The diversity of ectoparasites in Southeast Asia and flea-host associations remain largely understudied. We explore specialization and interaction patterns of fleas infesting non-volant small mammals in Bornean rainforests, using material from a field survey carried out in two montane localities in northwestern Borneo (Sabah, Malaysia) and from a literature database of all available interactions in both lowland and montane forests. A total of 234 flea individuals collected during our field survey resulted in an interaction network of eight flea species on seven live-captured small mammal species. The interaction network from all compiled studies currently includes 15 flea species and 16 small mammal species. Host specificity and niche partitioning of fleas infesting diurnal treeshrews and squirrels were low, with little difference in specialization among taxa, but host specificity in lowland forests was found to be higher than in montane forests. By contrast, Sigmactenus alticola (Siphonaptera: Leptopsyllidae) exhibited low host specificity by infesting various montane and lowland nocturnal rats. However, this species exhibited low niche partitioning as it was the only commonly recorded flea from rats on Borneo. Overall complementary specialization was of intermediate intensity for both networks and differed significantly from random association; this has important implications for specific interactions that are also relevant to the potential spread of vector-borne diseases.
Anaplasma marginale is the most prevalent tick-borne haemoparasite of cattle and causes huge economic losses to the dairy industry worldwide. This study aimed to determine the occurrence of A. marginale infection in blood and tick samples collected from livestock animals in the districts located in Khyber Pakhtunkhwa (KPK), Pakistan. A total of 184 blood and 370 tick samples were included in this study. It has never been reported that sheep, goats, and cattle in Tank, Ghulam Khan, Birmil and Miran Shah areas were infected with A. marginale. All samples of blood and ticks were collected through random sampling from March 2021 to January 2022 from cattle, sheep and goats and screened through PCR for anaplasmosis by using primer pairs of Anaplasma spp. Three hundred and seventy ticks were collected from infested hosts (120/184, 64.21%). Among the four morphologically identified tick species, the highest occurrence was recorded for Rhipicephalus sanguineus (n=138, 37.29%), followed by Rhipicephalus microplus (n=131, 35.4%), Rhipicephalus annulatus (n=40, 10.81%), Hyalomma anatolicum (n=31, 8.37%), and Hyalomma marginatum (n=30, 8.1%). The occurrence of female tick was highest (n=160, 43.24%), followed by nymphs (n=140, 37.38%) and males ticks (n=70, 18.9%). Among these ticks, A. marginale was detected in female ticks of R. microplus, and R. sanguineus. Molecular identification of A. marginale was confirmed in 120 out of 184 blood samples and 6 out of 74 tick samples. Overall, occurrence of A. marginale in blood and tick samples was found to be 65.21% and 8.1% respectively. Species-wise occurrence in blood samples of goats were 71.11% followed by sheep 68.31% and cattle 50%. Specie-wise occurrence of A. marginale in tick samples of cattle were 12.5% followed by goats 6.89%. The obtained sequence showed similarity with A. marginale reported from Kenya and USA. We report the first PCR based detection of A. marginale infection in blood samples and in R. sanguineus ticks of goats simultaneously.
Infective larvae of Wuchereria, Brugia, Breinlia, Dirofilaria and Setaria species from an experimental vector, Aedes togoi, are compared. The distinctive bubble-like caudal papillae of Wuchereria bancrofti are readily distinguishable from the protuberant ones of Brugia spp; the 'ear-like' papillae of Breinlia are distinct from the 'knob-like' ones of Dirofilaria or the 'thorn-like' terminal papilla of Setaria.
Paradistomoidella cerberi n.g., n.sp. and Paracanthostomum cerberi from Cerberus rhynchops, Xenopharynx pyriformis and Allopharynx mehrai from Ptyas korros, Neopronocephalus orientalis from Geoemyda spinosa, and Duthiersia expansa from Varanus salvator are all reported from the area of Kuala Lumpur, Malaysia. Paradistomoidella cerberi most closely resembles members of Paradistomoides but is characterized by relatively short caeca, a cirrus sac containing a bipartite rather than sinous internal seminal vesicle, and unevenly-sized suckers. Kuala Lumpur is a new locality for Paracanthostomum cerberi, X. pyriformis, A. mehrai, and D. expansa. Ptyas korros is a new host for X. pyriformis and G. spinosa is a new host for N. orientalis.
Thirteen bats, Tadarida mops de Blainville, collected from the Ampang district in Kuala Lumpur, Malaysia, were found positive for the trematodes Castroia kamariae sp. nov. and Limatulum kuziai sp. nov. Two distinct but morphologically similar forms of Castroia kamariae were recovered. The morphological type is apparently determined by its location in the host intestine.
Examination of naturally infected felids and viverrids in Malaysia confirmed previously published records which indicated that P. westermani occurred only in felid cats. Felis planiceps and F. temnickli were reported as new host records. Analysis of stomach contents revealed no crab remains in either family of cats, but confirmed that felids were strictly carnivorous while viverrids were often omnivorous. In feeding experiments, only viverrids ate the host crabs Potomiscus johorensis and Parathelphusa maculata. The probable transmission of P. westermani to felids via paratenic hosts was discussed.
Neodiplostomum (Conodiplostomum) ramachandrani Betterton, 1976 has been reported from four species of rodent hosts: Echinosorex gymnurus (Raffles): Rattus whiteheadi (Thos); R. muelleri (Jentink) and Callosciurus notatus (Boddaert). A comparison of trematodes recovered from these hosts revealed patterns of host-induced morphological variation taking place. Because N. (Conodiplostomum) ramachandrani shows little generic difference from Fibricola intermedius (Pearson, 1959) Sudarikov, 1960 it is transferred to the genus Fibricola and is now designated Fibricola ramachandrani (Betterton, 1976) Palmieri, Krishnasamy and Sullivan.
Myxosporean infection in marine water fishes has drawn less attention than in freshwater fishes, which resulted in a higher taxonomic variety in freshwater in Malaysia. This study aimed to address the gap by conducting a myxosporean survey on two commercially significant marine fish species, Nemipterus furcosus (Valenciennes) (Eupercaria incertae sedis: Nemipteridae) and Selar crumenophthalmus (Bloch) (Carangiformes: Carangidae), collected from the northeastern part of peninsular Malaysia. During the examination of the organs, two distinct Myxobolus Bütschli, 1882 species were discovered in the brain tissue of these fishes, despite the absence of any observable pathological signs. The two Myxobolus species were characterized through morphometry, morphology, and analysis of partial small subunit ribosomal RNA (18S rDNA) gene. As a result, Myxobolus acanthogobii Hoshina, 1952, which infects 2.3% of N. furcosus, is synonymous with a myxobolid species commonly found in Japanese waters, based on its morphological traits, tissue tropism, and molecular diagnostics. Furthermore, a novel species, Myxobolus selari n. sp., was described, infecting the brain of one (11%) individual S. crumenophthalmus. This unique species displayed distinctive features, placing it within a well-supported subclade primarily comprising brain-infecting myxobolids. Maximum likelihood analysis further revealed the close relationships among these brain-infecting myxobolids, underscoring the significance of tissue tropism and host taxonomy for myxobolids. This study represents the initial documentation of Myxobolus species within the southern South China Sea, shedding light on the potential diversity of marine myxosporean in this region. This article was registered in the Official Register of Zoological Nomenclature (ZooBank) as urn:lsid:zoobank.org:pub:7C400E35-7CB8-4DEE-92B7-F75FF3926441.
Matched MeSH terms: Fish Diseases/parasitology; Fishes/parasitology
Acanthamoeba, one of free-living amoebae (FLA), remains a high risk of direct contact with this protozoan parasite which is ubiquitous in nature and man-made environment. This pathogenic FLA can cause sight-threatening amoebic keratitis (AK) and fatal granulomatous amoebic encephalitis (GAE) though these cases may not commonly be reported in our clinical settings. Acanthamoeba has been detected from different environmental sources namely; soil, water, hot-spring, swimming pool, air-conditioner, or contact lens storage cases. The identification of Acanthamoeba is based on morphological appearance and molecular techniques using PCR and DNA sequencing for clinico-epidemiological purposes. Recent treatments have long been ineffective against Acanthamoeba cyst, novel anti-Acanthamoeba agents have therefore been extensively investigated. There are efforts to utilize synthetic chemicals, lead compounds from medicinal plant extracts, and animal products to combat Acanthamoeba infection. Applied nanotechnology, an advanced technology, has shown to enhance the anti-Acanthamoeba activity in the encapsulated nanoparticles leading to new therapeutic options. This review attempts to provide an overview of the available data and studies on the occurrence of pathogenic Acanthamoeba among the Association of Southeast Asian Nations (ASEAN) members with the aim of identifying some potential contributing factors such as distribution, demographic profile of the patients, possible source of the parasite, mode of transmission and treatment. Further, this review attempts to provide future direction for prevention and control of the Acanthamoeba infection.
Travels, migration and circulation of goods facilitate the emergence of new infectious diseases often unrecognized outside endemic areas. Most of emerging infections are of viral origin. Muscular Sarcocystis infection, an acute illness acquired during short trips to Malaysia, and Chagas disease, a chronic illness with long incubation period found among Latin American migrants, are two very different examples of emerging parasitic diseases. The former requires a preventive approach for travelers going to Malaysia and must be brought forth when they return with fever, myalgia and eosinophilia, while the latter requires a proactive attitude to screen Latin American migrant populations that may face difficulties in accessing care.
In 2011, we reported occurrence of natural human infections with Brugia pahangi, a filarial worm of dogs and cats, in a surburb of Kuala Lumpur, the capital city of Malaysia. Our preliminary entomological survey at that time suggested the mosquito species Armigeres subalbatus as the vector of the zoonotic infections. In this present report, we provide biological evidence to confirm our preliminary finding.
Non-isotopic polymerase chain reaction (PCR)-based single-strand conformation polymorphism and sequence analyses of the second internal transcribed spacer (ITS-2) of nuclear ribosomal DNA (rDNA) were utilized to genetically characterise ascaridoids from dogs and cats from China by comparison with those from other countries. The study showed that Toxocara canis, Toxocara cati, and Toxascaris leonina from China were genetically the same as those from other geographical origins. Specimens from cats from Guangzhou, China, which were morphologically consistent with Toxocara malaysiensis, were the same genetically as those from Malaysia, with the exception of a polymorphism in the ITS-2 but no unequivocal sequence difference. This is the first report of T. malaysiensis in cats outside of Malaysia (from where it was originally described), supporting the proposal that this species has a broader geographical distribution. The molecular approach employed provides a powerful tool for elucidating the biology, epidemiology, and zoonotic significance of T. malaysiensis.
Hard ticks taken from the Japanese serow, Capricornis crispus, in Yamagata Prefecture, Honshu, harboured infective larvae of onchocercid filariae after incubation from the 22nd to the 158th day. Haemaphysalis flava and H. japonica contained one to eight filarial larvae; females, males and a nymph of the ticks were infected. The 44 infective larvae recovered were 612-1,370 μm long, and 11 of them, 930-1,340 μm long, were studied in detail. The larvae possessed the morphologic characteristics of the larvae of the genus Cercopithifilaria, namely an oesophagus with a posterior glandular part, no buccal capsule and a long tail with three terminal lappets. Five types (A to E) of infective larvae were identified based on the morphologic characteristics. While to date five species of Cercopithifilaria have been described from the Japanese serow, a specific identification of the larvae found in this study was generally not possible. Only type E larvae could be tentatively assigned to Cercopithifilaria tumidicervicata, as they had a cervical swelling similar to that of the adults of this species. A key for the identification of the five larval types is presented. The study presents circumstantial evidences indicating that H. flava and H. japonica may transmit Cercopithifilaria spp. to Japanese serows. It also suggests the possibility that such filarial larvae will be found in hard ticks anywhere, because Cercopithifilaria is distributed worldwide, though this genus generally goes unnoticed, as its microfilariae occur in the skin, not in the blood, of host animals.
Stool examination of 249 early primary schoolchildren at 2 schools in north-eastern peninsular Malaysia revealed that 73 were infected with Ascaris lumbricoides, 103 with Trichuris trichiura, and 18 with hookworms. Infected children were treated with a single dose of 400 mg of albendazole. The school attendance records during a 60 d period before treatment and 2 consecutive 60 d periods after treatment were examined. The absenteeism rate did not improve more among infected children after treatment than it did among the uninfected control children. The correlation between worm intensity and the number of lost school-days was poor. There was no evidence that intestinal helminthiasis caused school absenteeism among this group of children.
Faecal samples of 56 common house crows (Corvus splendens Vieillot) were collected from the Petaling Jaya and Kelang districts of Selangor, peninsular Malaysia, and examined for coccidia. Intestinal tracts of 8 of the above crows wee histologically examined under light microscopy to determine the site of coccidial infection and the endogenous stages present. Fifty three (94.6%) crows had coccidial oocysts morphologically conforming to only one species of Isospora in their faeces at the time they were examined. The sporulated oocysts were found to be Isospora corviae (Ray et al. 1952) which has been emended to I. corvi. These oocysts are redescribed in greater detail. Corvus splendens is a new host record for I. corvi. Coccidial infection was observed in all the intestinal tracts and generally confined to the anterior two thirds of the intestine. The parasites occurred within intestinal epithelial cells, located usually above the host cell nucleus. Developmental stages of both the asexual and sexual phases were found in the epithelium, and are deemed to be the endogenous stages of I. corvi on the basis of the oocysts recovered from the same crows used for histological study. These stages are described here for the first time. The prevalence of I. corvi, its relationship with the host C. splendens, and its probable transmission from C. macrorhynchus are discussed.
Lesions associated with two species of tapeworms within the digestive tract of wild-caught specimens of the bull shark, Carcharhinus leucas, and the sicklefin weasel shark, Hemigaleus microstoma, from Malaysian Borneo are described. Portions of the glandular stomach and pyloric gut with parasites were removed and fixed in 10% formalin buffered in sea water. Whole mounts, histological sections of tissues with and without worms in situ, and scanning electron microscopy images of detached worms were examined. Both species of cestodes belonged to the trypanorhynch family Tentaculariidae. Heteronybelinia estigmena was found in large numbers parasitizing the pyloric gut of C. leucas; an unidentified tentaculariid was found in relatively small numbers in both the glandular stomach and pyloric gut of H. microstoma. Both species burrowed their scoleces deeply in the mucosa and attached via hooked tentacles and unciniform microtriches of the scolex. The lesions induced by the parasites were marked in both sharks and ranged from acute necrotizing to chronic granulomatous gastroenteritis. Regenerative hyperplasia and intestinal metaplasia of gastric epithelium were also present. The severity and character of pathology was causally linked to the intensity of infection, the attachment mode of the parasites, and to the anatomophysiological relationships within the gut of the host shark.
In order to obtain basic data on parasitic infections of Bornean orangutans, Pongo pygmaeus morio (Owen, 1837), in Danum Valley, Sabah, Malaysia, fecal examinations were conducted. Based on a total of 73 fecal samples from 25 individuals, cysts of Entamoeba coli, Entamoeba spp., and Chilomastix mesnili, cysts and trophozoites of Balantidium coli, and eggs of Trichuris sp. or spp., unknown strongylid(s), Strongyloides fuelleborni, and an unknown oxyurid, plus a rhabditoid larva of Strongyloides sp., were found. Mature and immature worms of Pongobius hugoti Baruš et al., 2007 and Pongobius foitovae n. sp. (Oxyuridae: Enterobiinae) were recovered from fecal debris and described. Pongobius foitovae is readily distinguished from P. hugoti by having a much longer esophageal corpus, a longer and distally hooked spicule in males, and a more posteriorly positioned vulva in female. Presence of plural species of non- Enterobius pinworms is a remarkable feature of the orangutan-pinworm relationship, which may reflect speciation process of the orangutans, host switching, and coevolution by pinworms.
Rural communities in Malaysia have been shown to be exposed to Coxiella, Borrelia and rickettsial infections in previous seroprevalence studies. Further research is necessary to identify the actual causative agents and the potential vectors of these infections. The arthropods parasitizing peri-domestic animals in these communities may serve as the vector in transmitting arthropod-borne and zoonotic agents to the humans. Molecular screening of bacterial and zoonotic pathogens from ticks and fleas collected from dogs, cats and chickens from six rural communities in Malaysia was undertaken. These communities were made up of mainly the indigenous people of Malaysia, known as the Orang Asli, as well as settlers in oil palm plantations. The presence of Coxiella burnetii, Borrelia, and rickettsial agents, including Rickettsia and Anaplasma, was investigated by performing polymerase chain reaction (PCR) and DNA sequencing. Candidatus Rickettsia senegalensis was detected in one out of eight pools of Ctenocephalides felis fleas. A relapsing fever group Borrelia sp. was identified from one of seven Haemaphysalis hystricis ticks tested. The results from the PCR screening for Anaplasma unexpectedly revealed the presence of Candidatus Midichloria sp., a potential tick endosymbiont, in two out of fourteen Haemaphysalis wellingtoni ticks tested. C. burnetii was not detected in any of the samples tested. The findings here provide evidence for the presence of potentially novel strains of rickettsial and borrelial agents in which their impact on public health risks among the rural communities in Malaysia merit further investigation. The detection of a potential endosymbiont of ticks also suggest that the presence of tick endosymbionts in the region is not fully explored.
Stray cats collected from Georgetown, Penang from 2008 to 2010 were screened for ectoparasites via fine-tooth combing. Two cats from a total 102 examined were infested with the dog louse, Heterodoxus spiniger. Both cats, a juvenile male and female were found in close contact with each other prior to capture. The number of lice ranged from 5 and 14 in the male and female cat respectively. Other ectoparasites recovered included the common cat flea, Ctenocephalides felis, one louse species Felicola subrostratus, one tick species Haemaphysalis bispinosa and one mite species of Listrophoridae. The present study reports for the first time the finding of H. spiniger on cats from peninsular Malaysia.
A study to determine the contribution of Giardia cysts and Cryptosporidium oocysts from cattle farms was carried out at the Langat Basin. This study investigated the contribution of cattle farms, located near Sungai Langat and Sungai Semenyih, towards river contamination with these cysts and oocysts. The findings showed that out of 24 samples of water taken from Sungai Semenyih, 4.2% was positive for Giardia cysts with a concentration of 1.3 cysts/L and 20.8% were positive with Cryptosporidium oocysts with a range of 0.7 - 2.7 oocysts/L. At Sungai Langat, from the 43 samples taken, 23.3% were positive for Giardia cysts with a range of 1.5 - 9 cysts/L whereas 11.6% were positive with Cryptosporidium oocysts with a range of 2.5 - 240 oocysts/L. Isolation of cysts and oocysts in bovine faecal materials revealed that 14.6% of faecal samples were positive for Giardia cysts which had a range of 75 - 1.3x104 cysts/g and 25% were positive for Cryptosporidium oocysts with a range of 50 - 3.9x105 oocysts/g. From the cattle wastewater, 98% were positive with oocysts and 6.7% with cysts. The concentrations were between 20 - 3.1x103 oocysts/mL for Cryptosporidium and 4 - 75 cysts/mL for Giardia. Given that the prevalence of Cryptosporidium and Giardia are high amongst the cattle and the positive findings of the (oo)cysts in the river samples, it could be deduced that there is a very high possibility of the cattle farms contaminating the river with Giardia cysts and Cryptosporidium oocysts. Viability study of Cryptosporidium oocysts in the surrounding soil and pond within the cattle farm showed that the viability of Cryptosporidium oocysts decreased with time. It was estimated that it will take 52 days for all the oocysts from both environment to be non-viable. With a viability rate of approximately 2 months in a cattle farm setup, river water contaminated with Cryptosporidium oocysts has a high chance of acting as an agent of transmission. As cattle farms are also inhabited by the owners and their families, this problem may pose a threat to humans (e.g. children) especially if they are dependent on the river water as their source of water for their daily activities.