جستجوی مقالات مرتبط با کلیدواژه "asymptomatic malaria" در نشریات گروه "پزشکی"

Asymptomatic malaria is a major challenge to be addressed in the implementation of the malaria elimina tion 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.

It was a case-study approach that was conducted in the Anarestan area. A total of 246 residents and immi grants living in the area at the age range of 4–60 years old were randomly selected to be tested for malaria by micro scope, 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.

The results indicated no positive cases of asymptomatic malaria among the participants tested by all methods.

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.

Asymptomatic malaria, which usually exists in low parasitemia, acts as the Plasmodium species reser voirs contributing towards malaria transmission. This situation hinders malaria elimination programs in endemic areas, thus necessitating an active case detection with a high sensitive method and treatment of cases. This is why we used a High Resolution Melting (HRM) assay to monitor the trend of asymptomatic malaria in a malaria endemic area of Iran which is under elimination program.

The peripheral blood was sampled from 271 clinically approved non-febrile individuals from a malaria en demic zone of southeastern Iran for asymptomatic malaria prevalence detection by microscopy, Rapid Diagnostic Tests (RDTs) and HRM methods. The HRM assay was done based on the amplification of 18S SSU rRNA gene.

The HRM assay revealed infections from three individuals out of 271 (1.1% asymptomatic malaria prevalence) from the participants, two Iranian natives with Plasmodium vivax infection and one Pakistani immigrant with P. falcipa rum infection. Neither microscopy nor RDTs detected Plasmodium spp infections from the 271 non-febrile individuals. The nucleotide sequencing analysis of the positive controls used in this study showed a close homology with the refer ence gene bank sequences of P. falciparum 3D7 (CPO16995.1) and P. vivax Sal-1(UO3079.1).

This study revealed a low frequency of asymptomatic malaria trend within malaria endemic areas of southeastern Iran which are under intense elimination program and also the ability of HRM assay in detecting low Plasmodium spp parasitemia beyond the limits of microscopy and RDTs.

This study was designed to detect, if there are asymptomatic malaria infections amongst native and immigrant population from Afghanistan and Pakistan countries in Sistan & Baluchistan Province of Iran, where is under the national malaria elimination program.

This cross-sectional study was performed among native individuals and resident immigrants in the southeastern province of Sistan & Baluchistan from May 2016 to Jul 2017. A total of 271 individuals were considered in this cross- sectional study based on microscopical method, Rapid Diagnostic Tests (RDTs) and PCR techniques. Out of 271 native and immigrant participants 140 (52%) and 131 (48%) were male and female, respectively.

None of the prepared samples was diagnosed as malaria positive case when was considered via above mentioned three techniques.

Neither native nor immigrant individuals had asymptomatic malaria, hinting that national malaria elimination program is performed according to planned schedule in the studied areas

Malaria is threatening more than half of Afghanistan population. Asymptomatic malaria is notable problem against malaria controlling strategies. In this study we evaluated the asymptomatic malaria status in Nangarhar Province, Afghanistan in 2017.

Overall, 296 finger blood samples were taken on DNA Banking Cards and microscopic slides from asymptomatic individuals in Jalalabad city. We used a novel post real time PCR high resolution melting analysis beside microscopy and semi-nested multiplex PCR to evaluate status of asymptomatic malaria in this city.

The prevalence of asymptomatic malaria in Jalalabad city was determined 1.7% (5/296), 7.43% (22/296) and 7.78% (26/296) by microscopy, Seminested multiplex PCR and qRT-PCR-HRM, respectively. Out of 26 positive cases were detected by qRT-PCR-HRM, 21, 1 and 4 cases were detected P. falciparum, P. vivax and mixed infection of P. falciparum and P. vivax, respectively.

Our data indicating on existence of significant number of asymptomatic reservoirs that assists in prolonged endemicity of the disease. On the other hand, the molecular methods are better alternatives for microscopy especially for monitoring of asymptomatic cases of malaria.

 Detection and monitoring of asymptomatic malaria cases, especially among immigrants, are the main parts of the successful malaria elimination program. To achieve this aim, a sensitive detection method is required.

 This study aimed to investigate immigrant asymptomatic malaria cases in Bandar Abbas district using microscopic, Rapid Diagnosis Test (RDT), and Nested PCR.

 In this cross-sectional study, 330 blood samples of immigrants living in Bandar Abbas were collected and their status in terms of Plasmodium infection was assessed using microscopic, RDT and Nested-PCR techniques.

 Five positive cases were found when molecular analysis was applied. However, microscopy and RDT methods showed no positive malaria cases.

 The results of this study are indicative of a big challenge to the malaria elimination program posed by presence of asymptomatic cases who migrated from malaria endemic areas. In addition, accurate diagnosis of asymptomatic malaria cases requires the use of molecular methods.

Malaria is a major global public health problem and a leading cause of morbidity and mortality in many countries. Malaria elimination is the common goal of World Health Organization and the health system in Iran. Following a decline in malaria cases in recent years, the malaria elimination program, technically supported by the WHO, has initiated since 2009 in Iran. In order to successfully implement a malaria elimination program, all positive cases particularly low parasitemia and asymptomatic cases are required to be detected. The main objective of this study was to identify asymptomatic malaria infection in a low transmission area in Rudan district, Hormozgan Province, southern Iran.
In this cross-sectional study a total of 200 blood samples were randomly collected from symptomless residents of Rudan to evaluate Plasmodium infection rate where microscope, RDT and nested-PCR techniques were used.
According to the analysis of microscopic methods, RDT and Nested-PCR, no asymptomatic cases were seen among the participants.
The results of this investigation reveal that Malaria Elimination Program is administrable in Rudan district irrespective of low-parasitemia and asymptomatic cases.

Asymptomatic malaria infection provides a reservoir of parasites, causing the persistence of malaria transmission. It accounts an important challenge for successful management of the control, elimination, and eradication programmes in any malaria-endemic region. This investigation was designed to assess the presence and the prevalence of asymptomatic carriers in Iranshahr district of Sistan and Baluchistan Province (2013-2014), with a considerable population movement, during the malaria elimination phase in Iran.
Finger-prick blood samples were collected from symptomless (n=250) and febrile (n=50) individuals residing in Iranshahr district, easthern Iran (Hoodian, Mand, Chah-e Giji, Jolgehashem, Esfand, Dalgan and Chahshour) during Jan 2013 to Dec 2014, and Plasmodium infections were detected using light microscopic and highly sensitive nested-PCR techniques.
Thick and thin Giemsa-stained blood smears were negative for Plasmodium parasites. In addition, based on nested-PCR analysis, no P. vivax, P. falciparum, and P. malariae parasites were detected among the studied individuals.
Investigation the absence of asymptomatic carriers in Iranshahr district was illustrated and achieving malaria elimination in this area is feasible in a near future.

Asymptomatic malaria (ASM) has been implicated in the development of hemolytic crisis in infected sickle cell anemia (SCA) patients worldwide. This study surveyed steady state SCA Nigerian patients for ASM to investigate the influence of malaria prevention behaviors and age on parasitaemia and multiplicity of infection (MOI). A total of 78 steady SCA patients aged 5 – 27 years on routine care at three health facilities in Lagos were investigated for ASM by light microscopy and PCR with a multiplicity of infection determined by genotyping block 2 of merozoite surface protein 1 (msp1) gene of Plasmodium falciparum (P. falciparum). Use of malaria prevention measures was captured using a semi-structured questionnaire. The prevalence rates of ASM (due to Pf only) by microscopy and PCR were found to be 27.3% and 47.4% respectively (P < 0.05) with a Mean + SEM parasite density of 2238.4 + 464.3 parasites/uL. Five distinct msp1 genotypes [K1 (2), MAD20 (2), RO33 (1)] were detected and significant (P<0.05) disparity in allele frequencies (K1, 91.8%, MAD20, 32.4%; RO33, 18.9%) was found. The overall MOI was 1.43 and 37.8% of infections were polyclonal (P<0.05). ASM was associated with non-use of preventive measures and occurred in 62.1% of SCA patients aged < 10y with lower MOI of 1.3 compared to 38.1% in older patients with a higher MOI of 1.5 (P<0.05). We conclude that PCR improved the diagnosis of ASM among Nigerian SCA patients with infections being of low complexity and associated with non-use of preventive interventions and R033 msp1 allele selection.

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. 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. 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. 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.

This study aimed at determining the prevalence and associated risk factors for asymptomatic malaria parasitaemia and anemia among blood donors in a private medical laboratory in Benin City, Nigeria. Venous blood was collected from a total of 247 blood donors. Malaria status, ABO, Rhesus blood groups and hemoglobin concentration of all partici­pants were determined using standard methods. The prevalence of asymptomatic malaria infection was higher among commer­cial blood donors than volunteer group (commercial vs. volunteer donor: 27.5 %vs. 13.8%; OR = 2.373, 95% CI = 0.793, 7.107, P = 0.174). Asymptomatic malaria was not significantly affected by gender (P = 0.733), age (P = 0.581), ABO (P= 0.433) and rhesus blood groups (P =0.806) of blood donors. Age was observed to significantly (P = 0.015) affect malaria parasite density with donors within the age group of 21-26 years having the highest risk. The prevalence of anemia was significantly higher among commercial donors (commercial vs. volunteer donors: 23.4% vs. 3.4%: OR = 8.551, 95% CI = 1.135, 64.437, P = 0.013) and donors of blood group O type (P =< 0.0001). Asymptomatic malaria parasitaemia and anemia was higher among commercial donors than voluntary donors. Mandatory screening of blood donors for malaria parasite is advocated to curb transfusion transmitted malaria and associ­ated sequelae.