Domiciliary nebulized pentamidine for secondary prophylaxis against Pneumocystis carinii pneumonia.

The viability of a programme for delivering aerosolized pentamidine within the patient's home setting for the secondary prophylaxis of Pneumocystis carinii pneumonia (PCP) has been explored with seven homosexual AIDS patients, the major objectives being the assessment of the safety and acceptability of the treatment and the discovery of the most suitable care setting (home, ward, outpatient clinic) for the administration of therapy. It is concluded that a domiciliary prophylaxis programme is a viable alternative.     

Pneumocystis carinii pneumonia in a HIV-positive patient]

The authors publish a case report of a young man, who have got a severe pneumonia, which did not recover after antibiotics treatment. When the cause of the immunosuppression was investigated, HIV positivity was found, and Pneumocystis carinii was recognised in the bronchoalveolar lavage fluid. The diagnosis of the lung complications and the possibilities of the treatment are discussed.     

Systemic dissemination of Pneumocystis carinii in a patient with acquired immunodeficiency syndrome

Pneumocystis carinii is usually considered a respiratory tract pathogen; however, there are reported cases of limited and generalized dissemination of the organism from the lungs of immunocompromised patients. We present the autopsy findings of a 29-year-old male with acquired immunodeficiency syndrome (AIDS) and recurrent Pneumocystis carinii pneumonia who developed abnormal liver function tests. The patient had received aerosolized pentamidine because of toxic reactions to other modes of therapy. The postmortem examination revealed Pneumocystis in the lungs, liver, spleen, kidney, myocardium, thymus, pancreas, thyroid gland, bilateral parathyroid and adrenal glands, gastrointestinal mucosa, perihilar and mesenteric lymph nodes, and bone marrow. A high index of suspicion, especially in patients treated with aerosolized pentamidine, may lead to an increased recognition of disseminated pneumocystosis. Dissemination of the infection may be due to failure of the aerosolized drug to achieve adequate blood levels. As AIDS patients survive longer because of the developing therapeutic arsenal, disseminated pneumocystosis may be encountered with increasing frequency in these immunocompromised patients.     

G-estimation of the effect of prophylaxis therapy for Pneumocystis carinii pneumonia on the survival of AIDS patients.

AIDS Clinical Trial Group Randomized Trial 002 compared the effect of high-dose with low-dose 3-azido-3-deoxythymidine (AZT) on the survival of AIDS patients. Embedded within the trial was an essentially uncontrolled observational study of the effect of prophylaxis therapy for pneumocystis carinii pneumonia on survival. In this paper, we estimate the causal effect of prophylaxis therapy on survival by using the method of G-estimation to estimate the parameters of a structural nested failure time model (SNFTM). Our SNFTM relates a subject's observed time of death and observed prophylaxis history to the time the subject would have died if, possibly contrary to fact, prophylaxis therapy had been withheld. We find that, under our assumptions, the data are consistent with prophylaxis therapy increasing survival by 16% or decreasing survival by 18% at the alpha = 0.05 level. The analytic approach proposed in this paper will be necessary to control bias in any epidemiologic study in which there exists a time-dependent risk factor for death, such as pneumocystis carinii pneumonia history, that (A1) influences subsequent exposure to the agent under study, for example, prophylaxis therapy, and (A2) is itself influenced by past exposure to the study agent. Conditions A1 and A2 will be true whenever there exists a time-dependent risk factor that is simultaneously a confounder and an intermediate variable.     

Pneumocystis carinii pneumonia in patients with a severe combined immunodeficiency

We describe three patients with Pneumocystis carinii pneumonia as the initial presentation of severe combined immunodeficiency disease. The pneumonia in the first patient was treated successfully with trimethoprim/sulphamethoxazole (Tmp/Smz). The second patient died despite therapy with Tmp/Smz and pentamidine. The third patient failed to respond to therapy with Tmp/Smz and pentamidine. He was subsequently treated with trimetrexate and leucovorin. Treatment with the new folic acid antagonist trimetrexate resulted in complete recovery. The case histories of these children serve to illustrate the clinical symptoms and new therapeutic modalities of P. carinii pneumonia in patients with immunodeficiency disease.     

HIV/AIDS相关性卡氏肺囊虫肺炎的临床特征和影像诊断

目的探讨HIV/AIDS相关性卡氏肺囊虫肺炎的临床特征和影像学征象.方法收集在援博茨瓦纳玛丽娜公主医院临床及病理证实的卡氏肺囊虫肺炎132例,血液HIV抗体检查均为阳性,对其临床特点、病理机制和影像征象进行综合分析.结果卡氏肺囊虫肺炎以干咳、呼吸困难和低热为典型症状而体征不明显,CD4计数通常＜200/μl;典型的影像学表现为两侧肺门到肺周围弥漫对称性的渗出性病变,分布于肺门周围,呈毛玻璃改变,病灶由肺门向周围肺野发展且呈明显的融合趋势.结论卡氏肺囊虫肺炎是HIV/AIDS常见的肺部机会性感染,典型的胸部影像学表现和明显的临床症状而体征轻微者,排除其他原因导致的免疫缺乏性疾病外,经血液检查证实HIV抗体阳性者应积极治疗,尽快获得病理学证据,高分辨率胸部CT扫描显示肺内浸润和肺气囊等病变明显强于X线平片.     

Is Pneumocystis carinii a deep mycosis-like agent?

Pneumocystis carinii is a widespread eukaryotic microorganism found in the lungs of healthy mammals, including humans. It is able to proliferate extensively in the alveoli, becoming an important agent of severe pneumonitis in immunosuppressed hosts, especially in persons suffering from AIDS. The taxonomic position of P. carinii is uncertain. Typical cytoplasmic organelles of eukaryotic cells have been found and described in the parasite. Biochemical research is hindered by the lack of an efficient in vitro culture system. Results of comparative study of nucleic acid sequences suggest that Pneumocystis is a fungus. However, ultrastructural, biochemical and nucleic acid homology insights appear as clearly insufficient to class Pneumocystis. Pneumocystis infection might be acquired, as deep mycoses, from environmental sources through the respiratory tract. Thus, the hypothesis of an environmental stage of the parasite must be considered. Pneumocystis might be seen as a widespread pathogenic dimorphous fungus. As fungal agents, P. carinii is able to disseminate from the infected lung to other organs. However, deep mycoses and pneumocystosis induce different histopathological changes in the host. Furthermore, deep fungal infections, unlike pneumocystosis, cannot be transmitted from one infested host to another one. Beside these two aspects, pneumocystosis shares many features with deep mycoses. Research on the epidemiology of pneumocystosis is needed.     

Does Pneumocystis carinii occur in Kenya?

An experiment was carried out exposing immuno-suppressed mice to the atmosphere to determine if transmission of Pneumocystis carinii occured in Kenya. Mice were killed at weekly intervals for four months and the lungs examined histologically for the presence of these parasites. None of the mice contracted even light infections and this, together with the lack of clinical evidence of this disease in immunosuppressed or neonatal cases, suggests that this parasite does not occur in Kenya. Possible reasons for this are discussed.     

Infection with Pneumocystis carinii is prevalent in healthy Gambian children

Pneumocystis pneumonia is rarely identified in the many immunosuppressed individuals with acquired immune deficiency syndrome (AIDS) and malnutrition in Africa. To test whether infection with Pneumocystis carinii occurs in the continent we conducted a comparative serological study, measuring by enzyme-linked immunosorbent assay antibodies to the parasite in 150 healthy young individuals from both Britain and the Gambian savanna. The prevalence of significant titres of antibody to P. carinii steadily increased with age and included more than 70% of both populations by 8 years of age. Infection with P. carinii is, therefore, common in the Gambia. Thus opportunistic pneumocystis pneumonia may be an important but largely unrecognized disease in the continent, though its impact is probably diminished by the prevalence of fatal tuberculous infection, particularly in the AIDS population.     

Attitudes to prevention among HIV-infected patients: the case of specific prophylaxis for Pneumocystis carinii pneumonia

Despite a consensus on the need for Pneumocystis carinii pneumonia (PCP) prophylaxis for HIV-infected patients with fewer than 200 CD4+ lymphocytes/mm3, the number of cases of PCP has remained stable, and about 70% involve patients who are not receiving prophylaxis. The aim of this study was to determine why these patients are not covered by prophylaxis. It was based on a retrospective analysis of semidirective interviews with 32 patients who developed PCP while not receiving prophylaxis. The reasons given were a lack of knowledge of risk factors for HIV infection, the fear of HIV testing, unawareness of the existence of PCP prophylaxis, a refusal to see a doctor in the absence of symptoms, unwillingness to be monitored and in four cases a failure of the doctor to prescribe prophylaxis.     

Cutaneous Mycobacterium kansasii infection in a patient with AIDS post initiation of antiretroviral therapy

The HIV pandemic has resulted in unique clinical presentations in patients, and their diagnosis and management pose challenges to physicians in the developing world. Due to limited resources and difficulties in laboratory diagnosis, most physicians treat according to the most likely etiological agent that might be causing the disease. In South Africa, when acid-fast bacilli are detected, anti-tuberculous treatment is commenced. However, it must be realized that not all acid-fast bacilli are Mycobacterium tuberculosis, and that there are nontuberculous mycobacteria that can cause infections. Clinicians should work closely with the medical microbiologist when unique cases arise to ensure optimal microbial detection, identification, and patient management. This paper describes a very rare case of self-resolving cutaneous Mycobacterium kansasii infection following the initiation of antiretroviral therapy and potentially associated with immune reconstitution inflammatory syndrome.