The main causes of death among children under 5 years of age are acute respiratory infection (17%) and diarrhoeal disease (16%), and children infected with human immunodeficiency virus (HIV) have greater morbidity and mortality related to these conditions (WHO, 2008). An estimated 2.1 million children in the world are living with HIV, 90% of whom live in sub-Saharan Africa. The incidence of infection remains high, with 430 000 new HIV infections in children annually. Almost one third of untreated infected infants will die in the first year of life, and up to 50% by 2 years of age.

Although tremendous progress has been made in identifying and treating infants and children with HIV infection, much remains to be done to scale-up and sustain effective prevention, care and treatment, especially of diarrhoea and pneumonia. Currently, only an estimated 15% of exposed infants are tested for HIV in the first 2 months of life, and coverage with paediatric antiretroviral therapy (ART) is 38% (WHO 2009). Coverage of HIV-infected and -exposed infants and children with co-trimoxazole prophylaxis, another highly effective, inexpensive, life-saving intervention, has remained unacceptably low, at about 8%. Interventions that delay morbidity and mortality from diarrhoea and pneumonia can make a significant contribution to the long-term survival of HIV-infected and -exposed infants and children.

The World Health Organization (WHO) departments of Child and Adolescent Health and of HIV/AIDS reviewed the evidence on management of diarrhoea and pneumonia in HIV-infected children, because of the substantial effects of these conditions on morbidity and mortality, potential differences in etiological agents (and thus in recommended empirical regimens) from those for uninfected infants and children, potential changes in the susceptibility of pathogens to co-trimoxazole prophylaxis in these children, and the lack of specific recommendations for this high-risk group. These guidelines are part of a comprehensive set of normative documents being prepared by WHO for the prevention and treatment of common conditions affecting HIV-infected and -exposed infants and children.

A group assessed the evidence on the basis of "grading of recommendations assessment, development and evaluation" (GRADE), and, during a consultation in October 2009, updated their recommendations for preventing and managing diarrhoea and pneumonia in HIV-infected and -exposed infants and children. The objectives were to summarize WHO recommendations for policy and practice, prepare GRADE "evidence profiles" and discuss the factors taken into account in deciding on the strength of recommendations. The group also identified gaps in knowledge and set priorities for further research.

The group’s recommendations for managing pneumonia and diarrhoea in HIV-infected infants and children are, in most cases, the same as those for management in uninfected children. Most studies providing evidence for recommendations were, however, conducted before widespread use of co-trimoxazole or ART.

The panel found insufficient evidence to justify separate recommendations for infants and children who have been exposed to HIV and for those suspected of or confirmed to have HIV infection. Previous recommendations on co-trimoxazole prophylaxis (WHO, 2006), provider-initiated testing and counselling (WHO, 2007) and safe water and hygiene (WHO, 2008) were incorporated into the guidelines in order to make them comprehensive. In accordance with the existing WHO recommendations on provider-initiated testing and counselling, the panel strongly recommended that all infants and children living in generalized epidemic settings and presenting with pneumonia or diarrhoea should have their HIV status determined.