There were a spate of recent complaints of insect bites and the entomological specimens received from various sources were identified to be those of cat flea (Ctenocephalides felis) and rat flea (Xenopsylla cheopis), the tropical bed-bug (Cimex hemipterus) and the dog louse (Heterodoxus spiniger). Only the fleas and the bed-bug are known to attack humans.
Forensic entomological specimens received by the Unit of Medical Entomology, IMR., from hospitals and the police in Malaysia in the last 3 decades (1972 - 2002) are reviewed. A total of 448 specimens were received. From these, 538 identifications were made with the following results: Eighteen species of cyclorrphaga flies were identified consisting of Chrysomya megacephala (Fabricius) 215 cases (47.99%), Ch. rufifacies (Masquart) 132 (29.46%), Ch. villeneuvi Patton 10 (2.23%), Ch. nigripes Aubertin 7 (1.56%), Ch. bezziana Villeneuve 4 (0.89%), Ch. pinguis (Walker) 1 (0.22%), Chrysomya sp. 47 (10.49%), Sarcophaga sp. 28 (6.25%), Lucilia sp. 21 (4.69%), Hermetia sp. 15 (3.35%), He. illucens (Linnaeus) 1 (0.22%), Hemipyrellia ligurriens (Wiedemann) 3 (0.67%), Hemipyrellia sp. 2 (0.45%), Ophyra spinigera 1 (0.22%), Ophyra sp. 6 (1.34%), Calliphora sp. 24 (5.36%), Synthesiomyia nudiseta (Wulp) 1 (0.22%) and Eristalis sp. 1 (0.22%). Other non - fly insect specimens are Pthirus pubis (Linnaeus) (Pubic louse) 2 (0.45%) and Coleoptera (Beetles) 1 (0.22%). Ch. megacephala and Ch. rufifacies were the commonest species found in cadavers from different ecological habitats. Sy. nudiseta is an uncommon species, thus far found only on cadavers from indoors. Sy. nudiseta is reported for the second time in Peninsular Malaysia. A total of 329 cases (73.44%) had a single fly infestation, 109 cases (24.33%) had double fly infestation and 10 cases (2.23%) had triple fly infestation. Five cases (1.12%) had eggs and 3 cases (0.67%) had larval stages that were not identifiable. No arthropods were retrieved from cadavers in 8 cases (1.79%). In conclusion, although large number of fly species were found on human cadavers, the predominant species are still those of Chrysomya.
The hornets are a group of venomous stinging insects that at times cause human death. A fatal case of a child stung by the lesser banded hornet Vespa affinis indosinesis is reported. Though often covered by the mass media, this constitutes the first scientifically reported case.
A considerable number of rat-borne ectoparasite studies have been conducted since the early 1930s in the Malayan Peninsula (now known as peninsular Malaysia). The majority of studies were field surveys and collections of specimens across the region, and were conducted primarily to catalogue the ectoparasite host distribution and discover novel species. This has generated a signification amount of information, particularly on the diversity and host distribution; other aspects such as morphology, host distribution and medical significance have also been investigated. Amongst the four main groups (mites, fleas, ticks, lice), rat-borne mites have received the most attention with a particular emphasis on chiggers, due to their medical importance. More recent studies have examined the distribution of ectoparasites in rats from different habitat type simplicating a high prevalence of zoonotic species infesting rat populations. Despite being capable of transmitting dangerous pathogens to human, the health risks of rat-borne ectoparasites appear to be small with no serious outbreaks of diseases recorded. Although an extensive number of works have been published, there remain gaps in knowledge that need to be addressed, such as, the distribution of under studied ectoparasite groups (listrophorids and myobiids), determining factors influencing infestation, and understanding changes to the population distribution over time.
We report a case of human intestinal myiasis in a 41-yr-old female patient presented at a clinic in Seri Kembangan, Selangor, Malaysia. Larvae passed out in the patient's feces were sent to the Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia. DNA barcoding confirmed the second case of intestinal myiasis in Malaysia involving the larvae of Clogmia albipunctatus (Duckhouse) (Diptera: Psychodidae). We review reported cases of myiasis and discuss the present case of intestinal myiasis in an urban patient.
We report an unusual cause of gastrointestinal infection occurring in a 1-year-old infant patient who was brought to a public hospital in Kuala Lumpur, Malaysia. Larvae passed out in the patient's feces were confirmed by DNA barcoding as belonging to the species, Lasioderma serricorne (F.), known as the cigarette beetle. We postulate that the larvae were acquired from contaminated food and were responsible for gastrointestinal symptoms in the patient. To our knowledge, this the first report of human canthariasis caused by larvae of L. serricorne.
Mosquitoes are principal vectors of major vector-borne diseases. They are widely found throughout urban and rural areas in Malaysia. They are responsible for various vector-borne diseases such as dengue, malaria, filariasis and encephalitis. A total of 158 mosquito larvae specimens were collected from the National Zoo, Malaysia, from 11 types of breeding habitats during the study period from end of May 2007 to July 2007. Aedes albopictus was the predominant species (35.4%), followed by Tripteroides aranoides (26.6%), Lutzia halifaxii (11.4%), Aedes alboscutellatus (10.1%), Aedes caecus (8.9%), Armigeres spp. (4.4%), Malaya genurostris (2.5%) and Culex vishnui (0.6%). It is important to have a mosquito free environment in a public place like the zoo. Routine larval surveillance should be implemented for an effective mosquito control program in order to reduce mosquito population.
The brown widow spider (Latrodectus geometricus Koch, 1841) has colonised many parts of the world from its continent of origin, Africa. By at least 1841, the species had successfully established populations in South America and has more recently expanded its range to the southern states of North America. This highly adaptable spider has been far more successful in finding its niche around the world than its famous cousins, the black widow, Latrodectus mactans, found in the south-eastern states of North America, and the red-back, Latrodectus hasselti, found mostly in Australia, New Zealand and Japan.
A 73-year-old Chinese man was admitted to the Accident and Emergency Premorbid Ward of a local hospital in Malaysia. The patient complained of shortness of breath with cough and was in a semi-conscious state. He was later admitted to an intensive care unit (ICU) of the hospital. Six days after admission 5-6 maggots were recoverd from the nasal cavity. The maggots were identified as the third-instar larvae of Lucilia cuprina Wiedmann (Diptera: Calliphoridae) based on the morphological characteristics. This patient was classified as having nosocomial myiasis. The presence of the third instar larvae indicated that the infestation was not more than three to four days. An adult sarcophagid identified as Parasarcophaga ruficornis (Fabricius) caught in the ICU where the patient was warded provided further evidence of the potential for the nosocomial infestation.
Piophila casei (Linnaeus) (Diptera: Piophilidae) is reported from human cadavers in two separate forensic cases for the first time in Malaysia. Both bodies were found indoors. The first case, was that of a male of unknown nationality and age and also contained maggots of the muscid Ophyra spinigera (Stein). The second case was a female Chinese whose body also contained other species of maggots but these were not identifiable.
A study of diurnal and nocturnal distribution of flies was conducted in Putrajaya. Six different ecological habitats were selected, namely: botanical garden, lake-area, administration building, wetland, jungle fringes and housing areas. Two different type of traps, cylinderical and rectangular in shape were used in the study. Baits used in these traps were yeast, sugar, salted fish, shrimp paste and fresh liver. Traps were placed at the sites throughout the diurnal and nocturnal periods. The time for sunrise and sunset was determined using a Geographical Positioning System gadget (GARMIN) at the sites. Both type of traps were equally effective in trapping flies. There was no significant difference between both types of traps in their ability to trap flies (p > 0.05). A total of 1,534 flies were collected and identified from both types of trap using the multiple baits and habitats. The collection consisted of 23 species of flies classified under 6 families. The highest number of flies were caught from the lake-area followed by botanical garden, administration building, housing areas, wetland and jungle fringes. The most dominant species was Chrysomya megacephala, followed by species of Sarcophagidae and Musca domestica. Diurnal period had more numbers of flies (81.55%) compared to the nocturnal periods (18.45%). Some species of flies were strictly diurnal, some exibited both diurnal and nocturnal activities while only one species was strictly nocturnal.
The house fly, Musca domestica has long been considered a potential agent for disease transmission ever since its existence. The general truth of this assertion remains undisputed till the present day in spite of increasing awareness toward an improved sanitation and better hygiene. The habitual movement of house fly from filthy substrata such as human faeces, animal excreta, carcasses, garbage, etc. makes them ideal candidates for disease transmission such as cholera, shigellosis, salmonellosis and others when settling on food. Fly as a potential mechanical vector of pathogenic bacteria was elucidated in this study by examining flies from various breeding sites such as food courts, dumping ground, food processing areas and poultry farm in Peninsular Malaysia. The flies were baited with 10% sugar solution on a glass slide in the field. All materials used for collection of samples were sterile. Bacteria from fly sample were isolated using the normal isolation technique. Bacillus sp., Coccobacillus sp., Staphylococcus sp., Microccus sp., Streptococcus sp., Acinetobacter sp., Enterobacter sp., Proteus sp., Escherichia sp., Klebsiella sp. and yeast cells were isolated from feaces, vomitus, external surfaces and internal organs of house fly. Newly emerged house fly did not harbour any bacteria.
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 diversity and distribution of ectoparasites and endoparasites infesting wild rat population of Carey Island was carried out from June to December 2010. A total of 81 rats were captured from various locations on Carey Island. Four rat species were identified namely, Rattus tiomanicus (45.7%), Rattus rattus diardii (25.9%), Rattus argentiventer (16%) and Rattus norvegicus (12.3%). Low diversity of ecto and endoparasites were observed infecting the rodent population with 8 ecto and 8 endoparasites species recorded. The ectoparasites recovered fell under 3 broad groups, namely mites (Laelaps nuttali, Laelaps echidninus, Laelaps sculpturatus, Listrophoroides sp. and Ornithonyssus bacoti), lice (Polyplax spinulosa and Hoplopleura pacifica) and tick (Ixodes granulatus) while endoparasites recovered were cestodes (Taenia taeniaformis and Hymenolepis diminuta) and nematodes (Nippostrongylus brasiliensis, Angiostrongylus malaysiensis, Mastophorus muris, Heterakis spumosa, Hepatojarakus malayae and Syphacia muris). The rat population was observed harbouring more than one parasite species. Analysis of data also showed neither intrinsic (host age, host sex) nor extrinsic (season) factors influenced the macroparasites community structure.
Adult mosquito collections were conducted for 12 weeks in two residential areas in Kuala Lumpur. The CDC light traps were compared using dry ice and yeast as sources of carbon dioxide attractants for mosquitoes. The efficacy of the dry ice baited trap was significant over yeast generated CO2 trap. The predominant species obtained were Culex quinquefasciatus, Stegomyia albopicta and Armigeres subalbatus.
Fannia pusio (Wiedemann) (Diptera: Fanniidae) is newly recorded from Malaysia. This record is based on 1male symbol 1female symbol from Sarawak, east Malaysia and 1male symbol 2female symbol from Selangor, peninsular Malaysia. It is included in the pusio group of Fannia wherein are included Fannia femoralis (Stein), Fannia howardi Malloch, Fannia trimaculata (Stein), Fannia leucosticta (Meigen) and Fannia punctiventris Malloch. The male of Fannia pusio is differentiated from other members of the group by the following features: hind femur with a swelling bearing a number of setae that are usually curled at tip; squamae creamy; tergite 1+2 broadly grey dusted at sides.
The prevalence of Enterobius vermicularis in four groups of adults, all trainee public health inspectors or public health nurses, aged 18-35 years and all living in hostels on campus was studied. The modified scotch tape technique was used and the subjects were taught to do the examination on themselves to detect the presence of eggs over a period of 6 successive mornings. Each was given an elaborately illustrated diagram on how and when to take the samples and given demonstration in groups. The samples were examined by trained people. Most of the subjects took samples on 6 consecutive days. Of the 119 subjects who returned samples, the overall prevalence of E. vermicularis was 9.2% and this was thought to be high for this particular age group. This was due to the higher prevalence (19.4%) in one group, whereas in the others the range was 3.5-8.0%. Based on the samples returned on the first day none of the subjects were detected as having the infection. After examination on 3 successive days (109 subjects) 10.1% were found to be infected (chi 2 = 10.704; d. f. = 1) and after examination on 6 successive days (72 subjects) 13.9% were found to be infected (chi 2 = 3.026; d. f. = 1). There was no significance between examination over 3 successive days and 6 consecutive days (chi 2 = 0.296; d. f. = 1). There was no difference in the prevalence between males and females.(ABSTRACT TRUNCATED AT 250 WORDS)
A survey was conducted in 4 paediatric wards in Malaysia to determine the distribution of various species of cockroaches and to examine their gut contents for bacteria. Cockroaches were trapped from food dispensing areas (kitchens), store rooms, cupboards and open wards. 104 cockroaches were caught, consisting of Periplaneta americana (67.3%), Blattella germanica (26%), P. brunnea (4.8%), and Supella longipalpa (1.9%). Bacteria were isolated from all cockroaches except 3 P. americana. Many bacterial species were identified, including the pathogenic and potentially pathogenic species Shigella boydii, S. dysenteriae, Salmonella typhimurium, Klebseilla oxytoca, K. ozaena and Serratia marcescens.
A survey was conducted to investigate the prevalence of Enterobius vermicularis in 1352 Chinese children between the ages of 6-12 years from the three National Type Chinese Primary Schools in Pulau Ketam in 1988, using the scotch-tape technique on three successive days. The overall prevalence was high (56.88%). The prevalence in Sin Bin School was significantly lower (50.86%) compared to the other two schools (56.60% and 61.04%). Prevalence was significantly higher amongst the 6-7 years age group (61.61%-70.18%) compared to other age groups (47.9%-59.29%). There was no difference in the prevalence between the boys and girls being 56.15% and 57.55% respectively.