Evaluation of Multiplex/Nested Polymerase Chain Reaction and Loop-Mediated Isothermal Amplification for Malaria Diagnosis in Southeastern Iran.

Malaria is one of the most serious health problems in many countries, including Iran. Accurate diagnosis is important regardless of the elimination status of a country. A cross-sectional study was performed on 105 people who were suspected to be positive for malaria infection in Sistan and Baluchistan, Iran. Blood smears (thin and thick films) were stained with 10% Giemsa. DNA was extracted from the prepared thin and thick films for molecular methods. Multiplex/nested polymerase chain reaction (mn-PCR), loop-mediated isothermal amplification (LAMP), and light microscopy (LM) were compared with nested PCR (nPCR) as a gold standard. Of 105 subjects, 52 (49.5%), 58 (55.2%), 58 (55.2%), and 63 (60%) were positive for malaria by LM, nPCR, mn-PCR, and LAMP, respectively. The sensitivity, specificity, and kappa were 92.1%, 100%, and 0.9 for LAMP and 100%, 100%, and 1 for mn-PCR, respectively. Eight cases of coinfection (Plasmodium vivax and Plasmodium falciparum) that were not detected by LM method were diagnosed by mn-PCR and LAMP. In the present study, the high sensitivity and specificity of LAMP and mn-PCR indicate that these two tests are good alternatives to nPCR for malaria diagnosis.

Seroprevalence of Toxocara spp. in children (3-13 years old) in Zahedan, Southeast of Iran.

Child Toxocariasis (CT) is one of the most important helminthic parasitic diseases in Iran. The current study was aimed to determine the seroprevalence of toxocariasis in children in Zahedan, southeast of Iran. In this cross-sectional study, serum samples of 373 children aged 3-13 years old referred to health centers in Zahedan were collected randomly with criteria based on the parameters that were used in earlier studies and examined for anti-Toxocara antibody using a commercial ELISA kit. Of the 373 recruited subjects, 206 (55.2%) were male and 167 (44.8%) were female. Most of the subjects (36.5%) were in the age group 3-4 years old. Anti-Toxocara antibodies were detected in the sera of five out of 373 individuals, corresponding to a seroprevalence rate of 1.3%. A significant correlation was found between the incidence of disease and eosinophilia, a history of contact with dogs or cats, as well as the consumption of raw vegetables and drinking of contaminated water. There was no significant correlation between prevalence and gender or age. The finding of this study revealed that the prevalent CT is relatively low in Zahedan region. The rate of CT infection in the southeast of Iran was lower than the rate in other parts of Iran.

Diagnosis of acute toxoplasmosis by IgG avidity method in pregnant women referred to health centers in south-eastern Iran.

Toxoplasmosis, one of the most common parasitic infections, can cause abortions in human. The purpose of this study was to determine seroprevalence of toxoplasmosis and acute form of toxoplasmosis in pregnant women. 208 pregnant women who referred to health centers in south-eastern Iran were taken under study after signing the informed consent forms and filling out the checklists. For those with high levels of IgG or IgM antibody titers, IgG Avidity test was performed to determine the acute infection. High level of IgG anti-body were found in sera of 81 pregnant women and 7 persons had borderline titer. IgM antibody results were positive in 33 and borderline in 4 cases. Then, the samples with positive and borderline results for IgM and IgG were evaluated by IgG avidity test. In this study, approximately 60% of pregnant women were not immune to risks posed by Toxoplasma gondii. Therefore, this group are at risk of acquiring primary infection of toxoplasmosis during gestation.

Evaluation of malaria multiplex/nested PCR performance at low parasite densities and mixed infection in Iran: A country close to malaria elimination.

BACKGROUND: Malaria is still a major public health problem in subtropical and tropical regions. The rapid and accurate diagnosis of malaria remains a challenge in most of the endemic areas. The primary objective of the present study was to evaluate the performance of multiplex/nested PCR in detecting Plasmodium falciparum at low parasite densities and mixed infection. METHODS: The study was performed in the Sistan-Baluchestan province of the southeastern Iran, from May 2015 to July 2016. A total of 105 patients suspected to malaria infection were enrolled in the study. The obtained DNA products, extracted from the thick/thin films, were analyzed by multiplex/nested PCR using genus-specific primers and compared with light microscopy. RESULTS: 43 samples were confirmed to be infected by microscopic examination. Among 43 microscopically diagnosed P. falciparum cases, 11.4% (12/105) were confirmed by multiplex/nested PCR, 36.2% (38/105) were confirmed as P. vivax, 1.9% (2/105) had mixed infections with P. falciparum and P. vivax. Among microscopy-negative samples, 10 samples turned malaria-positive in nPCR. In multiplex/nested PCR, the rate of mixed infections was 8.6% (9/105). When compared to LM, the sensitivity, specificity, positive predictive value and negative predictive value of multiplex/nested PCR were calculated to be 82.8, 91.5, 92.3 and 81.1%, respectively. CONCLUSION: In this study, we showed that microscopic examination of blood smears does not reliably distinguish Plasmodium species in the case of mixed infections. Therefore, it seems that multiplex/nested PCR is a good candidate for examining the presence of malaria parasites in clinically suspected but microscopically negative cases.

Seroprevalence of Anti-Toxoplasma Gondii Antibodies in Healthy Voluntary Blood Donors from Mashhad City, Iran.

OBJECTIVE: The present investigation aims to evaluate the prevalence of IgM and IgG anti-T. gondii antibodies and the associated risk factors among healthy blood donors in Mashhad city, Razavi Khorasan province, Iran. METHODS: We screened a total of 500 serum samples by census method from apparently healthy blood donors of the Mashhad Blood Transfusion Organization (MBTO) for IgG and IgM anti-T. gondii antibodies by enzyme linked immunosorbent assay (ELISA). RESULTS: We found that 29.6%, 25%, 1.4%, and 3.2% of tested donors were positive for anti-T. gondii antibodies, only IgG antibody, both IgM and IgG, and IgM antibody alone, respectively. Several risk factors which were significantly related to T. gondii seropositivity in the univariate analysis at P < 0.05 included female gender (OR = 3.222, P < 0.001), age more than 40 years (P = 0.026), and sausage/hot dog consumption (OR = 4.472, P < 0.001). CONCLUSIONS: The results of this study can be a warning for blood transfusion organizations to pay special attention to toxoplasmosis among blood donors and also design screening programs for prevention of transfusion-transmitted toxoplasmosis.