Parasite egg contamination of water and air in a suburban area of Hanoi, Vietnam

Contamination of water and air by soil-transmitted helminth eggs was investigated in a small village located in the suburbs of Hanoi, Vietnam. Water samples were collected from 29 households, two schools, two kindergartens, one restaurant, three ponds and 23 ditch sites during the rainy season. Water samples were also collected at the same places, except for one household and one restaurant, during the dry season. The water samples collected from households, schools, kindergartens and restaurant were comprised of well-water and rain-water. These samples included both water filtrated with sand and gravel and non-filtrated water. Two-liter water samples were examined for helminth eggs by either a centrifugation or flotation method. The contamination of air by helminth eggs was assessed by the method of Kroeger <I>et al</I>. (1992). Eggs in air were trapped on adhesive tapes hanging in rooms and in the area around 29 houses, two schools, two kindergartens, one restaurant and 18 utility poles.<br>Out of 63 water samples collected from households in the rainy season, helminth eggs were found in four water samples; one from non-filtrated well-water and three from filtrated well-water samples. The one non-filtrated water sample contained six eggs of <I>Toxocara</I> sp., while the three filtrated water samples contained one egg each of <I>Trichuris</I> sp., <I>Trichiuris</I> sp. and <I>Taenia</I> sp. No eggs were found in the water samples collected from schools, kindergartens or the restaurant in the rainy season. All water samples collected from ponds and ditches in the rainy season contained many helminth eggs. The eggs found were <I>Ascaris</I> sp., <I>Trichuris</I> sp., <I>Toxocara</I> sp., <I>Ascaridia galli</I>, hookworm, <I>Taenia</I> sp. and <I>Fasciola</I> sp. Examination of the adhesive tapes hanging in the air showed that four sites were contaminated by helminth eggs, i. e. one site near the house, two sites near the school and one site at a utility pole. The species of eggs found were <I>Trichuris</I> sp., <I>Ascaridia galli</I> and <I>Taenia</I> sp. The number of eggs found on tapes was only one or two. In the dry season, a few samples of well-water and rain-water collected from the residential area were contaminated with helminth eggs, and all samples collected from ponds and ditches contained many eggs of various species similar to those collected in the rainy season. The present study clearly indicates that, in our study area, the villagers were subject to infection from soil-transmitted helminthes directly and indirectly through water.

Study on the safety of antimalarial combination between piperaquin and dihydroartemisinin manufactured in Vietnam

The sub-chronic toxicity of an antimalaria combination between piperaquine phosphate (PQP) and dihydroartemisinin (DHA) at the doses of 64 and 100 mg of (PQP+DHA)/kg of body weight/day for 28 consecutive days in rabbits was investigated in this study. Results: rabbits acted and ate normally. At the doses of 64 mg of (PQP+DHA)/kg/day x 28 consecutive days, the body weights of rabbits increased statistical significantly at day N28 compared to days before using the combination (p0.05) after 28 days. At dose of 100 mg PQP+DHA/kg/day x 28 days, biochemical indicators (SGOT, SGPT, creatinin, protein and bilirubin) and hematological indicators (hemoglobin, erythrocytes, leukocytes, neutrophils and lymphocytes) did not change significantly (p>0.05) after 28 days but protein and monocytes increased significantly (p<0.05) on day 28

Residual effects of field house spraying with Alé 10SC (Alphacypermethrin) in North Vietnam

Evaluation of effectiveness of house spraying with Ale 10SC/m2 in malaria mosquitoe prevention by testing bioassay and etomological indicators as well as side effects in the community in implemented area from 11/2003-11/2004 at Quyet Chien commune, Tan Lac District, Hoa Binh province shows that using Ale 10SC spraying with 30mm/m2 with 6 months of residual on wooden and brick wall and the mosquitoe death rate is 51.3-52.6%. Ale 10SC spraying decreased the density of An.minimus domestically daytime and seeking blood. Ale 10SC spraying with 30mg/m2 in malaria transmitted mosquitoes does not have side effects on people using it directly and the community

Pilot study on community based malaria control in three districts of Nghe An province

The WHO supported study "Community-Based Strengthen Management of Primary Health" was carried out in three pilot districts of Tuong Duong, Thanh Chuong, Quynh Luu of Nghe An province. The management of malaria case, health education at the primary level was found to have been improved significantly. The malaria prevalence was considerably reduced as compared to that of the previous years. The community health workers appeared to be able to properly collect and analyze malaria related data and report to the authority with recommendations of shortcomings and difficulties; to consolidate and integrate primary health care activities; to tackle and solve effectively shortcomings so that take more political commitment for sustainable malaria control. The project has become a model for wider application at a decision by the Nghe An People Committee.

Malaria epidemiological stratification and intervention methods in the Vietnam's malaria control program

In 2003, the malaria epidemiological stratification and intervention method which based on the geography, landscape, elevation, malaria cases, malaria parasites and malaria vectors, was implemented over the country. This stratification method aims to identify zones with different levels of malaria endemicity and population at risk of each zone. Based on this stratification, a plan for malaria control based on vector control and malaria case management will be made for each zone. The results of the stratification showed that the malaria situation of Vietnam can be divided into five different zones as follows: non-malaria transmission zone including 4,534 communes with the population of 42,620,426 people accounted for 54% of the total population; zone with risk of malaria re-emergence including 2,923 communes with 18,485,308 people, accounted for 23%; zone with low malaria endemic including 1,928 communes with 9,949,205 people, accounted for 12%; zone with moderate malaria endemic including 1,003 communes with 5,540,104 people, accounted for 7%; zone with high malaria endemic including 771 communes with 3,074,115 people accounted for 4%. With the above results, the number of people needs to be protected by malaria control measures should be 37,154,286 or 46% of the total population. However, these measures should be focused on 3 endemic zones with a poulation of 18,563,244 people.

Field evaluation of the effectiveness of Alé 10SC (alphacypermethrin) in malaria vector control in Northern Vietnam

The study was designed to evaluate the effectiveness of bed-net impregnation with Ale l0SC at a dose 25mg a.i/m2 based on bioassays, entomological indices and to evaluate side effects and the influence of washing of bed-nets in terms of insecticide residual effects. The trials were conducted from November 2003 to November 2004 in Quyet Chien commune, Hoa Binh province's Tan Lac district. Polyester bed-nets impregnated with Ale l0SC at dose of 25mg ai/m2 were found to have 6-month residual effects and to remain effective in malaria vector control after one wash (60 days after treatment). Ale l0SC bed-net impregnation were found to reduce the density of day time indoor resting and human biting anopheline mosquitoes. There are unsignficant side effects among spraymen, dippers and villagers in the treatment areas caused by bed-net impregnation at dose of 25mg ai/m2 were observed.

Safety of piperaquine phosphate in rabbits

The sub-chronic toxicity of piperaquine phosphate was assessed in rabbits. Piperaquine phosphate (PQP), at the doses of 50 and 100 mg/kg of body weight per day for 28 consecutive days, was administered orally. The influences of PQP on rabbits' laboratory indices were observed during the PQP administration and after the treatment. Rabbits treated with PQP by oral administration were found to have normal action dinning. At the dose of 50mg/kg per day for 28 consecutive days, the body weights of rabbits was increased significantly during study period (p<0.05), but was not changed significantly at the dose of 100 mg/kg per dayx 28 days. PQP, at the dose of 50 mg/kg per day for 28 consecutive days, did not change significantly biochemical indices (SGOT,SGPT, bilirubin and protein) and some hematological indices (leukocytes, leukocyte formula and hemoglobin), but significantly increased erythrocytes and creatinine on days 14 and 28. At the treated dose 100mg/kg per dayx28days, biochemical indices (SGOT, protein) and some hematological indices (erythrocytes, leukocytes and leukocyte formula) did not change significantly during study period, but creatinine, bilirubin and SGPT were significantly changed

Malaria situation in Daklak in early 2003 and proposed solutions

Malaria situation in DakLak province in the first 5 months of 2003 has increased highly and unstable. High morbidity of malaria is concentrated in five districts of DakLak province: DakRlap, DakNong, DakSong, M’dRak and DakMil. These are far, newly established districts with very difficult conditions of transport, economy and numerous problems caused by the illegal migration of population. The most of local inhabitants of mainly districts are protected by insecticide such as house spraying or bednet impregnation with covering 80-90%. The vector control method now is practiced better but these activities mainly aimed at protecting the local inhabitant clusters or stably settled people while ignored the new settlers and people who frequently stay overnight in the swidden fields