Weight loss and anorexia

Weight loss is a major problem in AIDS and directly influences survival. The causes of weight loss are complex and several factors may coexist in individual patients. Anorexia may occur secondary to drug therapy, opportunistic infection, taste disturbance, or oral discomfort, resulting in inadequate food intake.

Simple dietary measures such as encouraging smaller, mor e frequent, meals may be helpful and a wide variety of nutritional supplements are available. Appetite stimulants such as megestrol acetate may be beneficial but weight gain is usually modest. Recombinant human growth hormone, although expensive, may partially reverse HIV-associated weight loss. In patients unable to tolerate oral feeding, enteral and parenteral feeding are alternative forms of nutrition but their efficacy and place in management are still being evaluated. Enteral nutrition offers a safer and cheaper alternative to total parenteral nutrition which is perhaps most useful in patients with severe diarrhoea, nausea, and vomiting, in whom fluid balance and control of symptoms has been difficult.

Box 7.2 Infective causes of diarrhoea

• Bacteria

• campylobacter, salmonella, shigella

• atypical mycobacteria

• Clostridium difficile

• Protozoa

• cryptosporidium

• microsporidia

• Isospora belli and cyclospora

• Viruses

• cytomegalovirus

• adenovirus

• (HIV)

Figure 7.3 Cryptosporidium on electromicrograph. Development stages of cryptosporidium on the surface of enterocytes (note microvilli). The cryptosporidia are surrounded by a parasitophorous vacuole, the outer layers of which are derived from host cell outer membranes

Box 7.3 Treatment of HIV-associated diarrhoea

• Specific

• antibiotics

• antivirals

• Fluid replacement

• Antidiarrhoeal agents

• loperamide

• diphenoxylate

• codeine

• Slow release morphine

• Subcutaneous diamorphine

Figure 7.4 Cytomegalovirus antigen demonstrated by immunofluorescence microscopy after culturing human fibroblasts with homogenised intestinal tissue