Intestinal protozoa are increasingly being studied because of their association with acute and chronic diarrhoea in immunocompromised as well as immunocompetent patients. Various community outbreaks due to contamination of water or food with these protozoa have further highlighted their importance in public health. Among these important pathogens are Giardia duodenalis, Entamoeba histolytica, Cryptosporidium parvum, Cyclospora cayetanensis, Isospora belli, and microsporidia. Except for the cyst-forming G. duodenalis and E. histolytica, the others are intracellular and form spores which are passed out with the faeces. These organisms are also found in various animals and birds and zoonotic transmission is thought to occur. These infections are distributed worldwide, with a higher prevalence in developing compared to developed countries. However, the relative importance of zoonotic infections especially in developing countries has not been studied in detail. The prevalence rates are generally higher in immunodeficient compared to immunocompetent patients. Higher prevalence rates are also seen in rural compared to urban communities. Most studies on prevalence have been carried out in developed countries where the laboratory and other health infrastructure are more accessible than those in developing countries. This relative inadequacy of laboratory diagnosis can affect accurate estimates of the prevalence of these infections in developing countries. However, reports of these infections in travellers and workers returning from developing countries can provide some indication of the extent of these problems. Most studies on prevalence of amoebiasis in developing countries were based on morphological identification of the parasite in faecal smears. As the pathogenic E. histolytica is morphologically indistinguishable from that of non-pathogenic E. dispar, estimates of amoebiasis may not be accurate. The epidemiology of human microsporidia infections is not completely understood. Two species, Enterocytozoon bieneusi and Encephalitozoon intestinalis, are associated with gastrointestinal disease in humans and it is believed that human to human as well as animal to human infections occur. However, the importance of zoonotic infections has not been fully characterised. G. duodenalis cysts, microsporidia and Cryptosporidium oocysts have been detected in various ground water resources, but their role in community outbreaks and maintenance of the infection has not been fully characterised. The taxonomic classification and pathogenic potential of B. hominis are still controversial. While considered by many as yeast, fungi or protozoon, recent sequence analysis of the complete SSUrRNA gene has placed it within an informal group, the stramenopiles. This review covers recent published data on these zoonotic infections and examines their public health importance in Asian countries.
Naegleria fowleri is a free-living amoeba, known as a causative agent for a fatal disease of the central nervous system (CNS) in man such as Primary amoebic meningoencephalitis (PAM). Factors contributing to its pathogenicity and its distribution in the environment have been investigated by previous researchers. In case of its pathogenicity, several enzymes such as phospolipase A and sphingomyelinase, have been proposed to probably act as aggressors in promoting PAM but no study so far have been conducted to investigate the presence of proteinase enzyme in this amoeba although a 56kDa cystein proteinase enzyme has been identified in Entamoeba histolytica as an important contributing factor in the amoeba's virulence. In this preliminary study, a pathogenic amoeba, Naegleria fowleri (strain NF3) was examined for the presence of proteinases. Samples of enzymes in this amoeba were analysed by electrophoresis using SDS-PAGE-gelatin gels. The results showed that this amoeba possesses at least two high molecular weight proteinases on gelatin gels; their apparent molecular weights are approximately 128 kDa and approximately 170 kDa. Band of approximately 128 kDa enzyme is membrane-associated and its activity is higher at alkaline pH compared with lower pH; at lower pH, its activity is greatly stimulated by DTT. The approximately 170 kDa band enzyme appears to be inactivated at pH 8.0, at lower ph its activity is higher and DTT-dependance. The activity of this enzyme is partially inhibited by inhibitor E-64 but markedly inhibited to antipain suggesting it belongs to the cysteine proteinase group.
The adulticidal activity of methanol extracts from three Malaysian plants namely Acorus calamus Linn., Litsea elliptica Blume and Piper aduncum Linn. against adult of Aedes aegypti (L.) were studied. Standard WHO bioassay tests were used to evaluate the effectiveness of these plant extracts. The hexane fraction from methanol extract of Acorus calamus rhizome was the most effective, exhibiting LC50 and LC90 values of 0.04 mgcm(-2) and 0.09 mgcm(-2) respectively. For L. elliptica, the methanol fraction also displayed good adulticidal property with the LC50 and LC90 values of 0.11 mgcm(-2) and 6.08 mgcm(-2) respectively. It is found that hexane fraction of the P. aduncum crude extract was the least effective among the three plants showing LC50 and LC90 values of 0.20 mgcm(-2) and 5.32 mgcm(-2), respectively. However, although A. calamus showed lowest LC values, the LT50 results indicated that the methanol fraction of L. elliptica was most potent extract among the extracts tested.
MeSH terms: Aedes; Methanol; Animals; Biological Assay; Culex; Hexanes; Plant Extracts; Plants; World Health Organization; Rhizome; Acorus; Calamus; Piper; Litsea
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.
Hartmannella sp is one of the free-living amoebae that have the ability to infect animal tissues because it has been found in human's nasal mucosa, dog's bronchial and turkey's intestine. Treatment for diseases inflicted by free-living amoebae is difficult because most of them infect and damage the host's tissues, so preventive measures are better to take rather than to cure the diseases. In this study, water taken from several stations namely Kampung Padang, Kampung Besut, Ibu Bekalan Setiu, Kampung Tasik, Kampung Guntung, Kampung Nyatoh, Kampung Penarik and Kampung Mangkok) along Sungai Setiu, Terengganu was examined for the presence of Hartmannella sp. The results of this study indicated that only Ibu Bekalan Setiu station was found positive to have the amoeba. Detail results on the water quality and nutrient contents measured in relation to the distribution of the amoeba at Ibu Bekalan Setiu station are presented and discussed.
This paper reviews the literature on human leptospirosis in Malaysia from its first description in 1925 until the present day. Fletcher diagnosed the first case of human leptospirosis in Malaysia in 1925. Following Fletcher, many investigations on human leptospirosis in Malaysia disclosed a high prevalence of infection. These investigations indicated that the disease was endemic in the country. Examination of 1993 suspected human cases of leptospirosis by Tan indicated 28 % of the cases were positive. In a recent survey, 2190 serum samples from patients with different clinical manifestations in the country disclosed 12.6% were positive for antibodies to leptospires. The risk to leptospiral infection with respect to occupation, location, sex, race and age groups was demonstrated. Both civilians and military personnel were affected. Thirty-seven serovars from thirteen serogroups have been identified in the country. Recent studies on animal leptospirosis showed that the disease was highly endemic in the animal population. It is considered that the majority of leptospirosis cases in humans were due to association of man with animals and disease-infected environment.
MeSH terms: Animals; Animal Population Groups; Humans; Leptospira; Leptospirosis; Malaysia; Male; Military Personnel; Occupations; Surveys and Questionnaires; Risk; Prevalence; Serogroup
Pseudorabies (Aujeszky's disease) is an economically significant disease of swine known to cause central nervous disorders, respiratory disease, reproductive failure and mortality in infected pigs. In attempts to eradicate the disease from becoming endemic, early detection is important to prevent further economic losses and to allow for detection and removal of infected pigs in domestic herds. Thus, a rapid and sensitive technique is necessary for the detection of the virus. For rapid and simple examination, an immuno - chromatographic lateral - flow assay system based on immunologic recognition of specific pseudorabies virus antigen was developed by utilising, as signal generator, colloidal gold conjugated to secondary antibody to detect primary or sample antibody in the sera of pseudorabies infected animals. The pseudorabies virus used as a capture antigen in the test strip was first cultivated in VERO cell culture and then purified by sucrose gradient separation to produce the viral protein concentration of 3.8 mg/ml. The standard pseudorabies antigens reacted well with the hyperimmune serum (HIS). The antibody detection system is basically composed of colloidal gold - labelled antibodies fixed on a conjugate pad, and the complementary pseudorabies antigen immobilised onto a nitrocellulose membrane forming capture zone. If the target antibody is present in a specimen, the colloidal gold-labelled antibody will form a complex with the antibody sample. Subsequently, the formed complex will migrate to the capture zone and is then bound to the solid phase via antigen - antibody interaction. As a result, a signal marker is generated by the accumulation of colloidal gold for detection confirmation. The results obtained demonstrated that the optimum combination of pseudorabies antigen needed as the capture reagent and gold conjugate as secondary antibody recognition marker was at a concentration of 0.38mg/ml and at 1:10 dilution factor respectively. The sensitivity of the solid - based test strip towards pseudorabies antibodies was high with a detection limit of 1 to 10,000 - dilution factor. The specificity of the assay was 100% with no cross - reaction being observed with other sera or antibodies. Accurate reading time needed for confirmation of the assay can be completed in 5 min with a whole blood sample of 25 microl. The colloidal gold - labelled antibody is stable at room temperature for 6 months or more (data not shown). Findings from this study indicated that the solid - based test strip assay system provided high sensitivity and specificity for the detection of pseudorabies at low levels of antibody concentration. The assay was rapid, simple, cheap, and does not require any sophisticated equipment. Thus, the solid based test strip will be a useful serological screening technique or for rapid diagnosis of an infectious disease in target populations of animals characterised by heterogeneous antibody responses.
Acanthamoeba is an uncommon cause of keratitis but one of the most severe because of the prolonged and painful course of the disease and poor visual outcome. Although contact lens use is the principal risk factor, about 10% of cases occur following trauma and exposure to contaminated soil or water. Two cases of Acanthamoeba keratitis involving women contact lens wearers have previously been reported in Malaysia but this is the first time, a non contact lens related Acanthamoeba keratitis is reported. The case involved a 28 year old Indonesian male construction worker who had a trauma of the right eye during work. His eye was struck by sand and dust particles after which he quickly washed with water from an open tank at the construction site. He experienced pain, redness, glaring and blurring of vision of the right eye three days later. The diagnosis was missed at initial presentation but culture of the corneal scraping had proven Acanthamoeba as the aetiological agent. The history and clinical findings of this trauma related Acanthamoeba keratitis are briefly discussed.
The crude methanol extracts of Gelsemium elegans leaves were assessed for their cytotoxic activity using the microculture 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay for cellular viability. This study utilized two different types of human cancer cell lines, CaOV-3 (human ovarian cancer cells) and MDA-MB-231 (human estrogen receptor negative breast cancer cells), allowing for comparison of toxicity of G. elegans against these two cancer cells lines. Our results showed that the methanol extract of G. elegans exhibited high cytotoxicity against the human ovarian cancer cell line CaOV-3 with an IC50 value of 5microg/ml after 96 h incubation. However, G. elegans displayed discernibly less toxicity against the MDA-MB-231 cells with an IC50 value 40microg/ml after 96 h incubation and this effect was dose- and time-dependent, up to 72h and 20-30 microg/ml. In conclusion, our results demonstrated that G. elegans is potently cytotoxic against the human ovarian cancer cell line CaOV-3 and to a lesser extend towards the human breast carcinoma cancer MDA-MB-231 cells, suggesting that the extract is selective towards CaOV-3 cells and may have a chemotherapeutic role for ovarian cancer treatment in the future.
Tick-borne encephalitis (TBE) is a viral infection of the central nervous system and is caused by tick bites, usually after travel to rural or forested areas. The disease is prevalent in Scandinavia, Western Europe, Central Europe and the former Soviet Union and East Asia including Japan. In Malaysia, so far there are no reported cases of TBE. In the present time, many illnesses have been attributed to traveling to other parts of the world. Thus it is important to carry out TBE prevalence study to determine whether the virus is present among Malaysian population. Samples (sera and CSF) from patients admitted to major MOH hospitals in Peninsular Malaysia and Sabah with a clinical diagnosis of encephalitis but is IgM negative for JE, were tested for TBEV IgM ELISA and TBEV IgG ELISA (DRG, Germany). Out of the 600 samples screened for TBEV IgG, all were non-reactive. In addition, out of the 100 samples screened for TBEV IgM, all the samples were also non-reactive. Our results indicate that currently TBE is not present in the Malaysian population. Among the reasons for this could be lack of the infection agent, absence of the suitable vector or subjects selected for the study did not fit the criteria of possible exposure to TBE infections. Hence we recommend that for any future study, the selection of subjects should include those who returned from tick-infested forested areas.
A survey was carried out to determine the prevalence of Toxoplasma gondii antibodies among cattle farmers and cattle in the Gombak District, Selangor. A total of 79 human and 73 cattle serum samples were tested for Toxoplasma gondii antibodies by the immunofluorescent technique (IFAT). Results of the survey showed that anti-Toxoplasma gondii antibodies were found in 27.8% of the farmers, while in cattle the positive rate was only 3.8%. The prevalence rate obtained in this study did not differ much from the prevalence reported in previous studies. This suggests that the same degree of risk to this infection exists in the community. In view of the relatively low antibody prevalence in cattle, the risk of acquiring this infection from consuming undercooked beef is realtively low. Further survey on larger sample size is needed to validate the observation.
MeSH terms: Farmers; Red Meat; Animals; Antibodies, Protozoan; Cattle; Humans; Surveys and Questionnaires; Toxoplasma; Prevalence; Sample Size
MeSH terms: Asia; Body Weight*; Health Promotion*; Humans; Life Style*; Malaysia; Obesity/prevention & control; School Health Services; Program Evaluation; Weight Loss; Oceania; Overweight
An analysis is presented of psychiatric research interviews conducted among the Iban, a longhouse dwelling people of Sarawak, Malaysia. It draws on transcripts of interviews recorded in the course of carrying out research into schizophrenia in this group. The article examines three different interview spaces within the longhouse--public, family, and private--in order to explore the interplay between ethnographic context and interview conversation. The public setting is notable for the number of relatives who join in and transform the communication from dyadic to collective interlocution; the role of repetition in recruiting them into the conversation is explored. Indirect contrast is the private space, which allows for a level of confidentiality commensurate with Western psychiatric research practice. Intermediate between the two is the family space. The communicative forms that correspond to these settings influence the way symptoms of schizophrenia are experienced and expressed in the Iban. Implications for the practice of psychiatry cross-culturally are examined.
Six new indole alkaloids, viz., (3S)-3-cyanocoronaridine (2), (3S)-3-cyanoisovoacangine (3), conolobine A (5), conolobine B (6), conolidine (7), and (3R/3S)-3-ethoxyvoacangine (8), in addition to 36 known ones, were obtained from the stem-bark extract of the Malayan Tabernaemontana divaricata. The structures were determined by NMR and MS analysis. The CN-substituted alkaloids showed appreciable cytotoxicity towards the KB human oral epidermoid carcinoma cell-line.
A survey was conducted to investigate the relationship between job satisfaction and job factors that affect work design in two automotives manufacturing companies in Malaysia. A set of multiple choices questionnaires was developed and data were collected by interviewing the employees at the production plant. Hundred and seventy male subjects between the ages of 18 to 40 years with the mean age of 26.8 and SD of 5.3 years and mean work experience of 6.5 and SD of 4.9 years took part in the survey. The survey focused on job factors, i.e. skill variety, task identity, task significance, autonomy and feedback. The results support the previous findings that job factors are significantly correlated to job satisfaction. Furthermore, it also highlights the significant influence of age, work experience and marital status.
MeSH terms: Adolescent; Adult; Age Factors; Automobiles*; Humans; Interviews as Topic; Job Satisfaction*; Malaysia; Male; Psychology, Industrial*; Surveys and Questionnaires; Task Performance and Analysis; Workplace/psychology*; Marital Status; Organizational Case Studies
The reactions of 2-chloropyrimidine with methylamine, ethylamine and piperidine gave the corresponding 2-N-methylamino-, 2-N-ethylamino- and 2N- piperidinopyrimidines, respectively. The fluorescence properties of these alkylamino derivatives in chloroform, ethyl acetate, carbon tetrachloride, acetone, ether, ethanol and methanol were studied. All the alkylamino derivatives showed the highest fluorescence intensity in polar protic solvents; thus 2-N-methylaminopyrimidine (highest fluorescence intensity at 377 nm when excited at 282 nm) and 2-N-ethylaminopyrimidine (highest fluorescence intensity at 375 nm, when excited at 286 nm) showed the highest fluorescence in methanol. In ethanol, 2-N-piperidinopyrimidine showed a fluorescence peak at 403 nm when excited at 360 nm and in chloroform it fluoresced at 392 nm when excited at 356 nm.
MeSH terms: Forms and Records Control/standards*; Hospital Information Systems/standards*; Humans; Malaysia; Medical Record Linkage/standards*; Time Factors; Efficiency, Organizational; Information Management/standards*; Organizational Case Studies
A cross-sectional study to assess job strain and its associated factors among lecturers of the School of Medical Sciences, Universiti Sains Malaysia (USM) and Faculty of Medicine, Universiti Kebangsaan Malaysia (UKM) was undertaken between August 2001 and May 2002. The original English version of the Job Content Questionnaire (JCQ) version 1.7 (revised 1997) by Robert Karasek based on the Job Strain Model was self-administered to 73 (response rate 58.4%) and 80 (response rate 41.7%) lecturers in the medical faculties of USM and UKM respectively. The prevalence of job strain (defined by low decision latitude and high psychological demand) in USM and UKM was 23.3% and 17.5%, respectively; the difference was not significant (p 2 0.05). Analysis showed that the associated factors of job strain in USM lecturers were psychological stressors (adjusted OR 1.2, 95% CI: 1.0, 1.4), created skill (adjusted OR 0.4, 95% CI: 0.2, 0.8), working in clinical-based departments (adjusted OR 18.9, 95% CI: 1.6, 22.7). The risk factors of job strain in UKM lecturers were created skill (adjusted OR 0.3, 95% CI: 0.1, 0.9), psychological stressors (adjusted OR 1.2, 95% CI: 1.0, 1.5) and co-worker support (adjusted OR 0.3, 95% CI: 0.1, 0.9). We conclude psychological stressors and created skill were nonprotective and protective, respectively, against job strain in both USM and UKM lecturers.
70 patients presented with acute asthma exacerbation requiring nebulised bronchodilator treatment at the emergency department of a teaching hospital in Kuala Lumpur, Malaysia, were interviewed over a two-week period in July 2001. The results showed that 45 (64%) patients had not been educated on the nature of asthma; 30 (43%) had not been advised on preventive measures or avoidance of triggers; 54 (77%) were not advised about the medications used and their side effects; 42 (60%) patients did not know the difference between reliever and preventive medications; 37 (53%) were unable to recognize features of worsening asthma and 68 (97%) were not told about the danger of non-prescribed self-medication or traditional medications. Only six (9%) patients were using peak flow meters and were taught self-management plans. The multiple regression results suggest that patients who were followed up at teaching hospital based clinics were better educated on asthma. In conclusion, asthmatic patients are still not educated well about their disease. Health care providers need to put more emphasis on asthma education so that the number of emergency room visits can be reduced.
Study site: Emergency department, University Malaya Medical Centre, Kuala Lumpur, Malaysia
Alkylphenols and most pesticides, especially organochlorine pesticides are endocrine-disrupting chemicals and they usually mimic the female hormone, estrogen. Using these chemicals in our environment would eventually lead us to consume them somehow in the food web. Several rivers in the State of Selangor, Malaysia were selected to monitor the level of alkylphenols and pesticides contamination for several months. The compounds were extracted from the water samples using liquid-liquid extraction method with dichloromethane and ethyl acetate as the extracting solvents. The alkylphenols and pesticides were analyzed by selected ion monitoring (SIM) mode using the quadrapole detector in Shimadzu QP-5000 gas chromatograph-mass spectrometer (GCMS). Recovery of most alkylphenols and pesticides were in the range of 50% to 120%. Trace amounts of the compounds were detected in the river water samples, mainly in the range of parts per trillion. This technique of monitoring the levels of endocrine-disruptors in river water is consistent and cost effective.
MeSH terms: Malaysia; Pesticides/analysis*; Phenols/analysis*; Water Pollutants, Chemical/analysis; Rivers/chemistry*