Human cystic echinococcosis is a chronic, complex and neglected infection. Its clinical management has evolved over decades without adequate evaluation of efficacy. Recent expert opinion recommends ...that uncomplicated inactive cysts of the liver should be left untreated and solely monitored over time ("watch-and-wait" approach). However, clinical data supporting this approach are still scant and published mostly as conference proceedings. In this study, we report our experience with long-term sonographic and serological follow-up of inactive cysts of the liver. From March 1994 to October 2013, 38 patients with 47 liver cysts, diagnosed as inactive without any previous treatment history, were followed with ultrasound and serology at 6-12 months intervals for a period of at least 24 months (median follow-up 51.95 months) in our outpatient clinic. In 97.4% of patients, the cysts remained inactive over time and in only one case was reactivation of the cyst detected. No complications occurred during the time of monitoring. During follow-up, serology tests for CE were negative at diagnosis or became negative in 74.1% and were positive or became positive in 25.9% of cases. Patients with inactive cysts on ultrasound but positive serological tests were also investigated by CT scan (chest and abdomen) to rule out extra-hepatic cyst localization. This study confirms the importance of a stage-specific approach to the management of cystic echinococcosis and supports the use of a monitoring-only approach to inactive, uncomplicated cysts of the liver. It also confirms that serology plays only an ancillary role in the clinical management of these patients, compared to ultrasound and other imaging techniques. The implications of these findings for clinical management and natural history of cystic echinococcosis are discussed.
Background The diagnosis of cystic echinococcosis (CE) is based primarily on imaging, in particular with ultrasound for abdominal CE, complemented by serology when imaging results are unclear. In ...rural endemic areas, where expertise in ultrasound may be scant and conventional serology techniques are unavailable due to lack of laboratory equipment, Rapid Diagnostic Tests (RDTs) are appealing. Methodology/Principal Findings We evaluated the diagnostic accuracy of 3 commercial RDTs for the diagnosis of hepatic CE. Sera from 59 patients with single hepatic CE cysts in well-defined ultrasound stages (gold standard) and 25 patients with non-parasitic cysts were analyzed by RDTs VIRapid HYDATIDOSIS (Vircell, Spain), Echinococcus DIGFA (Unibiotest, China), ADAMU-CE (ICST, Japan), and by RIDASCREEN Echinococcus IgG ELISA (R-Biopharm, Germany). Sensitivity, specificity and ROC curves were compared with McNemar and t-test. For VIRapid and DIGFA, correlation between semiquantitative results and ELISA OD values were evaluated by Spearman's coefficient. Reproducibility was assessed on 16 randomly selected sera with Cohen's Kappa coefficient. Sensitivity and Specificity of VIRapid (74%, 96%) and ADAMU-CE (57%, 100%) did not differ from ELISA (69%, 96%) while DIGFA (72%, 72%) did (p = 0.045). ADAMU-CE was significantly less sensitive in the diagnosis of active cysts (p = 0.019) while DIGFA was significantly less specific (p = 0.014) compared to ELISA. All tests were poorly sensitive in diagnosing inactive cysts (33.3% ELISA and ADAMU-CE, 42.8% DIGFA, 47.6% VIRapid). The reproducibility of all RDTs was good-very good. Band intensity of VIRapid and DIGFA correlated with ELISA OD values (r = 0.76 and r = 0.79 respectively, p<0.001). Conclusions/Significance RDTs may be useful in resource-poor settings to complement ultrasound diagnosis of CE in uncertain cases. VIRapid test appears to perform best among the examined kits, but all tests are poorly sensitive in the presence of inactive cysts, which may pose problems with accurate diagnosis.
Opinion Statement
Cystic echinococcosis (CE) is a chronic, complex, and neglected disease. Its treatment depends on a number of factors, such as location, size, and stage of the cysts, and ...availability of therapeutic options. Despite the wealth of scientific literature on treatment for echinococcosis, the current management of the disease is based on poor to moderate quality of evidence and recommendation strength. In addition, therapeutic strategies have been developed over time without systematic and adequate evaluation of their efficacy, effectiveness, and safety. This is due to the lack of large, longitudinal, controlled studies, which in turn is partly due to the chronicity of the disease which requires a follow-up of many years. The lack of adequate funding makes these costly trials impossible to implement. Although the recommended multidisciplinary and stage-specific approach may be available in referral centers, this is often not the case in many endemic countries, where the most affected populations have limited access to diagnosis and therapy, and where the risks associated with invasive procedures may be particularly high. The level of evidence on which clinicians have to rely is low. For the time being, patients should preferably be treated in referral centers only. Proper comparative clinical trials are urgently needed. Because of space constraints, this update will focus on the most frequent location of CE, the liver.
We describe a case of isolated acute appendicitis due to Aspergillus carneus in a neutropenic child with acute myeloid leukemia (AML) treated according to the AIEOP AML 2002/01 protocol. Despite ...prophylaxis with acyclovir, ciprofloxacin and fluconazole administered during the neutropenic phase, 16 days after the end of chemotherapy the child developed fever without identified infective foci, which prompted a therapy shift to meropenem and liposomial amphotericin B. After five days of persisting fever he developed ingravescent abdominal lower right quadrant pain. Abdominal ultrasound was consistent with acute appendicitis and he underwent appendectomy with prompt defervescence. PAS+ fungal elements were found at histopathology examination of the resected vermiform appendix, and galactomannan was low positive. A. carneus, a rare species of Aspergillus formerly placed in section Flavipedes and recently considered a member of section Terrei, was identified in the specimen. Treatment with voriconazole was promptly started with success. No other site of Aspergillus localization was detected. Appendicitis is rarely caused by fungal organisms and isolated intestinal aspergillosis without pulmonary infection is unusual. To our knowledge, this is the first report of infection due to A. carneus in a child and in a primary gastrointestinal infection.
Mass drug administration (MDA) programmes against Onchocerca volvulus use ivermectin (IVM) which targets microfilariae (MF), the worm's offspring. Most infected individuals are hyporesponsive and ...present regulated immune responses despite high parasite burden. Recently, with MDA programmes, the existence of amicrofilaridermic (a-MF) individuals has become apparent but little is known about their immune responses. Within this immunoepidemiological study, we compared parasitology, pathology and immune profiles in infection-free volunteers and infected individuals that were MF+ or a-MF. The latter stemmed from villages in either Central or Ashanti regions of Ghana which, at the time of the study, had received up to eight or only one round of MDA respectively. Interestingly, a-MF patients had fewer nodules and decreased IL-10 responses to all tested stimuli. On the other hand, this patient group displayed contrary IL-5 profiles following in vitro stimulation or in plasma and the dampened response in the latter correlated to reduced eosinophils and associated factors but elevated neutrophils. Furthermore, multivariable regression analysis with covariates MF, IVM or the region (Central vs. Ashanti) revealed that immune responses were associated with different covariates: whereas O. volvulus-specific IL-5 responses were primarily associated with MF, IL-10 secretion had a negative correlation with times of individual IVM therapy (IIT). All plasma parameters (eosinophil cationic protein, IL-5, eosinophils and neutrophils) were highly associated with MF. With regards to IL-17 secretion, although no differences were observed between the groups to filarial-specific or bystander stimuli, these responses were highly associated with the region. These data indicate that immune responses are affected by both, IIT and the rounds of IVM MDA within the community. Consequently, it appears that a lowered infection pressure due to IVM MDA may affect the immune profile of community members even if they have not regularly participated in the programmes.
Onchocerciasis affects an estimated 37 million people in Sub-Saharan Africa and Latin America, causing debilitating skin and eye disease and accounting for a global loss of 1 million ...Disability-Adjusted Life-Years. The discovery of Wolbachia bacterial endosymbionts in filarial nematodes, including Onchocerca volvulus, has revolutionised the understanding of the parasite’s biology and immunopathogenic mechanisms of disease, and has offered a novel approach to its treatment and control with anti-Wolbachia antibiotics. Treatment with doxycycline is effective at sterilising and killing adult O. volvulus worms, proving superior to standard microfilaricidal treatment with ivermectin and of great potential as an alternative strategy for the control of onchocerciasis. Although the length of the required treatment has raised concerns about the use of doxycycline in Mass Drug Administration (MDA) strategies, a recent trial in Cameroon demonstrated the feasibility of a six week course of doxycycline MDA delivered with a community-directed approach. In the work presented here we found a significant reduction in microfilaridermia prevalence and loads four years after doxycycline MDA distribution, demonstrating its long-term effectiveness and supporting its implementation in existing control strategies. Wolbachia peptidoglycan-associated lipoprotein stimulates innate and adaptive immune responses, contributing to disease pathogenesis through the induction of pro-inflammatory cytokines and recruitment of neutrophils. These features together with the cytokine milieu induced by filarial nematodes could support the development of a pro-inflammatory Type-17 immune response. In this work, PBMC from patients with onchocerciasis were found to produce only minimal levels of IL-17 in response to filarial extracts. On the contrary, a rich IL-17+ cell infiltrate was found surrounding adult worms in Wolbachia positive onchocercomas using immunohistochemistry (IHC), which was depleted from onchocercomas following doxycycline treatment. Although a high percentage of Th17 cells were present in this infiltrate compared to other diseases, the majority of IL-17 producing cells in nodules were neutrophils, within an extracellular trap-like structure. This unexpected result was consistent with the reported IL-17 production by human neutrophils using IHC in the literature, but could not be confirmed at the protein or the transcription level in vitro in this work. Wolbachia is responsible for an abundant neutrophil infiltration in Onchocerca-infected tissues. However, the role of neutrophils in the immune response to filarial parasites and their interaction with Wolbachia is poorly known. The work presented here showed that Wolbachia lipoprotein activates human neutrophils in vitro, supporting previous studies demonstrating the link between Wolbachia and neutrophils in the host inflammatory responses to O. volvulus infection. These results also indentify Wolbachia lipoprotein as a key molecule driving human neutrophil recruitment and activation.
Onchocerciasis affects an estimated 37 million people in Sub-Saharan Africa and Latin America, causing debilitating skin and eye disease and accounting for a global loss of 1 million ...Disability-Adjusted Life-Years. The discovery of Wolbachia bacterial endosymbionts in filarial nematodes, including Onchocerca volvulus, has revolutionised the understanding of the parasite’s biology and immunopathogenic mechanisms of disease, and has offered a novel approach to its treatment and control with anti-Wolbachia antibiotics. Treatment with doxycycline is effective at sterilising and killing adult O. volvulus worms, proving superior to standard microfilaricidal treatment with ivermectin and of great potential as an alternative strategy for the control of onchocerciasis. Although the length of the required treatment has raised concerns about the use of doxycycline in Mass Drug Administration (MDA) strategies, a recent trial in Cameroon demonstrated the feasibility of a six week course of doxycycline MDA delivered with a community-directed approach. In the work presented here we found a significant reduction in microfilaridermia prevalence and loads four years after doxycycline MDA distribution, demonstrating its long-term effectiveness and supporting its implementation in existing control strategies. Wolbachia peptidoglycan-associated lipoprotein stimulates innate and adaptive immune responses, contributing to disease pathogenesis through the induction of pro-inflammatory cytokines and recruitment of neutrophils. These features together with the cytokine milieu induced by filarial nematodes could support the development of a pro-inflammatory Type-17 immune response. In this work, PBMC from patients with onchocerciasis were found to produce only minimal levels of IL-17 in response to filarial extracts. On the contrary, a rich IL-17+ cell infiltrate was found surrounding adult worms in Wolbachia positive onchocercomas using immunohistochemistry (IHC), which was depleted from onchocercomas following doxycycline treatment. Although a high percentage of Th17 cells were present in this infiltrate compared to other diseases, the majority of IL-17 producing cells in nodules were neutrophils, within an extracellular trap-like structure. This unexpected result was consistent with the reported IL-17 production by human neutrophils using IHC in the literature, but could not be confirmed at the protein or the transcription level in vitro in this work. Wolbachia is responsible for an abundant neutrophil infiltration in Onchocerca-infected tissues. However, the role of neutrophils in the immune response to filarial parasites and their interaction with Wolbachia is poorly known. The work presented here showed that Wolbachia lipoprotein activates human neutrophils in vitro, supporting previous studies demonstrating the link between Wolbachia and neutrophils in the host inflammatory responses to O. volvulus infection. These results also indentify Wolbachia lipoprotein as a key molecule driving human neutrophil recruitment and activation.
To investigate the usefulness of serum cytokine dosage in the clinical management of cystic echinococcosis (CE), we analyzed serum levels of Th1 and Th2 cytokines in patients with hepatic CE in ...different cyst stages, CE1-2 (active), CE3a-3b (transitional), and CE4-5 (inactive). Ex vivo assessment of Th1 (IFN-γ) and Th2 (IL-4, IL-13, and IL-10) cytokines in sera was carried out using ELISA. IL-10 was undetectable in all serum samples of patients and controls, while a few sera contained measurable amounts of IFN-γ, IL-4, and IL-13. No statistically significant difference was found between the percentages of positive samples for each cytokine and the different groups analyzed (patients/controls, stage, number, location, and size of the cyst, serology, and sex of patients), with the exception of the association of IL-4 and IL-13 with the cyst stage. Overall, this investigation showed many limits of serum cytokine dosage as a marker of biological activity of echinococcal cysts. Because of low sensitivity and lack of specificity of this test, we believe that other ways to evaluate ex vivo biological activity of the cysts should be explored.
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