Severe Pneumonia in HIV-infected Infants–Clinical and Immunological Correlates. Trying to Improve Diagnosis and thereby Survival

Abstract

Severe pneumonia in infants who are HIV-infected is a common problem in many parts of the developing world, especially sub-Saharan Africa. It has emerged that the condition of severe hypoxic pneumonia in early infancy is a disease of many causes, most occurring together in the individual patient [1-3]. A frequent cause of severe pneumonia in infants is Pneumocystis jiroveci. This condition is usually diagnosed clinically and managed as ‘Pneumocystis pneumonia’ in the regions of the world where HIV-infected children live. Only in the last few years, has it become possible to make a microbiological diagnosis of Pneumocystis jiroveci based on Polymerase Chain Reaction (PCR) testing of airway secretions. However, in the developing world, such testing is largely unavailable and the clinical condition still poses an enormous problem. Pneumocystis jiroveci is a fungal organism that has a predilection for the immune-compromised host, and is a common pathogen in HIV-infected infants. The term PCP (pneumocystis pneumonia) was retained when Pneumocystis carinii was taxonomically renamed jiroveci [4]. Since the earliest reports of HIV infection, PCP has been recognized as a severe form of acute pneumonia. The disease may occur at any age, but is particularly common in early infancy [5]. PCP is recognized clinically by a distinct set of common criteria; hypoxic pneumonia, few pulmonary crackles, a reticular-nodular appearance on chest radiographs and an elevated lactate dehydrogenase (>500