Endemic Areas Of Bangladesh Research Articles

Entomological Survey for New Vector Incrimination and Re-Confirmation of Established Malaria Vectors in Endemic Areas of Bangladesh (4 Sentinel Sites)

In Bangladesh malaria is one of the major public health problems and there are 3 malaria endemic hill tract districts which are the major areas among the red zones of malaria enedemicity. This study was aimed at assessment of the new vector incrimination as well as re-confirmation of the established vectors in Naikhangchari, Thanchi, Laxmichari and Baghachari. The anopheline population were collected and tested to incriminate the vector of malaria and their role in transmission, to find out the sporozoite rate, determination of oocyst rate of parasite and entomological innocultaion rate was diagnosed. Anopheline mosquito samples were directly collected from the sites using human bait, cattle landing and CDC light traps. The collected mosquitoes were dissected to find out the sporozoite in the salivary gland, oocyst in the midgut and to see the ovary for determination of the mosquito’s status of parous or nail-parous to determine the length of gonotropic cycle. The highest collection of a primary vector An. philippinensis was in Laxmichari (186 samples) and the highest collection of a secondary vector species An. vagus was in Thanchi (392). After the dissection no sporozoite or oocyst were detected among the collected anopheles’ samples. The vectoral capacity of An. philippinesis should be re-evaluated in the further studies. The pick biting hours of An. philippinensis and An. vagus varied in the 3 study sites which is an important finding of this study.

Knowledge and Attitude of the Community People on Indoor Residual Spraying (IRS) Program at Kala-azar Endemic Area in Bangladesh

Visceral leishmaniasis also known as kala-azar is a chronic and potentially fatal parasitic disease in the world, affecting mainly the underprivileged people in the world. The success of the Kala-azar elimination program is mostly dependent on community participation which is an important aspect implemented by the world health organization in five south Asian countries. The participation of the community people mostly depends on the level of knowledge, attitude, and practice around risk factors associated with disease transmission among the population. This study was undertaken to assess the level of knowledge and attitude of the community people towards the indoor residual spraying (IRS) program in the Kala-azar endemic area. The study was carried out in 240 households by systemic random sampling on both hyper and moderate endemic areas in Bangladesh, and information was collected through a semi-structured questionnaire. Data from the study indicated that 44.6% of participants were illiterate, 99% had heard of kala-azar and 100% had heard about IRS. Team of IRS, family members, and neighbors play an important role as a source of information while the role of mass media was found to be limited. Almost all respondents who participate here seem to be that kala-azar is a serious health condition that drains family resources, but their attitude to doing beneficial activities of the IRS is not satisfactory because of their thought that it could be controlled by community effort. From the data, it is seen that people are knowledgeable about kala-azar, but disease transmission, infection origin, and control of the diseases are still not adequate. Their attitude toward indoor residual spraying program practice was not satisfactory. These findings suggest that it is necessary to continue and strengthen behavioral change through the implementation of the IRS program to progress the disease’s condition in the pandemic areas of Bangladesh.

Retraction: Awareness of residents about kala-azar and its related practices in two endemic areas of Bangladesh.

Retraction: Awareness of residents about kala-azar and its related practices in two endemic areas of Bangladesh.

Detection of Vector Mosquito of Filariasis in the Endemic Areas of Bangladesh

Background: Lymphatic Filariasis (LF), a mosquito born tropical parasitic disease, caused by Wuchereria bancrofti is not only a health but also a socio-economic problem in Bangladesh. Culex quinquefasciatus is the confirmed filarial vector in Bangladesh, so by controlling of this vector population, we can prevent this disease. To control this vector and decrease incidence of filariasis, we need to know studied mosquito’s sample in endemic areas.
 Aim and objectives: Aim of this study was to see mosquito population in search of vector species in the endemic zones of malaria and filarial. Then we confirmed presence of vector species at molecular level by species specific DNA fingerprinting.
 Methods: This cross-sectional entomological study was carried out in Hobiganj (Shatchori tea garden) and Moulvibazar district (Patrokhola and Madonmohonpur tea gardens). Mosquito was collected by paper cup with net, aspirator and torch light and vector mosquitoes were identified with stereoscopic microscope. After identification of the mosquitoes, these were stored in laboratory for analysis of the density of the vector mosquitoes in the endemic areas. Then the vector mosquitoes were identified through molecular method named Polymerase Chain Reaction (PCR).
 Result: 1427 female mosquitoes belonging to 28 species under 5 genera were collected from three tea gardens. Culex quinquefasciatus which is the confirmed filarial vector in Bangladesh was found high in number (20.74%) out of the total collected mosquitoes. Other mosquito’s species were found in various ratios. Then Culex quinquefasciatus vector was identified by PCR.
 Conclusion: As vector mosquitoes of LF are available in these tea gardens, the study concludes that these areas are highly LF endemic areas of Bangladesh. Through molecular method, the vector of LF can be identified certainly. As we identify the vector mosquito, thus we can prevent this LF disease at very early stage. So, these findings will be very beneficial and cost effective for a developing country like Bangladesh.

Bioaccessibility and speciation of arsenic in children's diets and health risk assessment of an endemic area in Bangladesh

This study determines the bioaccessibility of toxic and carcinogenic arsenic (As) in composite food samples and evaluates potential exposure from food intake in Bangladesh children. Total As (tAs), inorganic As (iAs) and bioaccessible As (BAs) in food composite samples consumed by children were compared between an exposed and a control group (based on As in drinking water). Total As concentrations in composite food samples of children exposed to mean As level of 331 µg/l in drinking and cooking water ranged from 586 to 1975 µg/kg, dry weight over 76–90 µg/kg in the unexposed group. Average iAs in food composites was 73.9% (range: 49.3–90.8%). The fraction of BAs using gastric and gastrointestinal phases was 91 ± 13% and 98 ± 11%, respectively. Daily intake of iAs in the exposed group ranged from 0.41 to 6.38 µg per kg body weight (BW), which was much higher than the unexposed group (0.08–0.15 µg per kg BW). High iAs content and BAs in composite food samples indicated the elevated risk to exposed children. Further research should include both adults and children using larger sample size to determine overall As exposure from food intake in Bangladesh, attention must be given to lowering of As in food.

Molecular Pattern of Anti-malarial Drug Resistance of Plasmodium falciparum in Bangladeshi Troops Working in Endemic Areas of Bangladesh and Africa

Members of Bangladesh Armed Forces work in two different malaria endemic area, Chittagong Hill Tracts (CHT) in Bangladesh and Sub-Saharan countries in Africa. This under-recognized group remained unexplored for long in respect to drug resistant falciparum malaria they usually suffer from. In this study, a total of 252 ‘dried blood samples on filter paper’ were collected between November 2014 and February 2016, from Plasmodium falciparum positive Bangladeshi troops working in Chittagong Hill Tracts (CHT), Bangladesh and five Sub Saharan African Countries namely, Central African Republic (CAR), Democratic Republic of Congo (DRC), Liberia, Mali and Ivory Coast. After DNA extraction from all these samples (94 from Bangladesh and 138 from African countries), plasmodium species was confirmed by a nested PCR following standard protocol with minor modifications. Thereafter, a multiplex nested PCR followed by restriction fragment length polymorphism (RFLP) method was employed to investigate the presence of chloroquine resistance marker ‘K76T mutation’ in P. falciparum chloroquine resistance transporters (pfcrt) gene and lumifantrine and mefloquine resistance marker ‘N86Y mutation’ in P. falciparum multidrug resistance1 (pfmdr1) gene. The P. falciparum DNA was confirmed in 35 (37.23%) Bangladeshi and 45 (28.48%) African samples. The ‘pfcrt (K76T) mutation’ that confers resistance to chloroquine, was detected in 93.10% Bangladeshi and 29.27% African samples. The ‘pfmdr1 (N86Y) mutation’ that confers resistance to lumifantrine and mefloquine, was detected in 20.69% Bangladeshi and only 2.44% African samples. The higher prevalence of chloroquine resistance of P. falciparum in Bangladesh than in African countries revealed that possible withdrawal of chloroquine from endemic areas and also periodic molecular survey to monitor pf resistance to chloroquine, mefloquine, lumefantrine and artemisinin among these troops working in both endemic areas.
 Bangladesh J Microbiol, Volume 37 Number 1 June 2020, pp 1-6

Detection of antibodies to recombinant truncated flagellin and sonicated whole cell antigen of Burkholderia pseudomallei in acute melioidosis and in healthy Bangladeshi individuals

Background and objectives: Several types of Burkholderia pseudomallei antigens have been used to determine the antibody response in acute and asymptomatic cases. In the present study, we have detected immunoglobulin G (IgG) antibody to recombinant truncated flagellin antigen (RTFA) of B. pseudomallei in the sera of acute melioidosis cases and healthy individuals from melioidosis endemic areas of Bangladesh by indirect enzyme-linked immunosorbent assay (ELISA). In parallel, IgG antibody to sonicated whole cell antigen (SWCA) of B. pseudomallei was determined to compare with anti-RTFA antibody.
 Methodology: Serum samples from culture confirmed melioidosis cases and from healthy individuals aged 21 years and above residing in melioidosis endemic rural areas were included in the study. Serum IgG antibody to RTFA and SWCA of B. pseudomallei was determined by indirect ELISA.
 Results: Out of 8 culture confirmed acute melioidosis cases, 7 (87.5%) and 8 (100%) were positive for anti-B. pseudomallei IgG antibodies by RTFA and SWCA methods respectively. Among 361 healthy individuals, the rate of seropositivity by RTFA-ELISA was significantly less than that of SWCA-ELISA (16.1% versus 26.8%; p = 0.001). The mean optical density (OD) of RTFA-ELISA of positive cases was significantly less than that of SWCA-ELISA in both melioidosis and healthy individuals (0.79±0.11 versus 2.4±0.08, p = 0.0001; 0.67±0.01 versus 1.27±0.02, p = 0.0001). The sensitivity and specificity of RTFA-ELISA were 88.9% and 100% respectively.
 Conclusion: Findings of the study suggest that multiple or combination of antigens should be used to study the seroprevalence of B. pseudomallei infection in a community. Also, prospective study is necessary to find out the duration of persistence of antibodies to different antigenic components of B. pseudomallei after exposure.
 Ibrahim Med. Coll. J. 2020; 14(1): 47-52

Effects of Climate on Sandflies and Leishmaniasis in Endemic Areas of Bangladesh

Introduction: Climate includes rainfall, temperature; humidity has shown significant influences on Leishmaniasis and development of sand flies. Kala-azar- a climate-sensitive disease, a public health problem and historically endemic in Bangladesh, nurtured in temperatures ranging from 7 to 37°C, with relative humidity above 70%. Longevity and survival of vector of Kala-azar has been geographically controlled by the climate which is hard to manoeuver.
 Objective:To observe the relationship of climate and its effects on the development of sand flies and Leishmaniasis (Kala-azar) in the endemic areas in Bangladesh.
 Materials and Methods: This cross sectional study was conducted at the endemic areas of, Bangladesh during the period of 2014-2017. Information on climate like rainfall, humidity and temperature were collected from local respective Upazilla Live Stock Office and Bangladesh Meteorological Department, Agargaon, Dhaka. Month wise data of Kala-azar cases were collected from Directorate General of Health Services.
 Results: Temperature, Rainfall and Humidity are important for survivability and activity of sandfly as well asleishmaniasis. Mean temp at the study areas was found at around 20℃ in the month of Jan, Feb and Nov, Dec. Round the year the Maximum and Minimum temp was maintained at neither to high nor to low (between 7 to 36.5℃). Annual average humidity of these study area was found over 70%. In the study areas maximum rainfall 300to 500 mm was from May to Sep where peak was in Jun to Sep. Annual average rainfall was recorded 1434 to 1584 mm at Pabna and 2084 to 2182 mm at Mymensingh. Study findings correlated that rainfall may or may not have effects with sand fly and leishmaniasis. This study depicted distinct peaks of Leishmaniasis seen in pre monsoon Feb, monsoon Sep and post monsoon Nov period which dictated the plethora of sand fly from Jun to Oct and also from Jan to Feb.
 Conclusion: Manoeuvring the climate is difficult and it does not change each year, it will play its own role. We can manoeuver the harbour and the vector of leishmaniasis.Within this climatic condition National Kala-azar Elimination Programme has been fighting since 2008 but Kala-azar has not come to Zero. Further resurgence can it be outweigh?
 Journal of Armed Forces Medical College Bangladesh Vol.14(1) 2018: 10-14

Awareness of residents about kala-azar and its related practices in two endemic areas of Bangladesh.

Kala-azar, a worldwide disease, is caused by the parasitic protozoan species of genus Leishmania and transmitted by species of sandflies. Awareness of the population about the disease is essential to run a successful control-strategies program. This cross-sectional study was conducted to assess the awareness of residents about it and related practices in two highly-endemic areas of Bangladesh. In total, 511 household respondents were selected conveniently from two unions (Kushmail and Kanihari) under two sub-districts (Trishal and Fulbaria) of Mymensingh district. Interviewer-administered questionnaires were used for assessing the awareness of the respondents about kala-azar and their practices. Knowledge scores were categorized as poor (<mean -1SD), average (mean ±1SD), good (>mean +1SD). Statistical tests were considered significant at p value of ≤5% (≤0.05). Chi-squared and Student's t-tests were performed for statistical analysis. The mean knowledge score of the respondents of Kanihari union regarding kala-azar was significantly higher than that of the respondents of Kushmail union (mean ±SD, 4.30 ±0.86 versus 4.12 ±0.75, p = 0.002). Of the respondents, 11% and 20% had good (>5.04), 77% and 72% had average (3.43-5.04), 12% and 8% had poor (<3.43) (GAP) knowledge on kala-azar in Kushmail union and Kanihari union respectively. However, the mean knowledge score of the respondents of Kanihari union relating sandfly was significantly lower compared to that of the respondents of Kushmail union (mean ±SD, 2.49 ±0.79 versus 2.65 ±0.85, p = 0.03). Of them, 22% and 19% had good (>3.39), 67% and 64% had average (3.39-1.75), and 11% and 17% had poor (<1.75) knowledge on sandfly in Kushmail union and Kanihari union respectively. More than 70% of the respondents from Kushmail and Kanihari mentioned only injection as the preferred treatment of kala-azar. Eighty-seven percent and 88% of the respondents in the two unions had chosen upazilla health complex for the treatment of their kala-azar. About 50% of the respondents in Kushmail and Kanihari liked to use coil or mat as a preventive measure to avoid sandfly bites. The findings of this study indicate the importance of awareness and related practices of the community people in two endemic areas that will help implement the kala-azar-elimination program successfully in Bangladesh.

Knowledge, attitudes, and practices regarding malaria control among the slash and burn cultivators in Rangamati Hill tracts of Bangladesh

BackgroundSlash and burn cultivators are a significant risk group for malaria in South-East Asia. As envisaged in the National Strategic Plan for Malaria Elimination, Bangladesh aims to achieve zero indigenous malaria transmission by 2030. For the national plan to move from malaria control to malaria elimination, targeting the population of slash and burn cultivators is of overriding importance.MethodsThe study used an explorative mixed method design to investigate the knowledge, attitudes, and practices (KAP) regarding malaria prevention and treatment in an endemic area of Bangladesh. Adult slash and burn cultivators in two sub-districts of the Rangamati District were selected and interviewed. Four focus group discussions were conducted, and this was followed by a cross-sectional quantitative survey with 200 participants.ResultsThe respondents’ general knowledge about malaria transmission and modes of prevention and treatment was good. However, there were some gaps regarding knowledge about specific aspects of malaria transmission and in particular about the increased risk associated with their occupation. Despite a much-reduced incidence of malaria in the study area, the respondents perceived the disease as life-threatening and knew that it needs rapid attention from a health worker. Moreover, the specific services offered by the local community health workers for malaria diagnosis and treatment were highly appreciated. Finally, the use of insecticide-treated mosquito nets (ITN) was considered as important and this intervention was uniformly stated as the main malaria prevention method.ConclusionsThe findings from this study on promising KAP characteristics in the slash and burn cultivator population are reassuring that the goal of malaria elimination by the year 2030 can be achieved in Bangladesh.

Active Case Search of Kala-azar in an Endemic Area of Bangladesh:

Visceral Leishmaniasis which is also known as kala-azar is one of the most alarming vector borne Disease in Bangladesh. Kala-azar elimination program was launched in Bangladesh in the year 2008. The primary goal of this program is to decrease the burden of Visceral Leishmaniasis as much as possible. Active case search method are currently using for detection of Visceral Leishmaniasis patient in the community. The successful active case search activity or method lies in preventing and reducing Visceral Leishmaniasis in Bangladesh. The purpose of this study was to assess the Active Case Search activity of Visceral Leishmaniasis Elimination Program in selective endemic area in Bangladesh. This cross-sectional study was conducted within the time frame of 1st January 2016 to 31st December 2016 at different unions of Fulbaria upazila in Mymensingh district using purposive sampling technique according to availability of the respondents and data was collected with pre-tested semi-structured questionnaire by face to face interview. A total number of 111 respondents were enrolled in this study as per selection criteria. Among 111 respondent’s male were 71(64%) and female were 40(36%) and 36 (32.4%) were farmer, 29 (26.1%) were students of different classes, 20 (18%) women were housewife, 11 (9.9%) respondents were in service, 6 (5.4%) were day Laborer and 7 (6.3%) had other profession. Regarding housing status most of them {81(72.98%)} had the kacha housing and only a few respondents {3 (2.7%)} had pakka housing. According to the distance of cowshed or cattle house of the majority of the respondents 95(85.6%) were in the nearest location from living room (Less than 12 feet). Among 111 respondents most of them {78(70.3%)} suffered from kala-azar and 33(29.7%) not suffered from kala- azar in the study area and among these 78 respondents 62(77.5%) found Post kala-azar Dermal Leishmaniasis (PKDL) spot on the body. Most of them 80(72.1%) stated that there was no regular routine visit of the health worker. 90 (81.1%) respondents mentioned that the frequency of Indoor Residual Spray (IRS) was once in a year and 21(18.9%) mentioned 2 times in a year. Among 111 respondents 78(70.27%) mentioned that last supply of Long Lasting Insecticide Net (LLIN) was more than 1 year ago,18(16.22%) mentioned before 6 month and 15(13.51%) before 1 year. This study permits to conclude that Active Case Search Activity of Visceral Leishmaniasis program in Bangladesh facing challenges due to lack of monitoring and supervision. Without strengthening of active case search activity, it is impossible to reach the goal.TAJ 2015; 28(2): 26-39

Lymphatic filariasis in Nilphamari district: An endemic area in Bangladesh

The present study was carried out in Nilphamari district, Filaria Hospital of Nilphamari district and from randomly selected three villages of Nilphamari Sadar and Paurasava, Sayedpur, Domar, Dimla, Joldhaka and Kishoreganj. The objectives of this study were to find out the status of lymphatic filariasis (LF) in Nilphamari district: An endemic area for LF in Bangladesh. The investigation was carried out among the inhabitants of the villages and the outdoor patients of Filaria Hospital in Nilphamari through a formatted questionnaire. The current status of this disease was 4.43% in Nilphamari Sadar and 3.25% in Paurasava, 4.10% in Sayedpur and similarly 4.82% in Domar, 5.86% in Dimla, 3.85% in Joldhaka and 4.70% in Kishoreganj. In Nilphamari district, it was found that male were more susceptible (58.84%) than female (41.16%). 76.22% male patients had hydrocoele and the disease showed its highest prevalence (41.16%) in the age group of 41-60 years.Bangladesh J. Zool. 46(1): 11-19, 2018

Exploring spatial and temporal patterns of visceral leishmaniasis in endemic areas of Bangladesh

BackgroundVisceral leishmaniasis is a considerable public health burden on the Indian subcontinent. The disease is highly endemic in the north-central part of Bangladesh, affecting the poorest and most marginalized communities. Despite the fact that visceral leishmaniasis (VL) results in mortality, severe morbidity, and socioeconomic stress in the region, the spatiotemporal dynamics of the disease have largely remained unexplored, especially in Bangladesh.MethodsMonthly VL cases between 2010 and 2014, obtained from subdistrict hospitals, were studied in this work. Both global and local spatial autocorrelation techniques were used to identify spatial heterogeneity of the disease. In addition, a spatial scan test was used to identify statistically significant space-time clusters in endemic locations of Bangladesh.ResultsGlobal and local spatial autocorrelation indicated that the distribution of VL was spatially autocorrelated, exhibiting both contiguous and relocation-type of diffusion; however, the former was the main type of VL spread in the study area. The spatial scan test revealed that the disease had ten times higher incidence rate within the clusters than in non-cluster zones. Both tests identified clusters in the same geographic areas, despite the differences in their algorithm and cluster detection approach.ConclusionThe cluster maps, generated in this work, can be used by public health officials to prioritize areas for intervention. Additionally, initiatives to control VL can be handled more efficiently when areas of high risk of the disease are known. Because global environmental change is expected to shift the current distribution of vectors to new locations, the results of this work can help to identify potentially exposed populations so that adaptation strategies can be formulated.

Environmental factors associated with the distribution of visceral leishmaniasis in endemic areas of Bangladesh: modeling the ecological niche

BackgroundVisceral leishmaniasis (VL) is a parasitic infection (also called kala-azar in South Asia) caused by Leishmania donovani that is a considerable threat to public health in the Indian subcontinent, including densely populated Bangladesh. The disease seriously affects the poorest subset of the population in the subcontinent. Despite the fact that the incidence of VL results in significant morbidity and mortality, its environmental determinants are relatively poorly understood, especially in Bangladesh. In this study, we have extracted a number of environmental variables obtained from a range of sources, along with human VL cases collected through several field visits, to model the distribution of disease which may then be used as a surrogate for determining the distribution of Phlebotomus argentipes vector, in hyperendemic and endemic areas of Mymensingh and Gazipur districts in Bangladesh. The analysis was carried out within an ecological niche model (ENM) framework using a maxent to explore the ecological requirements of the disease.ResultsThe results suggest that VL in the study area can be predicted by precipitation during the warmest quarter of the year, land surface temperature (LST), and normalized difference water index (NDWI). As P. argentipes is the single proven vector of L. donovani in the study area, its distribution could reasonably be determined by the same environmental variables. The analysis further showed that the majority of VL cases were located in mauzas where the estimated probability of the disease occurrence was high. This may reflect the potential distribution of the disease and consequently P. argentipes in the study area.ConclusionsThe results of this study are expected to have important implications, particularly in vector control strategies and management of risk associated with this disease. Public health officials can use the results to prioritize their visits in specific areas. Further, the findings can be used as a baseline to model how the distribution of the disease caused by P. argentipes might change in the event of climatic and environmental changes that resulted from increased anthropogenic activities in Bangladesh and elsewhere.

Soil Pattern and Breeding of Sandfly in Endemic Areas of Bangladesh

Introduction: Sandfly breeds in soil but is selective to identify soil favourable for their breeding. Soil covered by vegetation, marshy land, orchards and settlements shows high sandfly breeding in an endemic region. Besides,the presence of inorganic constituents of the soil was found to affect sandfly breeding.&#x0D; Objective: To identify soil pattern in Kala-azar endemic areas suitable for sandfly breeding, and the relationship of soil’s physical and chemical properties with their breeding which may help in taking feasible measure to control the vector of Kala-azar or Visceral Leishmaniasis (VL).&#x0D; Materials and Methods: The cross-sectional type of descriptive study was conducted in the Kala-azar endemic areas of Trishal and Fulbaria of Mymensingh, Madhupur of Tangail and Chatmohor of Pabna district, Bangladesh during the period of July 2015 to December 2015. From each site, 250 gm soil was collected and packed in a plastic container. All the samples were taken in the laboratory and were kept as it is for one week to configure the moisture and soil temperature maintaining the lab room temp at 28±2ºC and relative humidity at 75.0%±2.0. Soil samples were analysed for physical and chemical properties at the Soil Science Department of Sher-e-Bangla Agricultural University, Dhaka.&#x0D; Results: Total 48 soil samples were collected from Trishal, Fulbaria, Madhupur, Chatmohor and each sample was analysed for physical property (sand, silt, clay, porosity, water content), chemical constituents (pH, C, N, Ca, Mg, K, P, Fe). The mean from each district’s soil constituents (sand, silt, clay, porosity, water content) ranged from 17.36%-18.83%, 44.10%-45.46%, 35.70%-38.06% 41.98%-47.24% respectively and among the chemical constituents, pH ranged from 7.46-7.98, Carbon 0.92-0.98 Cmolkg-1, Nitrogen 0.174-0.184 Cmolkg-1, Calcium 4.83-6.21 Cmolkg-1, Magnesium 1.97-2.46 Cmolkg-1, Potassium as K2O 1.37-1.79 Cmolkg-1, Phosphorus as P2O5 12.60-13.78 Cmolkg-1, Iron as Fe2O3 9.54-10.06 Cmolkg-1 respectively.&#x0D; Conclusion: Physical and chemical characteristics of soil by area of endemicity have been postulated to afford suitable environment for sandfly breeding. This information of the breeding sites of phlebotomine sandflies could help to plan environmental intervention measures that would impede the breeding of these insects.&#x0D; Journal of Armed Forces Medical College Bangladesh Vol.13(1) 2017: 3-7

Sampling Design Influences the Observed Dominance of Culex tritaeniorhynchus: Considerations for Future Studies of Japanese Encephalitis Virus Transmission

Mosquito sampling during Japanese encephalitis virus (JEV)-associated studies, particularly in India, has usually been conducted via aspirators or light traps to catch mosquitoes around cattle, which are dead-end hosts for JEV. High numbers of Culex tritaeniorhynchus, relative to other species, have often been caught during these studies. Less frequently, studies have involved sampling outdoor resting mosquitoes. We aimed to compare the relative abundance of mosquito species between these two previously used mosquito sampling methods. From September to December 2013 entomological surveys were undertaken in eight villages in a Japanese encephalitis (JE) endemic area of Bangladesh. Light traps were used to collect active mosquitoes in households, and resting boxes and a Bina Pani Das hop cage were used near oviposition sites to collect resting mosquitoes. Numbers of humans and domestic animals present in households where light traps were set were recorded. In five villages Cx. tritaeniorhynchus was more likely to be selected from light trap samples near hosts than resting collection samples near oviposition sites, according to log odds ratio tests. The opposite was true for Cx. pseudovishnui and Armigeres subalbatus, which can also transmit JEV. Culex tritaeniorhynchus constituted 59% of the mosquitoes sampled from households with cattle, 28% from households without cattle and 17% in resting collections. In contrast Cx. pseudovishnui constituted 5.4% of the sample from households with cattle, 16% from households with no cattle and 27% from resting collections, while Ar. subalbatus constituted 0.15%, 0.38%, and 8.4% of these samples respectively. These observations may be due to differences in timing of biting activity, host preference and host-seeking strategy rather than differences in population density. We suggest that future studies aiming to implicate vector species in transmission of JEV should consider focusing catches around hosts able to transmit JEV.

Treatment seeking behavior of filariasis patients in a selected endemic area of Bangladesh

This descriptive cross-sectional study was carried out among 400 respondents from the rural area in Parbatipur Upazilla under Dinajpur district with the objectives to assess the knowledge, attitude, practice and gender discrimination of filariasis patients using a semi structured questionnaire through face to face interview. After collection of data, they were checked, verified, edited for consistency and entered into a computer. The statistical calculation and analysis were done to fulfill the objectives of the study. All the respondents were adult, age ranged from 20 to 71 years; mean (SD) was 41.3 (11.6). Among them 59.0% were female and 41.0% were male, about 90.5% were married, 68.5% were illiterate and 4.0% had higher secondary education. About 78.5% of the respondents in the studied area had no knowledge about the disease. All the respondents had incorrect concept about the causes of the disease. About 85% of the respondents mentioned that the symptoms of the disease was swelling of the hand and feet, 12.6% reported no specific symptoms or had no knowledge on symptoms of the disease; 67.8% of the men reported swelling of the scrotum. About 94% of the respondents did not know the easiest method of prevention. About 73.8% of the respondents delayed in receiving the treatment and 26.3% received treatment immediately after appeared of symptoms. About 51.5% respondents did not take the disease seriously and 48.5% did not receive advice from any one. From the respondents, 89.5% received treatment from homeopaths, 83.5% from kabiraj, and 7.8% from doctors with MBBS (from private clinics) and 0.3% from government hospitals. Analysis revealed that female respondents received different pattern of treatment than male counterpart. Active community participation should be ensured in designing community based education campaigns to make them socially acceptable and effective. Health workers, NGO workers, teachers, religious leaders, community leaders can play a key role convincing the patients to take modern treatment and enhancing the intake of full course of drugs against filariasis by the patients. Further study is needed using a large scale patients to observe the actual status of treatment seeking behavior of filariasis patients in the community.Mediscope Vol. 2, No. 2: July 2015, Pages 5-15

Leprosy incidence: six years follow-up of a population cohort in Bangladesh

With approximately 250,000 new leprosy cases detected annually, transmission of M. leprae appears to be ongoing in many areas of the world. By studying prospectively the number of leprosy patients found in a population sample at the beginning of the study (prevalence) and the number of new patients found during the 6-year observation period (incidence), we aim to understand better the transmission of M. leprae and the burden of disease. To establish the prevalence and incidence rates of leprosy in the general population of a high endemic area in Bangladesh, we followed prospectively 20,218 individuals from a random cluster sample of the population and examined them at 2-yearly intervals for 6 years. At intake we found 27 new leprosy cases, indicating a prevalence of previously undiagnosed leprosy of 13.3/10,000. Follow-up at 2, 4 and 6 years revealed 17, 16, and eight new cases, respectively, representing incidence rates of 4.0, 4.5 and 2.3/10,000 PYAR, respectively. The incidence rate over 6 years was 3.7/10,000 PYAR. The observed incidence rate is three times higher than the new case detection rate in the same area. Of all 68 new leprosy cases, five (7%) had MB leprosy. The proportion of children under 15 years was 24%. The proportion of female patients was 60%, but the incidence rate of leprosy was the same for males and females. The decline in incidence of leprosy in a general population sample is less pronounced than routine data from a control programme led us to expect.

Performance of a HRP-2/pLDH based rapid diagnostic test at the Bangladesh-India-Myanmar border areas for diagnosis of clinical malaria

BackgroundThe rapid diagnostic test (RDT) has been adopted in contemporary malaria control and management programmes around the world as it represents a fast and apt alternative for malaria diagnosis in a resource-limited setting. This study assessed the performance of a HRP-2/pLDH based RDT (Parascreen® Pan/Pf) in a laboratory setting utilizing clinical samples obtained from the field.MethodsWhole blood samples were obtained from febrile patients referred for malaria diagnosis by clinicians from two different Upazila Health Complexes (UHCs) located near the Bangladesh-India and Bangladesh-Myanmar border where malaria is endemic. RDT was performed on archived samples and sensitivity and specificity evaluated with expert microscopy (EM) and quantitative PCR (qPCR).ResultsA total of 327 clinical samples were made available for the study, of which 153 were Plasmodium falciparum-positive and 54 were Plasmodium vivax-positive. In comparison with EM, for P. falciparum malaria, the RDT had sensitivity: 96.0% (95% CI, 91.2-98.3) and specificity: 98.2% (95% CI, 94.6-99.5) and for P. vivax, sensitivity: 90.7% (95% CI, 78.9-96.5) and specificity: 98.9% (95% CI, 96.5-99.7). Comparison with qPCR showed, for P. falciparum malaria, sensitivity: 95.4% (95% CI, 90.5-98.0) and specificity: 98.8% (95% CI, 95.4-99.7) and for P. vivax malaria, sensitivity: 89.0% (95% CI,77.0-95.4) and specificity: 98.8% (95% CI, 96.5-99.7). Sensitivity varied according to different parasitaemia for falciparum and vivax malaria diagnosis.ConclusionParascreen® Pan/Pf Rapid test for malaria showed acceptable sensitivity and specificity in border belt endemic areas of Bangladesh when compared with EM and qPCR.

Time Series Analysis of Cholera in Matlab, Bangladesh, during 1988-2001

The study examined the impact of in-situ climatic and marine environmental variability on cholera incidence in an endemic area of Bangladesh and developed a forecasting model for understanding the magnitude of incidence. Diarrhoea surveillance data collected between 1988 and 2001 were obtained from a field research site in Matlab, Bangladesh. Cholera cases were defined as Vibrio cholerae O1 isolated from faecal specimens of patients who sought care at treatment centres serving the Matlab population. Cholera incidence for 168 months was correlated with remotely-sensed sea-surface temperature (SST) and in-situ environmental data, including rainfall and ambient temperature. A seasonal autoregressive integrated moving average (SARIMA) model was used for determining the impact of climatic and environmental variability on cholera incidence and evaluating the ability of the model to forecast the magnitude of cholera. There were 4,157 cholera cases during the study period, with an average of 1.4 cases per 1,000 people. Since monthly cholera cases varied significantly by month, it was necessary to stabilize the variance of cholera incidence by computing the natural logarithm to conduct the analysis. The SARIMA model shows temporal clustering of cholera at one- and 12-month lags. There was a 6% increase in cholera incidence with a minimum temperature increase of one degree celsius in the current month. For increase of SST by one degree celsius, there was a 25% increase in the cholera incidence at currrent month and 18% increase in the cholera incidence at two months. Rainfall did not influenc to cause variation in cholera incidence during the study period. The model forecast the fluctuation of cholera incidence in Matlab reasonably well (Root mean square error, RMSE: 0.108). Thus, the ambient and sea-surface temperature-based model could be used in forecasting cholera outbreaks in Matlab.