Rehydration** is the mainstay of therapy. * In cases of severe or persistent disease, use: * **Doxycycline** orally, 12-hourly for 10 days (adult 100 mg, child 8 years or older and less than 26 kg: 50 mg, child 8 years or older and 26 to 35 kg: 75 mg, child 8 years or older and more than 35 kg: 100 mg). * **Ceftriaxone**, **ciprofloxacin**, **norfloxacin**, and **trimethoprim+sulfamethoxazole** have also been used successfully for treatment. ## *Yersinia enterocolitis* * *Yersinia enterocolitica causes a spectrum of disease that includes acute enterocolitis, and mesenteric adenitis or pharyngitis with or without diarrhoea. It is usually foodborne. Postinfectious complications include reactive arthritis and erythema nodosum. * **Rehydration** is the mainstay of therapy. A benefit for antimicrobial therapy in immunocompetent patients with Yersinia enterocolitis has not been demonstrated and, because most acute infections are self-limiting, antibiotics are not indicated. * In immunocompromised patients or patients with persistent or extraintestinal disease, use: * **Ciprofloxacin** 500 mg (child: 12.5 mg/kg up to 500 mg) orally, 12-hourly for 5 days * **Norfloxacin** 400 mg (child: 10 mg/kg up to 400 mg) orally, 12-hourly for 5 days * **Trimethoprim+sulfamethoxazole** 160+800 mg (child 1 month or older: 4+20 mg/kg up to 160+800 mg) orally, 12-hourly for 5 days ## Antibiotic-associated diarrhea In most cases of antibiotic-associated diarrhoea, a pathogen is not identified. Clostridioides difficile is the pathogen in a significant minority of cases. If possible, stop antibiotics considered likely to be causing the symptoms. Prophylactic probiotics are widely used to prevent antibiotic-associated diarrhoea, but a large randomised controlled trial did not demonstrate a benefit. In immunocompromised patients, occasional cases of probiotic-associated bacteraemia have occurred. ## Travellers' diarrhoea Diarrhoea is the most common illness acquired overseas, affecting 20 to 50% of people travelling short term from developed to developing areas. * **Prevention of travellers' diarrhoea** The risk of travellers' diarrhoea can be substantially reduced by taking simple precautions in areas where clean water and food hygiene cannot be guaranteed. * **Treatment of travellers' diarrhoea** * **Mild disease:** Travellers' diarrhoea is usually self-limiting; mild cases require symptomatic treatment only. Rehydration is the mainstay of therapy; antidiarrhoeal drugs can be considered but should not be used in children. * **Moderate to severe disease:** Rehydration is the mainstay of therapy, and it is essential in young children. Antibiotics are effective for moderate to severe travellers’ diarrhoea, and self-treatment is often acceptable. A single large dose of antibiotics is usually effective, though a longer course should be used in patients with fever or bloody stools. * **Consider:** * **Azithromycin** 1 g (child: 20 mg/kg up to 1 g) orally, as a single dose * **Norfloxacin** 800 mg (child: 20 mg/kg up to 800 mg) orally, as a single dose * **Ciprofloxacin** 750 mg (child: 20 mg/kg up to 750 mg) orally, as a single dose * **Antimotility drugs can be used in combination with antibiotics in adult patients who do not have fever or bloody stools.** * **If fever or bloody stools are present, or if symptoms do not improve after the single large dose of antibiotic, continue with:** * **Azithromycin** 500 mg (child: 10 mg/kg up to 500 mg) orally, once daily for a further 2 days * **Norfloxacin** 400 mg (child: 10 mg/kg up to 400 mg) orally, 12-hourly for a further 2 days * **Ciprofloxacin** 500 mg (child: 12.5 mg/kg up to 500 mg) orally, 12-hourly for a further 2 days ## Persistent diarrhoea in returned travellers It is important to consider both infective and noninfective causes (eg postinfectious irritable bowel syndrome, lactose intolerance, coeliac disease) of persistent diarrhoea in a returned traveller. ## Outbreaks of diarrhoea in residential aged-care facilities To prevent spread in residential aged-care facilities, early recognition of infectious diarrhoea in residents and rapid implementation of infection control measures is crucial. * **Notify the local public health authority when an outbreak is suspected (more than two cases within 72 hours).** * **Clinical management of acute infectious diarrhoea in patients in residential aged-care facilities is the same as for other outbreaks.**