Opportunistic intestinal parasites in immunocompromised patients from a tertiary hospital in Monterrey, Mexico

Opportunistic parasites are still important agents causing morbidity and mortality in immunocompromised patients, particularly those living with HIV/AIDS. Few studies in Mexico have attempted to determine the prevalence of opportunistic intestinal parasites causing diarrhea in immunocompromised patients. A study was conducted to determine the intestinal parasites in HIV-positive and HIV-negative immunocompromised patients with diarrhea admitted to a tertiary care hospital in Monterrey, Mexico, from 2014 to 2015. Stool samples were examined for trophozoites, cysts, and eggs using the EGRoPe sedimentation-concentration technique and special techniques (modified Ziehl-Neelsen stain, modified trichrome stain). A total of 56 patients were included. The overall prevalence of intestinal parasitism was 64% (36/56); 22/36 patients were HIV-positive. Prevalence of opportunistic parasites was 69% in HIV-infected patients compared to 44% in HIV-negative patients (P = 0.06). Microsporidia were the most frequently identified parasites (24/36, 67%), followed by Cryptosporidium sp. (6/36, 17%), Sarcocystis sp. (4/36, 11%), Cystoisospora belli (3/36, 8%), and Cyclospora cayetanensis (1/36, 3%). Overall prevalence rates of microsporidiosis and cryptosporidiosis were 43% and 11%, respectively. Among HIV-infected patients, prevalence rates of microsporidiosis and cryptosporidiosis were 48% and 14%, respectively. We also report the first cases of intestinal sarcocystosis in Mexico, all in HIV-infected patients. In conclusion, microsporidia and coccidia are major parasitic agents causing diarrhea in immunocompromised patients, particularly HIV-infected patients.

Double - Trouble- Relapsing Leishmaniasis in a Virologically Suppressed HIV Positive Patient

We present a case of a middle aged male, with long standing retroviral disease on second line ART (Anti-Retroviral Therapy) with three episodes of visceral leishmaniasis diagnosed on bone marrow examination treated with a combination of liposomal amphotericin B and miltefosine.

Impact of helminth diagnostic test performance on estimation of risk factors and outcomes in HIV-positive adults

Background

Traditional methods using microscopy for the detection of helminth infections have limited sensitivity. Polymerase chain reaction (PCR) assays enhance detection of helminths, particularly low burden infections. However, differences in test performance may modify the ability to detect associations between helminth infection, risk factors, and sequelae. We compared these associations using microscopy and PCR.

Methods

This cross-sectional study was nested within a randomized clinical trial conducted at 3 sites in Kenya. We performed microscopy and real-time multiplex PCR for the stool detection and quantification of Ascaris lumbricoides, Necator americanus, Ancylostoma duodenale, Strongyloides stercoralis, and Schistosoma species. We utilized regression to evaluate associations between potential risk factors or outcomes and infection as detected by either method.

Results

Of 153 HIV-positive adults surveyed, 55(36.0%) and 20(13.1%) were positive for one or more helminth species by PCR and microscopy, respectively (p<0.001). PCR-detected infections were associated with farming (Prevalence Ratio 1.57, 95% CI: 1.02, 2.40), communal water source (PR 3.80, 95% CI: 1.01, 14.27), and no primary education (PR 1.54, 95% CI: 1.14, 2.33), whereas microscopy-detected infections were not associated with any risk factors under investigation. Microscopy-detected infections were associated with significantly lower hematocrit and hemoglobin (means of -3.56% and -0.77 g/dl) and a 48% higher risk of anemia (PR 1.48, 95% CI: 1.17, 1.88) compared to uninfected. Such associations were absent for PCR-detected infections unless infection intensity was considered, Infections diagnosed with either method were associated with increased risk of eosinophilia (PCR PR 2.42, 95% CI: 1.02, 5.76; microscopy PR 2.92, 95% CI: 1.29, 6.60).

Conclusion

Newer diagnostic methods, including PCR, improve the detection of helminth infections. This heightened sensitivity may improve the identification of risk factors for infection while reducing ability to discriminate infections associated with adverse clinical outcomes. Quantitative assays can be used to differentiate infection loads and discriminate infections associated with sequelae.

[Genotypes of Toxoplasma gondii isolates from HIV positive patients in Yunnan Province]

One hundred and fifty serum samples of HIV positive patients were collected in western Yunnan Province from September 2011 to December 2012. Toxoplasma gondii B1 gene was amplified by nested PCR. Genotyping of T. gondii isolates were performed by restriction fragment length polymorphism (RFLP) with Pm1 I and Xho I. 13 samples were found positive with the B1 gene (530 bp) amplification and belonged to type I. The sequencing results showed that 4 T. gondii B1 gene positive samples were identical, with 3 nucleotide variation compared with T. gondii strain RH (type I) B1 gene (GenBank No. AF179871), and in the other sample a "G --> A" mutation at 230bp was detected. The results indicated that the genotype of Toxoplasma gondii in HIV positive patients in Yunnan Province is type I.

[Serological investigation of Toxoplasma gondii infection in HIV positive cases in Dali and Dehong of Yunnan]

Serum samples were collected from HIV positive cases (927) and HIV, negative ones (80) from June 2010 to August 2011 in Dali and Dehong Prefectures of Yunnan. Serum anti-Toxoplasma gondii IgG was detected by ELISA. The overall anti-Toxoplasma gondii IgG positive rate among HIV positive cases and HIV negative ones was 35.1% (325/927) and 23.8% (19/80), respectively. In HIV positive cases, the seropositive rate was 30.3% (178/588) in Dali and 43.4% (147/339) in Dehong. The seropositive rate was significantly different among ethnic groups (chi2 = 28.433, P < 0.05). No significant difference was found among age groups (chi2 = 4.248, P > 0.05), and the age group of 41-60 showed the highest positive rate (36.1%, 103/285). The seropositive rate was 35.6% (203/571) in males and 34.3% (122/356) in females (chi2 = 0.158, P > 0.05).

Plasmodium falciparum infection significantly impairs placental cytokine profile in HIV infected Cameroonian women

BACKGROUND

Placental cytokines play crucial roles in the establishment and maintenance of pregnancy as well as protecting the foetus from infections. Previous studies have suggested the implication of infections such as P. falciparum and HIV in the stimulation of placental cytokines. This study assessed the impact of P. falciparum on placental cytokine profiles between HIV-1 positive and negative women.

MATERIALS AND METHODS

P. falciparum infection was checked in peripheral and placental blood of HIV-1 negative and positive women by the thick blood smear test. Cytokines proteins and messenger RNAs were quantified by ELISA and real time PCR, respectively. Non-parametric tests were used for statistical analyses.

RESULTS

Placental and peripheral P. falciparum infections were not significantly associated with HIV-1 infection (OR: 1.4; 95% confidence interval (95%CI): 0.5-4.2; p = 0.50 and OR: 0.6; 95%CI: 0.3-1.4; p = 0.26, respectively). Conversely, placental P. falciparum parasitemia was significantly higher in the HIV-1 positive group (p = 0.04). We observed an increase of TNF-alpha mRNA median levels (p = 0.02) and a trend towards a decrease of IL-10 mRNA (p = 0.07) in placenta from HIV-1 positive women compared to the HIV negative ones leading to a median TNF-alpha/IL-10 mRNA ratio significantly higher among HIV-1 positive than among HIV-1 negative placenta (p = 0.004; 1.5 and 0.8, respectively). Significant decrease in median secreted cytokine levels were observed in placenta from HIV-1 positive women as compared to the HIV negative however these results are somewhat indicative since it appears that differences in cytokine levels (protein or mRNA) between HIV-1 positive and negative women depend greatly on P.falciparum infection. Within the HIV-1 positive group, TNF-alpha was the only cytokine significantly associated with clinical parameters linked with HIV-1 MTCT such as premature rupture of membranes, CD4 T-cell number, plasma viral load and delay of NVP intake before delivery.

CONCLUSIONS

These results show that P. falciparum infection profoundly modifies the placenta cytokine environment and acts as a confounding factor, masking the impact of HIV-1 in co-infected women. This interplay between the two infections might have implications in the in utero MTCT of HIV-1 in areas where HIV-1 and P. falciparum co-circulate.

Enteric protozoan parasitic infection in HIV seropositive individuals with diarrhoea

A total of 78 HIV seropositive patients were included in the study from January 2004 to March 2006. Enteric protozoan parasitic infections were diagnosed by microscopic examination of stool by fresh wet mount, stool smears stained by modified Z.N., Trichrome and Calcofluor white stains. 20 samples (25.6%) revealed presence ofenteric protozoan parasites.

[Serological screening for Leishmania infantum in asymptomatic blood donors and HIV+ patients living in an endemic area]

Visceral leishmaniasis (VL) is endemic in Sicily (48 new cases in 2004, of which nine were in Agrigento). In southern Europe between 25-70 per cent of adult VL cases are related to HIV infection. The HIV cases have a high risk (1.5-9%) of developing VL either as a new infection or as the revival of a latent infection. We therefore carried out serologic screening to detect antibodies against L. infantum by IFAT in 1449 blood donors in Agrigento and the surrounding area (May-December 2005) and in 120 HIV+ in western Sicily, all of whom were asymptomatic and had no history of VL. L. DNA was assessed by nested PCR in blood samples of some seropositive donors. Of the 1449 blood donors, 11 (0.75%) were positive by IFAT and three of them were also positive in PCR. L. infantum seropositivity is most probably the expression of recent infection because the clearance of serum antibodies is rather fast (6-12 months) after VL. This is why blood donation by Leishmania seropositive donors, whether positive or negative by PCR, could constitute an infection risk especially for immunosuppressed recipients, who should receive deleukocyted blood. Moreover it could be useful to monitor HIV/Leishmania coinfection cases to avoid the risk of slatentization of L. infection when CD4+ levels are very low.

Microsporidiosis in South Africa: PCR detection in stool samples of HIV-positive and HIV-negative individuals and school children in Vhembe district, Limpopo Province

Microsporidia were initially recognized as pathogens of insects and fish but have recently emerged as an important group of human pathogens, especially in immune-compromised individuals, such as those with HIV infection. In this study, we used a PCR-RFLP assay confirmed by quantitative real-time PCR and trichrome staining to determine the prevalence of microsporidian infections among hospital patients and school children in Vhembe region. Enterocytozoon bieneusi was the only microsporidian species detected in these stool samples. It was found in 33 (12.9%) of 255 samples from the hospitals and in 3 (4.5%) of 67 samples from primary school children and was significantly associated (P=0.039) with diarrhea in HIV-positive patients (21.6%) compared to HIV-negative individuals (9%). However, microsporidian infections were not associated with intestinal inflammation as indicated by the lactoferrin test. These results suggest that microsporidia might be a cause of secretory diarrhea in HIV-positive patients. To our knowledge, this is the first report of E. bieneusi in the Vhembe region of South Africa. Further investigations are needed in order to clarify the pathogenesis of E. bieneusi in HIV-positive patients.

Prevalence of enteric protozoa in human immunodeficiency virus (HIV)-positive and HIV-negative men who have sex with men from Sydney, Australia

A prospective, comparative study of the prevalence of enteric protozoa was determined among human immunodeficiency virus (HIV)- positive and HIV-negative men who have sex with men (MSM) in Sydney, Australia. A total of 1,868 patients submitted stool specimens; 1,246 were from MSM (628 HIV positive and 618 HIV positive) and 622 from non-MSM were examined over a 36-month period. A total of 651 (52.2%) stool specimens from MSM were positive for protozoa compared with 85 (13%) from non-MSM. There was a significant difference in the prevalence of Blastocystis hominis, Endolimax nana, Entamoeba histolytica/dispar complex, Entamoeba hartmanni, Iodamoeba butschlii, and Enteromonas hominis detected between MSM and non-MSM (P<0.001). The only notable difference between HIV-negative and HIV-positive MSM was that HIV-infected MSM were found to more likely have a Cryptosporidium parvum infection. Entamoeba histolytica was found in 3 patients, E. dispar in 25, and E. moshkovskii in 17, all of whom were MSM. When compared with a control group, MSM were significantly more likely to harbor intestinal protozoa and have multiple parasites present. The results of this study show high rates of enteric parasites persist in MSM and highlight the importance of testing for intestinal parasites in MSM. This is the first report of E. moshkovskii from MSM.

Co-infection of malaria with HIV: an immunological perspective

Human immunodeficiency virus (HIV) and Plasmodium parasites are pathogens that induce significant perturbation and activation of the immune system. Due to their geographical overlap, there have been concerns that co-infection with the two pathogens may be a factor in the modification of their development, and in the severity and rate of disease progression that they induce. In this article, we have reviewed some of the studies that have addressed this topic and we have tried to provide immunological mechanisms to explain these potential interactions.

Cryptosporidiosis occurrence in HIV+ patients attended in a hospital, Brazil

Cryptosporidiosis occurrence was determined in HIV+ patient assisted in the Clinic of Infect-parasitic Diseases in a hospital of Nova Iguaçu, Rio de Janeiro, Brazil, in the period from Juy/1998 to March/1999. In order to research, seventy-five patient, carriers of diarrhea or not, were appraised. The samples of feces were collected and placed in saline solution with formaldehyde (5%). The Modified Ritchie technique was used for the oocysts research, and the smears were stained with Safranine O methylene blue. The results verified 9.33% of positive samples, with higher frequency of cases in patients of the masculine sex from 20 to 50 years old, however without significant difference.

Identification of a new microsporidian parasite related to Vittaforma corneae in HIV-positive and HIV-negative patients from Portugal

Fecal samples from 22 HIV-positive and 3 HIV-negative patients from Portugal with symptomatic diarrhea were diagnosed positive for microsporidia by microscopy, with most parasites detected significantly bigger than Enterocytozoon bieneusi and Encephalitozoon spp. Sequence characterization of the small subunit (SSU) rRNA gene identified a microsporidian parasite with 96% homology to two published Vittaforma corneae sequences. Phylogenetic analysis confirmed the genetic relatedness of this new microsporidian parasite to Vittaforma corneae as well as Cystosporogenes operophterae. Results of the study demonstrate the presence of a new human-pathogenic microsporidian species, which is responsible for significant number of infections in HIV-positive and HIV-negative patients in Portugal.

The identification and variability of the parasites causing leishmaniasis in HIV-positive patients in Italy

Between 1988 and 1998, 258 Leishmania strains from patients infected with HIV were characterized by iso-enzyme electrophoresis at the Istituto Superiore di Sanità (ISS) in Rome. Most (227) of the isolates came from 80 Italian patients with visceral leishmaniasis (VL), the rest from cases of Leishmania/HIV co-infection in other Mediterranean countries. Every strain was found to be Leishmania infantum. In Italy, 19 zymodemes of L. infantum were identified, broadly divided into three groups. Over 50% of the Italian patients were infected by the commonest agent of Mediterranean VL in HIV-negative individuals (zymodeme MON-1) whereas the remaining patients were infected by two distinct groups of zymodemes: one usually causing simple, self-resolving cutaneous leishmaniasis in HIV-negative patients, the other consisting of agents detected, so far, only in HIV-positive subjects. This last group, consisting of seven zymodemes, showed re-assortment patterns within electromorphs frequently observed in dermotropic L. infantum zymodemes. A similar grouping was also observed in the isolates from other Mediterranean countries. Basing on general data recorded at the ISS over the last 20 years, accurate identification of the geographical origin of the zymodemes was attempted by careful analysis of the patients' histories, using the iso-enzyme electromorphs as geographical markers. Furthermore, a polymorphism index (no. of zymodemes/no. of patients) was defined for each Leishmania species and geographical region, and used to assess the level of L. infantum zymodeme heterogeneity in Italy, before and after stratification by HIV status. The greatest zymodeme heterogeneity was found in Sicily (southern Italy), with nine zymodemes identified among only 30 HIV-positive patients.

Treatment of leishmaniasis in HIV-positive patients

Although, in southern Europe, there has been considerable experience in the treatment of visceral leishmaniasis (VL) in HIV-positive patients, the optimal therapy has yet to be established. Pentavalent antimony salts, free amphotericin B deoxycholate (ABD) and lipidic formulations of amphotericin B are the drugs most commonly used. Treatment with pentavalent antimonials requires daily injections for 28 days, is not well tolerated and leads to initial clinical cure in only 66% of the co-infected cases. Free ABD has to be given, intravenously, for just as long, has significant toxicity and leads to initial clinical cure in even fewer cases (62%). In a prospective, comparative trial, treatment of co-infected cases with a pentavalent antimonial was found to have similar efficacy and toxicity to treatment with free ABD. The duration of treatment and the associated toxicity may both be reduced by the use of lipidic formulations of amphotericin B. Anecdotal evidence and the results of non-randomized trials indicate that treatment with liposomal amphotericin B is highly effective. In a comparative trial, amphotericin B lipid complex was found to be not only as effective as a pentavalent antimonial but also better tolerated. At the moment, however, such lipidic formulations have only been tested against VL/HIV cases in Europe, not elsewhere in the world, and they remain very expensive. However successful the treatment in terms of initial clinical cure, almost all VL/HIV cases develop VL relapses. Although the data available on secondary prophylaxis are limited and often inconclusive, it appears that regular treatment with a pentavalent antimonial drug, liposomal amphothericin B or amphotericin B lipid complex can reduce the incidence of leishmanial relapses in HIV-positive patients with VL. The development of new regimens, use of new oral drugs (such as miltefosine) and the development of new antileishmanial drugs could all improve the treatment of HIV-related VL in the future.

Cryptosporidium Species and Genotypes in HIV-Positive Patients in Lima, Peru

Cryptosporidium parasites from a cross-sectional study conducted in two national hospitals in Lima, Peru were genetically characterized to determine the diversity of Cryptosporidium spp. in HIV-positive people. A total of 2,672 patients participated in this study and provided 13,937 specimens. Cryptosporidium oocysts were detected by microscopy in 354 (13.3%) of the patients. Analysis of 951 Cryptosporidium-positive specimens from 300 patients using a small subunit rRNA-based PCR-RFLP tool identified 6 genotypes; Cryptosporidium hominis was the species most frequently detected (67.5%), followed by C. meleagridis (12.6%) and C. parvum (11.3%). Cryptosporidium canis (4.0%), C. felis (3.3%), and Cryptosporidium pig genotype (0.5%) were also found. These findings indicate that C. hominis is the predominant species in Peruvian HIV-positive persons, and that zoonotic Cryptosporidium spp. account for about 30% of cryptosporidiosis in these patients.

Polymicrobial keratitis in an HIV-positive patient

We describe a case with non-responding polymicrobial spontaneous corneal ulceration in an HIV-positive patient. Acanthamoeba was among the microorganisms isolated.

[Diagnosis of coccidia and microspores in specimens of diarrheal feces from Cuban HIV seropositive patients: first report of microspores in Cuba]

The numerous specimens of liquid diarrheas received at the clinical parasitology laboratory of "Pedro Kouri" Institute of Tropical Medicine were studied searching for the presence of pathogenic agents of Coccidium subclass and of the microspore family. The conditions to diagnose microsporidia were created on July 13, 2000, and the method was incorporated to the battery of diagnostic techniques used in the laboratory. A cut-off was made after 4 months to analyze the positivity found. A frequency distribution study was conducted and it was observed that of the 170 studied samples, 51 proved to be positive for some protozoon, which represents 30% of positivity. The most frequently found species were Cryptosporidium parvum and microsporidium. Association of various species in a same sample was found in 13.1% of the positive samples. The most frequent associations were: Cryptosporidium parvum and Cyclospora cayetanensis, Cryptosporidium parvum and microsporidium, and Cyclospora cayetanensis and microsporidium, each with 2 patients. Association of 3 different species in a same sample was also found. All the individuals in the series were HIV seropositive and the most affected had less than 200 TCD4+ lymphocytes/mL. This was the first report of microsporidia in feces in Cuba. It was possible after applying and interpreting the technique previously described to identify this phylum. As there is a trend towards the increase of cases with HIV/AIDS infection, it is necessary that the laboratories have the indispendable reagents to perform the modified Didier's trichromic staining and that the professionals and technicians of the parasitology laboratories of the country be trained in the procedures for identifying and recognizing these opportunistic protozoa.

Evaluation of an immunofluorescent-antibody test using monoclonal antibodies directed against Enterocytozoon bieneusi and Encephalitozoon intestinalis for diagnosis of intestinal microsporidiosis in Bamako (Mali)

A 2-month study was carried out in Mali to evaluate an immunofluorescent-antibody test (IFAT) using monoclonal probes specific for Enterocytozoon bieneusi or Encephalitozoon intestinalis. Sixty-one human immunodeficiency virus (HIV)-seropositive adult patients and 71 immunocompetent children were enrolled. Microsporidia were detected in stools from 8 of 61 patients (13.1%) seropositive for HIV. A single species, E. bieneusi, was identified. All the children were negative for microsporidia. The sensitivity and specificity of IFAT were 100% compared with those of PCR, which was used as the "gold standard." Moreover, species identification by IFAT was more rapid and less expensive than that by PCR. These results show the suitability of IFAT for detection of microsporidia in developing countries.

Phase-1 studies of malariotherapy for HIV infecton

OBJECTIVE

To determine whether malariotherapy (an old therapy for treatment of neurosyphilis) improves some clinical and laboratory parameters of HIV-positive patients without iatrogenic complications.

METHODS

Total 8 asymptomatic HIV-1 positive subjects whose CD4 cell counts were over 250 x 10(6) cells/L were selected for the phase-1 studies of malariotherapy and were intravenously injected Plasmodia vivax to induce artificial malaria. Malaria was terminated with chloroquine after 10 to approximately 20 malarial fever episodes. Cell-bound CD4 levels were measured by APAAP (a solid-phase enzyme essay) and levels of neopterin (NPT), beta-2-microglobulin (B2M), soluble tumor necrosis factor receptor-2 (sTNF-RII), interleukin-2 (IL-2) and HIV P24 antigen were measured by ELISA. Patients were followed up to 24 to approximately 30 months.

RESULTS

CD4 levels increased in 5, NPT decreased in 7 of 8 patients; IL-2 increased in 5 of 6 patients after malariotherapy. The total trends of B2M and sTNF-RII basically remained stable. HIV P24 antigen remained undetectable in 6, remained detectably low level in 1 and experienced increase in 1 of 8 patients after malariotherapy. No any severe complications occurred in all 8 patients.

CONCLUSIONS

The results indicate that malariotherapy basically is safe for HIV infection and it seems that the therapy improves some immunological parameters of HIV patients.

Inverse association between BCG immunisation and intestinal nematode infestation among HIV-1-positive individuals in Uganda

Exposure to infections in infancy may induce a sustained bias in the immune response. In our study, previous BCG immunisation was associated with a reduced prevalence of intestinal nematode infection.

Prevalence of and factors associated with visceral leishmaniasis in human immunodeficiency virus type 1-infected patients in southern Spain

The actual prevalence of visceral leishmaniasis among human immunodeficiency type 1 (HIV-1)-infected patients in the Mediterranean basin remains unknown. There is also controversy about the risk factors for Leishmania infantum and HIV-1 coinfection. To appraise the prevalence of visceral leishmaniasis in patients infected with HIV-1 in southern Spain and to identify factors associated with this disease, 291 HIV-1 carriers underwent a bone marrow aspiration, regardless of their symptoms. Giemsa-stained samples were searched for Leishmania amastigotes. Thirty-two (11%) patients showed visceral leishmaniasis. Thirteen (41%) patients had subclinical cases of infection. Centers for Disease Control and Prevention (CDC) clinical category C was the factor most strongly associated with this disease (adjusted odds ratio [OR], 1.88 [95% confidence interval, 1.22 to 2.88]), but patients with subclinical cases of infection were found in all CDC categories. Female sex was negatively associated with visceral leishmaniasis (adjusted OR, 0.42 [95% confidence interval, 0.18 to 0.97]). Intravenous drug users showed a higher prevalence than the remaining patients (13.3 versus 4.9%; P = 0.04), but such an association was not independent. These results show that visceral leishmaniasis is a very prevalent disease among HIV-1-infected patients in southern Spain, with a high proportion of cases being subclinical. Like other opportunistic infections, subclinical visceral leishmaniasis can be found at any stage of HIV-1 infection, but symptomatic cases of infection appear mainly when a deep immunosuppression is present. There is also an association of this disease with male sex and intravenous drug use.

Pathologic outcome in HIV-seropositive individuals with nonspecific bronchoalveolar lavage cytology

OBJECTIVE

To determine the pathologic outcome in human immunodeficiency virus (HIV)-seropositive individuals with nonspecific bronchoalveolar lavage (BAL) cytology.

STUDY DESIGN

The study group consisted of 126 cytologically negative or nonspecific BAL specimens from HIV-seropositive adults. Concurrent microbial cultures and transbronchial biopsies, as well as subsequent pulmonary cytology, lung biopsy or autopsy results were reviewed. Additionally, the cytologic morphology of specimens from patients found to have a potential bacterial pathogen was reviewed.

RESULTS

In the 126 cases with nonspecific BAL cytology, a potential pulmonary pathogen was identified from a concurrent or subsequent pathologic specimen in 27% of cases, while no pathogen was identified in 73% of cases. Bacteria and fungi were the most common pathogens identified. Microbial cultures alone identified the pathogen in 59% of cases, while transbronchial biopsy added information in only 9%. Specimens with marked acute inflammation often yielded bacterial pathogens on microbial culture.

CONCLUSION

A potential pulmonary pathogen can be identified in 27% of HIV-seropositive individuals with negative BAL cytology using other diagnostic modalities. Bacterial pathogens are most common and are usually identified by microbial culture. Marked acute inflammation in a BAL specimen is often associated with bacterial pneumonia.

[Human intestinal microsporidiosis in Bamako (Mali): the presence of Enterocytozoon bieneusi in HIV seropositive patients]

A study was conducted between 1993 and 1996 in Bamako to determine the rate of occurrence of microsporidia in 88 patients. Most (80%) had chronic diarrhea associated with weight loss and 87.5% were HIV-positive. Intestinal microsporidia were detected in 32% of the patients infected with HIV-1, HIV-2, or coinfected with both strains. Microsporidiosis was also diagnosed in three of the eleven HIV-negative individuals (27%). Microsporidiosis was confirmed by electron microscopy in 6 HIV-positive patients and 1 HIV-negative individual. Enterocytozoon bieneusi was detected in each case. These results suggest that microsporidia are common pathogens in HIV-positive patients in Bamako. Cases of microsporidiosis have been reported for the first time in HIV-2-infected patients. The proportion of women microsporidiosis patients is higher in Mali than in industrialized countries. The presence of microsporidia in HIV-negative patients suggests that these parasites may be an underestimated cause of enteritis in developing countries.

Detection of Toxoplasma gondii by PCR and tissue culture in cerebrospinal fluid and blood of human immunodeficiency virus-seropositive patients

To investigate whether both tissue culture and PCR on a sequence from the repetitive rDNA could contribute to the diagnosis of toxoplasmosis, blood samples and, if they were available, cerebrospinal fluid (CSF) and aqueous humor samples from 72 human immunodeficiency virus-seropositive patients with suspected toxoplasmosis were prospectively tested. For 10 patients with fever of unknown origin but without confirmed toxoplasmosis, no Toxoplasma gondii was detected. For two patients with confirmed toxoplasmic uveitis, only PCR of aqueous humor samples was positive. Of 60 patients (48 with CSF samples) with neurological signs, 25 (from 13 of whom CSF samples were available) had confirmed cerebral toxoplasmosis and 10 had a positive PCR of CSF and/or blood samples, while for 1 patient culture of the CSF sample was also positive. Unlike tissue culture, PCR of rDNA is of value for the detection of cerebral toxoplasmosis in human immunodeficiency virus-seropositive patients, provided that both CSF and blood samples are available (sensitivity, 76.9%; specificity, 100%).

The relevance of laboratory diagnosis of human cryptosporidiosis and other coccidia

Human infection by Cryptosporidium spp and other coccidia are due to opportunist non-host specific microorganisms. In HIV seropositive patients, the gastrointestinal symptoms accompanying such infections may be serious and prolonged and may include nausea, low-grade fever, abdominal cramps, anorexia and watery diarrhoea. We studied 188 stool samples from 111 patients (84 men and 27 women) with diarrhoea. A modified Ziehl-Nielsen technique for the detection of Cryptosporidium spp and Isospora belli was employed. The mean age of the patients was 31 years. Cryptosporidium spp was seen in 18% (n = 20) of the patients, 90% (n = 18) of whom were HIV seropositive. Isospora belli was recorded only from HIV seropositive patients (5.4% of all the patients studied and 6.5% of those who were HIV seropositive). These data confirm the good results obtained with this technique for the identification of Cryptosporidium spp and other coccidia and also reaffirm the clinical importance of correctly diagnosing the cause of diarrhoea, particularly in HIV seropositive patients.

Intestinal parasites in HIV-seropositive Zambian children with diarrhoea

We undertook a study over a period of 9 months to define the frequency of parasitic infections in hospitalized children with diarrhoea between the ages of 15 months and 5 years. Every alternate day, mothers of all children admitted with diarrhoea between 09.00 hours and 12.00 hours to one of the wards of the Department of Pediatrics and Child Health of the University Teaching Hospital (UTH) in Lusaka, Zambia, were interviewed for enrollment of their children into the study. A total of 178 children with diarrhoea were enrolled in the study. Of these 44 (25 per cent) were HIV seropositive and 134 (75 per cent) were seronegative for HIV. Out of 44 HIV-seropositive patients, 20 (45 per cent) had acute diarrhoea and 24 (55 per cent) had chronic diarrhoea. Of the 134 HIV-seronegative patients, 68 had acute diarrhoea (51 per cent) and 66 (49 per cent) had chronic diarrhoea. At least one intestinal parasite was found in 34 out of the 178 children enrolled. The commonest parasites identified were Ascaris and Cryptosporidia. No associations were identified between parasite isolation and the following: age, sex, or socio-economic status. Cryptosporidium spp. was isolated from 6 out of 44 (14 per cent) HIV-seropositive children, while 8 out of 134 (6 per cent) seronegative children had the parasite (P = 0.01). HIV-seropositive children with chronic diarrhoea had significantly higher cryptosporidium identification rates than those HIV-seropositive children with acute diarrhoea [5 out of 24 (21 per cent) patients with chronic diarrhoea compared to 1 out of 20 (5 per cent) patients with acute diarrhoea; (P > or = 0.01)].(ABSTRACT TRUNCATED AT 250 WORDS)

Atypical cutaneous histological features of visceral leishmaniasis in acquired immunodeficiency syndrome

Cutaneous lesions in Mediterranean visceral leishmaniasis (VL) are very unusual, except for the presence of Leishmania organisms in cutaneous Kaposi's sarcoma in patients with acquired immunodeficiency syndrome (AIDS). We have identified two unusual cutaneous histological features of VL in three patients with AIDS not described previously; two had "silent leishmaniasis," and in the third, Leishmania organisms were present in sweat ducts, suggesting transepithelial elimination through eccrine sweat glands and/or eccrine epithelial tropism.

[Parasitic diseases in patients with impaired immune response. Clinical picture and diagnosis]

Patients with impaired immune system are frequently infected with various parasitic diseases. The clinical picture is characterized by unusual manifestations and frequently severe recurrences of infections which are not normally serious. Some almost parasitic microorganisms produce symptoms exclusively in patients with impaired immune system. Parasitic infections have become increasingly common with the increasing number of patients who live for prolonged periods with impaired immune systems, often as a result of infection with HIV. Among the numerous parasitic infections which are observed in man, there are a few which occur particularly frequently in patients with impaired immune systems. This is a brief review of the clinical pictures and diagnostic options in parasitic disease in individuals with impaired immune system with particular emphasis on infections caused by: Pneumocystis carinii, Toxoplasma gondii, Cryptosporidium ssp., Microspora, Entamoeba histolytica, Leishmania ssp., and Strongyloides stercoralis. In patients with impaired immunity, parasitic infections frequently cause nonspecific symptoms and, on account of the impaired immunity, antibodies to the parasite are not always produced. The diagnosis of these infections is, therefore, based on morphological demonstration of the microorganism concerned, culture, specific antigen or DNA defections.

New rapid staining methods of Cryptosporidium oocysts in stools

Two new extemporaneous negative-staining methods are proposed to detect Cryptosporidium oocysts in stools, using light-green and merbromine in 1% and 2% aqueous solution, respectively. A Ziehl-Neelsen stain as modified by Henriksen and Polhenz was used as a reference technique. A comparison between these two new stains and the reference, a modified Ziehl-Neelsen mod. method gave almost identical sensitivity and specificity. We propose their use in routine diagnosis for enteric cryptosporidiosis.

The clinical and parasitological presentation of Plasmodium falciparum malaria in Uganda is unaffected by HIV-1 infection

The relation between Plasmodium falciparum malaria and symptomatic human immunodeficiency virus 1 (HIV-1) infection was investigated in paediatric and adult patients in Kampala, Uganda, from 1987 to 1989. Both infections contributed largely to hospital morbidity. Of 1527 clinically suspicious in-patients, 61% were positive for HIV-1 infection. 52% of patients with positive HIV-1 serology fulfilled the World Health Organization clinical case definition for acquired immune deficiency syndrome (AIDS) in Africa. No association could be found between HIV-1 infection and malaria either in paediatrics or in adults. P. falciparum parasitaemia was present in 18% of all patients and no differences in prevalence of malaria infection or in parasite density could be demonstrated between HIV-1 positive and HIV-1 negative patients. The comparison of clinical symptoms showed typical differences in AIDS-related morbidity but no difference in malaria-specific morbidity. Also, the response to malaria treatment was the same in HIV-1 positive and HIV-1 negative patients. P. falciparum malaria does not appear to act as an opportunistic agent in AIDS patients in Uganda.

Persistent diarrhoea in Zairian AIDS patients: an endoscopic and histological study

To determine the aetiology of persistent diarrhoea in African patients with acquired immunodeficiency syndrome (AIDS), 42 patients with human immunodeficiency virus (HIV) and persistent diarrhoea were enrolled in a microbiological, endoscopic, and histological study. Cryptosporidium was the intestinal parasite most often identified (30%); Isospora belli was found in 12% of the patients. Histological examination of the duodenal mucosa showed a non-specific inflammatory reaction in a significantly higher number of HIV-seropositive patients (82%) than HIV-seronegative controls without diarrhoea (52%) (p = 0.02). Lymphocytes were more likely to be found in inflammatory reactions in HIV-seropositive patients than in controls (p less than 0.0001). Pathogens were observed in histological sections of the duodenum of HIV-seropositive patients only (p = 0.002) and included cryptosporidia (four patients) Isospora belli (one), Strongyloides stercoralis (one), and Cryptococcus neoformans (one). On histological examination the rectal mucosa of HIV-seropositive patients and controls was similar, except eosinophils were more likely to be present in inflammatory reaction in HIV-seropositive patients (p = 0.05) and enteric pathogens were observed only in HIV-seropositive patients (cytomegalovirus inclusion bodies (one) and Schistosoma mansoni (two). The aetiology of persistent diarrhoea in most African AIDS patients remains unclear.

[Technics for identifying Cryptosporidium spp. in feces: synthetic review and personal experience on anti-HIV seropositive, AIDS-related complex and AIDS subjects]

The authors describe the most common techniques used for the detection of Cryptosporidium spp. in the faeces. Coproparasitological investigations have been carried out on 216 patients anti-HIV seropositives, 192 of them with no symptoms, 5 with ARC and 19 with AIDS. The techniques that have been used are: the FPC concentration, the colouring of Henriksen and Pohlenz and modified Koster, the indirect immunofluorescent assay with monoclonal antibodies. Oocystis of Cryptosporidium spp. have been recovered in three patients, two ARC and one AIDS. On the ground of the authors' experiences the used techniques must be considered particularly suitable for the diagnosis of cryptosporidiosis.