Hemophagocytic lymphohistiocytosis-how common and how severe is it as a complication of malaria? Retrospective case series and review of the literature.

BACKGROUND: Infection-associated secondary hemophagocytic lymphohistiocytosis (sHLH) is a potentially life-threatening hyperinflammatory condition caused by various infectious diseases. Malaria has rarely been described as trigger. The aim of this study is to collect data on frequency, clinical spectrum, and outcome of sHLH induced by malaria. METHODS: We collected case numbers on malaria and malaria-associated sHLH from specialized centers in Germany from 2015 to 2022. In addition, we conducted a literature search on published cases of malaria-associated sHLH and systematically analyzed the literature regarding clinical and diagnostic criteria. RESULTS: We obtained data from 13 centers treating 1461 malaria cases with different Plasmodium species, of which 5 patients (0.34%) also were diagnosed with sHLH. The literature search revealed detailed case reports from further 51 patients and case series comprising the description of further 24 patients with malaria-associated sHLH. Most cases (48/80; 60%) were reported from Asia. The median time interval between onset of malaria symptoms and hospital admission was 7 days. Severe complications of sHLH were documented in 36% (20/56) of patients, including two patients with multiple organ failure in our case series. Only 41% (23/56) of patients received specific treatment for sHLH, nevertheless the mortality rate (CFR) of 5% is lower compared to the CFR reported for sHLH triggered by other infectious diseases (e.g., 25% in sHLH due to EBV infection). CONCLUSION: Malaria-associated sHLH appears to have a comparatively good prognosis but may still represent an underdiagnosed and potentially fatal complication of malaria, especially in resource-poor settings.

The implementation of the Kinyoun staining technique in a resource-limited setting is feasible and reveals a high prevalence of intestinal cryptosporidiosis in patients with HIV.

OBJECTIVES: In resource-limited settings, intestinal Cryptosporidial or coccidian infections are common causes of chronic diarrhea but usually remain undiagnosed by routine stool investigation. Here, the addition of the Kinyoun staining technique after stool concentration was evaluated as an easy and inexpensive method for diagnosis of intestinal parasitic infection in patients with HIV. METHODS: This cross-sectional study investigated patients with HIV with diarrhea and randomly selected patients with HIV without diarrhea as controls. Stool samples were examined by wet mount microscopy and Kinyoun staining after stool concentration. Clinical, sociodemographic, and behavioral data were collected. Statistical analysis was performed using chi-squared test and multivariate regression analysis. RESULTS: In total, 163 participants were included (62.0% female, mean age 38.2 [SD ± 10.7] years). Diarrhea was present in 52.1% (85/163). The prevalence of intestinal parasites was 18.4% (30/163). Cryptosporidial infections were more frequent among patients with diarrhea (12.9% [11/85] vs 1.3% [1/78], P = 0.005) and in patients with CD4+ cell count <200 cells/µl (25.9% [7/27] vs 3.7% [5/136], P = 0.001). Risk factors for intestinal parasitic infections were diarrhea and the habit of regularly eating uncooked food. Kinyoun staining was necessary for the detection of cryptosporidiosis. CONCLUSION: In our cohort, the prevalence of intestinal parasitic infection was high, especially after additional use of Kinyoun staining for detection of Cryptosporidia or intestinal coccidia. Considering its clinical relevance, particularly in individuals at risk, the implementation of this technique should be considered in resource-limited settings.

Schistosoma mansoni infection but not egg antigen promotes recovery from colitis in outbred NMRI mice.

BACKGROUND: The ability of intestinal helminths to manipulate the immune system of their host towards a Th2 response has been proposed to modulate auto-immune and allergic diseases. AIMS: This initial study investigated the anti-inflammatory potential of S. mansoni and soluble egg antigen (SEA) in a murine model of colitis. METHODS: Colitis was induced in female NMRI mice by 5% dextran sulfate sodium (DSS) for 7 days, either 9 weeks post-infection with S. mansoni or during treatment with SEA. In addition to clinical signs of colitis, colon histology, immunohistochemistry, and flow cytometry of leukocytes were performed. Colon cytokines were measured using a quantitative real-time technique. RESULTS: Infection with cercariae of S. mansoni attenuated DSS-induced colitis. Clinical symptoms such as weight loss and shortening of colon length were significantly prevented. Histological scores and cell infiltration were affected and expression of pro-inflammatory cytokines in the colons of infected DSS colitis mice was reduced. In contrast, application of SEA failed to improve colitis, even though some findings like earlier manifestation of inflammation and local induction of Th2 cytokines were similar to the effects of cercarial infection. CONCLUSIONS: The results presented here suggest that SEA treatment could not protect mice from acute colitis. However, both infection with S. mansoni and injection of SEA affect mucosal immune responses.

Improvement of a tissue maceration technique for the determination of placental involvement in schistosomiasis.

Schistosomiasis in pregnancy may cause low birth weight, prematurity and stillbirth of the offspring. The placenta of pregnant women might be involved when schistosome ova are trapped in placental tissue. Standard histopathological methods only allow the examination of a limited amount of placental tissue and are therefore not sufficiently sensitive. Thus, placental schistosomiasis remains underdiagnosed and its role in contributing to schistosomiasis-associated pregnancy outcomes remains unclear. Here we investigated an advanced maceration method in order to recover a maximum number of schistosome ova from the placenta. We examined the effect of different potassium hydroxide (KOH) concentrations and different tissue fixatives with respect to maceration success and egg morphology. Placental tissue was kept either in 0.9% saline, 5% formalin or 70% ethanol and was macerated together with Schistosoma mansoni infested mouse livers and KOH 4% or 10%, respectively. We found that placenta maceration using 4% KOH at 37°C for 24 h was the most effective method: placental tissue was completely digested, egg morphology was well preserved and alkaline concentration was the lowest. Ethanol proved to be the best fixative for this method. Here we propose an improved maceration technique in terms of sensitivity, safety and required skills, which may enable its wider use also in endemic areas. This technique may contribute to clarifying the role of placental involvement in pregnant women with schistosomiasis.

Pneumocystis pneumonia (PCP) and Pneumocystis jirovecii carriage in renal transplantation patients: a single-centre experience.

BACKGROUND: The Pneumocystis pneumonia is an increasing problem in transplanted patients: up to 25% suffer from Pneumocystis pneumonia, occurring during the first 6 months after transplantation. METHODS: From 2001 to 2009, we investigated 21 patients with pneumonia after renal transplantation for the presence of Pneumocystis jirovecii. The laboratory diagnosis was established by Grocott and Giemsa staining methods and Pneumocystis-specific mitochondrial transcribed large subunit nested polymerase chain reaction (PCR). The PCR was also used for the differentiation of Pneumocystis pneumonia from Pneumocystis carriage. RESULTS: Of 21 patients, 7 had a Pneumocystis pneumonia, 6 were Pneumocystis carriers and 8 patients were negative. Four out of seven Pneumocystis pneumonia patients and two out of six patients with Pneumocystis carriage had a delayed graft function. An acute cytomegalovirus infection after transplantation was not detectable in the patients with Pneumocystis pneumonia, but in three patients with Pneumocystis carriage. CONCLUSIONS: Pneumocystis pneumonia was present in 33.3% of transplanted patients with suspected pneumonia. An association between acute rejection or co-infections and Pneumocystis pneumonia or carriage in patients after renal transplantation cannot be excluded. In three out of seven Pneumocystis pneumonia patients, an overlapping of hospitalisation times and an onset of Pneumocystis pneumonia 6 months after transplantation was found. Thus, person-to-person transmission seems probable in these cases.

Confocal laser scanning microscopy, a new in vivo diagnostic tool for schistosomiasis.

BACKGROUND: The gold standard for the diagnosis of schistosomiasis is the detection of the parasite's characteristic eggs in urine, stool, or rectal and bladder biopsy specimens. Direct detection of eggs is difficult and not always possible in patients with low egg-shedding rates. Confocal laser scanning microscopy (CLSM) permits non-invasive cell imaging in vivo and is an established way of obtaining high-resolution images and 3-dimensional reconstructions. Recently, CLSM was shown to be a suitable method to visualize Schistosoma mansoni eggs within the mucosa of dissected mouse gut. In this case, we evaluated the suitability of CLSM to detect eggs of Schistosoma haematobium in a patient with urinary schistosomiasis and low egg-shedding rates. METHODOLOGY/PRINCIPAL FINDINGS: The confocal laser scanning microscope used in this study was based on a scanning laser system for imaging the retina of a living eye, the Heidelberg Retina Tomograph II, in combination with a lens system (image modality). Standard light cystoscopy was performed using a rigid cystoscope under general anaesthesia. The CLSM endoscope was then passed through the working channel of the rigid cystoscope. The mucosal tissue of the bladder was scanned using CLSM. Schistoma haematobium eggs appeared as bright structures, with the characteristic egg shape and typical terminal spine. CONCLUSION/SIGNIFICANCE: We were able to detect schistosomal eggs in the urothelium of a patient with urinary schistosomiasis. Thus, CLSM may be a suitable tool for the diagnosis of schistosomiasis in humans, especially in cases where standard diagnostic tools are not suitable.

Confocal laser scanning microscopy for detection of Schistosoma mansoni eggs in the gut of mice.

BACKGROUND: The gold standard for diagnosing Schistosoma mansoni infections is the detection of eggs from stool or biopsy specimens. The viability of collected eggs can be tested by the miracidium hatching procedure. Direct detection methods are often limited in patients with light or early infections, whereas serological tests and PCR methods fail to differentiate between an inactive and persistent infection and between schistosomal species. Recently, confocal laser scanning microscopy (CLSM) has been introduced as a diagnostic tool in several fields of medicine. In this study we evaluated CLSM for the detection of viable eggs of S. mansoni directly within the gut of infected mice. METHODOLOGY/PRINCIPAL FINDINGS: The confocal laser scanning microscope used in this study is based on the Heidelberg Retina Tomograph II scanning laser system in combination with the Rostock Cornea Module (image modality 1) or a rigid endoscope (image modality 2). Colon sections of five infected mice were examined with image modalities 1 and 2 for schistosomal eggs. Afterwards a biopsy specimen was taken from each colon section and examined by bright-field microscopy. Visualised eggs were counted and classified in terms of viability status. CONCLUSIONS/SIGNIFICANCE: We were able to show that CLSM visualises eggs directly within the gut and permits discrimination of schistosomal species and determination of egg viability. Thus, CLSM may be a suitable non-invasive tool for the diagnosis of schistosomiasis in humans.