The diagnostic accuracy of an indirect immunofluorescence antibody test (IFAT) for Strongyloides stercoralis at different serum antibody titers was evaluated. To assess diagnostic sensitivity, sera from 156 patients with known strongyloidiasis were collected. Negative control sera were obtained from a composite group of 427 subjects (blood donors and hospitalized patients). With an area under the receiver-operating characteristic plot of 0.98, the IFAT showed a high level of diagnostic accuracy for strongyloidiasis. An antibody titer of >1:20, with 97% sensitivity and 98% specificity, was identified as the diagnostic threshold with the best overall performance. Cross-reactions were evaluated with 41 additional samples from patients with other known helminth infections, and the IFAT detected low-titer positivity in only one subject with filariasis. A positive IFAT result at an antibody dilution of >1:80 was virtually 100% specific, with 71% sensitivity. To test the usefulness of the IFAT as a monitoring tool, the changes in specific-antibody titers after treatment in a group of 155 patients were evaluated. Seroreversion or a decrease in antibody titer of twofold or more was observed in 60% of the patients. Response to treatment was directly correlated to the initial antibody titer, and a baseline titer of >1:80 was identified as the best predictor of response. In conclusion, a positive IFAT result at an antibody dilution of >1:20 is the optimal cutoff for screening. A titer of >1:80, with virtually no false-positive result, is a reliable cutoff for a serological assessment of treatment efficacy and for inclusion in clinical trials.
BackgroundStrongyloidiasis may cause a life-threatening disease in immunosuppressed patients. This can only be prevented by effective cure of chronic infections. Direct parasitologic exams are not sensitive enough to prove cure if negative. We used an indirect immune fluorescent antibody test (IFAT) along with direct methods for patient inclusion and efficacy assessment.Methodology/Principal FindingsProspective, randomized, open label, phase III trial conducted at the Centre for Tropical Diseases (Verona, Italy) to compare efficacy and safety of ivermectin (single dose, 200 µg/kg) and thiabendazole (two daily doses of 25 mg/Kg for two days) to cure strongyloidiasis. The first patient was recruited on 6th December, 2004. Follow-up visit of the last patient was on 11th January, 2007. Consenting patients responding to inclusion criteria were randomly assigned to one of the treatment arms. Primary outcome was: negative direct and indirect (IFAT) tests at follow-up (4 to 6 months after treatment) or subjects with negative direct test and drop of two or more IFAT titers. Considering 198 patients who concluded follow-up, efficacy was 56.6% for ivermectin and 52.2% for thiabendazole (p = 0.53). If the analysis is restricted to 92 patients with IFAT titer 80 or more before treatment (virtually 100% specific), efficacy would be 68.1% for ivermectin and 68.9% for thiabendazole (p = 0.93). Considering direct parasitological diagnosis only, efficacy would be 85.7% for ivermectin and 94.6% for thiabendazole (p = 0.21). In ivermectin arm, mild to moderate side effects were observed in 24/115 patients (20.9%), versus 79/108 (73.1%) in thiabendazole arm (p = 0.00).ConclusionNo significant difference in efficacy was observed, while side effects were far more frequent in thiabendazole arm. Ivermectin is the drug of choice, but efficacy of single dose is suboptimal. Different dose schedules should be assessed by future, larger studies.Trial Registration Portal of Clinical Research with Medicines in Italy 2004–004693–87
In resource-limited countries, the diagnosis of pulmonary tuberculosis (TB) is based on clinical findings, chest radiography and the demonstration of acid-fast bacilli in sputum. Few data are available on the use of ultrasound (US) to diagnose pulmonary TB. Chest US was performed in patients with lung TB from a rural African setting, to look for signs of the disease and to clarify the role US may have in the diagnosis of pulmonary TB. Sixty adult patients diagnosed with lung TB underwent chest US. All patients had abnormal findings. The most frequent was a subpleural nodule (SUN), which was mostly multiple and also found in radiologically normal areas. Other findings were lung consolidations, cavitations, miliary patterns made of miniature SUNs, and pleural and pericardial effusions. Chest US is a complementary tool in evaluating patients with suspected lung TB in resource-limited settings where the disease has high prevalence.
The prevalence of schistosomiasis among recent refugees from sub-Saharan Africa in Italy is unknown. This is a retrospective review of African immigrants screened at Centre for Tropical Diseases of Negrar from March 2014 to February 2016. Of the 373 immigrants tested, 34% were positive at least at one schistosomiasis test. The proportion of positive ELISA serology was 103/373 (27.6%). At microscopy, infected subjects were 65/373 (17.4%), (51% Schistosoma haematobium, 38% Schistosoma mansoni, 11% both). CCA antigen for S. mansoni was positive in 47/373 individuals (12.6%). We found a particularly high positivity rate in subjects from Mali (72.1%) and Ivory Coast (48%). This "hidden epidemic" of schistosomiasis cannot be longer neglected, considering the risk of severe complications, and the effective and inexpensive treatment available.
Chagas disease, a neglected tropical disease that due to population movements is no longer limited to Latin America, threatens a wide spectrum of people (travellers, migrants, blood or organ recipients, newborns, adoptees) also in non-endemic countries where it is generally underdiagnosed. In Italy, the available epidemiological data about Chagas disease have been very limited up to now, although the country is second in Europe only to Spain in the number of residents from Latin American. Among 867 at-risk subjects screened between 1998 and 2010, the Centre for Tropical Diseases in Negrar (Verona) and the Infectious and Tropical Diseases Unit, University of Florence found 4.2% patients with positive serology for Chagas disease (83.4% of them migrants, 13.8% adoptees). No cases of Chagas disease were identified in blood donors or HIV-positive patients of Latin American origin. Among 214 Latin American pregnant women, three were infected (resulting in abortion in one case). In 2005 a case of acute Chagas disease was recorded in an Italian traveller. Based on our observations, we believe that a wider assessment of the epidemiological situation is urgently required in our country and public health measures preventing transmission and improving access to diagnosis and treatment should be implemented.
BackgroundSchistosomiasis is one of the most important neglected tropical diseases. If unrecognised and untreated, the chronic infection can lead to irreversible complications.MethodsRetrospective observational study aimed at describing clinical history, laboratory findings and imaging presentation of imported schistosomiasis diagnosed at the Centre for Tropical Diseases, Sacro Cuore Don Calabria Hospital of Negrar, Verona, Italy from 2010 to 2014. The aim of our study was to assess differences in demographic characteristics, clinical presentation, laboratory data and ultrasound findings between immigrants/visiting friends and relatives (VFR) from endemic countries (endemic group) and expatriates/travellers (non-endemic group).ResultsA total of 272 patients were retrieved: 234 in the endemic and 38 in the non-endemic group. Most of the patients acquired schistosomiasis in Africa (97.4%). Symptoms were reported by 52.9% of the patients; abdominal pain (36%), macroscopic hematuria (11.3%), and genito-urinary symptoms (7.4%) being the most frequently reported. Increased IgE and blood eosinophilia were observed in 169 (63.8%) and 130 (47.8%) patients, respectively. The proportion of positive serology was 250/272 (91.9%).The Circulating Cathodic Antigen CCA for Schistosoma mansoni was positive in 14/61 individuals (23%). At microscopy, infected subjects were 103/272 (37.9%). The species of Schistosoma found were S. haematobium (47.6%), S. mansoni (46.6%) or both (5.8%). Schistosomiasis was classified as confirmed in 103 (37.9%), probable in 165 (60.6%) and suspected in 4 (1.5%) cases using clinical presentation, laboratory data and ultrasound findings. The infection was further classified based on organ involvement: intestinal (17.9%), hepatosplenic (5.1%), urogenital (48.9%), and indeterminate (43.8%).The comparative analysis of endemic and non-endemic patients highlighted differences in sex and age. Endemic patients had more frequent ova identification (41.9% vs. 13.2%, P < 0.001) and increased IgE (70% vs. 26.3%, P < 0.001) when compared with non-endemic. Multivariate analyses showed that younger age, abnormal ultrasound findings and blood eosinophilia were significantly associated with positive microscopy (OR = 0.94, OR = 2.12, OR = 1.98, respectively).ConclusionsSymptoms, eosinophilia and abnormal ultrasound findings were present in about half of patients, without differences between groups. Many patients had positive serology but negative microscopy, indicating that schistosomiasis might be misdiagnosed. A combination of diagnostic tools may facilitate the diagnosis.Electronic supplementary materialThe online version of this article (10.1186/s40249-018-0440-5) contains supplementary material, which is available to authorized users.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.