During a period of four consecutive years, trypanosomosis surveys were conducted in a tsetse-infested and tsetse-free area of the Amhara Region of north-west Ethiopia. In each study area randomly selected communal cattle were sampled and their blood was investigated using parasitological diagnostic methods. At the same time the population of biting flies was sampled. The monthly average prevalence of trypanosome infections in cattle did not differ significantly between study areas. In both study areas, the prevalence of trypanosome infections was highest during the long rainy season. Trypanosome infections were mainly due to Trypanosoma vivax and they significantly reduced the average packed cell volume and the body condition of the animals. The monthly prevalence of infection was correlated with the density of biting flies, such as Tabanidae and Stomoxys spp., in the preceding month suggesting an important role of mechanical transmission in the epidemiology of trypanosomosis in both areas.
The animal-pathogenic oomycete Saprolegnia parasitica causes serious losses in aquaculture by infecting and killing freshwater fish. Like plant-pathogenic oomycetes, S. parasitica employs similar infection structures and secretes effector proteins that translocate into host cells to manipulate the host. Here, we show that the host-targeting protein SpHtp3 enters fish cells in a pathogen-independent manner. This uptake process is guided by a gp96-like receptor and can be inhibited by supramolecular tweezers. The C-terminus of SpHtp3 (containing the amino acid sequence YKARK), and not the N-terminal RxLR motif, is responsible for the uptake into host cells. Following translocation, SpHtp3 is released from vesicles into the cytoplasm by another host-targeting protein where it degrades nucleic acids. The effector translocation mechanism described here, is potentially also relevant for other pathogen-host interactions as gp96 is found in both animals and plants.
Trichuris Dysentery Syndrome (TDS) is a severe persistent trichuriasis associated with heavy worm build-up in the colon that continues to be neglected and underestimated in endemic countries. Trichuriasis is most prevalent in children in tropical countries, and that increases the risk of TDS. We reported a series of four preschool children of both genders chronically having TDS over a period ranging from several months to years presenting with anaemia. The hemoglobin levels ranged from 4.6 to 9.1 g/dl on first admissions. Despite treatment, the cases were reported to have failure to thrive with persistent anaemia. It was concluded that TDS should be considered in endemic areas among children presenting with chronic bloody diarrhea and anaemia.
One thousand and forty-five tissue samples of skeletal muscles, tongue, heart, diaphragm and esophagus were collected from 209 animals (43 sheep, 89 goats and 77 cattle) from an abattoir in Selangor between February and October, 2013. Each sample was divided into three pieces with each piece measuring 2-3 mm3. Each piece was then squeezed between two glass slides and examined microscopically at x 10 magnification for the presence of sarcocystosis. Three positive samples from each animal species were then fixed in 10% formalin for histological processing. Seven positive samples collected from each animal species were preserved at -80°C or 90% ethanol for gene expression studies. Microsarcocysts were detected in 114 (54.5%) animals by light microscopy (LM). The infection rates in sheep, goat and cattle were 86, 61.8 and 28.6% respectively. The highest rate of infection was in the skeletal muscles of sheep (64.9%) and goats (63.6%) and in the heart of cattle (63.6%). The cysts were spindle to oval in shape and two stages were recognized, the peripheral metrocytes and centrally located banana-shaped bradyzoites. 18S rRNA gene expression studies confirmed the isolates from the sheep as S. ovicanis, goats as S. capracanis and cattle as S. bovicanis. This, to the best of our knowledge, is the first molecular identification of an isolate of S. ovicanis and S. capracanis in Malaysia. Further studies with electron microscopy (EM) are required in the future to compare the features of different types of Sarcocysts spp.
Paederus fuscipes, a vector of Paederus dermatitis in most tropical and subtropical countries of the world have a high prevalence in human dwellings due to their positively phototaxic behaviour which has caused a tremendous impact on human health. In this paper, P. fuscipes dispersal flights were studied for two seasons of the rice cultivation phases in residential premises built close to rice field areas (≈32-60 m and 164 m) in mainland Penang, Malaysia. We examined the effects of different light illuminance, building floor level and their association with rice stages as a focal cause of P. fuscipes dispersion from the rice fields towards human dwellings. The present study showed a significant interaction between different light illuminances and rice cultivation phases in attracting P. fuscipes to disperse and invade human dwellings. The highest number of P. fuscipes was captured near the bright light. P. fuscipes flights increased in line with each floor level, and the highest captures took place at higher building floor levels (levels 2 and 3) compared to lower building floor levels (ground floor and level 1) of a three storey apartment in both rice seasons. This finding not only conveys a better understanding on P. fuscipes dispersal pattern, but also draws public attention on the occurrence of dermatitis linearis caused by the Paederus beetles.
Understanding determinants shaping infection risk of endangered wildlife is a major topic in conservation medicine. The proboscis monkey, Nasalis larvatus, an endemic primate flagship species for conservation in Borneo, is endangered through habitat loss, but can still be found in riparian lowland and mangrove forests, and in some protected areas. To assess socioecological and anthropogenic influence on intestinal helminth infections in N. larvatus, 724 fecal samples of harem and bachelor groups, varying in size and the number of juveniles, were collected between June and October 2012 from two study sites in Malaysian Borneo: 634 samples were obtained from groups inhabiting the Lower Kinabatangan Wildlife Sanctuary (LKWS), 90 samples were collected from groups of the Labuk Bay Proboscis Monkey Sanctuary (LBPMS), where monkeys are fed on stationary feeding platforms. Parasite risk was quantified by intestinal helminth prevalence, host parasite species richness (PSR), and eggs per gram feces (epg). Generalized linear mixed effect models were applied to explore whether study site, group type, group size, the number of juveniles per group, and sampling month predict parasite risk. At the LBPMS, prevalence and epg of Trichuris spp., strongylids, and Strongyloides spp. but not Ascaris spp., as well as host PSR were significantly elevated. Only for Strongyloides spp., prevalence showed significant changes between months; at both sites, the beginning rainy season with increased precipitation was linked to higher prevalence, suggesting the external life cycle of Strongyloides spp. to benefit from humidity. Higher prevalence, epgs, and PSR within the LBPMS suggest that anthropogenic factors shape host infection risk more than socioecological factors, most likely via higher re-infection rates and chronic stress. Noninvasive measurement of fecal parasite stages is an important tool for assessing transmission dynamics and infection risks for endangered tropical wildlife. Findings will contribute to healthcare management in nature and in anthropogenically managed environments.
A Giardia varani Lavier, 1923-like flagellate was found in the feces of a captive water monitor, Varanus salvator, originally caught wild from an unknown location in Malaysia. The parasite is similar in size and shape to Giardia lamblia, except that median bodies are rare and cysts are binucleate. A description of both the trophozoite and cyst stage of this flagellate is provided.
A catchment-scale investigation of the prevalence of Cryptosporidium and Giardia in the Kuang River Basin was carried out during the dry and rainy seasons. Water samples were collected from the Kuang River and its tributaries as well as a major irrigation canal at the study site. We also investigated the prevalence of gastrointestinal parasitic infection among dairy and beef cattle hosts. Cryptosporidium and/or Giardia were detected in all the rivers considered for this study, reflecting their ubiquity within the Kuang River Basin. The high prevalence of Cryptosporidium/Giardia in the upper Kuang River and Lai River is of a particular concern as both drain into the Mae Kuang Reservoir, a vital source of drinking-water to many local towns and villages at the research area. We did not, however, detected neither Cryptosporidium nor Giardia were in the irrigation canal. The frequency of Cryptosporidium/Giardia detection nearly doubled during the rainy season compared to the dry season, highlighting the importance of water as an agent of transport. In addition to the overland transport of these protozoa from their land sources (e.g. cattle manure, cess pits), Cryptosporidium/Giardia may also be re-suspended from the streambeds (a potentially important repository) into the water column of rivers during storm events. Faecal samples from dairy and beef cattle showed high infection rates from various intestinal parasites - 97% and 94%, respectively. However, Cryptosporidium and Giardia were only detected in beef cattle. The difference in management style between beef (freeranging) and dairy cattle (confined) may account for this disparity. Finally, phylogenetic analyses revealed that the Cryptosporidium/Giardia-positive samples contained C. ryanae (non-zoonotic) as well as Giardia intestinalis assemblages B (zoonotic) and E (non-zoonotic). With only basic water treatment facilities afforded to them, the communities of the rural area relying on these water supplies are highly at risk to Cryptosporidium/Giardia infections.
Toxoplasma gondii, a ubiquitous pathogen that infects nearly all warm-blooded animals and humans, can cause severe complications to the infected people and animals as well as serious economic losses and social problems. Here, one local strain (TgPIG-WH1) was isolated from an aborted pig fetus, and the genotype of this strain was identified as ToxoDB #3 by the PCR RFLP typing method using 10 molecular markers (SAG1, SAG2, alternative SAG2, SAG3, BTUB, GRA6, L358, PK1, C22-8, C29-2 and Apico). A comparison of the virulence of this isolate with other strains in both mice and piglets showed that TgPIG-WH1 was less virulent than type 1 strain RH and type 2 strain ME49 in mice, and caused similar symptoms to those of ME49 such as fever in piglets. Additionally, in piglet infection with both strains, the TgPIG-WH1 caused a higher IgG response and more severe pathological damages than ME49. Furthermore, TgPIG-WH1 caused one death in the 5 infected piglets, whereas ME49 did not, suggesting the higher virulence of TgPIG-WH1 than ME49 during piglet infection. Experimental infections indicate that the virulence of TgPIG-WH1 relative to ME49 is weaker in mice, but higher in pigs. This is probably the first report regarding a ToxoDB #3 strain from pigs in Hubei, China. These data will facilitate the understanding of genetic diversity of Toxoplasma strains in China as well as the prevention and control of porcine toxoplasmosis in the local region.
Matched MeSH terms: Swine Diseases/parasitology*; Toxoplasmosis, Animal/parasitology*; Sus scrofa/parasitology*
Ocular toxocariasis is prevalent among children. The symptoms and signs may mimic other ocular pathologies such as malignancies and other infectious diseases (such as toxoplasmosis and syphilis). We presented a case of progressive blurring of vision in a single eye of a 9-year-old boy. The presence of anti-toxocara antibody in serum samples helps to confirmation the diagnosis in our patient. Despite of treatment, the boy had lost his vision on the affected eye.
Plasmodium knowlesi has been recently identified as the "fifth human malaria species" following the discovery in Malaysian Borneo of a large focus of this simian malaria parasite in humans. Even though it shares microscopic similarities with Plasmodium malariae, it may cause severe illness with risk of fatality. We describe a case of P. knowlesi infection causing multi-organ failure in a patient who was successfully managed due to early recognition of the infection. Clinicians in this region should be more aware of the infection as it is not as rare as previously thought. This case write up highlight the case of severe malaria infection which presented with multi organ involvement which is caused by P. knowlesi.
Matched MeSH terms: Malaria/parasitology; Multiple Organ Failure/parasitology
Trichuris dysentery syndrome is caused by Trichuris trichiura which contributes to one of the most common helminthic infections in the world. It is associated with heavy colonic infection that manifests as mucoid diarrhoea, rectal bleeding, rectal prolapse, iron deficiency anaemia, and finger clubbing. Here, we report a case of trichuris dysentery syndrome complicated with severe chronic iron deficiency anaemia in a 4-year-old girl who required blood transfusion. The nematode was visualized on stool microscopic and colonoscopic examination. A longer duration of anti-helminthic treatment is required to achieve effective and better outcome.
Strongyloidiasis is an infection caused by the intestinal nematode Strongyloides stercoralis. Infected healthy individuals are usually asymptomatic, however it is potentially fatal in immunocompromised hosts due to its capacity to cause an overwhelming hyperinfection. Strongyloidiasis could be missed during routine screening because of low and intermittent larval output in stool and variable manifestations of the symptoms. We present two cases of strongyloidiasis occurring in children with solid organ malignancies suspected to have the infection based on their clinical conditions and treatment history for cancer. Both patients were diagnosed by molecular and serological tests and were successfully treated. Thus, strongyloidiasis in patients undergoing intensive treatment for malignancies should be suspected, properly investigated and treated accordingly.
Plasmodium knowlesi is a simian malaria parasite and is recently recognized as the fifth malaria parasite infecting humans. Manifestation of the infection may resemble other infection particularly dengue fever leading to inappropriate management and delay in treatment. We reported three cases of naturally acquired P. knowlesi in Hospital Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia. Clinical manifestations were quite similar in those cases. Microscopically, the diagnosis might be challenging. These cases were confirmed by polymerase chain reaction method which serves as a gold standard.
Infections and mTalignancies are common causes of pleural effusion. Among infectious causes, hyperinfection syndrome of Strongyloides stercoralis may occur in immunosuppressive patient. A 62-year-old man, known case of Non-Hodgkin lymphoma (NHL) was presented with recurrent NHL stage IV and had undergone salvage chemotherapy. Patient subsequently developed pneumonia with bilateral pleural effusion and ascites. We reported rhabditiform larvae of S. stercoralis in pleural fluid of both lungs without infiltration by lymphoma cells. Stool for microscopic examination also revealed rhabditiform larvae of S. stercoralis. This patient was a known case of NHL receiving chemotherapy resulting in immunosuppression state. Although S. stercoralis infection is not very common compared to other parasitic infections, it is common in immunosuppressive patients and may present with hyperinfection. Therefore, awareness of this parasite should be kept in mind in immunosuppressive patients.
Strongyloides stercoralis is a widespread, soil-transmitted helminth affecting humans. Autoinfection occurs in S. stercoralis infection and this leads to a continuous build-up of worm burden in human host. This may lead to hyperinfection syndrome which has the potential to cause serious life-threatening disease especially in immunocompromised and immunosuppressed patients. Thus, patient with underlying risk factors should be suspicious of having this infection as severe strongyloidiasis carries a high mortality rate if the diagnosis is delayed. Here, we report a case of S. stercoralis hyperinfection in a diabetic patient.
This paper reports the occurrence of helminth and protozoan infections on small ruminants from eight farms situated in Kinta and Perak Tengah district, Perak. The results of this survey indicate that helminthiasis and coccidiosis is rampant in sheep and goat farms. Several anthelmintics have been used for the control of helminths. The smallholders depended on health and extention services from the State Veterinary Department. This survey is part of an ongoing programme by the Department of Veterinary Services to upgrade services and report the current status of parasitic diseases in the state.
Antibodies to the protozoan parasite, Toxoplasma gondii were assayed in sera of 200 goats, 100 pigs, 126 cattle from various states of Malaysia, and 135 dogs and 55 cats around Ipoh region using an indirect fluorescence antibody test (IFAT, cut-off titer 1:200); antibodies were found in 35.5% of goats, 14.5% cats, 9.6% dogs, 7.9% local cattle and 4% yellow cattle but not in pigs. Results indicate that infection is most prevalent in goats.