Dengue infection is a major public health problem affecting millions of people living in tropical countries. With no suitable vaccines and specific antiviral drugs, treatment for dengue is usually symptomatic and supportive. Early diagnosis and recognition of severe disease is therefore crucial for better management of the patient. Two-dimension electrophoresis was used to identify disease-associated proteins that can be used for diagnosis and as drug targets for treatment. Two markers, identified by mass spectrometry analysis as alpha1-antitrypsin and NS1 proteins were found to be upregulated in dengue fever (DF; n=10) and dengue haemorrhagic fever (DHF; n=10) patients compared with healthy individuals (n=8). Both alpha1-antitrypsin and NS1 proteins were overexpressed two-fold in DHF patients compared with DF patients. Our study suggests that alpha1-antitrypsin and NS1 protein could be used as biomarkers as early indicators of DHF risk among patients with suspected dengue infection.
Helicobacter pylori infection is recognized as being strongly associated with chronic gastritis, duodenal ulceration and, probably, gastric carcinoma. Seroepidemiological studies have shown that a large proportion of healthy people have antibodies against H. pylori. A serological study was conducted in asymptomatic healthy blood donors in Northern Peninsular Malaysia to assess the seropositivity for H. pylori and to investigate the relationship with ethnic group, gender, ABO blood group and age. A total of 5370 serum samples collected from 3677 male and 1693 female donors in different age groups, and who had no gastrointestinal complaints, were studied with an in-house ELISA for the presence of H. pylori IgG and IgA antibodies. Seven hundred and sixty subjects (14.2%) were seropositive. The overall seropositivity did not differ with ethnicity, gender, ABO blood group and age among asymptomatic healthy blood donors in Northern Peninsular Malaysia.
An observational study was carried out to establish the existence of intestinal microsporidiosis among patients with and without gastrointestinal symptoms in Hospital Universiti Kebangsaan Malaysia, Malaysia. A total of 893 faecal specimens from hospitalized patients were examined for microsporidia using a modification of the usual Gram-chromotrope stain technique. One hundred and sixteen (13.0%) patients were positive for microsporidia: 84 (72.4%), 27 (23.3%) and 5 (4.3%) were low, moderate and high excreters of microsporidia spores, respectively. Of the 91 patients with available medical records, microsporidiosis was commonly observed in children aged 0-6 years (26.4%) and adults aged >or=31 years (57.2%). About one-third of this infection was observed in immunocompetent individuals. Among the immunosuppressive group, microsporidia were observed to be more prevalent in patients with haematological malignancy or a combination of malignancy and diabetes mellitus. About 74% of the patients who had microsporidia in their faeces had gastrointestinal symptoms, which could be related to infections or induced by immunosuppressive therapy. The role of microsporidia in causing gastrointestinal symptoms in this population is as yet unclear.
HeIicobacter pylori infection rate was determined in 697 consecutive patients with ulcer, gastritis, duodenitis and non-ulcer dyspepsia by endoscopy at a Malaysian hospital in 1999-2002. Biopsies of the gastric antrum and body were subjected to the urease test, Gram staining of impression smears and culture examination. Infection was defined as a positive result in at least one test. The infection rates were 32.1, 10.4, 20.0 and 16.2% in ulcer, gastritis, duodenitis and non-ulcer dyspepsia patients, respectively. Overall, the prevalence of H. pylori infection was 14.6%, with the rate among the Indian (21.7%), Chinese (19.2%) and Bangladeshi foreign worker (23.1%) groups significantly higher (P<0.05) than that of the Malays (5.8%). Generally, the prevalence rate among males (18.9%) was significantly higher (P<0.001) than that among females (9.0%), but for a particular ethnic group, such trend and significant differences (P<0.05) were observed only among the Malays. In terms of gender, the prevalence rates of Malay males and females were also significantly lower (P<0.05) than those of Chinese and Indians. In conclusion, there is a significant difference in H. pylori infection prevalence rates among ethnic groups (highest in Indians, then Chinese and unusually low in Malays) and gender groups (highest in males) in Malaysia.
A cross-sectional study to determine the current prevalence of anaemia and iron deficiency anaemia (IDA) and to investigate the possible risk factors for IDA was carried out on 241 aboriginal schoolchildren (120 boys, 121 girls) aged 7-12 years and living in remote areas in Pos Betau, Pahang, Malaysia. Haemoglobin (Hb) level was measured and serum iron status was assessed by serum ferritin (SF), serum iron (SI) and total iron binding capacity measurements. Socioeconomic data were collected using pre-tested questionnaires. All children were screened for intestinal parasitic infections. Overall, 48.5% (95% CI 42.3-54.8) of children were anaemic (Hb<12 g/dl). The prevalence of IDA was 34% (95% CI 28.3-40.2), which accounted for 70.1% of the anaemia cases. The prevalence of IDA was significantly higher in females than males. Low levels of mothers' education and low household income were identified as risk factors for IDA. Severe trichuriasis also found to be associated with low SF and SI. Logistic regression confirmed low levels of mothers' education and gender as significant risk factors for IDA. Improvement of socioeconomic status and health education together with periodic mass deworming should be included in public health strategies for the control and prevention of anaemia and IDA in this population.
This study was conducted to reassess the risk factors for giardiasis in communities of the Orang Asli (indigenous people) in Pahang, Malaysia. Stool samples were collected from 321 individuals (2-76 years old; 160 males, 161 females). Data were collected via laboratory analysis of faecal samples and a pre-tested standard questionnaire. River water samples were tested for Giardia cysts and Cryptosporidium oocysts. The overall prevalence of G. intestinalis infection was 23.7%. Children < or =12 years old had the highest infection rate and have been identified as a high risk group (odds ratio (OR)=6.2, 95% CI 1.5-27.0, P<0.005). The risk of getting giardiasis also appeared to be significantly associated with drinking piped water (OR=5.1, 95% CI 0.06-0.7, P<0.005) and eating raw vegetables (OR=2.4, 95% CI 0.2-0.6, P<0.005). In conclusion, sociodemographic factors have always been associated with the high prevalence of Giardia infections in Malaysia. However, the present study also highlights the need to look into the possibility of other risks such as water and food transmission routes. In future, it is necessary that these two aspects be considered in control strategies.
Vitamin A deficiency and malnutrition are still considered public health problems in rural areas of developing countries, including Malaysia. A cross-sectional exploration study was carried out on 281 Orang Asli (Aborigine) children aged between 2 and 15 years in Selangor, Malaysia. The overall prevalence of low serum retinol (<70 micromol/l) and hypoalbuminaemia (<35 g/l) were 25.2 and 7.8%, respectively. Univariate analysis showed that severe ascariasis, significant stunting and giardiasis were significantly associated with low concentration of serum retinol. As well as intestinal parasitic infections, low socio-economic status was a significant predictor of hypoalbuminaemia. Logistic regression analysis identified severe ascariasis and significant stunting as predictors of low serum retinol, while mixed intestinal parasitic infection and low household income were predictors of hypoalbuminaemia. In conclusion, control measures for intestinal parasitic infections should be included as one of the strategies for the prevention and control of malnutrition and vitamin A deficiency in this population.
Helicobacter pylori is one of the few remaining major pathogens that accompanied humans on their travels from Africa. A recently published study reports the unexpected finding of a low H. pylori prevalence among pregnant women in Zanzibar (Farag, T.H., Stolzfus, R.J., Khalfan, S.S., Tielsch, J.M., 2007. Unexpectedly low prevalence of Helicobacter pylori infection among pregnant women on Pemba Island, Zanzibar. Trans. R. Soc. Trop. Med. Hyg. 101). The apparent epidemiology of higher prevalence with higher socioeconomic status and decrease with age are unprecedented. As with many 'unexpected' events, a search of the literature reveals evidence of low prevalence populations in Java and Malaysia, with clues dating back to the mid-twentieth century. Why some populations apparently lost H. pylori infection remains an open question. However, the tools needed to resolve the dilemma are readily available and we hope investigators will soon rise to the challenge.
Four species of malaria parasites are known to infect humans. A fifth species, Plasmodium knowlesi, has been reported to infect humans in Malaysian Borneo. Here we report for the first time the incrimination of Anopheles latens as the vector of P. knowlesi among humans and monkeys in Sarawak, Malaysia.
This study evaluates and discusses the impact of the rural health improvement scheme in reducing the incidence of dysentery, enteric fever, cholera and viral hepatitis in Sarawak, Malaysia, using data compiled from state and federal health department reports. This study suggests that from 1963 to 2002, water supply intervention contributed to a more than 200-fold decrease in dysentery and a 60-fold decrease in enteric fever. Variations in reporting of viral hepatitis during that period make it difficult to detect a trend. Cholera was still endemic in 2002. Cholera and dysentery outbreaks, occurring when rural populations relied on contaminated rivers for their water supply, suggested that sanitation intervention was not as effective in reducing waterborne diseases. Recommendations are made for successive one-component interventions focusing on catchment management to ensure protection of current and alternative water supplies.
A pair of Mammomonogamus laryngeus roundworms in copula was recovered from the duodenum of a 72-year-old male Thai patient from Kanchanaburi Province. Eggs were also found in the stool of the patient. This is the first case of Mammomonogamus infection originating in Thailand, as the previous two reports from Thailand attributed the infection as originating in Malaysia. The occurrence of adult worms in the duodenum is unusual and differs from previous findings in the larynx, posterior pharynx, tracheal wall and bronchi. This adds a new dimension to the manifestation of the infection.
Surveys were conducted in malaria-endemic villages in the southern province of Attapeu, Lao PDR during various seasons over a 3-year period. All-night mosquito landing collections, blood surveys and a case-control study were conducted. Plasmodium falciparum was the predominant species, and slide positivity rates were higher during the transition/dry season compared with the wet season. Anopheles dirus A was found to be the primary vector, and sporozoite rates were highest during the transition/dry season. Anopheles dirus was found to be endophagic and endophilic. Not using insecticide-treated bed nets, houses close to breeding sites and sleeping away from home were risk factors associated with malaria.
A cross-sectional study to examine the association of giardiasis with protein-energy malnutrition, vitamin A deficiency and iron deficiency anaemia was conducted among Orang Asli children in Selangor, Malaysia. A total of 281 children aged 2-15 years were studied. The data were collected using structured questionnaires, anthropometric measurements and laboratory analysis of blood and faecal samples. The results showed that 24.9% of the children were infected with Giardia duodenalis, while 56.5, 61.3 and 15.1% had significant underweight, stunting and wasting, respectively. Giardiasis was statistically identified as a strong predictor of significant wasting in this study population.
The amino acid sequences of the envelope (E) protein of four encephalitogenic and five non-encephalitogenic dengue 3 virus strains isolated in Malaysia were determined and compared. Multiple sequence alignment revealed a high degree of similarity in the E protein of the strains suggesting that neurovirulence of these four encephalitogenic strains is not attributed to this protein.
A total of 753 serum samples from 6 institutions in 3 countries (Malaysia, Indonesia and India) were used to evaluate an immunochromatographic rapid dipstick test, Brugia Rapid, for diagnosis of Brugia malayi infection. The samples comprised sera from 207 microfilaria-positive individuals and 546 individuals from filaria non-endemic areas. The latter consisted of 70 individuals with soil-transmitted helminth infections, 68 with other helminth infections, 238 with protozoan infections, 12 with bacterial and viral infections and 158 healthy individuals. The dipstick is prepared with a goat anti-mouse antibody control line and a B. malayi recombinant-antigen test line. First, the dipstick is dipped into a well containing diluted patient serum, thus allowing specific anti-filarial antibody in the serum to react with the recombinant antigen. Then the dipstick is placed into an adjacent well containing reconstituted anti-human IgG4-gold. After 10 min, development of 2 red-purplish lines denotes a positive result and one line indicates a negative reaction. The overall results of the evaluation showed 97% sensitivity, 99% specificity, 97% positive predictive value and 99% negative predictive value. Brugia Rapid is thus a promising diagnostic tool for detection of B. malayi infection, and would be especially useful for the brugian filariasis elimination programme.
An IgG4 ELISA based on a novel recombinant antigen was evaluated for detection of Brugia malayi infection, using 2487 sera from various institutions: 2031 samples from Universiti Sains Malaysia, 276 blinded sera from 2 other institutions in Malaysia, 140 blinded sera from India and 40 blinded sera from Thailand. These sera were from various groups of individuals, i.e., microfilaraemics, chronic patients, endemic normals, non-endemic normals and individuals with other parasitic and bacterial infections. Based on a cut-off optical density reading of 0.300, the IgG4 ELISA demonstrated specificity rates of 95.6-100%, sensitivity rates of 96-100%, positive predictive values of 75-100% and negative predictive values of 98.9-100%. These evaluation studies demonstrated the high specificity and sensitivity of this test for the detection of active B. malayi infection. Thus, the IgG4 ELISA would be very useful as a tool in diagnosis and in elimination programmes for brugian filariasis.
The Helicobacter pylori infection rate was determined in 124 consecutive patients with duodenal ulcers (DU), gastric ulcers (GU), duodenal erosions or gastric erosions diagnosed by endoscopy at a single institution in north-eastern peninsular Malaysia in 1996-97. Biopsies of the gastric antrum and body were subjected to the urease test, Gram staining of impression smears, culture and histopathological examination. Serology was undertaken on all patients using a locally validated commercial kit. Infection was defined as a positive result in at least one test. The infection rates were 20% (10/50), 21.2% (7/33), 16.7% (1/6) and 17.1% (6/35) in DU, GU, duodenal erosion and gastric erosion patients, respectively. The infection rate among Malays [7.0%, (6/86)] was lower than in non-Malays [47.4% (18/38)] (P < 0.001). There was a higher infection rate among males, who constituted 62.1% (77/124) of the sample. Seventy-eight patients (62.9%) were receiving non-steroidal anti-inflammatory drugs (NSAIDs) and 33 patients (26.6%) were neither receiving NSAIDs nor were infected with H. pylori. The H. pylori infection rate among peptic ulcer patients in this predominantly Malay rural population appears to be the lowest reported in the world thus far. Empirical H. pylori eradication therapy in peptic ulcer patients is clearly not indicated in this community. The possible reasons for the low prevalence of H. pylori infection are discussed.
A serosurvey was conducted in 1995-97 among 1596 febrile patients from 8 health centres in Malaysia for antibodies against Orientia tsutsugamushi (OT), Rickettsia typhi (RT) and TT118 spotted fever group rickettsiae (SFGR) by using an indirect immunoperoxidase assay. A total of 51.4% patients had antibody against at least 1 of those rickettsiae. Antibody to SFGR was most prevalent (42.5%), followed by RT (28.1%) and OT (24.9%). The seroprevalences of antibodies to SFGR, RT or OT alone were 12.4, 3.6 and 4.3%, respectively. Antibodies against more than 1 species of rickettsiae were presence in 31.1% of the patients, suggesting the possibility of co-infection, previous exposures or serological cross-reactivities. Seroprevalence of the various rickettsiae varied according to locality, with SFGR antibodies being the most prevalent in most areas. There was no significant association of prevalence of rickettsial antibody with gender. The seroprevalence of OT, SFGR and RT increased with patient age but an increase of antibody titre with age was not significant. Those working in the agricultural sectors had significantly higher seroprevalence of OT, SFGR and RT than those not related with agricultural activities. Scrub typhus remains a public health problem with an estimated annual attack rate of 18.5%. Tick typhus and murine typhus as shown in this serosurvey appear much more widespread than scrub typhus in this country.