Immunochromatographic Dipstick Test Research Articles

Potential application of small myristoylated protein-3 evaluated as recombinant antigen and a synthetic peptide containing its linear B-cell epitope for the serodiagnosis of canine visceral and human tegumentary leishmaniasis

Serological tests are important tools for the diagnosis of Leishmania infection. However, they are not effective markers to diagnose asymptomatic cases of visceral leishmaniasis (VL) and patients developing tegumentary leishmaniasis (TL), since antileishmanial antibodies can be encountered in low levels resulting in false-negative results in the serological trials. In this context, antigens able to be recognized by antibodies in sera from both VL and TL patients will be desirable to be employed in a more sensitivity and specific diagnosis of disease. In the present study, a conserved Leishmania protein, small myristoylated protein-3 (SMP-3), which was showed to be conserved in different Leishmania species and an effective vaccine candidate against Leishmania infantum infection in a murine model, was cloned and the recombinant protein was evaluated as a serological marker for the diagnosis of human TL and canine VL. In addition, a linear B cell-specific epitope (MQKDEESGEFKCEL) was identified, synthetized and also investigated as a serological marker. As antigen controls, rA2 protein and antigenic Leishmania extracts (SLA) were used. Results showed that ELISA-rSMP-3 and ELISA-Peptide presented sensitivity and specificity values higher than 90% in both diseases in humans and canids, having identified all asymptomatic cases and did not present cross-reaction with cross-reactivity diseases in both mammalian hosts. On the other hand, sensitivity and specificity values were worst when rA2 or SLA were used as antigens in humans and dogs. In conclusion, results showed the efficacy and Leishmania SMP-3 protein, employed as a recombinant antigen or a B cell epitope, for the improvement of the serodiagnosis of human TL and canine VL. This candidate can be tested in other diagnostic platforms, such as rapid immunochromatographic dipstick tests, aiming its use in epidemiological studies in remote areas where laboratories are not readily accessible for conventional assays.

Prevalence of antibodies against visceralizing Leishmania spp. in brown rats from Grenada, West Indies.

Background and Aim:Leishmania spp. are known to cause disease in man and animals. Rats are considered important reservoir hosts and transmission takes place through the bite of female sand fly, Phlebotomus spp. To the best of our knowledge, there is no published information on Leishmania infection in rats in Grenada. This study was conducted to estimate the antibodies for visceralizing Leishmania spp. (VL) in rats (Rattus norvegicus) from Grenada.Materials and Methods:A total of 146 brown rats (R. norvegicus) were trapped live from two parishes (St. George and St. David) in Grenada. Following anesthesia, blood was collected from the heart through thoracic puncture. The serum was collected after the centrifugation of blood. Serum was tested for antibodies to VL. with a commercially available immunochromatographic dipstick test which is licensed for use in animals and humans.Results:The seroprevalence of antibodies against Leishmania spp. was found in 34 of 146 rats (23.3%; CI 95% from 16.70 to 30.99). No significant differences were found between sexes and young or adults. The prevalence between parishes (St. George and St. David) was also not significant.Conclusion:The results show that rats (R. norvegicus) in Grenada are exposed to Leishmania spp. The rats could play an important role in the transmission of leishmaniasis to humans and other animals in Grenada.

Comparative evaluation of immunochromatographic dipstick test (ICT) rk39, soluble antigen ELISA and IFAT for the sero-diagnosis of visceral leishmaniasis in Morocco

A rapid, sensitive and specific tool for detection of Leishmania infantum infection in Humans would be highly desirable, because it would allow control interventions in endemic areas of visceral leishmaniasis. This study was carried out at the Reference National Laboratory of Leishmaniasis (RNLL) in National Institute of Hygiene (NIH) Morocco, in order to evaluate the diagnostic potential of immunochromatographic dipstick test (ICT) rk39 in Moroccan suspected VL patients. A total of 49 admitted patients with strong clinical suspicion of VL and 40 healthy controls were investigated for the performance of the ICT rk39. Bone marrow smears were examined for microscopic detection of Leishmania amastigotes obtained from the admitted patients. Only PCR and smear positive cases were considered as gold standard as well as confirmed cases of VL. Out of 49 suspected patients, twenty four (48.9%) were found PCR and smear-positive and twenty three (46.9%) were positive for ICT rk39. Voluntary healthy controls, which included twenty persons from the endemic zone and twenty from non-endemic zone of VL, were found all negative for the strip test. The sensitivity in sera was 75% by ELISA and 87.5% by IFAT, compared with 95.8% for ICT rk39. Specificity was 95.8%, with both tests ELISA and IFAT, and 100% by ICT rk39 respectively. Present study findings again reinforce that the ICT rk39 is a simple, reliable and easy-to-perform non-invasive diagnostic tool for visceral leishmaniasis in the endemic area of Morocco.

Managing the spread of canine leishmaniosis in Europe

CURRENTLY, there is a threat of canine leishmaniosis spreading to higher latitudes and elevations in Europe because of climate change (Ready 2017), so it is important to consider how best...

Seroprevalence of Canine Leishmaniasis in Owned and Stray Dogs from Grenada, West Indies

The aim of this study was to estimate the seroprevalence of Leishmania antibodies in two populations of dogs (owned and stray) in Grenada, West Indies. Leishmainiasis caused by a hemoflagelate protozoan, is zoonotic disease that affects a wide range of animals including man. Dogs are considered main reservoir for the organism. Antibodies to Leishmania spp were determined in serum samples from 836 dogs (344 stray and 492 owned dogs) using qualitative immunochromatographic dipstick tests (ICTs) based on recombinant antigens specific for visceral leishmaniasis (Kalzar detect rapid test:In Bios, USA). Seropositivity for leishamanis spp. was detected in 23 dogs (2.7%, 95% confidence Interval (CI) 1.06% to 3.8%). Thirteen of these were stray dogs (3.7%) and ten were owned dogs (2.0%). Results from this study indicate that dogs in Grenada are exposed at a low level to leishamaniasis.

Evaluation of a Rapid Immunochromatographic Dipstick Test for Detection of Antibodies to Trypanosoma cruzi in Dogs Experimentally Infected with Isolates Obtained from Opossums (Didelphis virginiana), Armadillos (Dasypus novemcinctus), and Dogs (Canis familiaris) from the United States

Dogs are reservoir hosts for Trypanosoma cruzi , the causative agent of American trypanosomiasis. A rapid immunochromatographic dipstick test (ICT) is available commercially for canine serological testing. The ICT was developed with the use of sera from South American dogs, but it is not routinely used in the United States. We evaluated the utility of the ICT in detecting anti-T. cruzi antibodies in dogs from the United States. Dogs (N = 64) were experimentally infected with United States' isolates of T. cruzi from an opossum (Didelphis virginiana), an armadillo (Dasypus novemcinctus), and a domestic dog (Canis familiaris), and were tested after experimental infection. Sera from uninfected United States dogs (n = 79; hemaculture negative) were used as negative controls. In a blind study, sera were tested by the ICT and compared to the indirect immunofluorescent antibody test with the use of Brazil-strain epimastigotes as antigen. The sensitivity of the ICT was 91% and the specificity was 98% in dogs experimentally infected with United States isolates. Our study indicates that the ICT could be a useful screening tool for serological surveillance of canine T. cruzi exposure in the United States.

Rapid Detection of Trypanosoma cruzi in Human Serum by Use of an Immunochromatographic Dipstick Test

We evaluated a commercially available immunochromatographic dipstick test to detect Trypanosoma cruzi infection in 366 human serum samples with known serological results from Argentina, Ecuador, Mexico, and Venezuela. One hundred forty-nine of 366 (40.7%) and 171/366 (46.7%) samples tested positive by dipstick and serology, respectively. Dipstick sensitivity was calculated to be 84.8% (range between countries, 77.5 to 95%), and specificity was 97.9% (95.9 to 100%).

Tetanus Quick Stick as an applicable and cost-effective test in assessment of immunity status

Introduction Tetanus vaccine and immunoglobulin administration are challenging decisions mostly because of the fact that the current protocol for immunization against tetanus is based on 2 variables: the vaccination status of the patient and the nature of wound and its exposure. To solve this problem, Tetanus Quick Stick (TQS; Nephrotek Laboratory, Rungis, France), an immunochromatographic dipstick test, was developed to determine the tetanus immunity of the patients. The aim of this present study was to investigate the sensitivity, specificity, and the positive and negative predictive values and cost-effectiveness of TQS in the emergency department (ED) setting. Methods Blood samples were collected from 200 patients presenting to our ED. Information including demographic information, tetanus immunization status, wound description, and the preventive measures taken by the emergency physician were gathered by a preeducated nurse. Tetanus Quick Stick test and enzyme-linked immunosorbent assay were performed as the standard diagnostic test by an emergency physician and a laboratory technician, respectively; and results of the 2 techniques were compared. Result Overall, tetanus vaccine was administered to 141(70.5%) patients and immunoglobulin to 105 (52.5%) patients. The analysis revealed 88.1% sensitivity and 97.6% specificity for the TQS test. The positive and negative predictive values of TQS test were 99.3% and 66.1%, respectively. Our analysis is also showed a significant decrease in cost when TQS was applied for patients with dirty, tetanus prone wounds or injuries and unknown or incomplete vaccination history (€ 9.48 versus € 12.1). Conclusion This study revealed TQS test to be appropriate and cost-effective for ED use especially in evaluating patients who do not remember or cannot give their tetanus immunization history.

Prevalência de anticorpos antileishmania spp em cães de Garanhuns, Agreste de Pernambuco

Considering the unknown situation regarding canine visceral leishmaniasis in Garanhuns, this study had the aim of investigating occurrences of anti-Leishmania spp antibodies in domesticated and partially domesticated dogs, and the possible risk factors involved. In the first phase of the study, 256 blood samples were collected from dogs and subjected to the indirect fluorescent antibody test (IFAT) reaction at a dilution of 1:40. Additionally, 23 IFAT-positive samples were tested using an immunochromatographic dipstick test. In the second phase, new blood samples were collected from 18 dogs that were IFAT-positive in the first phase. These animals were retested using IFAT (1:40 and 1:80) and, additionally, by means of the polymerase chain reaction to investigate the Leishmania infantum DNA. Furthermore, 16 of these samples were retested using the immunochromatographic dipstick test. In the first phase of the study, 16% of the samples were IFAT-positive (1:40) and only three (13%) were positive in the immunochromatographic dipstick test. In the second phase, 12 samples were IFAT-positive at the dilution of 1:40, and seven were also positive at 1:80. None of the samples were positive in the polymerase chain reaction testing or in the immunochromatographic dipstick test. Clinical signs suggestive of visceral leishmaniasis were observed in 4.9% of the IFAT-positive dogs. There were no statistical differences in relation to age, sex or clinical status of the dogs, but there was a difference in relation to place of origin. The domesticated and partially domesticated dogs living in Garanhuns present anti-Leishmania spp antibodies, but are mostly asymptomatic.

Seroprevalence of Canine Leishmaniasis and American Trypanosomiasis in Dogs from Grenada, West Indies

Canine leishmaniasis and American trypanosomiasis (AT) are caused by related hemoflagellated parasites, Leishmania spp. and Trypanosoma cruzi, which share several common host species. Dogs are reservoirs for human infections by both pathogens. We determined the prevalence of antibodies to Leishmania spp. and T. cruzi in dogs from Grenada, West Indies. We examined 70 dog sera using the qualitative immunochromatographic dipstick tests (ICTs) based on recombinant antigens specific for visceral leishmaniasis and AT. Antibodies to visceral Leishmania were not detected in Grenadian dogs by ICT. Using the canine dipsticks for AT, antibodies to T. cruzi were determined in 3 (4.3%) of the 70 dogs. Results from this study indicate that dogs in Grenada are exposed in low levels to T. cruzi , but not to visceral Leishmania spp. at all.

Commercialized rapid immunoanalytical tests for determination of allergenic food proteins: an overview

Food allergies have become an important health issue especially in industrialized countries. Undeclared allergenic ingredients or the presence of "hidden" allergens because of contamination during the food production process pose great health risks to sensitised individuals. The EU directive for food labelling lists allergenic foods that have to be declared on food products by the manufacturers. The list includes gluten-containing cereals, crustaceans, eggs, fish, peanuts, soybeans, milk, various nuts (e.g. almond, hazelnut, and walnut, etc.), celery, mustard, sesame seeds, lupin, and molluscs. Reliable methods for detection and quantification of food allergens are needed that can be applied in a fast and easy-to-use manner, are portable, and need only limited technical equipment. This review focuses on the latest developments in food allergen analysis with special emphasis on fast immunoanalytical methods such as rapid enzyme-linked immunosorbent assays (ELISA), lateral-flow immunochromatographic assays (LFA) and dipstick tests. Emerging technologies such as immunochemical microarrays and biosensors are also discussed and their application to food allergen analysis is reviewed. Finally, a comprehensive overview of rapid immunochemical test kits that are currently available commercially is given in tabular form.

The rK39 immunochromatic dipstick testing: A study for K39 seroprevalence in dogs and human leishmaniasis patients for possible animal reservoir of cutaneous and visceral leishmaniasis in endemic focus of Satluj river valley of Himachal Pradesh (India)

The newly recognized endemic focus of leishmaniasis in Satluj river valley of Himachal Pradesh (India) has both localized cutaneous leishmaniasis (LCL) and visceral leishmaniasis (VL) predominantly caused by Leishmania donovani. Rapid rK39 immunochromatographic dipstick test detects circulating antibodies to recombinant K39 antigen of L. donovani-infantum complex and is highly specific/sensitive in diagnosing symptomatic or asymptomatic infection in humans and dogs. The sera from two VL patients and 13 LCL patients, and 31 dogs were subjected to rK39 immunochromatographic dipstick testing with an aim to identify possible animal reservoir for leishmaniasis in this endemic focus. The positive rapid rK39 immunochromatographic dipstick test in 100% VL and 31.8% LCL patients, and 6.5% dogs suggests that both VL and LCL in this focus are apparently being caused by L. donovani-infantum and that reservoir infection is perhaps being chiefly maintained in asymptomatic dogs. However, it needs corroborative evidence in the form of in-vitro parasite cultivation and/or PCR studies for confirmation. A more elaborate study is recommended.

Pretravel Consultation: Rapid Dipstick Test as a Decision Guidance for the Application of Tetanus Booster Vaccinations

When deciding whether to administer a tetanus vaccination--for international travel or injury--a subject's vaccination certificate should be investigated. As many people lack valid vaccination cards and are unable to recall their vaccination history, the Tetanos Quick Stick (TQS) test rapidly detects protective tetanus immunoglobulin IgG antibodies in whole blood, serum, or plasma. This immunochromatographic dipstick test yields a positive or negative result. Our study evaluates the effectiveness of the TQS test by comparing the binary TQS test results of 100 sera with the tetanus antibody levels as measured by the standardized enzyme-linked immunosorbent assay (ELISA) method. We used the TQS test to determine whether a person needed a tetanus booster vaccination. If the test showed a clearly visible line that was similar to the control line, the result was determined to be positive. All positive TQS test results had a concentration of IgG antibodies above 0.5 IU/mL as measured by ELISA, indicating that no booster vaccination was required. Similarly, in all cases with an antibody level below 0.1 IU/mL, where a vaccination would have been recommended based on the ELISA test result, the TQS test yielded a negative result. The positive predictive value and the specificity for the dipstick test were therefore 100%. The TQS test is a reliable, fast, and cost-effective means of identifying subjects with a preexisiting level of tetanus IgG antibodies above approximately 0.5 IU/mL. This can help to avoid unnecessary tetanus vaccinations in travel clinics, emergency departments, and practices of family doctors.

Cervical phosphorylated insulin-like growth factor binding protein-1 in prediction of preterm delivery

The aim of this study was to evaluate the phosphorylated isoform of insulin-like growth factor binding protein-1 (phIGFBP-1) in endocervical secretions as a predictor of preterm delivery in symptomatic and asymptomatic pregnant women. The study included 105 patients between 24 and 34 weeks' gestation with uterine contractions and 73 controls. Ph IGFBP-1 in cervical secretions was assessed in all patients by using a qualitative, immunochromatographic one-step dipstick test. Data analysis included Student's test, Chi-Square, Fisher's exact test and Kruskal Wallis variance analysis. Preterm birth rate was 19.04% (20/105) in the study group. Of the 25 patients with a positive phIGFBP-1 test, mean gestational age at delivery was 32.8+/-3.8, whereas of the 80 patients with a negative phIGFBP-1 test mean gestational age at delivery was 37.8+/-2.5, in the study group (P<0.05). The sensitivity, specificity, positive predictive value and negative predictive value for phIGFBP-1 in symptomatic patients were 70, 87.05, 56 and 92.5%, respectively, while in asymptomatic patients they were 40, 82.35, 14.28 and 94.91%, respectively. The phIGFBP-1 in cervical secretions is a potential specific marker for preterm delivery occurring before 37 weeks. Also cervical detection of phIGFBP-1 by immunochromatography is a rapid and easily applicable test that highly predicts preterm delivery.

Use of an Immunochromatographic Dipstick Test for Rapid Detection of Trypanosoma cruzi in Sera from Animal Reservoir Hosts

We evaluated an immunochromatographic dipstick test to detect Trypanosoma cruzi in canine serum samples from areas of endemicity (n = 141) and nonendemicity (n = 28) for Chagas' disease with known serological and xenodiagnostic test results. The dipstick test had a specificity of at least 94% and a sensitivity of at least 96%. The dipstick tested could become the first choice for screening purposes in disease surveillance or intervention programs.

Field evaluation of a rapid immunochromatographic dipstick test for the diagnosis of cholera in a high-risk population

BackgroundEarly detection of cholera outbreaks is crucial for the implementation of the most appropriate control strategies.MethodsThe performance of an immunochromatographic dipstick test (Institute Pasteur, Paris, France) specific for Vibrio cholerae O1 was evaluated in a prospective study in Beira, Mozambique, during the 2004 cholera season (January-May). Fecal specimens were collected from 391 patients with acute watery nonbloody diarrhea and tested by dipstick and conventional culture.ResultsThe overall sensitivity and specificity of the rapid test compared to culture were 95% (95% confidence interval [CI]: 91%–99%) and 89% (95% CI: 86%–93%), respectively. After stratification by type of sample (rectal swab/bulk stool) and severity of diarrhea, the sensitivity ranged between 85% and 98% and specificity between 77% and 97%.ConclusionThis one-step dipstick test performed well in the diagnosis of V. cholerae O1 in a setting with seasonal outbreaks where rapid tests are most urgently needed.

The value of the insulin-like growth factor binding protein-1 in the cervical–vaginal secretion detected by immunochromatographic dipstick test in the prediction of delivery in women with clinically unconfirmed preterm premature rupture of membranes

Objective: The aim of this study was to determine the value of detecting insulin-like growth factor binding protein-1 (IGFBP-1) in the cervical–vaginal secretion in the prediction of delivery in women with clinically uncorfirmed preterm premature rupture of membranes (PPROM). Material and methods: A total of 87 women, gestational age between 20 and 36 weeks were enrolled into this prospective study. Based on the clinical diagnosis, patients were grouped as clinically evident PPROM ( n = 25), clinically suspected PPROM ( n = 42) and women with intact fetal membranes ( n = 20). Detection of IGFBP-1 in the cervical–vaginal secretions was done using a one-step immunochromatographic dipstick test in all women. The outcome measures were gestational age at delivery, neonatal birth weight and duration of the interval between the test and delivery between women with positive and negative test results. Results: The test was positive in all 25 women (100% sensitivity) with clinically evident PPROM and all delivered prematurely, and negative in 19 out of the 20 (95% specificity) women with intact fetal membranes. Among 36 women with clinically suspected PPROM, 13 (36%) tested positive and 23 (63%) tested negative for IGFBP-1. In this group, the mean gestational age and birth weight at the time of delivery were significantly lower in patients with positive test (31.38 ± 2.6 weeks versus 38.61 ± 0.99 weeks and 1761 ± 527 g versus 3500 ± 355 g, P < 0.05 for both). Eleven (85%) of the 13 women with positive test, delivered within 2 weeks after the performance of the test whereas all the women with negative test results delivered after 2 weeks ( P = 0.001). The test had 100, 92, 84 and 100% sensitivity, specificity, positive predictive value and negative predictive value, respectively, for the outcome measure of test–delivery interval. Conclusion: The screening test for IGFBP-1 in the cervical–vaginal secretions is a useful adjunct in the prediction of delivery in women with clinically unconfirmed PPROM.

Rapid detection of Leishmania infantum infection in dogs: comparative study using an immunochromatographic dipstick rk39 test and direct agglutination

A rapid, sensitive and specific tool for detection of Leishmania infantum infection in dogs, would be highly desirable, because it would allow control interventions in endemic areas of Zoonotic visceral leishmaniosis (ZVL). In this study, we compared an immunochromatographic dipstick test with direct agglutination test (DAT) for detecting L. infantum infections in dogs from areas of ZVL endemic in Iran. The validity of the dipstick rk39 (Cypress Diagnostic Company, Belgium) for canine visceral leishmaniosis (CVL) was compared with a standard direct agglutination test on 116 clinically suspected dogs and 152 healthy controls from endemic areas of Ardabil and East Azerbaijan provinces, north-western of Iran for 1 year. A sensitivity of 70.9% and specificity of 84.9% were found at a 1:320 cut off titer when DAT confirmed cases were compared with healthy control. As the dipstick rk39 test is rapid, noninvasive and does not require much expertise or elaborate equipment, it can be used for screening and diagnosis of canine visceral leishmaniosis in remote endemic areas.

Rapid detection of Leishmania infantum infection in dogs: comparative study using an immunochromatographic dipstick rk39 test and direct agglutination

A rapid, sensitive and specific tool for detection of Leishmania infantum infection in dogs, would be highly desirable, because it would allow control interventions in endemic areas of Zoonotic visceral leishmaniosis (ZVL). In this study, we compared an immunochromatographic dipstick test with direct agglutination test (DAT) for detecting L. infantum infections in dogs from areas of ZVL endemic in Iran. The validity of the dipstick rk39 (Cypress Diagnostic Company, Belgium) for canine visceral leishmaniosis (CVL) was compared with a standard direct agglutination test on 116 clinically suspected dogs and 152 healthy controls from endemic areas of Ardabil and East Azerbaijan provinces, north-western of Iran for 1 year. A sensitivity of 70.9% and specificity of 84.9% were found at a 1:320 cut off titer when DAT confirmed cases were compared with healthy control. As the dipstick rk39 test is rapid, noninvasive and does not require much expertise or elaborate equipment, it can be used for screening and diagnosis of canine visceral leishmaniosis in remote endemic areas.

Detection of filaria-specific IgG4 antibodies using Brugia Rapid test in individuals from an area highly endemic for Brugia timori

The filarial parasite Brugia timori is of great public health importance in some islands of Eastern Indonesia. To establish a simple serological test for the identification and post-treatment monitoring of areas endemic for B. timori, a rapid immunochromatographic dipstick test (Brugia Rapid, BR) was evaluated on microfilaraemic and amicrofilaraemic individuals. This test is based on the detection of anti-filarial IgG4 antibodies that react with a recombinant Brugia malayi antigen (BmR1). In our study area on Alor island the prevalence of microfilaraemia was 26%. With the BR test, 100% of 196 sera from microfilaraemic persons and 76% of 563 sera from amicrofilaraemic persons, either symptomatic or asymptomatic, reacted positive. All 50 control sera from areas non-endemic for lymphatic filariasis gave negative BR test results. This study showed that the BR test can be also used to detect antibodies against B. timori. Due to the high prevalence of IgG4 antibodies as detected by the BR test (81%), no significant correlation with the prevalence of microfilaraemia could be detected within the endemic village. The BR test also shows great promise to be employed as a monitoring tool for B. timori in the framework of the Global Program to Eliminate Lymphatic Filariasis (GPELF).