Toxoplasmosis is a parasitic zoonotic disease caused by Toxoplasma (T.) gondii. Limited data are available on the occurrence of T. gondii in women especially pregnant women in Pakistan. The present study aimed to determine the occurrence and risk factors associated with T. gondii in pregnant and non-pregnant women in Punjab Province, Pakistan. A cross-sectional study was conducted and 593 samples were collected from pregnant (n = 293) and non-pregnant (n = 300) women of District Headquarter Hospitals of Chiniot, Faisalabad, Jhang and Okara, Pakistan. Data related to demographic parameters and risk factors were collected using a pretested questionnaire on blood sampling day. Serum samples were screened for antibodies (IgG) against T. gondii using ELISA. A univariant and binomial logistic regression was applied to estimate the association between seropositive and explanatory variables considering the 95% confidence interval. P value ⩽0.05 was considered statistically significant for all analysis. Out of 593, 44 (7.42%) women were seropositive for T. gondii IgG antibodies. Occupation, age, sampling location, socioeconomic status, contact with cat, pregnancy status and trimester of pregnancy were significantly associated with seropositivity for T. gondii antibodies. Location and trimester of pregnancy were identified as potential risk factors for T. gondii seropositivity based on binomial logistic regression. Toxoplasma gondii is prevalent in pregnant and non-pregnant women. Therefore, now a necessitated awareness is required to instruct the individuals about these infectious diseases (toxoplasmosis) and their control strategies to maintain the health of human population. Moreover, health awareness among public can help the minimization of T. gondii infection during pregnancy and subsequent risk of congenital toxoplasmosis.
This study examines the persistence of predisposition to Ascaris lumbricoides and Trichuris trichiura during repeated chemotherapy in an urban community in Kuala Lumpur, Malaysia. Significant predisposition was observed over 2 periods of reinfection with and without age-standardization of data. Analysis of different age groups indicated that predisposition was most strongly detectable in the younger age classes. The intensities of infection with both parasites were strongly correlated at each cycle of intervention, suggesting that individuals were similarly predisposed to both species.
In this study, we report the occurrence of echinostomatid eggs in feces of wildlife, domestic animals and humans frequenting the forest–oil palm plantation interface in the Kinabatangan (Sabah, Malaysia), and discuss potential implications for public health. Using microscopy, we detected echinostomatid eggs in six host species, including Asian palm civets (Paradoxurus hermaphroditus [13/18]), leopard cats (Prionailurus bengalensis [3/4]), long-tailed macaques (Macaca fascicularis [1/10]), domestic dogs [3/5] and cats [1/1], and humans [7/9]. Molecular analysis revealed a close genetic proximity of civet echinostomatids to Artyfechinostomum malayanum, a zoonotic parasite of public health relevance. The intermediate hosts for A. malayanum have been reported in at least 3 districts in Sabah, suggesting that all the necessary elements required for the completion of the parasite's life cycle are present. Our findings point at the presence of zoonotic trematodes in an area with high human–wildlife interaction and highlight the potential public and animal health concern of zoonotic trematode infection in the context of Southeast Asia's rapidly changing ecosystems.
Plasmodium knowlesi is a simian malaria of primarily the macaque species of South East Asia. While it was known that human infections could be induced during the years of malariotherapy, naturally occurring P. knowlesi human infections were thought to be rare. However, in 2004, knowlesi infections became recognized as an important infection amongst human populations in Sarawak, Malaysian Borneo. Since then, it has become recognized as a disease affecting people living and visiting endemic areas across South East Asia. Over the last 12 years, clinical studies have improved our understanding of this potentially fatal disease. In this review article the current literature is reviewed to give a comprehensive description of the disease and treatment.
Two vivax-like parasites, believed to be true P. vivax but in abnormal form, are described. The deviation from normal appearances was probably due, it is suggested, to growth in an abnormal environment.
Unusual tumour-like pathologies caused by mysterious cells termed 'X-cells' have been reported from numerous fish groups worldwide. After nearly 100 years of research, the tumour-like growths have recently been shown to be caused by a protozoan parasite. In the present study, histopathology and small subunit ribosomal DNA (SSU rDNA) sequences are used to assess whether the X-cell parasite infecting Atlantic dab Limanda limanda L. is distinct from the X-cell parasite infecting Japanese flounder and goby, and to determine their systematic position within the protists. SSU rDNA from Scottish dab was 89.3% and 86.7% similar to Japanese X-cell sequences from flounder and goby respectively, indicating that the parasite infecting dab in the Atlantic is distinct from the Pacific species. Histological studies revealed significant gill pathology and demonstrated the precise location of the parasites within the gill tissues using specific in situ hybridization probes. Phylogenetic analyses showed that the X-cell parasites from Scotland and Japan form a monophyletic group within the Myzozoa, and are basal alveolates. However, ultrastructure of X-cells from dab fails to confirm this systematic placement.
Matched MeSH terms: Fish Diseases/parasitology*; Flatfishes/parasitology*; Protozoan Infections, Animal/parasitology*
Serological tests may yield false-negative results for specific antibodies detection before or at the early seroconversion phase. Tests that detect circulating antigens of Angiostrongylus cantonensis would therefore be of value in diagnosis to distinguish current or past infection. Here, a quick, easy to perform, portable and inexpensive diagnostic device for detection of 31-kDa A. cantonensis specific antigens had been developed. This sandwich dot-immunogold filtration assay (AcDIGFAAg), for detecting active angiostrongyliasis was produced using anti-A. cantonensis polyclonal antibody dotted on the nitrocellulose membrane as a capture agent and colloidal gold-labelled anti-31 kDa A. cantonensis antibody as a detection agent. A well-defined pink dot, indicating positivity, was seen readily by naked eye within 10-15 min. The AcDIGFAAg detected A. cantonensis-specific antigens in cerebrospinal fluid samples from 4 out of 10 serologically confirmed angiostrongyliasis cases and 2 out of 5 suspected cases with negative anti-A. cantonensis antibodies. Among the 19 patient sera with A. cantonensis infection, 2 showed positive reaction by AcDIGFAAg. No positive AcDIGFAAg reaction was observed in all the serum samples with other parasitic diseases, and the healthy controls. The present 'AcDIGFAAg' enables rapid qualitative detection of the specific 31-kDa antigens of A. cantonensis in clinical samples with potential for application even under resource-limited settings.
The ascaridoid nematode of cats from Kuala Lumpur, Malaysia, previously identified morphologically as Toxocara canis, was characterized using a molecular approach. The nuclear ribosomal DNA (rDNA) region spanning the first internal transcribed spacer (ITS-1), the 5.8S gene and the second internal transcribed spacer (ITS-2) was amplified and sequenced. The sequences for the parasite from Malaysian cats were compared with those for T. canis and T. cati. The sequence data showed that this taxon was genetically more similar to T. cati than to T. canis in the ITS-1, 5.8S and ITS-2. Differences in the ITS-1 and ITS-2 sequences between the taxa (9.4-26.1%) were markedly higher than variation between samples within T. canis and T. cati (0-2.9%). The sequence data demonstrate that the parasite from Malaysian cats is neither T. canis nor T. cati and indicate that it is a distinct species. Based on these data, PCR-linked restriction fragment length polymorphism (RFLP) and single-strand conformation polymorphism (SSCP) methods were employed for the unequivocal differentiation of the Toxocara variant from T. canis and T. cati. These methods should provide valuable tools for studying the life-cycle, transmission pattern(s) and zoonotic potential of this parasite.
Dirofilaria immitis is a parasitic nematode that survives in the circulatory system of suitable hosts for many years, causing the most severe thromboembolisms when simultaneous death of adult worms occurs. The two main mechanisms responsible for thrombus formation in mammals are the activation and aggregation of platelets and the generation of fibrin through the coagulation cascade. The aim of this work was to study the anticoagulant potential of excretory/secretory antigens from D. immitis adult worms (DiES) on the coagulation cascade of the host. Anticoagulant and inhibition assays respectively showed that DiES partially alter the coagulation cascade of the host and reduce the activity of the coagulation factor Xa, a key enzyme in the coagulation process. In addition, a D. immitis protein was identified by its similarity to the homologous serpin 6 from Brugia malayi as a possible candidate to form an inhibitory complex with FXa by sodium dodecyl sulfate polyacrylamide gel electrophoresis and mass spectrometry. These results indicate that D. immitis could use the anticoagulant properties of its excretory/secretory antigens to control the formation of blood clots in its immediate intravascular habitat as a survival mechanism.
18S rDNA sequences from 4 isolates of Babesia gibsoni originating from Japan, Malaysia and Sri Lanka were compared with a previously published, 0.5 kb portion of the 18S rDNA from a B. gibsoni isolate from California, USA, and with the corresponding 18S rDNA sequences of other Babesia spp. Distance, parsimony and maximum likelihood analyses showed almost identical genotypes among the small canine Babesia from Asia, but an unexpectedly distant genetic relationship to that from the USA. While the American isolate segregated together with B. equi, the Asian isolates showed a close relationship to B. divergens and B. odocoilei. These results indicate that small Babesia of dogs originating from North America and Asia belong to different, genetically distantly related species.
Matched MeSH terms: Babesiosis/parasitology*; Dog Diseases/parasitology*
The microsporidian genus Nosema is characterized by development in direct control with host cell cytoplasm, diplokaryotic nuclei throughout development and disporous sporogony. The genus Vairimorpha exhibits the same features plus an octoporous sporogony producing uninucleate spores in a sporophorous vesicle. A microsporidium from diamondback moth, Plutella xylostella, falls between Nosema and Vairimorpha in that it initiates but fails to complete the octosporous sequence in this host. The name Vairimorpha imperfecta n.sp. is proposed. Merogony is mainly by formation of buds from multinucleate meronts, the buds remaining attached in chains. Diplokaryotic spores measure 4.3 x 2.0 microns (fresh) and have 15.5 coils of the polar tube in 1 rank. The octosporous sporogony is aborted owing to irregular formation of nuclear spindles, incomplete cytoplasmic fission and bizarre deposition of electron-dense episporontal secretions. Phylogenetic analyses of the sequences of the small subunit rRNA genes of V. imperfecta and of several Nosema and Vairimorpha spp. place V. imperfecta in a clade with Nosema spp. from Lepidoptera rather than in the clade containing the more typical species of Vairimorpha. It is suggested that the ancestors of the Vairimorpha/Nosema complex of species exhibited both disporous and octosporous sporogonies, as does the type species of Vairimorpha, Vairimorpha necatrix. It would follow that true Nosema spp. have lost the ability to express an octosporous sequence and that V. imperfecta is in the process of losing it. It is proposed that the genera Nosema and Vairimorpha be placed in the same family Nosematidae Labbé 1899, rather than in separate families and orders as at present.
Brugia malayi is one of the parasitic worms which causes lymphatic filariasis in humans. Its geographical distribution includes a large part of Asia. Despite its wide distribution, very little is known about the genetic variation and molecular epidemiology of this species. In this study, the internal transcribed spacer 1 (ITS1) nucleotide sequences of B. malayi from microfilaria-positive human blood samples in Northeast Borneo Island were determined, and compared with published ITS1 sequences of B. malayi isolated from cats and humans in Thailand. Multiple alignment analysis revealed that B. malayi ITS1 sequences from Northeast Borneo were more similar to each other than to those from Thailand. Phylogenetic trees inferred using Neighbour-Joining and Maximum Parsimony methods showed similar topology, with 2 distinct B. malayi clusters. The first cluster consisted of Northeast Borneo B. malayi isolates, whereas the second consisted of the Thailand isolates. The findings of this study suggest that B. malayi in Borneo Island has diverged significantly from those of mainland Asia, and this has implications for the diagnosis of B. malayi infection across the region using ITS1-based molecular techniques.
Nucleotide sequences were obtained for the second internal transcribed spacer of the ribosomal gene repeat and for part of the mitochondrial-cytochrome c oxidase subunit I gene from geographical isolates of Paragonimus westermani from Japan, China, Korea, Taiwan, the Philippines, peninsular Malaysia and Thailand. Sequences were obtained from several other species of Paragonimus for comparative purposes. Two groups were recognized within P. westermani: an NE group (China, Japan, Korea, Taiwan) which was relatively uniform and included both diploid and triploid forms, and a southern group (Malaysia, Thailand, Philippines), members of which were genetically distant from one another. According to both ITS2 and COI data, genetic distances among P. westermani isolates equalled or exceeded those between some distinct species of Paragonimus. The ITS2 sequences were conserved relative to COI sequences. Substitutions among the latter may be approaching saturation within the genus Paragonimus.