The Indirect Fluorescent Antibody Test (IFAT) and thin blood smears were conducted to establish the prevalence of Ehrlichia canis infection in dogs presented for treatment by pet owners at five private and one government veterinary clinic. Results showed that 15% of the dogs were positive for the parasite via IFAT, but none using blood smears. However, infected dogs did not show severe clinical symptoms of canine monocytic ehrlichiosis (CME).
One hundred sera of Malaysian cattle were used in this seroprevalence study for bovine babesiosis. All sera were obtained from the Serological Unit of the Veterinary Research Institute (VRI), Ipoh, Perak. The sera were tested using a Veterinary Medical Research & Development (VMRD) commercial Indirect Immunofluourescent Antibody Test (IFAT) kit. The results showed that 17.0% were found to be positive for Babesia bovis, 16.0% for Babesia bigemina, and 9.0% for both B. bovis and B. bigemina infections.
Using the cow-baited trap (CBT) method, 1,845 Anopheles mosquitos, comprising 14 species, were caught in malaria-endemic area of Hulu Perak district, Peninsular Malaysia. The two dominant species were An. barbirostris (18.59%) and An. aconitus (18.86%). Anopheles maculatus, the main malaria vector, constituted 9.11% of the total number of mosquitos sampled. Three hundred and seventy-seven Anopheles larvae, comprising 8 species, were sampled using the North Carolina Biological Station dipper. Anopheles barbirostris larvae amounted to 64.69% of the total number of larvae; An. aconitus accounted for 10.65% of larvae. Seven habitats were identified as breeding places of Anopheles. Most species were found to breed in paddies, fishponds, and rivers. Other less popular habitats were temporary pools, mountain streams, and spring wells.
Until today, malaria is still one of the most important diseases in Malaysia. This is because Malaysia is located within the equatorial zone with high temperatures and humidities, usually important for the transmission of malaria. The number of malaria cases were estimated to be around 300,000 before the launching of the Malaria Eradication Program (MEP). The program was successful in reducing the numbers progressively during the 1967-1982 period. During the period 1980-1991, the highest number of malaria cases recorded for the country was 65,283 in 1989 (16,902 in Peninsular Malaysia, 47,545 in Sabah and 836 in Sarawak) whilst the lowest was 22,218 (10,069 in Peninsular Malaysia, 11,290 in Sabah and 859 in Sarawak) in 1983. In Malaysia, there are 434 species of mosquitos, representing 20 genera. Of these, 75 species are Anopheles that comprise of 2 subgenus, i.e. Anopheles and Cellia. Of the 75 species, only 9 have been reported as vectors: An. maculatus, An balabacensis, An. dirus, An. letifer An. campestris, An. sundaicus, An. donaldi, An. leucophyrus and An. flavirostris. The behavior, seasonal abundance, biting activities and breeding sites of these species are discussed.
A study on the distribution of malaria in Hulu Perak district, Peninsular Malaysia was carried out between January and December 1993. The study encompassed the distribution of malaria cases according to sex, age and profession. A total of 332 cases were recorded, with 182 cases occurring in males. The highest infection was observed in the above 15 years old age group. Forest workers (loggers, rattan collectors and forest product gatherers) were the group most exposed to the disease (32.8%), followed by both plantantion workers (32.2%) and aboriginal communities (32.2%). Army and police personnels (2.1%) were also infected. Plasmodium falciparum was the most common species of malaria in the area.
This study aimed to represent the first report of the ovicidal and larvicidal activity of the methanolic leaf extract of Manihot esculenta (cassava) against eggs and larvae of susceptible and resistant strains of Trichostrongylus colubriformis. As well as, to determine the total tannin compounds, antioxidant activity and toxicity of the extract. The egg hatch test was used to evaluate ovicidal activity against unembryonated eggs, whereas larval feeding inhibition assay and MTT-formazan assay were used to evaluate larvicidal activity against first (L(1)) and infective (L(3)) larvae, respectively. The results showed no significant differences were detected between the sensitivities of susceptible and resistant strains of T. colubriformis to the extract. Eggs, L(1) and L(3) were significantly affected (P<0.001) compared with negative control, and L(1) were more sensitive than the eggs and L(3). The total tannin compounds were investigated using tannin quantification assay and determined by 254.44 TAE/mg. The antioxidant activity was evaluated using the DPPH radical scavenging assay and the median inhibition concentration (IC(50)) was determined by 2.638 mg/ml. Acute oral toxicity at dose of 5,000 mg/kg, and sub-chronic oral toxicity at 500 and 1,000 mg/kg of the extract were observed in male and female Sprague-Dawley (SD) rats. The acute oral toxicity revealed that the median lethal dose (LD(50)) of methanolic extract of cassava leaves on SD rats was greater than 5,000 mg/kg, whereas the sub-chronic oral toxicity did not show observed adverse effects at 500 and 1,000 mg/kg per day for 28 days. In conclusion, the methanolic extract of cassava leaves has direct ovicidal and larvicidal activity against T. colubriformis strains with a safety margin for animals, and it may be potentially utilized as a source of natural antioxidants.
The large stomach worm, Haemonchus contortus, commonly known as "the barber's pole worm", is a blood-sucking nematode found in the abomasa of sheep and goats. This work is the first documentation on the ND4 sequences of H. contortus from sheep and goats in Malaysia and Yemen and the results provide a preliminary insight on the genetic differences of H. contortus found in the two countries. In general, this study showed a high degree of diversity and low population structure of this species within the same country in comparison with higher genetic structuring at a wider geographical scale. The results also showed that the majority of genetic variance was within H. contortus populations. The Malaysian sheep and goat populations investigated appeared to share the same isolate of H. contortus while different isolates may be found in Yemen which must be taken into account in the design of an effective control strategy. Analysis of the internal transcribed spacer-2 (ITS-2) confirmed that all samples investigated in this study belonged to H. contortus. However presence of other Haemonchus species parasitizing these two hosts can only be confirmed by further detailed studies.
Anthelmintic resistance of gastrointestinal nematodes is considered as one of the main limiting factors causing significant economic losses to the small ruminant industry. The anthelmintic properties of some plants are among the suggested alternative solutions to control these parasitic worms. The present study investigated the anthelmintic activity of neem (Azadirachta indica) and cassava (Manihot esculenta) leaf extracts against the susceptible and resistant strains of one of the most important nematodes in small ruminants, Teladorsagia (Ostertagia) circumcincta. Three different in vitro tests: egg hatch test, larval development assay, and larval paralysis assay were used to determine the efficiency of neem and cassava extracts on three pre-parasitic stages of T. circumcincta. The LC(50) was determined for the most potent extract in each plant as well as the phytochemical tests, total tannin quantification and cytotoxicity on peripheral blood mononuclear cells of goats. The results revealed a high anthelmintic activity of neem methanol extract (NME) and cassava methanol extract (CME) on both strains of T. circumcincta without significant differences between the strains. The first stage larvae were more sensitive with the lowest LC(50) at 7.15 mg/ml and 10.72 mg/ml for NME and CME, respectively, compared with 44.20mg/ml and 56.68 mg/ml on eggs and 24.91 mg/ml and 71.96 mg/ml on infective stage larvae.
Blood from most of the residents of a remote village in northern peninsular Malaysia, bordering Thailand, was examined for malaria parasites monthly for 1 year. Plasmodium vivax was the commonest infection, but P. falciparum and mixed infections also occurred. Monthly collections of the malaria vector, Anopheles maculatus showed a positive correlation between mosquito densities and malaria positivity in the human population and a negative correlation with rainfall.
A comparative seroprevalence study on bovine trypanosomiasis and anaplasmosis was conducted. Sera of adult cattle and buffaloes of different breeds from farms from five different states in Malaysia were collected and tested for the presence of Trypanosoma evansi antibodies by CATT and Anaplasma marginale antibodies by c-ELISA. Of the 116 samples, 14.7% tested positive for bovine trypanosomiasis and 77.6% for bovine anaplasmosis.
Haemonchus contortus is a highly pathogenic nematode parasite of sheep and goats. This work was conducted to investigate the population and host variations of the parasitic nematode H. contortus of sheep and goats from Malaysia and Yemen. Eight morphological characters were investigated, namely the total body length, cervical papillae, right spicule, left spicule, right barb, left barb, gubernaculum and cuticular ridge (synlophe) pattern. Statistical analysis showed the presence of morphological variation between populations of H. contortus from Malaysia and Yemen, with minor variation in the synlophe pattern of these isolates. Isolates from each country were grouped together in the scatterplots with no host isolation. Body, cervical papillae and spicule lengths were the most important characters that distinguished between populations of the two countries. This variation between Malaysia and Yemen may be attributed to geographical isolation and the possible presence of a different isolate of this worm in each country.
Twelve species of Anopheles were collected by using cow-baited net trap in a malarial endemic village in northern Peninsular Malaysia. Anopheles maculatus which is the main malaria vector with its densities were related to drought. An. aconitus, An. kochi and An. philippinensis were less susceptible to P. falciparum and P. vivax infection, and are not considered important in falciparum or vivax malaria transmission. Biting activities of An. kochi and An. vagus were primarily active after dusk and steadily declined after midnight. An. maculatus and An. aconitus showed biting activities throughout the night but An. maculatus showed two peaks of biting activity in the first half of the night.
The efficacy of the larvicidal and pupicidal agent (Agnique) MMF was evaluated against larvae of An. arabiensis and Culex (Diptera: Culicidae) under field conditions in Bahary Locality, Khartoum, Sudan. At an applied dosage of 0.25 ml/m2, MMF resulted in 89.4, 79.8 and 88.2% reductions in L3-L4 instars An. arabiensis and 63.5% in Culex larvae (all stages) 24 to 72 hours post-treatment. Pupae were completely eliminated (100%) within 24 hours posttreatment. The earlier instars (L1-L2) of An. arabiensis were more tolerant with a 62.5% reduction at 72 hours post-treatment compared to (L3-L4) instars and pupae. At 7-days post-treatment Agnique gave a 57.5% reduction in L1-L2 and 92.6% in L3-L4 instar larvae of An. arabiensis and 57.3% and 86.4% in Culex larvae and pupae, respectively. We conclude that Agnique can perform effectively against L3-L4 instars and pupae of An. arabiensis for only 1 week, and 3 to 4 days against L1-L2 instars of Culex spp.
Nine species of Anopheles mosquitoes were collected biting humans indoors and outdoors in a malaria endemic village in northern Peninsular Malaysia. Outdoor biting was higher than that observed indoors. Biting of An. maculatus was observed throughout the night. Peak indoor biting occurred at 2130 h while outdoor biting was higher after midnight. Outdoor biting of Anopheles barbirostris and An. sinensis was observed throughout the night with several peaks after the second half of the night. Outdoor biting activities of An. kochi and An. philippinensis were primarily active after dusk and steadily declined after 2130 h.
Using cow-baited net traps in the coastal and hilly areas of northern peninsular Malaysia, 21 species of Anopheles mosquitoes were found. The distribution of common Anopheles is presented. The composition of the anopheline mosquito fauna was more diversified in the coastal areas than in the hilly areas. The displacement of Anopheles sundaicus by Anopheles subpictus and the disappearance of Anopheles hackeri in the coastal area were noted.