Soil contaminated with helminth eggs and protozoan cysts is a potential source of infection and poses a threat to the public, especially to young children frequenting playgrounds. The present study determines the levels of infection of helminth eggs in soil samples from urban and suburban playgrounds in five states in Peninsular Malaysia and identifies one source of contamination via faecal screening from stray animals. Three hundred soil samples from 60 playgrounds in five states in Peninsular Malaysia were screened using the centrifugal flotation technique to identify and determine egg/cyst counts per gram (EPG) for each parasite. All playgrounds, especially those in Penang, were found to be contaminated with eggs from four nematode genera, with Toxocara eggs (95.7%) the highest, followed by Ascaris (93.3%), Ancylostoma (88.3%) and Trichuris (77.0%). In addition, faeces from animal shelters were found to contain both helminth eggs and protozoan cysts, with overall infection rates being 54% and 57% for feline and canine samples, respectively. The most frequently occurring parasite in feline samples was Toxocara cati (37%; EPG, 42.47 ± 156.08), while in dog faeces it was Ancylostoma sp. (54%; EPG, 197.16 ± 383.28). Infection levels also tended to be influenced by season, type of park/playground and the texture of soil/faeces. The occurrence of Toxocara, Ancylostoma and Trichuris eggs in soil samples highlights the risk of transmission to the human population, especially children, while the presence of Ascaris eggs suggests a human source of contamination and raises the issue of hygiene standards and public health risks at sites under investigation.
Six species of strigeoid trematodes are reported from Malaysia. One new genus and 3 new species are described: Apatemon (Apatemon( jamesi sp. n (Strigeidae); cercaria Cotylurus sullivani sp. n. (Strigeidae); Neodiplostomum (Neodiplostomum) sp. (Diplostomatidae); Fibricola ramachandrani (Diplostomatidae); Pseudoscolopacitrema otteri gen. n. et sp. n. (Diplostomatidae); and cercaria Cyathocotyle malayi sp. n. (Cyathocotylidae). The life cycles of A. jamesi and C. malayi have also been investigated.
The development of Breinlia booliati is described in its natural host, Rattus sabanus and in an inbred strain of laboratory albino rat. The growth of the parasite is similar in both the rat hosts. The third moult occurs between six-eight days and the final moult between 24-28 days. Larvae were recovered initially from the skin and carcass. After five weeks, developing stages were seen only in the thoracic and abdominal cavities, the site of development of the adult worms. Worms became sexually mature by 11-12 weeks and there was considerable growth in length of the female worms after this stage.
Breinlia booliati exhibited nocturnal subperiodicity in its natural host, Rattus sabanus in contrast to experimentally infected laboratory-reared albine rats which showed irregular fluctuations of microfilariae throughout the 24 hour cycle. All the infected albino rats showed a prepatent period between 11-14 weeks postinoculation. Three patterns of microfilaraemia were discerned during the course of infection 38/49 rats displayed a single peak, 4/49 displayed 2 peaks about 12-15 weeks apart and 7/49 showed a sustained high plateau-like pattern of microfilaraemia. Cortisone had no effect on microfilarial levels when administered to rats near postpatency and some at postpatency.
Stunkardia minuta sp. n. was recovered from the small intestine and rectum of 5 box-tortoises (Cuora amboinensis) in Malaysia. The average body size (L X W) is 11-42 X 2-35 mm; oral sucker 1-51 X 1.02; oral pouches 0-21 X 0.18; ventral sucker 1-67 X 1-43; oesophageal bulb 0-54 X 0-54; ant. testis 0-95 X 0-98; post. testis 0-94 X 0.94; seminal vesicle 0-82 X 0-24; ootype 0-21 X 0-41; ovary 0-41 X 0-34; and egg 121 X 83 micrometer. Although morphologically similar to S. dilymphosa, S. minuta is distinct from any other reported member of the Paramphistomidae.
A new genus of the Monogenea, Teraplectanum n. g., is proposed for two new species of diplectanids found on the gills of Terapon theraps Cuvier collected off Carey Island, Peninsular Malaysia. The genus is based on a unique arrangement of the male reproductive system. In the new species spermatozoa stored in the seminal vesicle and secretions stored in the prostatic reservoir are transferred into, and mixed to form semen within, a special sclerotized auxiliary piece (SAP), and not within the copulatory tube as occurs in the majority of monogeneans. Teraplectanum species also possess a unique sclerotized vaginal loop through which the vaginal tube passes en route from the vaginal pore to the seminal receptacle. The two new species are Teraplectanum crassitubus n. sp. (type species) and T. angustitubus n. sp. They differ from each other mainly in the morphology of their copulatory tube: in T. crassitubus, the proximal region of this tube is thicker compared to the slender proximal region in T. angustitubus, although in both cases the tube tapers and twists distally. Of the known diplectanid species, only Diplectanum undulicirrosum Zhang et al., 2000 (currently considered incertae sedis) possesses such sclerotized hard parts, which suggests the same type of arrangement of the male reproductive system. Consequently, D. undulicirrosum is re-assigned to this new genus as Teraplectanum undulicirrosum (Zhang et al., 2000) n. comb. The copulatory tube of T. undulicirrosum is similar to the slender, undulating copulatory tube of T. angustitubus but does not taper distally as in the latter species.
The influence of soil texture (silt, sand and laterite) and flotation solutions (saturated NaCl, sucrose, NaNO3, and ZnSO4) upon the recovery of Toxocara ova from seeded soil samples with the centrifugal flotation technique was investigated. Soil samples of different texture were artificially seeded with Toxocara spp. ova and subjected to a centrifugal flotation technique which used various flotation solutions. The results showed significant (P < 0.001) interactions between the soil types and the flotation solutions. The highest percentage of ova recovery was obtained with silty soil (34.9-100.8%) with saturated NaCl as the flotation solution (45.3-100.8%). A combination of washing of soil samples with 0.1% Tween 80, and flotation using saturated NaCl and a 30 min coverslip recovery period was used to study the prevalence of contamination of soil samples. Forty-six soil samples were collected from up to 24 public parks/playgrounds in urban areas of Petaling Jaya and suburban areas of Serdang. The prevalence of Toxocara species in the urban and suburban areas was 54.5% and 45.8% respectively.
A six year old child living in Singapore was found to be
infected with the cestode Bertiella studeri. Apparent cure was affected by use of Dichlorophen.
This paper reports the experimental transmission of a bird parasite into jirds. Infective larvae of Cardiofilaria nilesi obtained from laboratory colonized Coquillettidia crassipes mosquitoes which had fed on an infected chicken were inoculated subcutaneously into jirds. The number of larvae per jird varied from 10 to 228. Microfilaraemia appeared 22 to 89 days after inoculation of the infective larvae. Experiments were carried out with 24 jirds through six generations extending over a period of 22 months and 17 produced patent infections. At present 8 infected jirds are being maintained in the laboratory; their patent periods ranging from 6 to 13 months. However, the longest patent period observed was about thirteen months. The percentage of adults recovered in autopsied jirds ranged from 0 to 40 with an average of 16. The chicken showed a microfilarial periodicity with the peak microfilarial density around 2200 hours. However, in jirds there was a change in sub-periodicity. This model in the jird may be very useful for the screening of filaricides and in immunological work.