Tropical Parasitology最新文献

Introduction: Giardiasis is one of the greatest public parasitic infections causing diarrheal and also known to be associated with high morbidity and mortality, among the children's particularly in developing countries with less cleanliness practices. Thus, studying genomic variety of Giardia intestinalis aids to improve our perspective related to the variability in the genome of the parasite.

Materials and methods: In this cross-sectional study, 1006 stool samples were collected from the rural (n = 500) and urban settings (n = 506) from the children (<15 years) with and without symptoms and were screened for the presence of G. intestinalis by polymerase chain reaction (PCR) targeting triosephosphate isomerase gene. Further, all PCR-positive amplicons were subjected to restriction fragment length polymorphism using RsaI restriction enzyme.

Results: Of the total 1006 stool samples, 500 samples from rural screened by PCR 108 (21%) were found to be positive for assemblage A, 116 (23.2%) belong to assemblage B, and 5 (1%) were mixed assemblages (A + B). Whereas in urban, of the 506 samples screened by PCR, 92 (18.1%) were found to be positive for assemblage A, 93 (18.3%) assemblage B, and 10 (1.9%) were mixed assemblages (A + B). No significant difference was found between the G. intestinalis assemblages with clinical details of symptomatic and asymptomatic in children.

Conclusions: This signifies the first study inspection in our location to shed lights and delivers some preliminary data on assemblages and subassemblages. The results suggest that anthroponotic transmission could be a foremost transmission path for giardiasis among the study population.

Background: Strongyloides stercoralis, the causative agent of strongyloidiasis, is a parasitic worm that has larvae capable of reinfecting the same host. This nematode infection is therefore difficult to treat and to achieve total cure. Information about genetic variation and differences in drug susceptibility between strains is needed to improve treatment outcomes.

Aim: To develop a polymerase chain reaction (PCR) to identify the intra-species variation among 13 S. stercoralis isolates collected from Bangladesh, USA and Australia.

Material & methods: PCR assays were designed by using primers targeting S. stercoralis internal transcribed spacer (ITS) regions 1 and 2. Sequence data generated by these PCR products were compared to the existing ITS1/2, 18S and 28S rRNA gene sequences in GenBank for phylogenetic analysis.

Results: Intra-species single nucleotide polymorphisms (SNPs) were identified in ITS1 and in the 5.8S rRNA gene. The generated phylogram grouped the 13 isolates into dog, Orangutan and human clusters.

Conclusion: This method could be used as an epidemiological tool to study strain differences in larger collections of S. stercoralis isolates. The study forms the basis for further development of an ITS-based assay for S. stercoralis molecular epidemiological studies.

Introduction: A range of assays have been developed to detect specific antileishmanial antibody, such as rK 39 immunochromatographic test (ICT), KE 16 ICT, ELISA test, and indirect immunofluorescent antibody test (IFAT), which play a crucial role in serological diagnosis of visceral leishmaniasis (VL). However, limited published reports are available on the utility of serological test (IFAT test/rk 39), smear examination, and culture in the diagnosis of VL and post-kala-azar dermal leishmaniasis (PKDL) in our country.

Materials and methods: We present utility of serological test (IFAT test/rK 39), smear examination for Leishmania donovani (LD) bodies, and culture in 2589 samples from 2294 VL/PKDL suspected patients (January 2009-December 2019) tested in Centre for Arboviral and Zoonotic diseases, National Centre for Disease Control, New Delhi, India, for laboratory diagnosis of VL/PKDL.

Results: A total of 80/553 (14.4%) cases were confirmed of VL (74/522 cases by demonstration of LD bodies in bone marrow smear examination, 5/12 in splenic smear examination 1/19 by culture) and 4/21 (19.0%) cases were confirmed of PKDL (demonstration of LD bodies in slit skin smear examination. In our study 197/1368 (14.4%) cases were diagnosed positive by IFAT, 34/646 (5.2%) cases by rk 39 ICT for VL/PKDL by demonstration of specific antileishmanial antibodies.

Conclusion: As the goal of elimination of VL as a public health problem is approaching, apart from serological tests such as rk 39 and IFAT, direct methods of detection such as (parasitic demonstration in BM smear, culture, and molecular tests) for Leishmania may play a crucial role for achieving a correct diagnosis and treatment. We also concluded that IFAT though not field-friendly, its optimal use as an adjunct test with BM smear in all stages of infections may be required. Further rk39 is a simple, reliable, noninvasive, and field-friendly test for diagnosis VL, especially in endemic areas.

Filariasis is a common public health problem in the Indian subcontinent. Microfilariae are usually detected in the peripheral circulation; however, the clinical manifestations are related to the lymphatic system primarily. The breast is an uncommon site for filariasis, and the lesion clinically mimics malignancy. We should consider filariasis in the differential diagnoses of breast lumps, especially in endemic areas. Fine-needle aspiration cytology from the breast lump allows easy detection of filarial infection, and this can be managed by medical treatment, thereby avoiding surgical procedures.

Background: Giardia is a diarrheagenic eukaryotic parasite that consists of at least eight morphologically identical but genetically distinct genotypes. Human giardiasis is caused mainly by A and B assemblages.

Aim and objectives: The study aimed to compare the performance of gdh polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and tpi assemblage-specific primers in genotyping of G. intestinalis.

Materials and methods: Stool samples of 315 children were microscopically screened for G. intestinalis. Positive samples were genotyped using tpi assemblage-specific primers and gdh semi-nested PCR-RFLP techniques.

Results: The prevalence of Giardia was 18.1%. The detected genotypes using tpi and gdh approaches were assemblage A (15.8% vs. 12.7%) and assemblage B (36.8% vs. 74.5%) as single infections and mixed assemblages A and B (47.4% vs. 12.7%). The two approaches showed a moderate agreement (kappa index = 0.413, P < 0.001). PCR-RFLP of gdh gene revealed that sub-assemblages BIII and BIV were equally detected (30.9% each). The remaining samples were equally divided between sub-assemblage AII, mixed BIII and BIV, and mixed AII and BIII (12.7% each). A significant association was detected between the retrieved sub-assemblages and the presence of symptoms.

Conclusions: Although both approaches confirmed the predominance of assemblage B, the use of assemblage-specific primers is more effective in elucidating the true picture of mixed assemblage infection.

Human dicrocoeliosis caused by Dicrocoelium dendriticum is reported sporadically from various parts of the world. D. dendriticum, a liver fluke has a complex life cycle with two intermediate hosts‒the land snail and the ant. True human infection occurs by ingestion of the second intermediate host, but spurious infections have occurred after consumption of undercooked animal liver. We report a case of a 20-year-old female who presented with abdominal pain, diarrhea, and itchy skin rashes all over the body. Stool microscopy revealed numerous eggs of D. dendritricum. A brief discussion of the medical literature is presented.

Background and objectives: Pregnancy malaria is a major underestimated global public health problem. To understand the involvement of oxidative stress (OS) in the pathophysiology of placental malaria, OS biomarkers, malondialdehyde (MDA), uric acid (UA), and superoxide dismutase (SOD) levels were analyzed and correlated to placental histopathological changes and pregnancy outcomes.

Methods: A hospital-based study was conducted in Mangaluru, Karnataka, India, to analyze the changes in hematological parameters and the serum OS biomarker levels. Histological analysis of placenta, associated complications, and pregnancy outcomes were compared using Kruskal-Wallis test, and pairwise comparison between two groups was made by Mann-Whitney U-test. Correlations were calculated by Pearson's and Spearman's rank correlations.

Results: Among 105 pregnant women, 34 were healthy controls and the infected group comprised of Plasmodium Vivax (Pv) (n = 48), Plasmodium falciparum (Pf) (n = 13), and mixed (n = 10) malaria infections. Of 71 infected cases, 67.6% had mild malaria, whereas 32.4% had severe malaria. The white blood cell and C-reactive protein levels were found to increase, whereas hemoglobin, red blood cell, and platelet levels decreased during both types of malarial infections. The MDA and UA values increased and SOD levels decreased particularly during severe Pf infections. Histological changes such as syncytial knots, syncytial ruptures, and fibrinoid necrosis were observed particularly during Pf infections and leukocyte infiltration was observed in Pv malaria.

Conclusion: Evaluation of MDA, UA, and SOD levels can serve as an indicator of OS during pregnancy malaria. The OS during pregnancy may lead to complications such as severe anemia, pulmonary edema, intra uterine growth retardation, premature delivery, and low birth weight, not only during Pf but also in Pv malaria. It is important to create awareness among rural and immigrant population residing in Mangaluru and its surroundings about required preventive measures and free government-supported antenatal care services.