Pneumocystis carinii pneumonia in patients with AIDS in Central Africa

Chest X-ray Features of HIV-Associated Pneumocystis Pneumonia (PCP) in Adults: A Systematic Review and Meta-analysis

Background

The performance of chest x-ray (CXR) features for Pneumocystis pneumonia (PCP) diagnosis has been evaluated in small studies. We conducted a systematic review and meta-analysis to describe CXR changes in adults with HIV-associated laboratory-confirmed PCP, comparing these with non-PCP respiratory disease.

Methods

We searched databases for studies reporting CXR changes in people >15 years old with HIV and laboratory-confirmed PCP and those with non-PCP respiratory disease. CXR features were grouped using consensus terms. Proportions were pooled and odds ratios (ORs) generated using random-effects meta-analysis, with subgroup analyses by CD4 count, study period, radiology review method, and study region.

Results

Fifty-one studies (with 1821 PCP and 1052 non-PCP cases) were included. Interstitial infiltrate (59%; 95% CI, 52%-66%; 36 studies, n = 1380; I2 = 85%) and ground-glass opacification (48%; 95% CI, 15%-83%; 4 studies, n = 57; I2 = 86%) were common in PCP. Cystic lesions, central lymphadenopathy, and pneumothorax were infrequent. Pleural effusion was rare in PCP (0%; 95% CI, 0%-2%). Interstitial infiltrate (OR, 2.3; 95% CI, 1.4-3.9; I2 = 60%), interstitial-alveolar infiltrate (OR, 10.2; 95% CI, 3.2-32.4; I2 = 0%), and diffuse CXR changes (OR, 7.3; 95% CI, 2.7-20.2; I2 = 87%) were associated with PCP diagnosis. There was loss of association with alveolar infiltrate in African studies.

Conclusions

Diffuse CXR changes and interstitial-alveolar infiltrates indicate a higher likelihood of PCP. Pleural effusion, lymphadenopathy, and focal alveolar infiltrates suggest alternative causes. These findings could be incorporated into clinical algorithms to improve diagnosis of HIV-associated PCP.

Pneumocystis jirovecii colonisation in HIV-positive and HIV-negative subjects in Cameroon

OBJECTIVE

To determine the prevalence of Pneumocystis pneumonia (PCP), a major opportunistic infection in AIDS patients in Europe and the USA, in Cameroon.

MATERIALS AND METHODS

Induced sputum samples from 237 patients without pulmonary symptoms (126 HIV-positive and 111 HIV-negative outpatients) treated at a regional hospital in Cameroon were examined for the prevalence of Pneumocystis jirovecii by specific nested polymerase chain reaction (nPCR) and staining methods. CD₄ counts and the history of antiretroviral therapy of the subjects were obtained through the ESOPE database system.

RESULTS AND CONCLUSION

Seventy-five of 237 study participants (31.6%) were colonised with Pneumocystis, but none showed active PCP. The Pneumocystis colonisation rate in HIV-positive subjects was more than double that of HIV-negative subjects (42.9% vs. 18.9%, P < 0.001). In the HIV-positive group, the colonisation rate corresponds to the reduction in the CD₄ lymphocyte counts. Subjects with CD₄ counts >500 cells/μl were colonised at a rate of 20.0%, subjects with CD₄ counts between 200 and 500 cells/μl of 42.5%, and subjects with CD₄ counts <200 cells/μl of 57.1%. Colonisation with Pneumocystis in Cameroon seems to be comparable to rates found in Western Europe. Prophylactic and therapeutic measures against Pneumocystis should be taken into account in HIV care in western Africa.

Review of human immunodeficiency virus type 1-related opportunistic infections in sub-Saharan Africa

Understanding the natural history of human immunodeficiency virus type 1 (HIV-1) and opportunistic infections in sub-Saharan Africa is necessary to optimize strategies for the prophylaxis and treatment of opportunistic infections and to understand the likely impact of antiretroviral therapy. We undertook a systematic review of the literature on HIV-1 infection in sub-Saharan Africa to assess data from recent cohorts and selected cross-sectional studies to delineate rates of opportunistic infections, associated CD4 cell counts, and associated mortality. We searched the MEDLINE database and the Cochrane Database of Systematic Reviews and Cochrane Clinical Trials Register for English-language literature published from 1990 through April 2002. Tuberculosis, bacterial infections, and malaria were identified as the leading causes of HIV-related morbidity across sub-Saharan Africa. Of the few studies that reported CD4 cell counts, the range of cell counts at the time of diagnosis of opportunistic infections was wide. Policies regarding the type and timing of opportunistic infection prophylaxis may be region specific and urgently require further study.

Clinical signs and symptoms in the assessment of immunodeficiency in men with subtype C HIV infection in Harare, Zimbabwe

PURPOSE

Providing low-cost interventions such as co-trimoxazole as prophylaxis against opportunistic infections among HIV-infected individuals depends on the identification of those at risk. This article describes the prevalence of self-reported signs and symptoms and CD4 cell counts in a cohort of 447 HIV seropositive men. A scoring system using self-reported signs and symptoms was developed and tested in the prediction of low CD4 cell counts. This approach may allow health care providers in low-resource settings to predict severe immunodeficiency and to provide care.

METHOD

Data on clinical manifestations of HIV infection and blood samples for HIV serology were collected prospectively from an ambulatory cohort of men seen at their workplace at enrollment and every 6 months thereafter. CD4+ cell counts were obtained on samples testing positive on ELISA. Using data reduction techniques and logistic modeling, we developed a prognostic score system.

RESULTS

20% of the men had CD4+ cell counts below 200. All reported signs and symptoms were more frequent in men with less than 200 CD4+ cell counts compared to men with CD4+ cell counts greater than 200. History of malaria, fever, lymphadenopathy, persistent diarrhea, persistent cough, and skin infections robustly predicted low CD4+ count. A scoring system equation was developed based on the coefficients of the multivariate logistic regression: 1x(tuberculosis) + 3.2x(herpes zoster) + 4.5x(malaria) + 5.7x(fever) + 5.8x(cough) + 8.2x(lymphadenopathy) + 8.5x(skin infection). Setting the score cutoff value greater than or equal 5, the model had moderately high sensitivity of 61% and specificity of 72%. The scoring system had an overall classification error rate of 30%.

CONCLUSION

By using this simple scoring system, physicians can correctly identify 72% of patients who do not require immediate intervention, thereby channeling scarce resources to those who have both low CD4+ cell counts and symptoms and are most likely to benefit from prophylactic and antiretroviral interventions.

AIDS in Africans living in London

OBJECTIVES

To investigate the presentation of HIV infection and AIDS amongst Africans diagnosed with AIDS living in London.

METHODS

Identification of all AIDS cases of African origin attending four HIV specialist centres in South London--Guy's, King's, St George's and St Thomas' Hospitals--up to March 1994, by retrospective review of case notes of all HIV positive patients.

RESULTS

Of 86 patients (53 women, 33 men) studied, 59 (69%) were from Uganda. The most frequent AIDS-defining diagnoses were: Pneumocystis carinii pneumonia (PCP) 21%, tuberculosis (TB) 20% (extrapulmonary TB 14%, pulmonary TB 6%), cerebral toxoplasmosis 14%, oesophageal candida 13%, cryptococcal meningitis 11%, wasting 6%, herpes simplex infection > 1 month 5%, Kaposi's sarcoma 5%, other 6%. Cytomegalovirus retinitis was diagnosed in one case. Late presentation was common; 70% were diagnosed HIV positive when admitted to hospital. The diagnosis of AIDS was coincident with a first positive HIV test result in 61%. The mean CD4 counts at both HIV and AIDS diagnoses were similar in both men and women: 87 x 10(6)/l and 74 x 10(6)/l in men and 99 x 10(6)/l and 93 x 10(6)/l in women respectively. Overall, TB 21 (24%) (extrapulmonary TB 12, pulmonary TB 9) was either the AIDS-defining diagnosis or was detected within three months of this event. Sixty-two per cent of TB cases were diagnosed within twelve months of entry to the UK compared to 34% of all other AIDS cases. The prevalence of STD was very low; genital herpes was the commonest STD: 17% of the women, 9% men; 28% of the men and 11% of the women tested had a positive TPHA test. In cases known to be HIV-positive prior to an AIDS diagnosis, 41% took prophylaxis for PCP and 45% had taken zidovudine (ZDV). Forty two of the study participants had 89 children: 59 of these children had mothers in the study. Overall, 37 (42%) of the children had lost at least one parent at the time of data assessment.

CONCLUSIONS

PCP and TB were the most common initial AIDS-defining diagnoses. The majority of TB cases were diagnosed within 12 months of entry to the UK. An AIDS-defining diagnosis was the first manifestation of HIV-related illness in the majority of patients. Because of late presentation to medical services, access to treatments for HIV infection and prophylaxis against opportunistic infections was limited. Extending the role of clinics and staff into the community might facilitate both earlier presentation and access to services. Future provision of local services will need to be sensitive to the requirements of individuals from different cultures and backgrounds.

Pulmonary complications of human immunodeficiency virus infection in Bujumbura, Burundi

To determine the types of pulmonary disease associated with human immunodeficiency virus (HIV) infection, we conducted a prospective study of 302 consecutive patients admitted for acute respiratory disease to a university hospital in Bujumbura, Burundi. Diagnoses were made according to well-defined criteria. Of the total, 222 patients (73.5%) were HIV seropositive, with women younger than men. Features suggestive of underlying HIV infection were the clinical findings of oral thrush, peripheral lymphadenopathy, or herpes zoster and the radiographic abnormalities of hilar-mediastinal adenopathy or a reticulonodular infiltrate. Tuberculosis and community-acquired pneumonia occurred with approximately equal frequency in the HIV-seropositive and seronegative groups. Pneumocystis carinii pneumonia was diagnosed in 11 patients, all seropositive. Gram-negative bacteremia, especially Salmonella typhimurium, occurred in 23 seropositive patients (10.4%). A total of 24 seropositive patients died during the initial hospitalization, and 11 others required readmission; no seronegative patients died or were rehospitalized. We conclude that HIV infection is a major risk factor for the development of acute respiratory diseases in adults of sufficient severity to require hospitalization in Bujumbura. In this Central African country, where exposure to virulent bacterial pathogens is ubiquitous, tuberculosis, pneumonia, and salmonellosis occur with much greater frequency than classic AIDS-defining opportunistic infections or malignancies.

Nucleotide sequence variation in Pneumocystis carinii strains that infect humans

The nucleotide sequences of a portion of the large-subunit mitochondrial rRNA gene of Pneumocystis carinii derived from 12 patients were examined. Five sequences were found to be identical to the prototype sequence reported by Sinclair et al. (K. Sinclair, A. E. Wakefield, S. Banerji, and J. M. Hopkin, Mol. Biochem. Parasitol. 45:183-184, 1991). Six sequences differed from the prototype sequence at one to three positions. The remaining sequence was markedly different from the prototype sequence and appeared to be a hybrid of the human and rat P. carinii sequences. The results of this study indicate the existence of multiple P. carinii strains infecting humans and suggest that coinfections of animal and human P. carinii strains in the same host are possible.

[Pulmonary tuberculosis and HIV seropositivity at the Principal Hospital of Dakar (Senegal)]

In a prospective survey conducted in 1990 in the Principal Hospital of Dakar, pulmonary tuberculosis was 2.3 times more frequent in HIV seropositive patients (12.5%) than in HIV seronegative patients. We studied 22 cases of pulmonary tuberculosis in HIV+ patients and compared them with a control group of HIV- patients admitted for pulmonary tuberculosis. Tuberculosis occurred in 6 out of 22 asymptomatic HIV+ patients, in 15 out of 22 patients with clinical AIDS and in 1 patient with ARC syndrome. Clinical signs were the same as in controls, except for patients with advanced AIDS who developed cardinal signs. TB intra-dermal reactions were more often negative in HIV+ patients, notably those with HDV1, expressing immunodepression. Radiological images were typical in 81% of patients and in 86% of controls. However, concomitant infections were common in both groups, with atypical radiology and hyperleukocytosis. At light microscopy, there was no difference in the frequency of acid and alcohol fast bacilli between the two groups. The mortality rate was increased in HIV+ patients, but this was not due to tuberculosis. Relapses were frequent in both groups, due to poor compliance with treatment.