Importance of tissue sampling, laboratory methods, and patient characteristics for detection of Pneumocystis in autopsied lungs of non-immunosuppressed individuals.

To understand the epidemiological significance of Pneumocystis detection in a lung tissue sample of non-immunosuppressed individuals, we examined sampling procedures, laboratory methodology, and patient characteristics of autopsy series reported in the literature. Number of tissue specimens, DNA-extraction procedures, age and underlying diagnosis highly influence yield and are critical to understand yield differences of Pneumocystis among reports of pulmonary colonization in immunocompetent individuals.

Molecular typing of Pneumocystis jirovecii found in formalin-fixed paraffin-embedded lung tissue sections from sudden infant death victims.

Previous studies have provided histological evidence of an association between primary Pneumocystis infection and sudden infant death syndrome (SIDS). The aim of this work was to determine the species of clustered Pneumocystis organisms found in formalin-fixed paraffin-embedded (FFPE) lung tissue sections from Chilean sudden infant death (SID) victims. This approach needed first to optimize a DNA extraction method from such histological sections. For that purpose, the QIAamp DNA Isolation from Paraffin-Embedded Tissue method (Qiagen) was first tested on FFPE lung tissue sections of immunosuppressed Wistar rats inoculated with rat-derived PNEUMOCYSTIS: Successful DNA extraction was assessed by the amplification of a 346 bp fragment of the mitochondrial large subunit rRNA gene of the Pneumocystis species using a previously described PCR assay. PCR products were analysed by direct sequencing and sequences corresponding to Pneumocystis carinii were found in all the samples. This method was then applied to FFPE lung tissue sections from Chilean SID victims. Pneumocystis jirovecii was successfully identified in the three tested samples. In conclusion, an efficient protocol for isolating PCR-ready DNA from FFPE lung tissue sections was developed. It established that the Pneumocystis species found in the lungs of Chilean SID victims was P. jirovecii.

Itraconazole or allopurinol in the treatment of chronic American trypanosomiasis: the regression and prevention of electrocardiographic abnormalities during 9 years of follow-up.

Several drugs are now known to have useful activity against Trypanosoma cruzi, the causative agent of human American trypanosomiasis (Chagas disease). However, the long-term effects of chemotherapy on the electrocardiographic (ECG) abnormalities associated with this disease have only been assessed for benznidiazole. In the present study, the ECG changes in 299 cases of chronic Chagas disease were followed for 9 years after treatment with itraconazole (N = 136) or allopurinol (N = 163). Among the 97 cases who were found to have ECG abnormalities immediately prior to their treatment, the two drugs appeared equally effective, such abnormalities being corrected in 23 (50%) of the 46 cardiopathy cases given itraconazole and 25 (49%) of the 51 given allopurinol (P > 0.05). Both of these 'cure rates' are much higher than the 8.1% frequency of abnormal-normal conversion observed among 198 'historical controls' (i.e. cases of chronic Chagas disease who had been left untreated; P < 0.05). Itraconazole appeared better than allopurinol at preventing the development of cardiopathy in the cases who appeared electrocardiographically normal at baseline. Among 202 such cases, only two (2.2%) of the 90 treated with itraconazole but 28 (25.0%) of the 112 given allopurinol were found to have developed ECG abnormalities during follow-up (P < 0.05). Therefore, although itraconazole and allopurinol are equally effective at reversing ECG alterations, itraconazole offers better protection against the development of new ECG abnormalities among those with chronic Chagas disease.

Distribution of Pneumocystis carinii f. sp. hominis types in the lung of a child dying of Pneumocystis pneumonia.

Pneumocystis f. sp. hominis causes pneumonia in immunocompromised persons. In order to determine the types and distribution of P. carinii organisms within a single human lung, multiple samples were obtained from the lung of a child who died of P. carinii pneumonia. P. carinii DNA was detected in all of the samples and 2 different genotypes of P. carinii were identified, with uneven distribution in the lung, demonstrating that infection of the human lung is not necessarily clonal, and that different P. carinii genotypes may predominate in different areas of the lung.

Identification of Pneumocystis carinii in the lungs of infants dying of sudden infant death syndrome.

BACKGROUND: Recently Pneumocystis carinii has been identified in a significant number of infants diagnosed as having died from sudden infant death syndrome (SIDS) in South America and Europe. METHODS: We examined lung sections of 79 infants who died with a diagnosis of SIDS in Rochester, NY, and Connecticut for the presence of P. carinii. RESULTS: Organisms with a characteristic silver stain appearance for P. carinii were identified in 14% of the lung sections. CONCLUSIONS: These data suggest that a possible link between some cases of SIDS and infection with P. carinii should be further evaluated and that infection of young infants may serve as an important reservoir for human P. carinii.

Search for primary infection by Pneumocystis carinii in a cohort of normal, healthy infants.

To determine whether Pneumocystis carinii is associated with clinical illness in the competent host, 107 normal, healthy infants were enrolled in a 2-year prospective cohort study in Chile. P. carinii was identified by specific stains and nested--deoxyribonucleic acid (DNA) amplification of the large subunit mitochondrial ribosomal ribonucleic acid gene of P. carinii f. sp. hominis, and seroconversion was assessed by enzyme-linked immunosorbent assay of serum samples drawn every 2 months. P. carinii DNA was identified in nasopharyngeal aspirates obtained during episodes of mild respiratory infection in 24 (32%) of 74 infants from whom specimens were available for testing. Three (12.5%) of those 24 infants versus 0 of 50 infants who tested negative for P. carinii had apnea episodes. Seroconversion developed in 67 (85%) of 79 infants who remained in the study by 20 months of age and occurred in the absence of any symptoms of disease in 14 (20.8%). The study indicates that P. carinii DNA can be frequently detected in healthy infants, and it raises the hypothesis that they may be an infectious reservoir of P. carinii in the community. Further investigation is needed to identify whether P. carinii causes overt respiratory disease in infants.

Candidal meningitis in children with cancer.

Candidal meningitis is a rare disease that is seen most frequently in neonates, neurosurgical patients, and the immunocompromised host. We describe a series of 12 children with cancer (all of whom had leukemia) who had candidal meningitis develop. Univariate analysis revealed that duration of fever, antibiotic therapy, and profound neutropenia and use of total parenteral nutrition were significantly associated (P<.05) with candidal meningitis in children with cancer, compared with matched control subjects. Only duration of profound neutropenia (P=.08) and use of total parenteral nutrition (P=.06) approached significance in the multivariate analysis. One species of Candida, Candida tropicalis, was responsible for 11 of the 12 cases, indicating increased pathogenicity of this organism in CNS disease. The cases were invariably fatal, supporting aggressive treatment of candidal meningitis in immunocompromised patients and further study of the prevention, diagnosis, and management of C. tropicalis meningitis.

[Severe apnea: an early sign of Pneumocystis carinii pneumonia in an HIV-negative infant]. / Apnea severa: signo precoz de neumonía por Pneumocystis carinii en un lactante VIH negativo.

A few reports in the medical literature suggest an association between Pneumocystis caring and apnea in small infants. This patient, a 1 month 20 days old, HIV negative, infant girl weighing 2,000 grams was admitted to hospital after presenting a severe episode of apnea with cyanosis and bradycardia. She progressively developed bronchopneumonia by P. carinii that required prolonged mechanical ventilation with high ventilatory parameters. The clinical course of this patient illustrates that apnea can be an early sign of P. carinii infection in small infants. Early diagnosis and specific therapy might prevent morbidity and mortality and also decrease the length of hospitalization.

Transmission of Pneumocystis carinii DNA from a patient with P. carinii pneumonia to immunocompetent contact health care workers.

The transmission of Pneumocystis carinii from person to person was studied by detecting P. carinii-specific DNA in prospectively obtained noninvasive deep-nasal-swab samples from a child with a documented P. carinii pneumonia (PCP), his mother, two contact health care workers, and 30 hospital staff members who did not enter the patient's room (controls). Nested-DNA amplification was done by using oligonucleotide primers designed for the gene encoding the mitochondrial large subunit rRNA of rat P. carinii (P. carinii f. sp. carinii) that amplifies all forms of P. carinii and internal primers specific for human P. carinii (f. sp. hominis). P. carinii f. sp. hominis DNA was detected in samples from the patient and all of his contacts versus none of the 30 hospital staff members. The results, as previously shown in murine models of P. carinii pneumonia, document that person-to-person transmission of P. carinii is possible. This observation suggests that immunocompromised patients not on PCP prophylaxis should not enter the room of a patient with PCP, and it also raises the question as to whether healthy contacts can transmit the disease to immunocompromised patients at risk.

Association of primary Pneumocystis carinii infection and sudden infant death syndrome.

To delineate clinical and histological features of the first Pneumocystis carinii infection affecting the immunocompetent host, P. carinii-specific histological stains were performed on autopsy lung specimens from 534 consecutive pediatric patients (those with AIDS and malignancies were excluded) in Santiago, Chile. P. carinii clusters were found in 4 (25%) of 16 infants who died of no apparent cause at arrival to the emergency department, and in 10 (2.9%) of 342 infants who died of multiple conditions at the hospital (P=.002, Fisher's exact test). This prompted us to analyze additional series of infants with sudden infant death syndrome (SIDS). In 161 additional SIDS cases, 47 (35.1%) of 134 infants from Chile and 4 (14.8%) of 27 infants from Oxford, United Kingdom, were found to have P. carinii clusters in the lungs. The quantity of P. carinii cysts was small compared with the numbers seen in immunocompromised hosts with P. carinii pneumonitis. This study provides histological evidence that primary P. carinii infection is associated with SIDS.

Search for extrapulmonary Pneumocystis carinii in an animal model.

Pneumocystis carinii-infected immunosuppressed ferrets and rats were searched for P. carinii cysts and trophozoites in extrapulmonary organs, including the heart, liver, stomach, kidney, and spleen. Foci of P. carinii were found in the liver or kidney of 4 (10%) of 40 ferrets but in no extrapulmonary sites of 30 rats with P. carinii pneumonitis. Attempts to identify P. carinii from immunosuppressed rat or ferret blood or propagate the organism intraorbitally in immunosuppressed rats were unsuccessful. Pneumocystis carinii was identified from aspirated stomach contents of ferrets but in none of the rats infected with P. carinii pneumonitis.

Limited persistence in and subsequent elimination of Pneumocystis carinii from the lungs after P. carinii pneumonia.

The purpose of this study was to determine the period of persistence of Pneumocystis carinii in the lungs after P. carinii pneumonitis (PCP). After primary PCP was induced with dexamethasone, experimental rats were moved to a high-efficiency particulate air-filtered isolator to prevent further exposure to environmental P. carinii and allowed to recover. At intervals thereafter, sample groups were transferred to a second isolator and reimmunosuppressed with dexamethasone to provoke PCP if P. carinii were present. Reactivation of PCP was assessed by histologic examination, counts of cysts per gram of lung, and DNA amplification using nested polymerase chain reaction. A sequential and progressive decrease in P. carinii was detected. Thus, P. carinii is cleared from the lungs of > or = 75% of animals within 1 year after an episode of PCP, implying that persistence of latent organisms is limited.

Azithromycin for treatment of severe Cryptosporidium diarrhea in two children with cancer.

Two children with cancer received azithromycin for Cryptosporidium-associated diarrhea that was unresponsive to supportive care. One child had choleriform diarrhea requiring daily fluid replacement of up to 65% of his total body weight; the other had protracted diarrhea and wasting. In both cases, administration of azithromycin was followed by prompt clinical improvement.

Modulating effect of dietary carbohydrate supplementation on Candida albicans colonization and invasion in a neutropenic mouse model.

We studied the effect of dietary carbohydrate supplementation on Candida albicans colonization and invasion of the gastrointestinal tract in a neutropenic mouse model. Mice inoculated with C. albicans were allowed free access to standard chow and drinking water supplemented with either glucose or xylitol or no carbohydrates (control). On days 33 through 36 postinoculation, the mean +/- standard error log10 CFU of C. albicans per gram on the mucosal surface, determined by quantitating CFU dislodged in the first wash of the gastric wall, was significantly higher in mice given the glucose supplement: 7.20 +/- 0.09 (glucose) versus 5.38 +/- 0.28 (xylitol) and 5.11 +/- 0.33 (control) CFU/g (P < or = 0.05 for each comparison by Fisher's protected least-significant-difference test). Fecal cultures also yielded the highest quantities of C. albicans in the glucose group. Invasion of the gastric wall by C. albicans correlated well with surface colonization in glucose-supplemented animals. Eight of 10 mice in this group, all with > 10(6) CFU/g, showed extensive invasive growth, as compared with only 2 of 26 mice in the remaining groups (P = 0.00006 by Fisher's exact test). These results indicate that dietary glucose intake is a key determinant of C. albicans growth in the gastrointestinal tract. The data provide an experimental rationale for clinical trials to decrease the intake of glucose or its utilization by C. albicans in immunocompromised patients.