Four new and one unidentified species of Neohaliotrema Yamaguti, 1965 were obtained from the gills of the Indo-Pacific sergeant Abudefduf vaigensis (Quoy & Gaimard) off Pulau Langkawi, Malaysia. The five species, N. malayense n. sp., N. bombini n. sp., N. andamanense n. sp., N. parvum n. sp. and an unidentified Neohaliotrema sp. (similar to N. macracanthum Zhukov, 1976), are described and distinguished based mainly on features of the haptor. Species of this genus are divisible into two groups, the 'maomao group', with two pairs of morphometrically modified 'marginal' hooks and a fenestrated haptor, and the 'gracile group', with morphologically similar marginal hooks and an entire haptor. With the exception of N. bombini n. sp., the species described fit within the 'maomao group'. It is suggested that the more complex Neohaliotrema species of the 'maomao group' have modified hooks 1 and 2 on a haptoral 'isthmus' between two large apertures, i.e. 'windows', whereas the less complex species lacking these features are those of the 'gracile group'. Neohaliotrema spp. have only a single pair of pigmented eye-spots. A fenestrated haptor is unique to the Neohaliotrema spp. of the 'maomao group'. The generic diagnosis of Neohaliotrema is amended to include new data and a key to its known species is presented.
Neopolystoma liewi sp. n. is described from the conjunctival cavity of the Malayan box turtle Cuora amboinensis (Daudin, 1802), in Peninsular Malaysia. This is the first record of Neopolystoma in Malaysia and the fourth polystomatid species described from C. amboinensis. Of the 27 Malayan box turtles examined, 8 were found to be infected. A maximum of 2 parasites per eye and 4 individuals per host was recorded. N. liewi sp. n. differs from all other members of the genus by possessing few and short genital spines and small marginal hooks. The oncomiracidium has 64 ciliated cells arranged symmetrically about the sagittal axis.
A 16-year-old female from Rantau Panjang, Kelantan reported having diarrhoea for three months. During this period, she lost 15 lb in weight and was treated with antibiotics and anti-spasmodic tablets with no improvement. Stool examinations by private laboratories revealed "worm-like eggs". She was treated for worms with mebendazole which helped to reduce the symptoms but not completely. The patient continued passing out the abnormal "worm-like eggs" which were later identified as pollen grains.
Hepatocystis bainae n. sp., parasite on the Microchiropteran bat, Hipposideros galeritus is described and differentiated from Hepatocystis rodhaini; it is characterized by the type of the microgametocytes ("diffuse"), the small size of the hepatic schizonts and the repartition of the colloide.
Eimeria tenggilingi is described from the pangolin or scaly anteater, Manis javanica, in Malaysia. The spheroid to subspheroid oocysts average 18.9 X 17.8 mum. The oocyst wall is composed of 3 layers, each approximately 0.6 mum thick. The 2 outer layers are striated and yellowish green. The inner layer is dark brown. One or 2 polar granules are present, but an oocyst residuum is absent. Ellipsoid sporocysts average 12.4 X 6.2 mum. A sporocyst residuum is present. This is the first Eimeria species reported from a host in the order Pholidota.
Description of four new species of Heligmosome Nematodes parasites of the gut of Trichys lipura: --Heligmonella limbooliati n. sp. has a synlophe of Heligmonella-type and a bursa related to Cordicauda. --Cordicauda trichysi n. sp. is characterized by the relatively small dorsal lobe of the bursa, numerous cuticular ridges and the origin of the 8th rib at the distal third of the dorsal rib. --C. malayensis is closely related to C. trichysi (the female of the two species are morphologically identical but the two species can be separated by the larger dorsal lobe of the bursa and the longer spicula of C. malayensis). --C. magnabursa n. sp. is separated from the other species of the genus by the peculiar morphology of the bursa and the female's tail, dorsally bent. The fauna of Trichys is compared to that of Atherurss africanus, which is parasitized by 8 coparasites species: One Heligmonella and seven Paraheligmonina. From a phyletic as well as an ecological point of view (relative abundance and species location in the gut) the two fauna seem to have evolved in a parallel way, one in Africa, one in Asia, from a single Heligmonella type Nematode, after the host's partition.
The ultrastructure of the human skeletal muscle sarcocyst found in Malaysia is reported. Sarcocyst-positive, formalin-fixed tongue tissues were postfixed in osmium tetroxide. The primary cyst wall consisted of a thin membrane supported by osmiophilic material that was interrupted regularly by vesicle-like invaginations. Although there were no cytophaneres, stubby protrusions of the primary wall were observed. These protrusions were accentuated by dense, curvilinear material externally. The primary wall was wavy over about half the cross section of the cyst. The granular ground substance underlying the primary wall occasionally contained hitherto undescribed coiled microtubular structures. Branching septa extended from the ground substance into the cyst, separating mature merozoites into compartments. A few peripheral metrocytes and many laminated myelin figure-like structures, probably degenerating merozoites, were found. Although the human muscular sarcocyst has the same basic ultrastructure as those found in other animals, the stubby protrusions and coiled microtubular structures in the ground substance have not been described previously in nonhuman animals.
The ultrastructure of sarcocysts of macro- and microscopic species of Sarcocystis was compared from naturally infected water buffalo from India. Grossly visible sarcocysts had walls consisting of cauliflower-like villar protrusions, typical of S. fusiformis. The sarcocyst wall of the microscopic species of Sarcocystis was 6.4 microns thick and consisted of tightly packed conical villar protrusions that were 9.6 microns long and 3.7 microns wide at the base. At approximately 3 microns above the base, the distal two-thirds of the villar protrusion became conical shaped and was bent laterally at an angle of 45 degrees to the sarcocyst surface. The granular layer beneath the villar protrusions was 0.9 microns thick. In S. levinei the granular layer was 1.9 microns thick, the villar protrusions were narrow and it had a highly undulating primary cyst wall. Whether the microscopic S. levinei-like sarcocysts of Indian and Malaysian water buffalo are distinct species of Sarcocystis will require further investigation.
The phoretic association between Macrocheles muscaedomesticae and flies that inhabited poultry manure in a poultry farm in Sungai Buloh, Selangor, Malaysia was studied. The effects of temperature, relative humidity and fly abundance on phoretic rates also were investigated. The most abundant fly species found was Musca domestica; Musca sorbens, Chrysomyia megacephala and Ophyra chalcogaster were present in relatively large numbers. Representatives of ten families of mites were found on collected Mu. domestica. The most common mite was Ma. muscaedomesticae (Macrochelidae), found on all four species of flies mentioned above. The highest infestation (2.0%) occurred on O. chalcogaster but Mu. domestica had the highest average number infested (5.7). The ventral part of the housefly's abdomen was the most common site of mite attachment. Usually only one mite was found attached per fly. The highest phoretic rate recorded was 64.4 Ma. muscaedomesticae per 1000 Mu. domestica. There was no correlation between phoretic rates and Ma. muscaedomesticae abundance, nor was relative humidity a factor. However, a positive correlation was recorded in this host species between phoretic rates and temperature.
Four zoonotic parasites, Sarcocystis spp., Toxoplasma gondii, Trichinella spp. and Taenia spp were screened in exotic meats. A total of forty-six (n=46) meat samples from various species of exotic animals were received from all the 14 states in Malaysia from January 2012 to April 2012. All exotic meat samples were examined macroscopically and histologically for the four zoonotic parasites. Results by histological examination of exotic meats showed the presence of Sarcocystis and Toxoplasma cysts at 8.7% (n=4) and 4.3% (n=2) respectively. No Trichinella spp. and Taenia spp. were found.
Description of the male Pterygodermatites nycticebi (Mönnig, 1920) unknown until the present study, and a study of the cephalic and cuticular structures of the female. This rictularid has a morphological evolution comparable to that of other males of the Rictulariidae parasitic in viverrid carnivores and in primates.
Malaysian Sciuridae are often parasitised by 2 species of Hepatocystis which were described as a single species Hepatocystis vassali malayensis by Field and Edeson, (1950). One of them corresponds to the majority of forms seen by Field and Edeson; it is redescribed herein and raised to specific status: H. v. malayensis becomes H. malayensis Field and Edeson, 1950. By the morphological characteristics of its gametocytes and schizonts, H. malayensis is related to H. kochi. The evolution of tissue schizonts studied at liver biopsies and autopsies of squirrels captured shortly before examination is of a peculiar type: an immunological tissue reaction appears with the hyperinfestation of the Rodents and controls the growth of the schizonts.
Hepatocystis brayi n. sp. is described and separated from the second species parasitising Malaysian Sciuridae, H. malayensis Field and Edeson, 1950. H. brayi is characterized by: 1) the evolution of its tissue schizonts which are intracellular throughout all their development; the cytoplasm and the nucleus of the host cell are highly hypertrophied; 2) the scarcity of the colloid. The schizogony persists for several months in the liver of infected animals and the gametocytaemia apparently undergoes seasonal relapses. H. brayi is a parasite of hosts occurring in the middle and under canopy, H. malayensis the middle and top canopy.
Despite the medical, veterinary and forensic relevance of myiasis-causing flies, knowledge of their diversity in Saudi Arabia is limited especially in the southern region. Therefore, a survey of myiasis-causing flies in the Jazan region was carried out using Red Top Fly Catcher traps baited with either decomposing beef liver or a lure composed primarily from fishmeal during the period April 2013-March 2014. Twelve known species were identified and recorded in this study, seven species of them belonging to Calliphoridae (Chrysomya, Lucilia, and Hemipyrella) and five species belonging to Sarcophagidae (Sarcophaga). Two of these species were recorded for the first time for Saudi Arabia, namely Hemipyrella pulchra (Wiedemann, 1830) and Sarcophaga (Liosarcophaga) exuberans Pandellé, 1896. Images of the species recorded are also provided for the first time. The results expand the knowledge of geographical distribution, fauna, and habitat of the myiasis-causing flies in Saudi Arabia. Biological information and world-wide geographical distribution of these species are included together with some taxonomic remarks.
Much effort has been devoted by the World Health Organization (WHO) to eliminate soil-transmitted helminth (STH) infections by 2030 using mass drug administration targeted at particular risk groups alongside the availability to access water, sanitation and hygiene services. The targets set by the WHO for the control of helminth infections are typically defined in terms of the prevalence of infection, whereas the standard formulation of STH transmission models typically describe dynamic changes in the mean-worm burden. We develop a prevalence-based deterministic model to investigate the transmission dynamics of soil-transmitted helminthiasis in humans, subject to continuous exposure to infection over time. We analytically determine local stability criteria for all equilibria and find bifurcation points. Our model predicts that STH infection will either be eliminated (if the initial prevalence value, y(0), is sufficiently small) or remain endemic (if y(0) is sufficiently large), with the two stable points of endemic infection and parasite eradication separated by a transmission breakpoint. Two special cases of the model are analysed: (1) the distribution of the STH parasites in the host population is highly aggregated following a negative binomial distribution, and (2) no density-dependent effects act on the parasite population. We find that disease extinction is always possible for Case (1), but it is not so for Case (2) if y(0) is sufficiently large. However, by introducing stochastic perturbation into the deterministic model, we discover that chance effects can lead to outcomes not predicted by the deterministic model alone, with outcomes highly dependent on the degree of worm clumping, k. Specifically, we show that if the reproduction number and clumping are sufficiently bounded, then stochasticity will cause the parasite to die out. It follows that control of soil-transmitted helminths will be more difficult if the worm distribution tends towards clumping.
It has been tested and proven that vaccination is still the best strategy to combat infectious diseases. However, to date, there are still no vaccines against human soil-transmitted helminthic diseases, despite their high prevalence globally, particularly in developing countries and rural areas with tropical climates and poor sanitation. The development of vaccines against helminths is riddled with obstacles. Helminths have a complex life cycle, multiple stages within the same host with stage-specific antigen expression, and the ability to regulate host immune reactions to evade the immune response. These elements contribute to the main challenge of helminthic vaccines: the identification of effective vaccine candidates. Therefore, this article reviews the current progress and potential future direction of soil-transmitted helminthic vaccines, particularly against Trichuris trichiura, Ascaris lumbricoides, Strongyloides stercoralis, Necator americanus and Ancylostoma duodenale. The study design employed was a systematic review, using qualitative meta-summary synthesis. Preclinical studies and clinical trials on the development of protein subunit vaccines against the five soil-transmitted helminths were searched on PubMed and Scopus. Effectiveness was indicated by a reduction in worm burden or larval output, an increase in specific IgG levels, or an increase in cytokine production. Our findings show that only the hookworm vaccine against N. americanus is in the clinical trial phase, while the rest is still in exploratory research and pre-clinical development phase.