Integration and evaluation of cutaneous leishmaniasis laboratory diagnosis in the primary health care laboratory network

Background:The lack of an integrated national system prevents the Islamic Republic of Iran from registering and reporting all cases of cutaneous leishmaniasis.Aim:To establish a laboratory network for the improvement of diagnosis and surveillance of cutaneous leishmaniasis in endemic areas of the Islamic Republic of Iran using parasitological and molecular methods.Methods:This descriptive, cross-sectional, pilot study examined 49 laboratories in the 2 endemic areas for cutaneous leishmaniasis in the Islamic Republic of Iran. Samples were taken for identification of the dominant Leishmania species from individuals with cutaneous leishmaniasis referred to the laboratories and had not travelled to other endemic regions. Statistical analysis was conducted using SPSS version 25.0. Using the primary healthcare laboratory network, we established a 3-level surveillance system. We compared misdiagnosis, new cases, clinical relapses, treatment resistance, and treatment failure before and after establishment of the network.Results:Network implementation reduced relapse of cutaneous leishmaniasis. After the laboratory training, the average misdiagnosis rate decreased from 49.3% to 4.2% for positive microscopic slides and from 31.6% to 12% for negative slides. Correct diagnosis was significantly higher in the study areas after the intervention.Conclusion:Implementation of a cutaneous leishmaniasis laboratory network can enhance diagnosis, unify diagnostic methods and improve patient care.

Prediction of malaria cases in the southeastern Iran using climatic variables: An 18-year SARIMA time series analysis

Objective: To predict future trends in the incidence of malaria cases in the southeast of Iran as the most important area of malaria using Seasonal Autoregressive Integrated Moving Average (SARIMA) model, and to check the effect of meteorological variables on the disease incidence. Methods: SARIMA method was applied to fit a model on malaria incidence from April 2001 to March 2018 in Sistan and Baluchistan province in southeastern Iran. Climatic variables such as temperature, rainfall, rainy days, humidity, sunny hours and wind speed were also included in the multivariable model as covariates. Then, the best fitted model was adopted to predict the number of malaria cases for the next 12 months. Results: The best-fitted univariate model for the prediction of malaria in the southeast of Iran was SARIMA (1,0,0)(1,1,1)12 [Akaike Information Criterion (AIC)=307.4, validation root mean square error (RMSE)=0.43]. The occurrence of malaria in a given month was mostly related to the number of cases occurring in the previous 1 (p=1) and 12 (P=1) months. The inverse number of rainy days with 8-month lag ( =0.329 2) and temperature with 3-month lag ( =-0.002 6) were the best predictors that could improve the predictive performance of the univariate model. Finally, SARIMA (1,0,0)(1,1,1)12 including mean temperature with a 3-month lag (validation RMSE=0.414) was selected as the final multivariable model. Conclusions: The number of malaria cases in a given month can be predicted by the number of cases in the prior 1 and 12 months. The number of rainy days with an 8-month lag and temperature with a 3-month lag can improve the predictive power of the model.

Morphometric discrimination between females of two isomorphic sand fly species, Phlebotomus caucasicus and Phlebotomus mongolensis (Diptera: Phlebotominae) in endemic and non-endemic foci of zoonotic cutaneous leishmaniasis in Iran

Objective: To delineate reliable morphological characteristics for identifying and separating female Phlebotomus caucasicus and Phlebotomus mongolensis which exist sympatrically in the main foci of zoonotic cutaneous leishmaniasis in Iran. Methods: Sand flies were collected using sticky trap papers from active colonies of rodent burrows installed from 16 catching sites. Morphometric measurements were analyzed of 87 Phlebotomus caucasicus and 156 Phlebotomus mongolensis. Univariate and multivariate analysis were carried out to determine significant morphometric variables for discrimination of the two species. Finally, seven morphological characteristics of 65 female Phlebotomus caucasicus and 124 female Phlebotomus mongolensis were described. Results: Univariate and multivariate analyses of 10 morphometric variables via Discriminant Function Analysis (DFA) and Principal Component Analysis (PCA) showed that five morphometric variables had an accuracy of 100% for discriminating female Phlebotomus caucasicus and Phlebotomus mongolensis. Moreover, PCA revealed that the five morphometric variables with the highest loadings separated these two species. Morphological studies on antennal flagellum (and its associated structures) and mouth-parts of female specimens demonstrated significant differences in several structures. Conclusions: The results show that morphological and morphometrical features can be used to discriminate two female isomorphic species, Phlebotomus caucasicus and Phlebotomus mongolensis accurately.

Visceral leishmaniasis among children in an endemic area of northwestern Iran between 2016 and 2017: An epidemiological study

Objective: To clarify the epidemiological aspects of visceral leishmaniasis in Kaleybar and Khoda-Afarin districts, north-west of Iran. Methods: A total of 1 420 human (children under 12 years) samples, 101 domestic dogs samples (Canis familiaris), and 577 female sand fly samples were collected. Sera of human and dogs were tested using the direct agglutination test, and sand flies were identified at species level using the microscopic method. Furthermore, a structured questionnaire was applied to evaluate the correlation between the potential risk factors and the related clinical signs/ symptoms with the human and dogs' seropositivity. Results: Totally, 2.18% of human samples were positive at titers≥: 800; among them, 13 cases (41.94%) were above 1:3 200, and clinical symptoms were observed in all of them except for an 11-year old girl. Anti-Leishmania infantum antibodies were found at titers ≥1: 320 in 9.90% of dogs' samples, half of them had at least one sign of canine visceral leishmaniasis. Moreover, 10 Phlebotomus species were identified in the study areas, and Phlebotomus (Larroussius) major group was the predominant species. There are significant correlations between the presence of anti-Leishmania infantum antibodies and the fever (P<0.001), anemia (P=0.001) and weight loss (P=0.016) in children. On the other hand, significant correlations were revealed between the Leishmania infection and the shelter (P=0.039), cutaneous lesion (P=0.005), lymphadenopathy (P=0.001) and weight loss (P<0.001) in the infected dogs. Conclusions: Visceral Leishmania infection is prevalent in rural areas of Kaleybar and Khoda- Afar districts located in East-Azerbaijan province, therefore active detection and treatment of visceral leishmaniasis cases should not be neglected.

Serologic Tests of IgG and IgM Antibodies and IgG Avidity for Diagnosis of Ocular Toxoplasmosis

This prospective study was aimed to detect acute and chronic ocular toxoplasmosis by comparison of anti-Toxoplasma gondii IgM and IgG antibody levels and IgG avidity test. One hundred and seventeen patients with ocular toxoplasmosis (OT) who referred to the Farabi Eye Hospital, Tehran, Iran were included in this study. Of the patients, 77 cases were positive for anti-T. gondii IgG, and 8 cases were positive for anti-T. gondii IgM. IgG avidity test revealed 11, 4, and 102 cases were low, intermediate, and high, respectively, and 6.8% and 9.4% of cases were positive for IgM and IgG avidity tests, respectively (P=0.632). Agreement (Kappa value) between paired tests IgG-IgM, IgG-IgG avidity, and IgM-IgG avidity was 0.080, 0.099, and 0.721, respectively (P < 0.05). This study showed that conventional serologic tests (IgM and IgG levels) and IgG avidity correlate well each other and can be used to differentiate recent infections from old OT. It seems that reactivated old infections rather than recently acquired infections are majority of Iranian OT patients.

In vitro and in vivo susceptibility of Leishmania major to some medicinal plants

Objective To evaluate the efficacy of some medicinal plants and systemic glucantime in a comparative manner against the causative agent of cutaneous leishmaniasis both in vitro and in BALB/c mice. Methods For in vivo testing, inbred mice were challenged with Leishmania major parasites and the resultant ulcers were treated with extract based-ointments applied topically two times per day for a period of 20 days. A group of 56 mice were randomly divided into 7 subgroups. The control group received the ointment void of extracts, whereas the reference group received glucantime only. The efficacy of treatments was evaluated by measuring ulcer diameter, parasite burden and NO production. Results Our results indicated that plant extract based-ointments were effective in reducing ulcer size and parasite burden in spleens, but their effects did not differ significantly from that of glucantime. The plant extracts tested in this study were able to increase NO production that helped parasite suppression. Conclusions Our findings indicate that the tested plant extracts are effective against Leishmania major both during in vitro and in vivo experiments, but further researches are required to recommend a potential plant extract as an alternative drug.

First Paleoparasitological Report on the Animal Feces of Bronze Age Excavated from Shahr-e Sukhteh, Iran

Shahr-e Sukhteh (meaning burnt city in Persian) in Iran is an archeological site dated back to around 3,200-1,800 BC. It is located in Sistan and Baluchistan Province of Iran and known as the junction of Bronze Age trade routes crossing the Iranian plateau. It was appointed as current study area for paleoparasitological investigations. Excavations at this site have revealed various archeological materials since 1967. In the present study, sheep and carnivore coprolites excavated from this site were analyzed by means of rehydration technique using TSP solution for finding helminth eggs. Dicrocoelium dendriticum, Capillaria sp., and Taenia sp. eggs were identified, while some other objects similar to Anoplocephalidae and Toxocara spp. eggs were also retrieved from the samples but their measured parameters did not match those of these species. The present paper illustrates the first paleoparasitological findings of Bronze Age in eastern Iran supporting the economic activities, peopling, and communication as well as the appropriate condition for zoonotic helminthiasis life cycle in Shahr-e Sukhteh archeological site.

Study on leishmania infection in cats from Ahar, East Azerbaijan province and north west Iran by parasitological, serological and molecular methods

Objective: To study Leishmania infection in cats and its potential role in transmission of the disease to human by parasitological, serological and molecular methods in Ahar District, East Azerbaijan Province. Methods: In this study, 65 cats from different parts of Ahar Province were trapped. The cats were anesthetized with chloroform and blood samples were taken from jugular vein and tested by direct agglutination test. Spleen and liver smear samples were prepared in order to microscopically examine these organs, and also cultured in Novy-MacNeal-Nicolle and Roswell Park Memorial Institute 1 640 media. Finally, spleen tissue DNA was extracted to perform polymerase chain reaction analysis. Results: In direct agglutination test, 4 (6%) cats had a positive titer, while 14 (22%) cats had a titer of 1:80 which was suspected for an infection and 47 (72%) cats were negative. Culture results were negative and in polymerase chain reaction no amplification was observed. Conclusions: We found no case of feline visceral leishmaniasis. It needs more extensive studies by using a larger number of cats to firmly establish leishmaniasis in this area.

Visceral Leishmaniasis in Rural Areas of Alborz Province of Iran and Implication to Health Policy

Visceral leishmaniasis (VL) or kala-azar mainly affects children in endemic areas. This study was conducted to determine the seroprevalence of VL using direct agglutination test (DAT) in children living in rural districts of Alborz Province located 30 km from Tehran capital city of Iran. Multi-stage cluster random sampling was applied. Blood samples were randomly collected from 1,007 children under 10 years of age in the clusters. A total of 37 (3.7%) of the studied population showed anti-Leishmania infantum antibodies with titers of > or =1:800. There was a significant association between positive sera and various parts of the rural areas of Alborz Province (P or =1:3,200 indicated kala-azar clinical features and treated with anti-leishmaniasis drugs in pediatric hospital. The findings of this study indicated that Leishmania infection is prevalent in rural areas of Alborz Province. Therefore, it is necessary to increase the awareness and alertness among physicians and public health managers, particularly in high-risk rural areas of the province in Iran.

Visceral Leishmaniasis without Fever in an 11-Month-Old Infant: a Rare Clinical Feature of Kala-azar

Visceral leishmaniasis or kala-azar is an endemic parasitic disease in some parts of the world which is characterized by fever, splenomegaly, and pancytopenia in most of the cases. Herein we report an 11 month-old male infant with diagnosis of kala-azar who presented with pallor, hepatosplenomegaly, failure to gain weight, and no history of fever. Surprisingly, fever started after beginning of meglumine antimoniate treatment in this patient. As far as we are aware of, this is a rare presentation of visceral leishmaniasis. Therefore, clinicians especially in endemic areas are highly recommended to include kala-azar among differential diagnosis of unexplained anemia without fever to prevent misdiagnosis of this potentially fatal, but treatable condition.

Overexpression of Ubiquitin and Amino Acid Permease Genes in Association with Antimony Resistance in Leishmania tropica Field Isolates

The mainstay therapy against leishmaniasis is still pentavalent antimonial drugs; however, the rate of antimony resistance is increasing in endemic regions such as Iran. Understanding the molecular basis of resistance to antimonials could be helpful to improve treatment strategies. This study aimed to recognize genes involved in antimony resistance of Leishmania tropica field isolates. Sensitive and resistant L. tropica parasites were isolated from anthroponotic cutaneous leishmaniasis patients and drug susceptibility of parasites to meglumine antimoniate (Glucantime(R)) was confirmed using in vitro assay. Then, complementary DNA-amplified fragment length polymorphism (cDNA-AFLP) and real-time reverse transcriptase-PCR (RT-PCR) approaches were utilized on mRNAs from resistant and sensitive L. tropica isolates. We identified 2 known genes, ubiquitin implicated in protein degradation and amino acid permease (AAP3) involved in arginine uptake. Also, we identified 1 gene encoding hypothetical protein. Real-time RT-PCR revealed a significant upregulation of ubiquitin (2.54-fold), and AAP3 (2.86-fold) (P<0.05) in a resistant isolate compared to a sensitive one. Our results suggest that overexpression of ubiquitin and AAP3 could potentially implicated in natural antimony resistance.

Preparation and evaluation of a glycerol-preserved direct agglutination antigen for long-term preservation: a comparative study of the detection of anti-Leishmania infantum antibodies in human and dog

OBJECTIVE@#To prepare and evaluate a glycerol-preserved antigen from an Iranian strain of Leishmania infantum (L. infantum) for use in glycerol-preserved direct agglutination tests (GP-DAT) as an alternative to freeze dried direct agglutination tests (FD-DAT) that use freeze-dried antigen.@*METHODS@#Glycerol-preserved DAT antigen was prepared and stored at different temperatures. We tested antigen stored at 4 °C, 22-37 °C and 50 °C over a period of 365 days. Seven hundred twenty-nine serum samples were collected from different geographical zones of Iran from 2007-2009, and 80 of these samples were pooled to produce sera. Each pooled serum contained 10 sera. All positive and negative pooled sera were separately tested for anti-L. infantum antibodies with GP-DAT, FD-DAT and formaldehyde-fixed direct agglutination test (FF-DAT) antigens; tests were performed on both human and dog sera over a period of 12 months.@*RESULTS@#There was strong agreement between the results obtained using GP-DAT and FD-DAT antigens stored at 22-37 °C for 12 months for both human (100%) and dog (100%) pooled sera. The direct agglutination test results were highly reproducible (weighted kappa: GP=0.833, FD=0.979 and FF=0.917).@*CONCLUSIONS@#Because GP-DAT antigen is highly stable over a range of temperatures and is easy to transport in the field, this type of antigen may be particularly useful in areas with endemic visceral leishmaniasis.

A Recombinant Plasmodium vivax Apical Membrane Antigen-1 to Detect Human Infection in Iran

In Iran, Plasmodium vivax is responsible for more than 80% of the infected cases of malaria per year. Control interventions for vivax malaria in humans rely mainly on developed diagnostic methods. Recombinant P. vivax apical membrane antigen-1 (rPvAMA-1) has been reported to achieve designing rapid, sensitive, and specific molecular diagnosis. This study aimed to perform isolation and expression of a rPvAMA-1, derived from Iranian patients residing in an endemic area. Then, the diagnostic efficiency of the characterized Iranian PvAMA-1 was assessed using an indirect ELISA method. For this purpose, a partial region of AMA-1 gene was amplified, cloned, and expressed in pET32a plasmid. The recombinant His-tagged protein was purified and used to coat the ELISA plate. Antibody detection was assessed by indirect ELISA using rPvAMA-1. The validity of the ELISA method for detection of anti-P. vivax antibodies in the field was compared to light microscopy on 84 confirmed P. vivax patients and compared to 84 non-P. vivax infected individuals. The ELISA cut-off value was calculated as the mean+2SD of OD values of the people living in malaria endemic areas from a south part of Iran. We found a cut-off point of OD=0.311 that showed the best correlation between the sera confirmed with P. vivax infection and healthy control sera. A sensitivity of 81.0% and specificity of 84.5% were found at this cut off titer. A good degree of statistical agreement was found between ELISA using rPvAMA-1 and light microscopy (0.827) by Kappa analysis.

IgG Avidity ELISA Test for Diagnosis of Acute Toxoplasmosis in Humans

Serum samples, 100 in the total number, were collected from different laboratories in Tehran, Iran and tested for anti-Toxoplasma specific IgG and IgM antibodies using indirect immunofluorescent antibody test (IFAT). Using the IgG (chronic) and IgM (acute) positive samples, the IgG avidity test was performed by ELISA in duplicate rows of 96-well microtiter plates. One row was washed with 6 M urea and the other with PBS (pH 7.2), then the avidity index (AI) was calculated. Sixteen out of 18 (88.9%) sera with acute toxoplasmosis showed low avidity levels (AI60). Six sera had borderline ranges of AI. The results showed that the IgG avidity test by ELISA could distinguish the acute and chronic stages of toxoplasmosis in humans.

IgG Avidity ELISA Test for Diagnosis of Acute Toxoplasmosis in Humans

Serum samples, 100 in the total number, were collected from different laboratories in Tehran, Iran and tested for anti-Toxoplasma specific IgG and IgM antibodies using indirect immunofluorescent antibody test (IFAT). Using the IgG (chronic) and IgM (acute) positive samples, the IgG avidity test was performed by ELISA in duplicate rows of 96-well microtiter plates. One row was washed with 6 M urea and the other with PBS (pH 7.2), then the avidity index (AI) was calculated. Sixteen out of 18 (88.9%) sera with acute toxoplasmosis showed low avidity levels (AI60). Six sera had borderline ranges of AI. The results showed that the IgG avidity test by ELISA could distinguish the acute and chronic stages of toxoplasmosis in humans.

Real-Time RT-PCR on SAG1 and BAG1 Gene Expression during Stage Conversion in Immunosuppressed Mice Infected with Toxoplasma gondii Tehran Strain

Toxoplasmic encephalitis is caused by reactivation of bradyzoites to rapidly dividing tachyzoites of the apicomplexan parasite Toxoplasma gondii in immunocompromised hosts. Diagnosis of this life-threatening disease is problematic, because it is difficult to discriminate between these 2 stages. Toxoplasma PCR assays using gDNA as a template have been unable to discriminate between an increase or decrease in SAG1 and BAG1 expression between the active tachyzoite stage and the latent bradyzoite stage. In the present study, real-time RT-PCR assay was used to detect the expression of bradyzoite (BAG1)- and tachyzoite-specific genes (SAG1) during bradyzoite/tachyzoite stage conversion in mice infected with T. gondii Tehran strain after dexamethasone sodium phosphate (DXM) administration. The conversion reaction was observed in the lungs and brain tissues of experimental mice, indicated by SAG1 expression at day 6 after DXM administration, and continued until day 14. Bradyzoites were also detected in both organs throughout the study; however, it decreased at day 14 significantly. It is suggested that during the reactivation period, bradyzoites not only escape from the cysts and reinvade neighboring cells as tachyzoites, but also converted to new bradyzoites. In summary, the real-time RT-PCR assay provided a reliable, fast, and quantitative way of detecting T. gondii reactivation in an animal model. Thus, this method may be useful for diagnosing stage conversion in clinical specimens of immunocompromised patients (HIV or transplant patients) for early identification of tachyzoite-bradyzoite stage conversion.

Production and Evaluation of Toxoplasma gondii Recombinant GRA7 for Serodiagnosis of Human Infections

The precise diagnosis of the acute toxoplasmosis in pregnant women and immunocompromsied patients has critical importance. Most of the commercially available assays use the whole Toxoplasma soluble extract as the antigen. However, the assays currently available for the detection of specific anti-Toxoplasma antibodies may vary in their abilities to detect serum immunoglobulins, due to the lack of a purified standardized antigen. The aim of this study was production and evaluation of the usefulness of the recombinant Toxoplasma gondii GRA7 antigen for the serodiagnosis of Toxoplasma gondii IgM and IgG by ELISA. A total of 70 T. gondii IgM positive sera, 74 T. gondii IgG positive sera, and 60 sera from subjects who were not infected with T. gondii were examined. These sera were shown different absorbance values in ELISA test. To control the specificity of the rGRA7 other parasitic diseases, for example, echinococcosis, malaria, leishmaniasis, fascioliasis, and strongyloidiasis were tested of which none showed positive results. Sensitivity and specificity of the generated recombinant IgG ELISA in comparison with commercial ELISA (com ELISA) were 89% and 90%, and the sensitivity and specificity of the generated recombinant IgM ELISA were 96% and 90%, respectively. The results obtained here show that this antigen is useful for diagnostic purposes.