Discordance Therapeutic Protocol of Cystic Echinococcosis With WHO Guideline: A Descriptive Study Based on Liver Ultra-Sonographic Data in North Khorasan Province, Northeastern of Iran.

BACKGROUND: Cystic echinococcosis (CE), a helminth-associated zoonosis caused by Echinococcus granulosus, poses a significant public health problem, particularly in pastoral-rearing regions. The lack of uniform guidelines led to variations in CE management. Based on ultrasound data, the World Health Organization Informal Working Group on Echinococcosis (WHO-IWGE) classification system categorizes cysts into active, transitional, and inactive groups. This study assesses whether the therapeutic approach from liver human operation cases in North Khorasan province aligns with the WHO-IWGE reference based on ultrasound data. METHODS: The research is based on ultrasound data from liver CE human operation cases collected between 2018 and 2022. This retrospective study investigates the therapeutic protocol for (CE) in North Khorasan Province, Iran, comparing it with the WHO-IWGE guidelines. We collect data from previously registered patients' medical information from our studied area's main CE surgical hospital. Moreover, as the first hospitalized survey in Iran, this study reveals insights into patient demographics, cyst stage prevalence, and treatment modalities. RESULTS: Notably, more than half of the patients were treated for CE1 stage cysts, and CE4 cases, which generally do not require surgery, underwent open surgery. The results suggest a need for adherence to the "watch-and-wait" approach in specific cases. All patients underwent successful surgeries, but we do not have access to follow-up data from patients after discharge. CONCLUSIONS: This descriptive study contributes to understanding the implementation of WHO guidelines in a regional context, shedding light on the challenges and variations in CE management. It seems, retraining courses for surgeons are required to update their knowledge of standard CE diagnostic and treatment methods.

Absence of Asymptomatic Malaria Reservoirs in an Area with a Previous History of Local Malaria Transmission: A Successful Experience in Line with the Malaria Elimination Program in Iran.

Background: Asymptomatic malaria is a major challenge to be addressed in the implementation of the malaria elimination program. The main goal of the malaria surveillance system in the elimination phase is to identify reliably all the positive cases of malaria reliably (symptomatic and asymptomatic) in the shortest possible time. This study focused on the monitoring of asymptomatic malaria reservoirs in areas where local transmission had been previously established. Methods: It was a case-study approach that was conducted in the Anarestan area. A total of 246 residents and immigrants living in the area at the age range of 4-60 years old were randomly selected to be tested for malaria by microscope, RDT, and nested-PCR techniques. The inclusion criterion for participants to be entered into the study was the absence of specific symptoms of malaria. Moreover, participants who have been taking antimalarials for the last month were excluded from the study. Results: The results indicated no positive cases of asymptomatic malaria among the participants tested by all methods. Conclusion: The results of this study have shown that, without concerns for asymptomatic parasitic patients, a malaria elimination program has been successfully implemented within the studies area. In addition, the findings emphasized the existence of a strong malaria surveillance system in this area.

Molecular Method Is Essential to Identify Asymptomatic Malaria Reservoirs: A Successful Experience in the Malaria Elimination Program in Iran.

Background: The accurate diagnosis of malaria cases, especially asymptotic and low-parasitemia patients, using robust molecular methods (nested-PCR) have been emphasized. The goal of this study was to detect active cases of malaria in areas with a history of local malaria transmission focusing on the use of molecular tools to ensure that the malaria elimination program has been implemented successfully. Methods: In this cross-sectional study, 816 blood samples were taken from immigrants and local residents of malaria-endemic areas in Hormozgan province, Iran. In order to identify asymptomatic malaria parasite reservoirs, the samples were examined using microscopic, RDT, and nested-PCR techniques. Results: About twelve positive asymptomatic malaria cases were identified when the molecular method (nested-PCR) was used. The positivity rates among immigrants and local residents were 2.07% and 0.93%, respectively. No positive cases were detected using microscopic and RDT methods. Conclusions: The finding of the research emphasize that in addition to microscopy and RDTs methods, sensitive molecular tools as a standard and essential strategy are needed in the diagnosis and detection of asymptomatic parasite reservoir.

Spatio-temporal Prediction of the Malaria Transmission Risk in Minab District (Hormozgan Province, Southern Iran).

INTRODUCTION: Malaria is the most important parasitic disease in tropical and subtropical regions, with more than 240 million cases reported annually. In Iran, indigenous cases occur in its south-eastern region. The aim of this study is to assess the environmental risk of malaria transmission in an endemic area of southern Iran. METHODS: The study was carried out in Minab district (Hormozgan province, southern Iran), with the aim to assess the environmental risk of malaria, based on a spatio-temporal study, using Growing Degree Days (GDD)-based predictions, larval habitat ecology, MaxEnt spatial predictions and malaria transmission data. RESULTS: The Gradient Model Risk index showed the highest malaria transmission risk period to be during January-April and October-December. The ecological conditions of water bodies of larval habitats of the four vector species (Anopheles culicifacies, A. dthali, A. fluviatilis and A. stephensi) were assessed, with A. stephensi being the most prevalent and the most widely distributed species. CONCLUSION: These findings, together with the MaxEnt Anopheles predictive distribution models, allowed identifying villages in danger of malaria transmission in Minab district. This spatio-temporal prediction of malaria transmission risk should be incorporated in the design of malaria control initiatives towards a local malaria early warning system. Moreover, the proposed transmission risk model can be extrapolated, at local scale, to other malaria endemic areas of tropical and subtropical regions.

Intestinal Parasitic Infections among Intellectually Disabled Individuals in Bandar Abbas County, Southern Iran.

Intellectually disabled individuals are more prone to parasitic infections due to their unusual behaviors, immune and nutrient deficiencies, and living conditions. The current study is aimed at evaluating the prevalence of intestinal parasites in institutionalized intellectually disabled individuals in Bandar Abbas County in the south of Iran. Subjects of the study were 119 individuals, living in an intellectually disabled individual care center. Demographic features of the subjects including age, sex, intellectual disability type, and duration of their stay in the center were recorded. A stool sample was taken from each subject and evaluated by direct wet mount and formalin-ethyl-acetate concentration methods. Samples were also examined, using trichrome and modified acid-fast permanent staining. The mean age of the subjects was 27.6 (±2.24), ranging from 4 to 60 years old. Of the 119 participants, 55 (46.2%) were male, and 64 cases (53.8%) were female. Overall, 31 individuals (26.1%, 95% CI: 18.4-34.9) were found to be infected with at least one type of intestinal parasite. Blastocystis hominis, as the most common detected parasite, was detected in 13 (10.1%), Entamoeba coli in 12 (10.1%), Giardia lamblia in 5 (4.2%), Cryptosporidium in 2 (1.7%), Iodamoeba butchlii in 2 (1.7%), and Endolimax nana in 1 (0.8%) of participants. Three cases had coinfection with Blastocystis hominis and Entamoeba coli, one case was infected with Blastocystis hominis and Giardia lamblia, and one case was coinfected with Giardia lamblia and Entamoeba coli. There were no statistically significant associations between intestinal parasitic infection and gender, age, type of intellectual disability, or duration of stay in the care center (P > 0.05). The findings of the present study indicate a relatively high prevalence of parasitic infections in people with intellectual disabilities in Bandar Abbas, southern Iran. Noteworthy is the high prevalence of Blastocyst and also the presence of Cryptosporidium infection in these people. Periodic treatment of these people and improvement of their maintenance conditions can be considered for the prevention and control of intestinal parasitic infection in these people.

Candida auris and COVID-19: A health threatening combination.

Since its first emergence in December 2019, due to its fast distribution throughout the world, SARS-COV-2 become a global concern. With the extremely increased number of hospitalized patients, this situation provided a potential basis for the transmission of nosocomial infections. Candida auris is a multidrug-resistant pathogen with improved transmission dynamics and resistance traits. During the worldwide spread of COVID-19, cases or outbreaks of C. auris colonization or infection have been reported. Resistance to antifungal drugs has been observed in the causative agents of the majority of such cases. The focus in this review is on COVID-19-associated C. auris infections (case studies/outbreaks) and the pandemic's potential effect on antifungal drug resistance.

Spatial Modelling of Malaria in South of Iran in Line with the Implementation of the Malaria Elimination Program: A Bayesian Poisson-Gamma Random Field Model.

BACKGROUND: Malaria is the third most important infectious disease in the world. WHO propose programs for controlling and elimination of the disease. Malaria elimination program has begun in first phase in Iran from 2010. Climate factors play an important role in transmission and occurrence of malaria infection. The main goal is to investigate the spatial distribution of incidence of malaria during April 2011 to March 2018 in Hormozgan Province and its association with climate covariates. METHODS: The data included 882 confirmed cases gathered from CDC in Hormozgan University of Medical Sciences. A Poisson-Gamma Random field model with Bayesian approach was used for modeling the data and produces the smoothed standardized incidence rate (SIR). RESULTS: The SIR for malaria ranged from 0 (Abu Musa and Haji Abad districts) to 280.57 (Bandar-e-Jask). Based on model, temperature (RR= 2.29; 95% credible interval: (1.92-2.78)) and humidity (RR= 1.04; 95% credible interval: (1.03-1.06)) had positive effect on malaria incidence, but rainfall (RR= 0.92; 95% credible interval: (0.90-0.95)) had negative impact. Also, smoothed map represent hot spots in the east of the province and in Qeshm Island. CONCLUSION: Based on the analysis of the study results, it was found that the ecological conditions of the region (temperature, humidity and rainfall) and population displacement play an important role in the incidence of malaria. Therefore, the malaria surveillance system should continue to be active in the region, focusing on high-risk areas of malaria.

High Seroprevalence of Toxocara Infection among Mentally Retarded Patients in Hormozgan Province, Southern Iran.

Mentally retarded individuals are more likely to become infected with soil-transmitted infections including toxocariasis. The current study aimed to determine the serostatus of toxocariasis among institutionalized mentally retarded individuals in Hormozgan Province, in the south of Iran. Subjects of the study were 117 mentally disabled individuals, including children and adults, maintained in a charity-based institution. Three millilitres of venous blood was taken from each subject. While sampling, demographic features of the subject were documented in a questionnaire. An ELISA system based on Toxocara larvae excretory-secretory antigens (TES) was utilized to detect anti-Toxocara IgG antibodies in the sera of the patients. The mean age of the subject was 27.6 (±12.31) years and consisted of 55 (47%) males and 62 (53%) females. Out of 117 cases, 33 (28.2%) were seropositive for toxocariasis. The seroprevalence was higher in females (37.1%) than males (18.2%), and the difference was statistically significant (p < 0.05). Out of 117 subjects, 76 (64.9%) had severe and 41 (35.1%) had profound mental retardation. Anti-Toxocara antibodies were detected in 18 (23.7%) patients with severe and 15 (35.6%) patients with profound mental retardation. The highest seroprevalence rate of toxocariasis (44.4%) was observed in the age group of ≤10 years followed by 21-30 years old (36.7%). No statistically significant association was seen between the age and also the duration of residency in the care center and seropositivity of toxocariasis (p > 0.05). The current study represents the high prevalence of toxocariasis in mentally retarded patients in Hormozgan Province, southern Iran. The elevated seroprevalence rate of toxocariasis in the current study indicates that these subjects constitute a high-risk group for Toxocara infection, which may be attributed to their behavioral patterns.

Restricted genetic heterogeneity of the Plasmodium vivax transmission-blocking vaccine (TBV) candidate Pvs48/45 in a low transmission setting: Implications for the Plasmodium vivax malaria vaccine development.

Plasmodium vivax is the most widespread malaria species parasitizing humans outside Africa, with approximately 100 million cases reported per year. Most human cases of P. vivax are asymptomatic with low parasitemia, making active case detection-based elimination programme challenging and less effective. Despite the widespread distribution of P. vivax, no effective vaccines are currently available. Transmission blocking vaccines have recently emerged as potential vaccine candidates to reduce transmission rates to below the essential levels required for the maintenance of the parasite life cycle. Here, we demonstrated that P. vivax was the predominant species found in a malaria-endemic area, although P. vivax/P. falciparum co-infections were also common. Through genomic sequence analysis and neighbor-joining algorithms, we demonstrated limited genetic heterogeneity in the P. vivax transmission-blocking vaccine candidate Pvs48/45 among clinical isolates of P. vivax. Restricted genetic polymorphism occurred at both nucleotide and amino acid levels. The most frequent mutation was A â†’ G at nucleotide position 77 (46.7%), whereas the least frequent was C â†’ T at nucleotide position 1230 (3.3%). The occurrence of single nucleotide polymorphisms (SNPs) distribution at 6/8 positions (75%) led to changes in amino acid sequences in the Pvs48/45 loci, whereas 2/8 (25%) of SNPs resulted in no amino acid sequence variations. Consistently, the nucleotide diversity in the Pvs48/45 locus among the P. vivax population studied was extremely low (π = 0.000525). Changes in amino acid sequences in the Pvs48/45 protein did not result in substantial conformational modifications in the tertiary structures of these proteins. Unveiling the population genetic structure and genetic heterogeneity of vaccine target antigens are necessary for rational design of transmission-blocking antibody vaccines and to monitor the vaccine efficacy in clinical trials in endemic areas for malaria.

Prevalence of Cryptosporidium spp. in water: a global systematic review and meta-analysis.

Cryptosporidium spp., as a genus of protozoan intestinal parasites, is recognized as responsible for cryptosporidiosis. The present study was conducted to provide an overview of the prevalence of Cryptosporidium based on water. In this regard, some databases such as Scopus, PubMed, Embase, and Web of Science were screened in order to retrieve the related citations from 1 January 1983 to 10 September 2019. The pooled prevalence of Cryptosporidium spp. was calculated by using a random effect model (REM) based on defined subgroups, including countries, water type, treatment conditions (treated and untreated), economic condition, World Health Organization (WHO) regions, and method of detection. In contrast, this index for treated and untreated water was 25.7% and 40.1%, respectively. Also, the overall prevalence of Cryptosporidium spp. among all water types was defined as 36 (95% CI: 31.4-40.7). The rank order of prevalence of Cryptosporidium spp. based on water type was wastewater (46.9%) > surface water (45.3%) > raw water (31.6%) > drinking water (25.5%) > reservoirs water (24.5%) > groundwater (18.8%) > swimming pool water (7.5%) > marine water (0.20%). Identifying the key contributing factors to Cryptosporidium spp. survival can help provide solutions at both local and global scales.

A comprehensive entomological survey and evaluation of the efficacy of different therapies on a suspected delusional parasitosis case.

OBJECTIVE: Delusional parasitosis (DP) is one type of psychotic disorders. It is a multifactorial disorder with different etiologies. Given that very little attention is paid to entomological survey in these cases, a comprehensive study was designed and performed for the first time in Iran on a suspected DP case and its home from Shiraz during 2018-2019. METHODS: In this study, entomological survey, dermatological studies, and psychological and psychiatric interventions were done respectively on a 40-year-old man who was referred to as a suspected case of DP. RESULTS: No medical importance arthropods were collected from the patient's home. He was not infected with lice and other ectoparasites. Skin samples were negative for scabies, but he was infected with Demodex folliculorum at low level. Psychiatric studies showed that he was a secondary DP case with depression. No effect and partial remission were reported after treatment with risperidone (2-6 mg/d) and olanzapine (5 mg/d), respectively. Therapeutic effects of hypnotism were also not satisfactory. CONCLUSIONS: In Iran, the most important challenges these patients faced with are as follows: the absence of a specific referral center, patients resort to self-treatment or traditional methods, and lack of a certain duration and dosage of antipsychotic for these cases. Comprehensive clinical trials should be done on this rare syndrome at the national level for better understanding the epidemiological profile of DP and finding the best method of treatment for Persian community.

Pattern of disinfectants use and their adverse effects on the consumers after COVID-19 outbreak.

BACKGROUND AND OBJECTIVE: The aim of this study was to investigate the pattern of disinfectants use within outbreak of COVID-19 and estimate their adverse effects on the consumer's health. METHODS: In this descriptive-analytical study, 1090 participants were entered into the study without age and gender limitations. A researcher-made electronic checklist containing 43 questions was applied to collect data. The checklist included three sections: demographic characteristics (8 questions), disinfection of body and non-living surfaces (21 questions), and adverse effects of disinfectants on health (15 questions). RESULTS: 87% of participants used the incorrect proportions of water and alcohol to make this disinfectant available at home. The percentage of people with wrong proportion of sodium hypochlorite was 74.2%. Approximately 42% of participants experienced at least one disorder on their hands, feet, eyes, respiratory or gastrointestinal systems after sequential uses of disinfectants. The most common disorders among the participants were found to be skin dryness (76.3%), obsession (42.2%), skin itching (41.2%), coughing (41.1%), and eyes irritation (39.5%). The mean frequency of hand washing and hand disinfecting were 15.28 and 10.74 times per a day, respectively, and the clean-up in case of surfaces was 2.99 times a day. The frequency of hand washing and disinfecting in women group (16.4 and 11.2 times a day) were higher than in men (14.0 and 10.3 times a day) group. In addition, these self-care actions in married people (15.6 and 11.0 times a day) were higher compared to those in single people (14.0 and 10.6 times a day). CONCLUSION: Being unaware of participants with instruction for preparation and use disinfectants may harm their health. Therefore, it is suggested that the authorities provide the necessary training program for public through official media.

Investigating the frequency of free-living amoeba in water resources with emphasis on Acanthamoeba in Bandar Abbas city, Hormozgan province, Iran in 2019-2020.

OBJECTIVE: These amoebas can cause dangerous illnesses when they accidentally enter the human body, so it is necessary to determine various forms of organisms in water resources to prevent the danger they can cause and risks to human health. Currently, in Bandar Abbas, there is no sufficient information about the distribution of Acanthamoeba, and we intended to study its frequency and determine the related genotypes. RESULTS: Out of 83 water samples collected from different resources in the city, 31 plates (37.3%) were found to be positive for free-living amoebae. Of these, five were identified as Acanthamoeba (6%) by culture method and 8 (9.6%) by molecular method. Positive sample sequence analysis enabled us to distinguish two genotypes of T4 (7 cases) and T15 (1 case) in this study.

Clinico-Hematological Findings of Acute Pediatric Visceral Leishmaniasis Referred to the Northeast of Iran during 2005-2015.

BACKGROUND: To characterize the epidemiological, clinical, hematological and biochemical features of 33 cases hospitalized with pediatric visceral leishmaniasis (PVL) in North Khorasan Province of Iran from 2005 to 2015. METHODS: The serological, hematological and biochemical tests were employed in 33 children between 8 months to 6 yr with a final diagnosis of acute visceral leishmaniasis (VL). The diagnosis of VL was established by microscopic demonstration of Leishmania spp. amastigotes inactive bone marrow aspiration (BMA). RESULTS: The most common presenting features were anemia (82.5%), fever (75%), and hepatosplenomegaly (45.4%). Various hematological parameters showed that most patients were suffering from moderate to severe microcytic hypochromic anemia (78.8% had RBC count less than 4 million cells/ul, 67.7% Hb less than 8 fl). 66.7% of them were leukopenic (WBC: less than 5× 10 3 /µL) and 24.2% had decreased platelet counts. Pancytopenia was observed in 18.2% of cases. MCV, MCH, and MCHC levels were below the reference range in 88%, 90% and 85.1% of the patients respectively. Moreover, aspartate transaminase (AST) and alanine transaminase (ALT) levels were increased in 53.33% and 6.66% of the patients respectively. 92.9% of cases were C-reactive protein (CRP) positive. Bone marrow was found hyper-cellular in all of them, and myeloid to erythroid ratio (M/E) was more than 4 in 39.1% of cases. Plasma cells slightly were increased in 60% of patients and megakaryocytes were decreased in thrombocytopenic patients. CONCLUSION: Bone marrow/splenic aspiration still remains the gold standard test despite its risk and pain for patients.

Level of circulating steroid hormones in malaria and cutaneous leishmaniasis: a case control study.

Epidemiological and clinical studies have shown a great difference in the severity and prevalence of infectious diseases in men and women and various studies have shown that the key immunological factors are affected by sex-associated hormones. Considering the role of sex hormones in various infections, the current study aimed to determine the level of sex hormones in patients with cutaneous leishmaniasis (CL) and malaria and compare it with those of healthy controls. The survey was designed as a case-control study. Peripheral blood was collected from thirty male malaria patients, sixty patients (equal number of both sexes) with cutaneous leishmaniasis and ninety healthy subjects. Disease confirmations were done through microscopic examination of either peripheral blood smears, in case of malaria, or Giemsa-stained lesion imprint slides for CL. The level of testosterone, progesterone and estrogen were measured in malaria and CL patients along with healthy subjects, using an ELISA commercial kit. Age of participants was 18-35 years (mean 25.39 ± 4.70) for CL patients and 14-41 years (mean 27.63 ± 9.09) for malaria patients. Differences between the age of patients and the healthy subjects were insignificant. The level of testosterone in malaria patients (1.44 ± 0.12 ng/mL) was lower than control group (1.46 ± 0.06, ng/mL) but the differences were not statistically significant (p > .05). The concentration of testosterone in CL patients (1.49 ± 0.03 ng/mL) was higher than those of control group (1.46 ± 0.06 ng/mL), and the difference was statistically significant (p  = 0.05). Although the concentration of estrogen and progesterone in CL patients were lower than controls, still the differences were not statistically significant (p > 0.05). Findings of the current study demonstrated a significant difference in the serum level of testosterone in CL patients in comparison with the healthy subjects whereas such difference was not seen in malaria patients.

Prevalence of intestinal parasitic infection among primary school children in southern Iran.

A cross-sectional study was carried out to determine the prevalence of intestinal parasites in primary school children in Bandar Abbas, southern Iran during January to March 2016. Single stool samples were collected from 1465 participants by clean stool cup. The questionnaire was prepared on the basis of demographic characteristics. The diagnosis was made on the basis of the direct wet mount, formalin-ether concentration, and Ziehl-Neelsen and trichrome stained slides. Out of the 1465 school children examined, six species of intestinal parasites were identified with an overall prevalence of 95 positive students (6.5%). Prevalence of protozoan infections (6.2%) was significantly higher than helminth infections (0.3%). The most common protozoan species were Giardia lamblia (n = 42, 2.9%) and Blastocystis hominis (n = 31, 2.1%). Only two cases of Hymenolepis nana and two cases of Enterobius vermicularis were detected. The prevalence of parasitic infections was higher in boys (n = 52, 7%) than girls (n = 41, 5.7%), but the difference was not significant. The parasitic infections were higher among the children whose parent's education was less than high school diploma (p = 0.000), and there was also a significant association between the parents' jobs and the intensity of parasitic infection. The prevalence of intestinal parasites, compared to the previous studies in this area, was significantly lower; that is mainly due to an increase in the quality of life and parents' education as well as the accessibility to health services. The most prevalent intestinal parasite was G. lamblia; therefore, it is recommended that more emphasis is applied to controlling and preventing this parasitic infection by washing hands, particularly before each meal course.

Cloning and Sequence Analysis of Recombinant Plasmodium vivax Merozoite Surface Protein 1 (PvMSP-142 kDa) In pTZ57R/T Vector.

BACKGROUND: Carboxy-terminal 42 kDa region of Plasmodium vivax merozoite surface protein-1 is considered as an important antigen in blood stage. Since, this region has been observed to be polymorphic among isolates of P. vivax, it is significant to survey on different regions of this antigen in various areas of the world. METHODS: In the present study, the genetic diversity of cloned PvMSP-142 kDa gene from an Iranian patient is analyzed. Parasite DNA was extracted from a P. vivax - infected patient in Iran. The region of PvMSP-142 kDa was amplified by PCR, cloned into pTZ57R/T vector and then sequenced. RESULTS: Sequencing of cloned PvMSP-142 kDa gene clearly has a high degree of homology (95%) with reference Sal-I sequence and also with the homogeneous sequences from some studied countries (97%). Thirty eight SNPs (single nucleotide polymorphism) were identified in cloned PvMSP-142 kDa gene which the mutations had localized in the 33 kDa fragment (PvMSP-133 kDa), while there was nearly no variation in the 19 kDa fragment (PvMSP-119 kDa). 2 out of 38 mutations were found as to be novel haplotypes. CONCLUSION: High similarity of cloned PvMSP-142 kDa gene in comparison to reference sequence and other sequences could be beneficial as a remarkable molecular marker for serological diagnostic kits of P. vivax in malarious neighboring countries of Iran and around the world.

Efficiency of Nested-PCR in Detecting Asymptomatic Cases toward Malaria Elimination Program in an Endemic Area of Iran.

BACKGROUND: The aim of this study was to detect low parasite and asymptomatic malaria infections by means of three malaria diagnostic tests, in a low transmission region of Minab district, Hormozgan Province, southern Iran. METHODS: Blood samples of 200 healthy volunteers from Bagh-e-Malek area were evaluated using microscopic, rapid diagnostic tests (RDT) and nested-PCR to inspect malaria parasite. RESULTS: The results showed no Plasmodium parasite in subjects by means of microscopy and RDT. However, 3 P. vivax positive samples (1.5%) were discovered by Nested-PCR while microscopy and RDT missed the cases. CONCLUSION: Microscopy as the gold standard method and RDT correctly identified 98.5% of cases, and molecular analysis is sensitive and reliable, especially in the detection of "asymptomatic" infections for active case surveillance. Regarding the existence of asymptomatic malaria in endemic area of Hormozgan, Iran, nested-PCR could be considered as a sensitive tool to interrupt malaria transmission in the country, beside the microscopic and RDT methods.

Survey for asymptomatic malaria cases in low transmission settings of Iran under elimination programme.

BACKGROUND: In malaria endemic areas, continuous exposure to Plasmodium parasites leads to asymptomatic carriers that provide a fundamental reservoir of parasites, contributing to the persistence of malaria transmission. Therefore, in the present investigation, the presence and prevalence of malaria asymptomatic cases were determined to evaluate the reservoir of infection in two malaria endemic areas with a previous history of malaria transmission in the south of Iran, Bashagard and Ghale-Ganj districts of Hormozgan and Kerman provinces, respectively, where malaria transmission has been drastically reduced in the recent years. METHODS: The population samples (n = 500 from each of the studied areas) were randomly collected from non-febrile, long-term residing, aged two to over 60 years, during 20092010. Three identical surveys were carried out in both study areas and in each phase all the consent participants were interviewed and clinically examined. In all, three surveys to detect hidden parasite reservoirs (both Plasmodium falciparum and Plasmodium vivax), thick and thin blood smears and a highly sensitive nested-PCR were applied. In addition, the sero-prevalence survey for detecting malaria exposure was done by using a serological marker. RESULTS: In this study, P. vivax and P. falciparum parasites were not detected by light microscopy and nested-PCR assay in all three surveys of samples. Antibody responses against P. vivax and P. falciparum were detected in 1% and 0.2% of the total examined individuals, respectively, in Bashagard district. Regarding to Ghale-Ganj district, about 0.9% of the individuals had IgG -specific antibody to P. vivax at the first and second surveys, but at the third survey 0.45% of the participants had positive antibody to P. vivax parasite. IgG -specific antibody to P. falciparum was detected in 0.2% of the participants at the first and follow-up surveys. The overall regional differences were not statistically significant (P > 0.05). CONCLUSION: Taken together, the lack of asymptomatic carrier with the evidence of extremely low sero-positive to both P. vivax and P. falciparum among examined individuals supported the limited recent transmission in the studied areas and, therefore, these parts of Iran have potential to eliminate the disease in the next few years. However, continued follow up and action are still needed in both studied areas and also in their neighbouring province, Sistan and Baluchistan, which has the highest reported cases of malaria in Iran and also, has the largest border line with Afghanistan and Pakistan, with no elimination activities. This data will provide useful information for managing elimination activities in Iran.