A recently published comment on a report of Plasmodium knowlesi infections in Vietnam states that this may not accurately represent the situation in the study area because the PCR primers used may cross-hybridize with Plasmodium vivax. Nevertheless, P. knowlesi infections have been confirmed by sequencing. In addition, a neighbour-joining tree based on the 18S S-Type SSUrRNA gene shows that the Vietnamese samples clearly cluster with the P. knowlesi isolates identified in Malaysia and are distinct from the corresponding P. vivax sequences. All samples came from asymptomatic individuals who did not consult for fever during the months preceding or following the survey, indicating that asymptomatic P. knowlesi infections occur in this population, although this does not exclude the occurrence of symptomatic cases. Large-scale studies to determine the extent and the epidemiology of P. knowlesi malaria in Vietnam are further needed.
Sex ratios are subject to distortion by a range of inherited parasites. Although it has been predicted that the presence of these elements will result in spatial and temporal variation in host sex ratio, testing of this hypothesis has been constrained by availability of historical data. We here determine spatial and temporal variation in sex ratio in a interaction between a butterfly and male-killing Wolbachia bacteria by assaying infection presence in museum specimens, and from this inferring infection prevalence and phenotype in historical populations. Comparison of contemporary and museum samples revealed profound change in four of five populations examined. Two populations become extremely female biased, associated with spread of the male-killer bacterium. One evolved from extremely female biased to a sex ratio near parity, resulting from the infection losing male-killing activity. The final population fluctuated widely in sex ratio, associated with varying frequency of the male killer. We conclude that asynchronous invasion and decline of sex-ratio distorters combines with the evolution of host suppressors to produce a rapidly changing mosaic of sex ratio. As a consequence, the reproductive ecology of the host species is likely to be fundamentally altered over short time scales. Further, the study demonstrates the utility of museum specimens as "silent witnesses" of evolutionary change.
Cutaneous larva migrans is a common parasitic skin disease that can be easily prevented by wearing 'protective' footwear. However, this has been under-emphasized in terms of what constitutes the protective footwear. Even though the disease resolves spontaneously, the significant duration of the disease along with severity of pruritus make treatment unavoidable. Here, we present a very long-standing creeping eruption, which puzzled many attending clinicians handling the case, and the possibility of long socks as a causal effect on the development of cutaneous larva migrans infection.
Since 2004, malaria with a "fifth" plasmodium, Plasmodium knowlesi (common in macaque monkeys), has been diagnosed in a number of people in Southeast Asia. This article gives a short overview of the epidemiology, clinical picture, diagnostics and treatment of P. knowlesi infection.
Genomic DNA of Blastocystis isolates released into 0.1% Triton X-100 was suitable for amplification and yielded similar results as the genomic DNA extracted with standard kit. The specific B. hominis primers (BH1: GCT TAT CTG GTT GAT CCT GCC AGT and BH2: TGA TCC TTC CGC AGG TTC ACC TAC A) successfully produced the PCR product of about 1,770 bp with all the 7 Blastocystis isolates tested. The restriction fragment length polymorphism (RFLP) patterns yielded by 13 out of 25 restriction endonucleases showed that the 7 isolates could be grouped into 4 subgroups: subgroup-1 consisted of isolate C; subgroup-2 of isolates H4 and H7; subgroup-3 of isolates KP1, Y51 and M12; and subgroup-4 of isolate 27805. The differences between subgroups manifested as clear-cut RFLP patterns. A common band of 230 bp was revealed by Eco R1 in all the Blastocystis isolates tested. The band of about 180 bp was revealed by Alu I, differentiated symptomatic from asymptomatic isolates of this parasite, and might indicate the pathogenicity of this parasite.
A serologic study of Toxoplasma antibodies among 501 foreign migrant workers in Malaysia was conducted in a plantation and detention camp. The highest prevalence rate of 46.2% was among Nepalese workers. Statistical analysis indicated the IgG positivity rate among local residents was significantly higher than the migrants studied (p < 0.05). The IgM positivity rate showed no significant difference between the two groups (p > 0.05). No significant difference in the prevalence rate was noted between the migrants and the local workers when grouped by agricultural and non-agricultural occupations (p > 0.05). The continuous introduction of these infections may influence the epidemiology and further compromise efforts in control and prevention. It is therefore important to monitor of non-notifiable diseases.
Many cases of myiasis have been reported in Malaysia. This is the second reported case of auricular myiasis caused by Chrysomya bezziana. The patient was a 41-year-old, mentally retarded, Orang Asli man. He was brought to the clinic by his mother with a complaint of pain and bleeding in his right ear for 3 days. On examination, blood and multiple maggots were seen packed in the external auditory canal of the right ear. A total of 39 live maggots were removed and maintained until they developed into 3rd instar larvae, which were later processed and identified as Chrysomya bezziana. The patient was discharged with amoxicillin 500 mg three times a day for 1 week.
Blastocystis hominis has been regarded as an enigmatic parasite as many aspects of its basic biology remain uncertain. Many reproductive processes have been suggested for the organism; however, to date, only the binary fission has been proven. Plasmotomy is one of the modes of reproduction previously suggested to be seen in in vitro cultures. The present study provides trichrome and acridine orange staining evidence for the existence of nucleic acid suggestive of division of nucleus into multinucleate forms with the respective cytoplasm dividing giving rise to two or three progeny B. hominis. Transmission electron micrographs further confirmed that these daughter cells had respective surrounding surface coat, mitochondria, and vacuoles.
We are reporting a case of an eye lesion caused by an adult Brugia malayi. The patient was a 3-year-old Chinese boy from Kemaman District, Terengganu, Peninsular Malaysia. He presented with a one week history of redness and palpebral swelling of his right eye. He claimed that he could see a worm in his right eye beneath the conjunctiva. He had no history of traveling overseas and the family kept dogs at home. He was referred from Kemaman Hospital to the eye clinic of Hospital Tengku Ampuan Afzan, Kuantan, Pahang, Malaysia. On examination by the ophthalmologist, he was found to have a subconjunctival worm in his right eye. Full blood count revealed eosinophilia (10%). Four worm fragments, each about 1 cm long were removed from his right eye under general anesthesia. A thick blood smear stained with Giemsa was positive for microfilariae of Brugia malayi. A Brugia Rapid test done was positive. He was treated with diethylcarbamazine.
Study site: Opthamolagy clinic, Hospital Tengku Ampuan Afzan
Soil-transmitted helminthiases are a public health problem in rural communities. A cross-sectional study of the prevalence and distribution of Ascaris lumbricoides, Trichuris trichiura and hookworm was conducted in 281 Orang Asli children (aborigines) aged between 2 and 15 years, from 8 Orang Asli villages in Selangor, Malaysia. All the children were infected with soil-transmitted helminthes, with 26.3% of the children infected either with A. lumbricoides, T. trichiura or hookworm and 72.6% having mixed infection. The overall prevalences of A. lumbricoides, T. trichiura and hookworm were 61.9, 98.2 and 37.0%, respectively. Approximately 19.0, 26.0 and 3.0% of the children had severe infection of ascariasis, trichuriasis and hookworm infection, respectively. The prevalences and mean egg per gram (epg) counts for A. lumbricoides and T. trichiura were not significantly dependent on age, therefore age-dependent convexity was not seen in this study. However, the results of this study reveal an age-dependent prevalence and mean epg count in children with hookworm infection. We conclude that ascariasis, trichuriasis and hookworm infection are still prevalent and therefore a public health concern in Orang Asli communities. Severe ascariasis and trichuriasis may lead to other health and medical problems.
A total of 66 fecal specimens obtained from patients infected with human immunodeficiency virus (HIV) from Kajang Hospital were screened for Cryptosporidium oocysts. The fecal specimens were concentrated using the formalin ethyl acetate concentration technique, stained with modified Ziehl-Neelsen and confirmed with immunofluorescence stain. It was established that 2 (3.0%) were positive for Cryptosporidium. The two cases involved a Chinese local man (with diarrhea) and an Indonesian foreigner (without diarrhea). A higher index of suspicion for clinical cryptosporidiosis in HIV patients, including those with chronic weight loss with or without diarrhea, is recommended. In addition, laboratory testing for Cryptosporidium in HIV-infected patients is highly recommended in order to have a better understanding of the epidemiology and management of the disease in Malaysia.
Malaria is still one of the most important vector-borne diseases in Malaysia, particularly in remote areas. This retrospective study was carried out to find the prevalence of malaria among patients admitted to UMMC Kuala Lumpur, from 1994-2003. A total of 86 malaria cases were analyzed. Most cases occurred among foreigners [57% (49 cases)] while Malaysians constituted 43% (37 cases). Among foreigners, Indonesians constituted the most [57% (28 cases)]. Among Malaysians, most cases occurred among the Chinese [35% (13 cases)] followed by the Malays [30% (11 cases)]. Males [70%(60 cases)] were more commonly affected. The majority of cases were within the 20-39 year age group (69%). Three species of malaria parasites were reported, of which Plasmodium vivax constituted the most [55%( 47 cases)], followed by Plasmodium falciparum [29% (25 cases)], and only four cases (5%) of Plasmodium malariae. Nine percent (8 cases) were mixed infections. In this study, 12%(10 cases) developed chloroquine resistance: 7 cases of P. falciparum, and 3 cases of P. vivax. The most common complications were jaundice and anemia [77% (23 cases)], followed by blackwater fever [13% (4 cases)] and cerebral malaria [10% (3 cases)]. Most of the complications were due to P. falciparum [43% (13 cases)]. There were no reported deaths. This new source of malaria coming from foreigners must be given serious attention, as it has great potential of increasing malaria cases in urban Malaysia.
Pandanothrips gen. n. is described, with three new species inhabiting Pandanus: P. ryukyuensis sp. n. from Japan, P. wangi sp. n. from Malaysia, and P. hallingi sp. n. from Australia. This new genus shows no relationship to Projectothrips Moulton, the only other Thripinae genus known to be associated with Pandanus. Pandanothrips is superficially similar to Danothrips Bhatti, a genus of leaf feeding thrips. The morphological relationships among these genera are discussed, and an illustrated key to the species of Pandanothrips is provided.
Diagnosis of human toxocariasis, caused by Toxocara canis or Toxocara cati, normally relies on a combination of the presence of clinical signs and symptoms backed by positive serology. The use of Toxocara excretory-secretory antigen (TES) in ELISA assays increases the test specificity. However, in tropical countries where soil-transmitted helminths are endemic, cross-reactivity from antibodies to these intestinal parasites poses a significant limitation for Toxocara serodiagnosis. To increase the specificity of serodiagnosis, we compared the use of IgG-ELISA to the use of IgG4-ELISA using commercially manufactured TES-coated plates. The sensitivity of the IgG-ELISA was 97.1%, while that of the IgG4-ELISA was 45.7%; the specificities were 36.0 and 78.6%, respectively. The study shows that employing both assays can improve the serodiagnosis of toxocariasis. An IgG4 immunoassay would also be useful in the secondary screening of antigen clones in the effort to develop improved serological tests for toxocariasis.
Malnutrition including vitamin A and iron deficiency and parasitic diseases have a strikingly similar geographical distribution with the same people experiencing both insults together for much of their lives. Parasitic infections are thought to contribute to child malnutrition and micronutrient deficiency through subtle reduction in digestion and absorption, chronic inflammation and loss of nutrients. Parasites may affect the intake of food; it's subsequent digestion and absorption, metabolism and the maintenance of nutrient pools. The most important parasites related to nutritional status are intestinal parasites especially soil transmitted helminthes, Giardia duodenalis, Entamoeba histolytica, followed by other parasites such as the coccidia, Schistosoma sp. and malarial parasites.
Despite the continuous efforts to improve the quality of life of Orang Asli (Aborigines) communities, these communities are still plagued with a wide range of health problems including parasitic infections. The first part of this study aimed at determining the prevalence of soil-transmitted helminth (STH) infections and identifying their associated factors among rural Orang Asli children.
Parasite infestation of the testicular tunica and spermatic cord by filariae are rarely reported and may present with few clinical signs, depending upon the stage. Occasionally, it may mimic a testicular tumor. We present a case of a 29-year-old man who presented with left testicular swelling and discomfort for 4 months. Clinical examination and imaging suggested an intrascrotal cystic lesion with a normal left testis. However, the intraoperative findings revealed a tumor-like mass; hence, a left orchidectomy was performed. However, histopathology reported a diagnosis of a cystic testicular tunica and spermatic cord with parasite infection. Here, we review the literature of scrotal and testicular parasite disease and discuss the course of the appropriate management involved.