Bio-efficacy of Long Lasting Insecticidal Mosquito Nets (LLINs) on Malaria Vector Anopheles Mosquitoes in Malaria-Endemic Areas of Myanmar

Sixty used Long Lasting Insecticidal Nets (LLINs) from six malaria endemicareas of States and Regions of Myanmar were assessed for their bio-efficacy againstAnopheles mosquitoes. Total ten nets were collected from the randomly selectedhousehold of each area. Insecticide susceptibility and bio-efficacy test were doneaccording to WHO testing method. Results revealed that a total of 4470 mosquitoes of 12Anopheles species including main vector and secondary vectors were collected in highdensity in Beelin, Taungoo, Pyin Oo Lwin, Kamamaung and Hpa-an. All collectedmosquitoes were found susceptible to insecticides as recommended by the WHO. Bioefficacy of PermaNet 2.0, DAWA TANA, Yorkool, BASF, Net protect and Yahe LLINs netswere 12(100%), 11/12(91.67%), 4(100%), 8(100%), 5(100%) and 19(100%)respectively. The DAWA TANA net had 20% sensitivity after repetitive washing. Thesensitivity of LLINs nets was higher for all selected areas of States and Regions inMyanmar. The study suggested that there is need to distribute a large number of effectiveLLINs nets in malaria endemic areas as well as the replacement of expired, less effectiveand very old LLINs nets with a new one is also necessary. LLINs nets are very effectiveAnopheles mosquitoes control tools and it can reduce the human-vector contact effectively.Moreover, research on bio-efficacy evaluations of the LLINs nets is required regularly tomaintain and control the transmission of malaria through Anopheles mosquitoes.

The role of NS-1 antigen in early diagnosis of Dengue hemorrhagic fever in Yangon Children Hospital.

Detection of dengue virus NS1 antigen in patients’ sera serves as a supplementary assay for early diagnosis of dengue cases. This study evaluated the usefulness of NS-1 antigen for early diagnosis of dengue infection in children by use of a commercial immunochromato-graphic based SD Dengue Duo rapid test. The accuracy of SD Dengue Duo NS-1 antigen test was compared against a gold standard RT-PCR test in 117 children with suspected dengue infection attending YCH. All the children included in this study were tested for blood for complete picture and platelet count together with SD Dengue Duo rapid test. Among 117 samples, 65 serum samples were randomly selected and tested by RT-PCR. The sensitivity of SD Dengue Duo NS1 antigen assay was 40% (95% confidence interval) and specificity was 80% (95% confidence interval) as there were more secondary dengue cases in study population.The accuracy of NS1 antigen assay against RTPCR in patients with reduced platelet count showed that the sensitivity of NS1 antigen assay was 100% (95% confidence interval) and specificity was also 100% (95% confidence interval) when the platelet count was below 40,000.The result of this study demonstrated that the sensitivity and specificity of NS-1 antigen assay, at the time of low platelet count below 40,000, when specimens were collected within 5 days of fever, were relatively high compared to sensitivity and specificity of antibody detection. With the considerations for limitations such as NS1antigen assay being less sensitive in secondary dengue cases, in children, for diagnosis of dengue in early stage, with thorough clinical history and examination and also with platelet count, NS1 assay deserves inclusion in the diagnostic evaluation.

High frequency of HIV-1 and hepatitis C co-infection among young Thai men: evidence for a changing pattern of HIV transmission in Thailand.

To assess whether patterns of HIV transmission have changed in Thailand, we tested for antibody to hepatitis C virus (HCV) as a marker for parenterally acquired infection among HIV-infected and uninfected young Thai men. Antibody to HCV was present in 49.5% of HIV-infected men and 2.2% among uninfected men. These data suggest that a significant number of HIV infections among young men in Thailand may be associated with injection drug use.

ABO blood groups and susceptibility to Malaria

A total of 425 villagers from four malaria endemie villages in Kanbaunk village tract, Yephyu Township. Taninthayee Division were examined for the presence of malaria parasites in blood and ABO blood groups with the aim to find out if there are any differences in the parasite positive rate among the ABO bolld groups. The distribution of blood groups was 22 per cent, 35 per cent, 38 per cent and 5 per cent for A,B,O and AB blood groups respectively. their allotment are similar to other parts of the country. the parasite positive rate in all persons irrespective of blood group was 23 per cent P. falciparum and P. vivax accounting for 81 per cent and 19 per cent respectively. when the parasite positive rates were compared among the 4 blood groups, they were 20 per cent, 14 per cent, 16 per cent and 14 per cent respectively but there was no significant difference among different blood groups. The ratio of P. falciparum and P. vivax did not differ significantly among the four blood groups. Thus, according to our results ABO blood groups have no relation with malaria susceptibility.

Correlation between immunofluorescence assay (IFA) positivity and malaria endemicity in Myanmar

Immunofluorescence assay (IFA) for intra-erythrocytic Plasmodium falciparum parasite was determined in all ages and both sexes of permanent inhabitants of 3 villages in Myanmar with differing malaria endemicity. According to the WHO criteria, malaria endemicity depends on the parasite positive rate and spleen rate and the 3 villages could be characterized as one village each of hypoendemicity, mesoendemicity and hyperendemicity. The prevalence of IFA positivity were 30 per cent , 71 per cent and 97 per cent and the mean IFA titers were 800, 13,800 and 174,000 in the hypo, meso and hyperendemic villages respectively.. Thus, there is a good correlation between malaria endemicity and the IFA positivity and mean IFA titers. These data indicate that IFA assay can be used to assess malaria endemicity and applicable where proper epidemiological surveys especially in low and medium endemic areas are not possible.

The level of knowledge, attitude and practice in relation to malaria in Oo-do village, Myanmar.

A knowledge, attitude and practice (KAP) study concerning the nature and prevention of malaria was carried out in a rural area of Myanmar. According to the findings, many (over 40%) people do not have a clear cut knowledge on the transmission of malaria. Only one fourth of them had chemoprophylaxis before going to the forest, but they do not have the proper knowledge of the chemoprophylaxis regarding the type and dosage. Although there is acceptable knowledge (about 80% of the subject knew that mosquito bite causes malaria) and positive attitude towards malaria (100% of respondents agreed that malaria was a serious health problem in this area and 97% of respondents agreed that they would like to participate in malaria control activities), it is necessary to increase the community awareness of the transmission of the disease, its consequences and ways and means to control the disease to a minimum, especially in endemic areas.

Effects of beta-thalassaemia trait on pregnancy and foetal outcomes

Ten cases of pregnant mothers with confirmed beta-thalassaemia trait were studied for any complications occurred during pregnancy and labour and after birth. All cases were found to have no complications during pregnancy and labour giving normal full-term vaginal delivery. All the newborns were also found to have normal birth weight and have no complications. These findings indicate that beta- thalassaemia trait has no deleterious effects on pregnancy and foetal outcomes. No active interventions are required during antenatal care throughout pregnancy in beta-thalassaemia trait.

Assessing the accuracy of respiratory rates at different counting periods and methods

The respiratory rates of 198 children (aged 2-59 months) suffering from acute respiratory infections (ARI) were monitored by observation, palpation and auscultation (Gold standard). Two 30-second and one 60-second counts were obtained. The difference among respiratory rate counts determined simultaneously by observation, palpation and auscultation in relation to their mean count was analyzed for 60-second counting period, 30 plus 30-second period and 30-second doubled. The variability among the different counting methods and counting periods was not significantly different whether the children were feeding, sleeping, resting and awake or awake but not resting. The data from the study suggest that respiratory rate counting either by observation or palpation are similar in accuracy and one minute's counting either at a stretch or 30-second doubled or two blocks of 30-second intervals are also similarly accurate.

Is oral rice-based electrolyte solution superior to glucose electrolyte solution in acute chidhood diarrhoea?

In a controlled trial of oral rehydration therapy, the efficacy and safety of rice-based electrolyte solution was compared with standard WHO oral rehydration solution. Ninety eight male children aged 4 months to 10 years presenting with watery diarrhoea of less than 72 hours prior to hospitalization were studied. 48 were treated with standard WHO oral rehydration solution (ORS) and 50 patients with an improved formulation which contained 100 gm of rice (instead of glucose) with 25 mg of amylase in addition to electrolytes. The clinical characteristics of the two groups on, admission were comparable. Although there was a consistent trend towards reduction in stool volume and better gain in body weight in children with cholera treated with rece-based ORS, significant difference was noted only in 6-12 hour stool output and in the first 6 hour weight gain. Stool volume was significantly reduced during the 24 to 48 hour perild in all diarrhoeal patients receiving rice-based ORS. Thus, amylyte digested rice-based ORS is as effective as the Standard WHO ORS and have some therapeutic advantage in the treatment of acute childhood diarrhoea.

Assessment of the erythrocyte protoporphyrin test for screening of iron deficiency anaemia

A total of 84 apparently healthy children between ages of 1-12 years were screened for iron deficiency with the erythrocyte protoporphyrin (EP) test. Serum iron, total iron binding capacity in serum, percent transferrin saturation, haematocrit and haemoglobin values were also determined together with the screening test. Comparing the relationship between EP and percent transferrin saturation, using a percent transferrin saturation value < 10 percent as the criterion of iron deficiency, the optimal cut off limit for the EP test appears to be 80 ug/dl of rbcs. At this level, this screening test showed a sensitivity of 74 percent and specificity of 95 percent and the positive and negative predictive values were 82 percent and 93 percent respectively. thus EP assay which is less expensive and easy to perform can be used as a screening test for the detection of iron deficiency.

Comparative study on detection of urease activity by CLO Test Kit and Microtiter Biopsy Urease Test Kit for evaluation of Helicobacter pylori

A Microtiter Biopsy Urease Test (MBUT) for the detection of Helicobacter pylori was evaluated in the drug trial study conducted in the Endoscopy Department of New Yangon General Hospital. The MBUT was compared with commercially available urease test (CLO Test). Both CLO test and MBUT were performed on antral and fundal gastric tissues biopsied from 35 subjects who underwent upper gastrointestinal endoscopy. 29 (83 percent) cases were positive for Helicobacter pylori when tested by CLO test and MBUT. Thus the sensitivity and specificity of MBUT relative to CLO test was both 100 percent respectively. Tested by MBUT, the urease reaction was positive in 83 percent of cases within 2 hours and 90 percent within 3 hours. Tested by CLO test, it was positive in 60 percent of cases within 2 hours and 67 percent within 3 hours. the accuracy of MBUT was thus similar to that of CLO test for the detection of Helicobacter pylori. Moreover, MBUT is not expensive, can be prepared locally, packed in test kit form and can be supplied to gastroenteroscopy units for diagnostic and treatment purposes.