The child with HIV and gastroenteritis

HIV-infected children may be severely immunosuppressed (for example, at first presentation) and develop severe or persistent gastroenteritis due to unusual opportunistic organisms, or they may be stable on HAART and develop gastroenteritis with the same pathogens that cause gastroenteritis in HIV-uninfected children.

1. HIV disease staging

Note the stage of the child's illness.

• The more severely immunosuppressed, the more likely to have minimal signs and serious pathology. Note the stage of the child's HIV disease.
• Look in notes or on results system for recent letters and CD4 count. A recent undetectable viral load indicates that adherence to antiretroviral therapy has been good.
• The CD4 count or percentage indicating severe immune suppression is age dependent

WHO classification of HIV-Associated Immunodeficiency in Infants and Children, 2006 (in WHO, Antiretroviral therapy of HIV infection in infants and children in resource-limited settings: towards universal access. Recommendations for a public health approach. 2006, Geneva, World Health Organisation. Annex C page 94)

2. Causes of gastroenteritis

Most children with diarrhoea/vomiting will have an infectious cause:

Certain conditions are WHO Stage IV (AIDS-defining) illnesses:

• Disseminated mycobacteriosis (eg MAC)
• Chronic cryptosporidiosis
• Chronic Isospora infection
• Histological diagnosis of CMV infection.

Not all children with diarrhoea and vomiting have gastroenteritis!

Consider the differential diagnosis:

• Other infections

• Surgical conditions

• Medical conditions

• Medication

3. History

• Past history from parents or clinic letters (parents may find it difficult to reiterate history due to stigma)
• Take a good history of the current illness
• Is this acute diarrhoea or persistent (>14 days) diarrhoea?
• Description of diarrhoea

• Medication history (recently started HAART?)
• Immunisation history
• Travel history (including malaria prophylaxis)
• Note any acute or chronic weight loss

4. Examination

• ABC, signs of shock and acidosis
• Assessment of dehydration
• Signs of toxicity / sepsis
• Signs of other pathology mimicking / masking gastroenteritis

5. Investigations

• All HIV-infected children with diarrhoea should have the following investigations undertaken:

• Other investigations should be conducted depending on the clinical situation (see Management below).

6. Management

Acute diarrhoea

• Salmonella: ciprofloxacin or ceftriaxone
• Shigella: ciprofloxacin
• Campylobacter: oral erythromycin or ciprofloxacin

• If an HIV-infected child with acute diarrhoea is not improving on standard treatment, discuss with an HIV paediatrician
• It is important to ensure that antiretroviral drugs have been given and tolerated while the child is unwell.

• What medication is the child taking?
• Has the child missed any doses?
• If vomited within 1 hour of dose – should be given again. If unable to take, or keep down medication need to admit and give via NGT. Ondansetron can be given prior to dose in order to give best chance of tolerating dose.
• Liquid medication is often large in volume – if not tolerating liquids with ondansetron consider use of crushed tablets.
• Viral load will increase and resistance to drugs will develop if antiretroviral drugs are not given regularly.

Persistent diarrhoea

• Persistent diarrhoea is common in HIV-infected children and repeated investigations may be required to identify a cause
• Unexplained persistent diarrhoea (>14 days), not responding to standard treatment, is a WHO Stage III disease
• Pay particular attention to weight and nutrition
• Send daily stools for culture/OCP/virology for 3 days
• Check stool reducing substances
• Involve a dietician and consider use of a hydrolysed formula
• Discuss with HIV paediatrician regarding empirical course of treatment with metronidazole (7 days) and/or ciprofloxacin
• Consider endoscopy / jejunal biopsy ± colonoscopy if persistent culture-negative diarrhoea

• Send biopsy to histopathology (ask for CMV, Cryptosporidium, fungal and AFB stains)
• Send biopsy for culture (including mycobacteria) and virology.

Severe immunosuppression

• Children with advanced HIV disease may have overlapping and interacting problems of immunodeficiency, enteric infection, malabsorption and malnutrition
• Involve an HIV paediatrician early in their care
• Children with advanced disease and diarrhoea may be very sick at presentation:

• Repeated investigations should be undertaken to look for all of the conditions listed below.
• In cases of severe immunosuppression and culture-negative diarrhoea, the cause may be HIV enteropathy and HAART is needed for improvement
• In cases of severe malabsorption, may need therapeutic drug monitoring to assess levels of antiretroviral drugs

Cryptosporidium

• Highly contagious, spread through childcare centres, recreational facilities such as swimming pools, water supply (despite chlorination – only boiling kills oocysts)
• Usually frequent, persistent, non-bloody watery diarrhoea
• Abdominal cramps, vomiting, anorexia
• n severely immunosuppressed (CD4<50) can present as cholera-like illness
• Diagnosis: modified ZN stain or Auramine (ask lab specifically)
• No agent has proven efficacy in immunocompromised patients
• Oral nitazoxanide may have some efficacy:

• Most children need HAART to enable immune reconstitution and clearance of organisms
• Unproven efficacy for paromomycin and azithromycin, but trial of treatment may be warranted.

Microsporidiosis

Isospora / cyclospora

• CMV

• Mycobacterium avium complex

• Environmental organisms
• Typical presentation with persistent diarrhoea, weight loss, fever, abdominal pain
• May have anaemia, leucopenia, thrombocytopenia
• Mycobacterial blood cultures required for diagnosis
• Treat with clarithromycin and ethambutol (± rifabutin) up to 8-12 weeks plus HAART.