A review of concurrent infections of malaria and dengue in Asia

Concurrent infections of malaria and dengue are when both of these mosquito-borne diseases occur simultaneously in an individual. In this review, reported cases with these co-infections in Asia are discussed. The focus is on the overlapping clinical presentations and the difficulties encountered in differential diagnosis. Also, cases reported in some special conditions, viz., pregnancy, foetal infections, and co-infections with one or more other infectious agents are highlighted. Due to similar clinical presentations of malaria and dengue, these co-infections may give rise to an incorrect diagnosis. Moreover, the treatment regimens for these co-infections are not the same as those for mono-infections. Hence, a delay in implementing the appropriate treatment regimen for these concurrent infections due to poor diagnosis can be fatal. The present review is intended to increase awareness about the clinical significance and the importance of these co-infections among clinicians, public health workers and health authorities in the Asian region. Though malaria-dengue concurrent infections are seldom reported from the Asian region, it is probably increasing particularly in the countries known to be endemic for both of the above diseases. A compulsory reporting of the incidences of malaria-dengue concurrent infections is recommended.

Epidemiological Characteristics of Strongyloidiasis in Inhabitants of Indigenous Communities in Borneo Island, Malaysia

Epidemiological study on strongyloidiasis in humans is currently lacking in Malaysia. Thus, a cross-sectional study was carried out to determine the prevalence of Strongyloides stercoralis infection among the inhabitants of longhouse indigenous communities in Sarawak. A single stool and blood sample were collected from each participant and subjected to microscopy, serological and molecular techniques. Five species of intestinal parasites were identified by stool microscopy. None of the stool samples were positive for S. stercoralis. However, 11% of 236 serum samples were seropositive for strongyloidiasis. Further confirmation using molecular technique on stool samples of the seropositive individuals successfully amplified 5 samples, suggesting current active infections. The prevalence was significantly higher in adult males and tended to increase with age. S. stercoralis should no longer be neglected in any intestinal parasitic survey. Combination of more than 1 diagnostic technique is necessary to increase the likelihood of estimating the ‘true’ prevalence of S. stercoralis.

Epidemiological Characteristics of Strongyloidiasis in Inhabitants of Indigenous Communities in Borneo Island, Malaysia

Epidemiological study on strongyloidiasis in humans is currently lacking in Malaysia. Thus, a cross-sectional study was carried out to determine the prevalence of Strongyloides stercoralis infection among the inhabitants of longhouse indigenous communities in Sarawak. A single stool and blood sample were collected from each participant and subjected to microscopy, serological and molecular techniques. Five species of intestinal parasites were identified by stool microscopy. None of the stool samples were positive for S. stercoralis. However, 11% of 236 serum samples were seropositive for strongyloidiasis. Further confirmation using molecular technique on stool samples of the seropositive individuals successfully amplified 5 samples, suggesting current active infections. The prevalence was significantly higher in adult males and tended to increase with age. S. stercoralis should no longer be neglected in any intestinal parasitic survey. Combination of more than 1 diagnostic technique is necessary to increase the likelihood of estimating the ‘true’ prevalence of S. stercoralis.

The chemical, heavy metal and microbial quality of well water in an urbanised village in the Klang Valley

Background: The public health issue of consuming groundwater is a major concern because people often extract groundwater directly from the aquifers either through wells or boreholes without treating it with any form of filtration system or chlorine disinfection. Based on the Malaysian National Drinking Water guidelines the current study was designed to provide a better understanding on the variable factors that are influencing the quality of well-water in an urbanised village in Malaysia. Well water quality assessment of heavy metals, chemicals, microbial and physical parameters were carried out for Sungai Buloh Village in the Klang Valley to ensure it was safe for human consumption. Materials and Methods: Water samples were collected from wells at four sites (Sites A,B,C,D), a river and a tap inside a house in Sungai Buloh village. Soil was sampled from the riverbed and area surrounding the wells. Samples were collected every two months over a one year duration from all sites. The water samples were processed and examined for viruses, coliforms and protozoa as well as for heavy metal contaminants. Results: The turbidity and colour ranged in the average of 0.57-0.13 Nephelometric Turbidity (NTU) and 4.16- 5.00 Total Conjunctive Use (TCU) respectively for all sites except Site C. At Site C the turbidity level was 2.56 ± 1.38 NTU. The well-water was polluted with coliforms (1.2 to 2.4 x 10 3 CFU/100 ml) in all sites, E. coli (0.12 - 4 x 10 2 CFU/100 ml CFU/ 100 ml) and Cryptosporidium oocysts (0.4 cysts/100 ml). All the heavy metals and chemical parameters were within the Malaysian Guidelines’ limits except manganese. The average pH ranged from 5.44 - 6.62 and the temperature was 28 ºC. Conclusion: In summary, the well water at Sungai Buloh is considered unsafe for consumption due to pollution. Therefore the major thrust will be to provide better quality of drinking water to the residents of the village.

Phylogenetic analysis and identification of Sarcocystis spp. found in rodents in Peninsular Malaysia

Background: The tissue specimens used for extraction of DNA in this study were from rodents trapped in four states in Peninsular Malaysia, namely Kedah, Kelantan, Selangor and Johor. Methods: Histological sections of these rodent muscle tissues stained with hematoxylin and eosin showed infection with Sarcocystis spp. Based on these results, the current study was carried out to determine the phylogenetic relationship among the identified Sarcocystis spp. in these rodents. The formalin fixed paraffin embedded (FFPE) rodent muscle blocks were subjected to DNA extraction and followed with semi nested PCR targeting 5’ and 3’ regions of 18S rRNA of Sarcocystis spp. Results: Phylogenetic analysis showed two distinct groups of Sarcocystis spp. among the rodents in Peninsular Malaysia. Most of the identified Sarcocystis spp. were genetically closely related to Sarcocystis rodentifelis and Sarcocystis muris and were also observed to be genetically closely related to Sarcocystis sp. ex Columba livia and Sarcocystis sp. cyst type I ex Anser albifrons. Conclusion: Further classification to confirm these Sarcocystis spp. was not possible as only partial sequences of 18S rRNA was available and this was insufficient for optimal differentiation.

The importance of data in developing environmental health guidelines – an IMU perspective

The global environment is in a dynamic flux due to rapid development. As a result of this, new diseases are emerging and old diseases are re-emerging in many parts of the world. Therefore there is a constant need for appropriate data for formulation of effective policies to mitigate the adverse effects of environmental degradation on human health. The Kyoto Protocol of 1997 is a milestone that sets the direction for good environmental management initiatives and the success of this depends on good data. Malaysia currently has the Environmental Quality Act 1974 in place to control environment related problems. However good guidelines must be developed to keep the initiatives for good environmental management on course, for this we need good data. The Centre for Environmental and Population Health at IMU, coordinates research activities in specific thrust areas in an endeavour to produce important data that is required for developing appropriate guidelines for environmental health.

Climate change and its impact on public health – A review of the global environment

Climate change is a product of human actions. The extreme events such as flash floods, droughts, heat waves, earthquakes, volcano eruptions and tsunamis seen in the world today are the result of indiscriminate human intrusion into the environment. Vulnerable countries and populations are the most affected by these climatic events. This places a burden on the resources of these countries. The Kyoto Protocol is a milestone in environmental management and the impetus created by it must be maintained by carrying out the much needed research into appropriate mitigating measures that will alleviate the climate change impact globally. A paradigm shift is needed in addressing the associated risks on human health to assess socioeconomic determinants and the related impacts on disease burden. Some wealthy nations emphasize economic benefits and downplay sustainability goals, health and equality. However the rising cost of energy is beginning to influence their outlook towards this issue. The implications on economics, human health and wellbeing are implicit. In order to strike a balance between disadvantaged and privileged nations, many international agencies are spearheading various research agenda to improve adaptation programmes on effects of changing climatic conditions on health. Malaysia too has such programmes initiated under its 5-year development plans.

Prevalence of Sarcocystis spp. in rodents in Peninsular Malaysia

The aim of the study was to assess the prevalence of Sarcocystis infection in wild and peri-urban rodents in some states in Peninsular Malaysia. The thigh muscle from these rodents were formalin preserved, sectioned and stained with hematoxylin and eosin and examined under light microscopy. Of the 146 muscle tissue examined only 73 were positive for Sarcocystis infection. Morphological identification showed the presence of some new morphological types to be present. Different species of Sarcocystis were seen in the sections but more extensive studies are needed to identify them to species level.

Validation of ICD 10 on congenital anomalies in the state of Penang

Background: Database on hospital records like discharge data, birth and death certificates are widely used for epidemiological and research studies. However there are a very few validation studies on these data. The aim of this study was to validate and assess the accuracy of the ICD 10 database on congenital anomalies in the state of Penang. This study was carried out for three years, from 2002 to 2004. Methods: The list of cases coded under the general coding “Q” was extracted and approximately 30% of cases were randomly selected from the list. Medical records for the selected cases were checked and discrepancies for the diagnoses between the medical records and the ICD 10 data base were recorded for three years. Verification was done for basic demographic variables and the coding of the diseases. Discrepancies, sensitivity and specificity were calculated. Results: The ICD 10 database for congenital anomalies are classified into two types: Type 1 and Type 2. Discrepancies on demographic information were found among the age of patients (babies with congenital anomalies). In Type 1, there was a discrepancy of about 0.02 % to 0.05% probability that a congenital anomaly case can be recorded as non congenital anomaly in the ICD 10. In Type 2 there was a discrepancy that a non-congenital anomaly was classified as congenital anomaly and this ranged from 26.7% to 50.0%. The sensitivity ranged from 96.85% to 97.98%, thus it can be concluded the ICD 10 database is highly sensitive while the specificity ranged from 50.00% to 78.57 %. In other words the ICD 10 is not accurate when classifying the non- congenital anomaly cases. A fair percentage of non-congenital anomaly cases were classified as CA in the ICD 10 database. Conclusion: Even though hospital databases are used as a baseline data for a number of research and epidemiological studies it cannot be used at face value. Validation of these data is necessary before any conclusions can be drawn or intervention measures are undertaken.

Environmental Health And Building Related Illnesses

Malaysia has good environmental laws to protect the outdoor environment and public health. However there are no laws governing indoor air quality (IAQ) and the knowledge among the public about its importance is also lacking. Environmental professionals think it is not a priority and this influences the policy decisions in the country. Therefore there is a need to create awareness by way of research, education and other promotional activities. What is much needed at this time is the establishment of standards for the conduct of risk assessment studies. To establish standards we need reliable data which can be used to develop appropriate guidelines for the purpose of mitigation and adaptation programmes. IAQ can have significant influence on health resulting in drop in productivity and economy of a country. It has been estimated that in the US, building related illnesses (BRI) symptoms have a relationship with decrease (3 to 5%) in work performance in an affected population resulting in an annual loss of US$60 billion in revenue. However, based on efficient management programmes they have also projected that the potential annual savings can be in the region of US$10 to 30 billion. This establishes that fact that good management programmes based on efficient guidelines is of economic value to a country and wellbeing of the population. The IMU has embarked on a research programme to collect the much-needed data for the framing of a good IAQ guideline for Malaysia.

Cercarial Dermatitis In Kelantan, Malaysia An Occupation Related Health Problem

Introduction : Kelantan, an east coast state of Peninsular Malaysia is rich in culture and supports a population that is dependent on agriculture. The crops cultivated are mainly paddy and rubber but in recent years tobacco is beginning to gain importance over paddy. We centered our study around Bachok District which is about 25 kilometers east of Kota Bharu, the state capital. Methods: Based on case reports we focused our study on cercarial dermatitis and also recorded the socioeconomic status of the people in the four study villages. Result: The ducks and cows were the common livestock kept by the farmers and these were found to be significantly associated (P=0.05) with the occurrence of dermatitis. Cercariae shedding by snails were found in waters used for irrigation. Conclusion : The results indicate that cercarial dermatitis is occupation specific, and its debilitating effect was having an influence on the socioeconomic status and general wellbeing of the population in these villages. The dermatitis occurred only during the field preparation and transplanting stages of paddy and was found to be significantly associated (P=<0.05) with the source of water used for irrigation. The water sources for irrigation was mainly from the river and irrigation canal and the snail Indoplanorbis exustus infected with schistosome cercariae was found to be abundant in both these sources during these stages. The ducks and cows were the common livestock kept by the farmers and these were also found to be significantly associated (P=0.05) with the occurrence of dermatitis. Therefore we concluded that the dermatitis among paddy farmers in Bachok District was due to an animal schistosome.