Công trình nghiên cứu khoa học: Báo cáo tại hội nghị khoa học toàn quốc chuyên ngành sốt rét-ký sinh trùng-côn trùng giai đoạn 2001-2005. Tập 2. Ký sinh trùng và côn trùng y học

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Assessment of mass deworming by mebendazole after 3, 6 and 18 months in Quynh Luu district, Nghe An province

The study was conducted from September 2003 to April 2005 to assess results of the mass de worming campaign in 5 primary schools in Quynh Luu district, central province of Nghe An. A pre-intervention survey showed a cumulative worm prevalence of 98%, of which the highest rate was Trichuris infection: 85.1 % followed by Ascaris: 83.6% and hookworm 30.3%. No difference of infection between females and males was found. Mixed infection was high with 54.3% double infection with Ascaris and Trichuris (88%), and 24.8% of triple infection, while a low single infection rate (20.8%) of which Trichuris was predominant, was found. A low prevalence of high intensity of infections was found with Ascaris (6.5%), hookworm (1%), Trichuris (0.5%) while a high prevalence of low intensity was found with all examined samples. The worm prevalence was found reduced after periodical mass deworming (every six months) with mebendazole 500mg, single dose. The cumulative infection reduced from 98% to 84.5% after six months and 72.2% after 18 months. Similarly, the Ascaris infection came down from 83.6% to 52.7% and 32.7%, the Trichuris from 85.1% to 70.6% and 56.1%. However, hookworm infection remained nearly unchanged (30.3% to 31.3% and 31.1%). The high and moderate intensity of infection was also reduced after intervention. The egg counts were reduced by 60% after 6 months, 73% after 18 months (after the third treatment) with Ascaris. Accordingly, it was reduced by 40% and 70%, respectively with Trichuris. No changes were found with hookworm. The intestinal worm infection control project supported by WHO has been a successful project in term of both technical and social aspects. The project was performed with good compliance of school children, their parents and teachers. Expertise and qualification of the provincial staff were also enhanced with regard to public health in general, and intestinal worm infection control, in particular.

Clonorchiasis in the Central provinces and intial measures of control

The study was conducted in 4 selected sites of 4 central provinces of Vietnam (Phu Yen, Quang Ngai, Quang Nam, and Binh Dinh). The examination of 2,249 stool samples showed an average infection rate of 13.16%; of which Binh Dinh occupied the highest proportion (31.78%), followed by Quang Nam (4.62%), Phu Yen (0.46%), and Quang Nam (0.45%). The infection density was of mild level, with an approximate 228 eggs per 19 stool. Treatment and health education were among the interventionalliver fluke control measures conducted at the pilot commune of My Chanh (Phu My district, Binh Dinh). The study found a better understanding and awareness of the local community towards liver fluke infection. Praziquantel 600mg (at 25mg/kg of body weight in 2 divided doses for 3 days) for use at field showed an egg clearance rate up to 77.52%. After one year of conducting measures at My Chanh commune, the liver fluke infection rate decreased by 74.10%, and the infection density by 76.75% compared with the previous intervention.

Control of intestinal worm infection in primary school children in Thua Thien-Hue province

Intestinal worm infections were investigated during 2002-2005 in 25 representative primary schools in Phu Loc district (Thua Thien-Hue province). A cumulative infection rate of 70.21 % was found, of which Ascaris: 55.48%, Trichuris: 26.71 %, hookworm: 37.33% and mixed infection of 2 or 3 species of worm: 38.2%. An intervention program including health education and mass deworming with mebendazole 500mg/single dose was carried out and appeared highly effective. The cumulative infection rate was found reduced by 63.46%, Ascaris 93.44%, Trichuris: by 44.80%, hookworm by. 64.79% and double infection by 77.95%. No more triple infection was found after the intervention. An expansion of control program of intestinal worm infections with the same activities of health education and mass deworming has, thereafter, been conducted in the entire province covering 3.872 primary schools with 122.221 school children and 6.015 teachers in 150 communes, towns. The good results have been achieved that considerably contributed to the community health care, especially school health care in the province. It is, therefore, recommended to sustain the program in the coming years.

ELISA confirmation of suspected human cysticercosis

During 9-year period 1992-12/2000, 3,814 serum samples collected from the patients suspected of having parasites were tested by ELISA to detect antibodies to Cysticercus cellulosae. A total of 163 (4.3%) serum samples were found positive. In term of clinical manifestation, neurocysticercosis forms (76.8%) were predominant including headache (31.2%), seizures (28.4%), intracrianial hypertension (26.9%), and paralysis (16.7%). Other clinical signs included subcutaneous nodules, (4.9%), ocular nodules (1.4%), and asymptomatic form (17.6%). Patients with neurocysticercosis forms were CT-scanned showing the changes in 73.6% of cases.

Effects of albendazone and praziquantel on seric glutamo-oxalo transaminase (SGOT) and seric glutamo-pyruvic transaminase (SGPT) in taenia cysticercosis treatment courses

The study was conducted in the Clinic of the National Insitute of Malariology, Parasitology and Entomology. Effects of albendazone and praziquantel on seric glutamo-oxalo transaminase (SGPT) and seric glutamo-pyruvic transaminase (SGPT) were investigated in 11 cystycercosis patients treated with three regimen courses: albendazole 7.5mg/kg/twice/24 hours x 30 day (regimenl), albendazole lOmg/kg/twice/24 hours x 20 days (regimen 2), and praziquantel 15mg/kg/twice/24 hours x 15 days (regimen3). Analysis of SGOT and SGPT made after each treatment course of albendazole showed an increase of SGOT and SGPT with the courses 1 and 2. However, they were found normalized one month after interruption of treatment (P > 0.005). Praziquantel (regimen 3) was found not to affect SOOT and SGPT in all treatment courses (P > 0.005).

Effects of de-worming on physical development of primary school children (6-11 years old)

A study on effects of the mass de-worming on physical development of primary school children was conducted in two years 2000-2001 in two primary schools of Sam Son town, Thanh Hoa province. Stool samples were collected from 495 school children and examined by Kato-Katz technique. Anthropometric indicators (height, weight) were measured. Two groups of intervention and control were divided among the enrolled school children. The prevalence of intestinal helminths as Ascaris lumbricoides, Trichuris trichura and hookworm was found to be 83.5%, 92.2%, 5.6%, respectively while it was 87.5%, 98.9%, 51.3%, respectively in the control group. Prevalence of Ascaris lumbricoides, Trichuris trichura and hookworm was markedly reduced in the study group after two rounds of treatment with mebendazole 500mg single dose with 6 month interval. It was found that there was a markerable relation between de-worming and malnutrition statu. The malnutrition status was significant decreased one year after intervention.

Enzyme polymorphism of Cx.quiquefasciatus say, 1823

During 2001-2005, nine enzyme systems were analyzed by using cellulose acetate electrophoresis of 8 wild caught collections of Cx.quiquefasciatus adults at different endemic places of W.bancrofti filariasis. There were differences found in allele frequencies of some polymorphic loci between the mosquito populations collected at the various geographical places and filariasis endemic levels. The observed average heterozygosity of the Cx.quiquefasciatus collections was found higher in the filariasis endemic areas (27.42%) than that in the non-endemic places (18.44%). The observed average heterozygosity of the Cx.quiquefasciatus collections of the "rural" environment was higher (24.09%) than that of the "urban" landscape (18.44%). Our findings suggested that those populations of mosquito with closer geographic and environmental conditions to one another have gained the higher genetic relationship. The mosquito population in the study site of Dien Tan, where W.bancrofti filariasis is present has a low genetic relationship and is different from three other study populations as a separated branch.

Epidemiological characteristics of intestinal helminth infection at 3 Highland provinces and intervention method in some pilots

Parasitological and KAP surveys were carried out in the highland provinces of Gia Lai, Kon Tum and Dak Lak, where 8.059 human stool samples were collected and examined for helminthes infection and some factors affecting on helminth infection in these provinces were also investigated showing a cumulative helminth infection rate from 46.32 to 51.75%, of which hookworm, Ascaris, Trichuris trichura were 39.76-46.67%; 4.91-10.63%, and 0.56-2.09%, respectively. Clonorchis sinensis infection was only found at some areas where the local people have a habit of eating raw-fish. Taenia saginata infection was found scattered with a low rate. In the KAP surveys, many people were found not to know the way of helminth infection (42.67-68.33%) and how to control it (43.16-84.50%). The rate of houses with no latrines was 7080.84%. The pilot intervention was simultaneously conducted at 6 primary schools by the combination of health education and mass de-worming with mebendazole 500 mg, single dose. One year later, the average infection rate was reduced by 56.68-71.16 %, of which, Ascaris from 46.21-78.64 %. Infection intensity of hook worm after the intervention was reduced 73.76-81.89% and Ascaris was 63.09-87.5%. Knowledge, attitude, and practice of the school children were significantly improved.

Epidemiology, pathological signs and treatment of paragonimiasis in Yen Bai provinces Luc Yen district

Paragonimiasis survey was carried out in 6 communes of Luc Yen district during 2002-2003. A total of 1.143 stool samples and 367 sputum samples were examined showing a positive rate of 0.5% and 6.8%, respectively. Twenty six Paragonimus patients were found in three communes of Khanh Hoa, An Lac and Dong Quan, most of which were children (80.8%). All the patients were found to have previously eaten baked stream crab. Almost all households in the foci were found to have poor hygienic condition with no latrine or under-standard latrine as well as the habit of free defecating and free roaming of domestic animals outside shelters. 198 stream crabs (Potamicus species) were examined showing the infection rate of Paragonimus metacercaria over 90%, while the examination of 173 water field crabs (Parathelphusa species) was negative. The species of Paragonimus was identified by PCR as Paragonimus heterotremus. Main symptoms of the Paragonimus patients were prolonged cough (100%), blood sputum (97.8%), breathlessness on exertion (100%), chest pain (80.7%) tachypnea (73%), rales (69%), no rales (31%). Non-pulmonary signs were subcutaneous nodules (7.6%), hepatomegaly (3.8%), headache (46%) were also found. Chest films showed infiltrates (61.9), nodues (57.1 %). Small cavities (9.5%), lesions were in the lower lobe (90.4%), enlargement of the hilar lymph nodes (23.8), pleural effusion (9.5%). Blood examination showed eosinophilia of 88.4%. The patients were treated with praziquantel 25mg/kg thrice daily for 2 consecutive days, 92% patients were cured with no eggs and symptoms found three months after drug administration.

Foodborne helminthic infection in pork, beef and freshwater fish in Hanoi, Vietnam

Food is indispensable protein-energy resource for human life. Recently, food safety has become a health problem, including infection with parasites. According to a study carried out in the slaughterhouses and markets in Hanoi city in 2003-2004, the inspection of 9.755 cattle and 138.298 pigs showed only one pig infected with Cysticercus (infection rate of 0.0723 %), inspection of 1.557 beef stalls and 5.570 pork stalls in 5 Hanoi markets showed only one pig in Thanh Cong market infected with Cysticercus (the infection rate of 0.018%). Seven of 10 species of freshwater fishes examined by microscopy were found infected with liver fluke metacercaria. The infection rate in Carassius carassius: 21.7% (13/60), Mylophryngodon piceus: 13.3% (8/60), Clarias fuscus: 6.7% (4/60), Cyprinus carpi: 3.3%(2/60), Ophicephalus maculates of 3.3%(2/60), Tilapia mossambica of 1.7% (1/60), Cirrhina molitorella of 1.7% (1/60). Eel infected with Gnathostoma spinigerum owas 6.7% (4/60). Metacercaria of liver fluke were identified as Clonorchis sinensis. Inspection of 100 samples of raw fish, 200 samples of raw-pork, 50 samples Qf raw-beef showed only one raw-fish sample infected with liver fluke larvae (1%) in 37 Cua Nam restaurant. A survey on alive Clonorchis sinensis metacercaria in raw-fish was made in Nam Dinh province and survey on Paragonimus heterotremus metacercaria in grilled crab (the dish was prepared by local people) was made in Yen Bai province. The rate of live metacercaria infection in raw-fish was 93-95% and the rate of live metacercaria in baked-crab was 23.3-65%. The results of this study have significantly contributed to the assessment of parasitic germs contamination of food in Hanoi, particularly in meat and fish. These results are also an alarm for the poor hygienic conditions of food to control.

Helminthic infection in three communes in the mountainous province of Lao Cai

Lao Cai is a northwest mountainous province where the local people, especially in the high and remote areas still remain lots of backward customs as using no latrine and eating baked crab. The previous surveys showed a high proportion of the local people (39.5%) eating baked crab, and the Potamicus infection of crab was 69.9%. A study on paragonimiasis was conducted in three communes from June 2000 to March 2001. A total of 2.149 stool samples examined by Kato technique showed a cumulative of worm infection of 96.1 %, of which Ascaris 88.7%, hookworm 67.7%, Trichuris 34%, paragonimiasis 0.28%, and taeniasis 4.1 %. A high mixed infection (70.5%) was found. Direct examination of sputum samples collected from three communes showed a paragonimiasis infection rate of 3.2%.

Helminthic infection prevention in 2000-2005 and the direction on the helminthic infection prevention government project to 2010

Initial using molecular method for identifying species and disstribution of man trematode and cestodes in Vietnam

During 2003-2005, samples of adult worm and larvae of main trematode and cestode collected from 31 provinces over Vietnam were identified for species using morphology and confirmed by molecular method (PCR techniques) using mitochondrial genome of cob, coxl, nadl, and 18S Ribosome. These sequencing genome were compared with original strains from China, Thailand, Korea, Japan, Australia, Mexico, Indonesia, Tanzania, America... These samples have been identified by molecular method as Paragonimus heterotremus; Fasciola gigantica (hybrid with F.hepatica); Clonorchis sinensis in the North, Opisthorchis viverrini in the South; Fasciolosis bush; human Taenia asiatica; human Taenia solium (including Cysticercus cellulosae).

Intestinal worm infection in school children and use of living water resource and latrine

Relation between intestinal worm infection and hygienic conditions was investigated during two years 2004-2005. Stool samples of 414 school children collected in three pilot communes in the mountainous district of A Luoi (Thua Thien-Hue province) were examined. The cumulative intestinal worm infection was found to be 66.18%, of which Ascaris lumbricoides, Trichuris trichllria, hookworm and mixed infection with two or three species of worm were 54.11%, 13.04%, 36.47%, and 28.26%, respectively. In the surveys conducted in 21 communes and towns of this district, the rate of hygienic latrine was 60.33%. The coverage of hygienic latrine was low (0.51 hygienic latrine/ a household), on average, one per 10 persons. The available latrines are mainly open-ground holes ( 61.28%) and self filtered-water treated ones ( 21.71 %). Hygienic water was usable only 71.87% of the households, of which 36.64%, 41.40% and 24%, respectively used tap water, tank-filtered water, ground-well water or spring water. The poorly hygienic utilization of latrines and life-water recommended to urgently carrying out appropriate measures to control the intestinal worm infection in children.

Investigation of helminthies infection in three communes of Bao Yen district, Lao Cai province

A study was designed and conducted from 1999 to 2001 to evaluate the heminthies infection in three communes of Luan Thuong, Long Khanh and Luong Son of Bao Yen district, Lao Cai province where the local people have the backward habits of life and agriculture. A total number of 1,426 stool samples collected from the three investigated sites was examined by Kato method. A high cumulative infection rate of helminthiasis (90.5%) was found, of which Ascaris: 77.3%, hookworm: 65.7%, Trichuris: 20.8%, lung fluke 1.54% and Taenia: 1.12%. The mixed infection rate was 45.6%. The examination of 452 sputum samples showed a lung fluke infection rate of 4.42%.

Leishmaniasis survey in the Northeast province of Quang Ninh

An initial investigation on epidemiology and entomology of leishmaniasis was conducted in Ha Long city and Cam Pha town, where leishmaniasis patients were previously confirmed by the Vietnam-Sweden hospital in 200l. Clinical examinations were made with 1,236 people for sorting suspected leishmaniasis patients. The suspected patients were examined with different techniques. Giemsa stained samples of peripheral blood (377 persons), born marrow (290 persons including 64 HIV infected ones) were examined, and parasites were cultured in N.N.N. (Novy-MacNeal-Nicolle) medium. The Giemsa staining examination was also made with animal samples of dog peripheral blood (170 dogs), born marrow, liver, spleen (10 dogs), and rat born marrow and liver (100 rats). No positive cases were found. Light traps were used in the entomological study resulted in catching 104 sand flies (45 males and 59 females). They were classified as Phlebotomus genus, Phlebotomus (Anaphlebotomlls) stanton; species.

Lymphatic filariasis in five provinces of Vietnam

Lymphatic filariasis prevalence was investigated in the provinces of Lam Dong, Dak Lak, Gia Lai, Kom Turn (Plateau) and Ninh Thuan. Examination of night blood collected from 5,734 residents in these provinces showed two positive cases (0.3% or 2/658) in Phuoc Thanh commune (Ninh Thuan province's Bac Ai district). Entomological surveys were also conducted in 8 communes of 4 Plateau provinces. Presence of primary W.bancrofti vectors as Cx.quinquefasciatus and Cx. vishnui was found with relatively high percentage and density. Inconsiderable percentage of primary vector of B.malayi was collected. Microfilaria was not found in dissection of 1.191 mosquitoes.

Mode of transmission of soil-transmitted helminhthiasis in a moderning community in Vietnam

To elucidate the mode of transmission of soil-transmitted helminhthiasis (STH), human stool sample, soil and dust, vegetables, fingers and nails, and water and air were studied in a rapidly modernizing suburb of Hanoi, Vietnam. 72.6% of the examined inhabitants was found infected with any Ascaris, Trichuris and hookworm. Parasite eggs were found in 63.2% of 290 soil samples, 46.2% of 344 dust samples, 30% of 317 vegetable samples, 7.5% of 506 finger samples and 3.1% of 326 snail samples, 1.4% of 290 air samples, and 33.5% of 197 water samples. Environments were found highly contaminated with parasite eggs, especially Ascaris and Trichuris eggs. It is suggested that the unhygienic habits of the local villagers such as using night soil or compost as fertilizer that have not been treated or treated with not enough time, eating raw vegetables, not washing hand before meal or after defecating, free roaming or keeping livestock outside of the animal shelters are risky factors for contamination of the environments.

Morphology and PCR determination of Clonorchis sinensis in Kim Son district of Ninh Binh province

A foci of liver fluke is endemic in Tan Thanh commune (Kim Son district of the southeast coastal province of Ninh Binh). Both techniques of morphology and PCR were applied to identify the species of parasites collected form this commune. In the PCR study, two pairs of primers designed for this research appeared able to identify specifically the mitocondrial CoxI gene and allowable to distinguish Opisthorchis viverini from Clonorchis sinenesis. The species of liver fluke collected form the study site of Tan Thanh commune has been determined by both morphological signs and PCR analysis as Clonorchis sinensis.

Relationship between anaemia with intestinal parasitic infection in school children in mountainous commune of Thanh Hoa province

A cross-sectional survey was carried out in October 2004 in Xuan Khang primary school, Nhu Thanh district, Thanh Hoa province. 512 primary school children were interviewed and examined their faecal samples for detecting worm eggs in stool by Kato-Katz methods. They also were taken blood for measurement of hemoglobin concentration by Kits of Human Ltd. The findings were as follow: the proportion of anaemia in Xuan Khang school children was 22.1%. There was no significant difference of anaemia rate by sex and classes, but it was very significant different by ethnic groups. The anaemia rate in school children of Muong, Thai and Kinh ethnic groups was 30.5%, 30.9% and 15.3%, respectively. The cumulative intestinal parasitic infection rate of Xuan Khang school children was 87.7% of which Ascaris lumbricoides, Trichuris trichura and hookworm were 46.3%, 73.4%, 39.5%, respectively. The majority of intestinal parasitic infection cases was of mild infection of which Ascaris lumbricoides (60.3%), Trichuris trichura (71.6%) and hookworm (86.6%). The infection of hookworm was determined to be the high risk factors for anaemia with OR = 1.9. Especially, when the intensity of hookworm infection accounts for 2000 - < 4000 epg with OR = 2.1 and >= 4000 epg with OR = 10.1.

Sero-epidemiological investigation of cysticercosis in the Southern provinces

During a nine year period 1992-2000, a total of 3.814 serum samples collected from the patients suspected of having parasite infection were ELISA tested for antibodies to Cysticercus cellulosae. A prevalence of 4.3% (163/3.814 samples) was found. The infection rate was found different varying from 1 year to 79 years of age with the pick from 26 to 30 years old (14.7%) and from 36 to 40 years old (15.9%). The infection rate was also varied with genders (56.4 % of males and 43.6% of females). The patients came mainly from Ho Chi Minh city and the provinces of An Giang, Tay Ninh, and Dong Nai. The survey also revealed that most of the patients had poor knowledge about the disease and the way of transmission.

Situation of Lymphatic filariasis in Bac Ai district of Ninh Thuan province and its control

Lymphatic filariasis survey was conducted in Bac Ai district of Ninh Thuan province (that borders with Khanh Vinh district of Khanh Hoa province) where the ethnic minority groups of Raglay are 96% of the total district population. A prevalence of 0.6% of lymphatic filariasis was found in the whole district. The mass treatment with diethylcarbamazine and albendazole was conducted in the district in two years 2003 to 2005. A high percentage (94%) of the doseable people (or 82% of the total district population) was treated. Inconsiderable side effects were found after mass administration with diethylcarbamazine 6mg/kg/body and albendazole 400mg, adult single dose.

Situation of filariasis mosquitoes and susceptibility of Cx.quinquefasciatus and Cx.vishnui to insecticides in the endemic area of Wuchereria bancrofti filariasis

Studies on filariasis mosquitoes and susceptibility of Cx.quinquefasciatus and Cx. vishnui to insecticides were conducted in September 2004 and May-2005 at Khanh Trung commune, Khanh Vinh district, Khanh Hoa province. 22 mosquito species belonging to 5 genus have been found. A high density of main vectors of W.bancrofti filariasis, but very low density of vectors of B.malayi filariasi.s were found. Microfilaria was not found in dissection of 805 mosquitoes of 6 species (An.barbumbrosus, An.vagus, Cxfuscocephala, Cx quinquefasciatus, Cx.tritaeniorhynchus and Cx.vishnui) Cx.quinquefasciatus was found highly resistant to lambdacyhalothrin, alphacypermethrin and malathion with mortalities rates of 11%, 21% and 60,5%, respectively. Similarly, the mortalities of CX.vishnui were 19.76%, 23.83% and 13%-17%.

Species composition of medical arthropod in some places along Ho Chi Minh road

A survey on species composition of medical arthropod was conducted in 21 places along the Ho Chi Minh road from Kon Tum to Thanh Hoa. A total of 19.622 samples of medical arthropod belonging 182 species have been collected including 3 species of flea (Siphonapttera), 6 species of tick (Ixodidea), 17 species of chigg (Trombiculidea), 21 species of flea (Gamasoidea), 1 species of louse, 88 species of mosquito, 45 species of flies and one species of yellow fly. They belong to 49 genus, 15 families, 3 orders (order Siphonaptera, order Acarina and order Diptera), two classes (class Insecta and class Arachida) belonging Arthropoda The distribution of the found species were found as follow: Twenty species were found in 8 provinces (three species of flea, one species of tick, 7 species of Anophelinea and 9 species of ClIlicinae; twenty one species found in 5-7 provinces and 96 species found in 1-4 provinces (except for flies). Most of species vector species were found in different surveyed places (10 to 21 places). More than 10.000 arthropod specimens have been collected.

Supplement study of entomological indices of Aedes aegypti in Vietnam

Supplement entomological studies (adult mosquito, larvae, breeding sites) of Aedes aegyti conducted at 22 places in 10 provinces and cities showed that the indices of adult mosquito and larvae were still high, particularly in the coastal plain regions. In 20 places, the Breatau index in 15 places (75%) was over 50, 3 places (6.66%) over 200. In 17 places (85%) the container index was over 10%. The density of mosquito in 6 places (33.33%) was over one mosquito/house. The water containers were diversified in the coastal areas of South Vietnam where the local people were lack of fresh and clean water. In average, there were 3.5 to 6.5 water containers/house, while it was from 1 to 2.5containers/house recorded in the other areas. Three kinds of breeding sites for mosquito of flower jars, anti-ant pots and discarded garbage were of more than 50% of total water containers, which need to be cared in Ae.aegypti control.

Susceptibility of Aedes aegypti to insecticides in Vietnam

During 2000 to 2002, studies on the susceptibility of Aedes aegypti to insecticides were conducted at 22 places in 11 provinces and cities in four different regions of Vietnam. Aedes aegypti was found susceptible to malathion, but resistant to DOT in almost of all the study sites. It continues to be susceptible to the pyrethroid group of insecticides (permethrin, lambdacyhalothrin. deltamethrin and alphacypermethrin) in many places in the Northern regions, but is resistant to these insecticides in many places in the Southern and Central Highlands in Vietnam. However, the species was found highly and widely resistant to entofenprox.

Therapeutic efficacy of Triclabendazole in treatment of human fascioliasis

Human fasciolosis has recently been widely found in many regions of Vietnam confirmed by clinical and para-clinical examinations. Therapeutic efficacy of the specific treatment drug for this disease-triclabendazole (provided by WHO) was investigated in a study conducted in the Hospital for Tropical Diseases, Ho Chi Minh city from November 2004 to August 2005. A total number of 53 patients treated with single dose of triclabendazole 10 mg/body weight were found to have good compliance. All clinical symptoms disappeared 24 hours after the drug administration and three days later the patients were allowed to leave hospital with the good healthy status: pinky face, no abdominal pain and fever, normal vital signs, and good general status. All the patients were requested to return to hospital for re-checking after three months. However, only 18 of them had followed the request due to the objective reasons. The returned ones were found to have good health state with no resurgent clinical features and normal laboratory findings except for a slow decrease of antibody titer. The remaining patients were followed up via phones and letters showing their good health status. Triclabendazole was found to be a good anti-fascioliasis drug with high safety and efficacy and low side effects, and is recommended to widely use in treatment of fascioliasis.

Therapeutic efficacy of triclabendazole in threatment of fasciolopsis

Triclabendazole was used in treatment of 249 fascioliasis patients selected from 25 provinces including 19 Northern and 6 Southern ones. Two different doses were used for two groups: l0mg/kg/body for 226 patients, and 20mg/kg/body for 43 others, twice use per day with the interval 6-8 hours after meals. Symptoms on these fascioliasis patients were found as positive ELISA test with Fasciola gigantica antigen (100%), prejudice in liver by ultrasound (87.9%), pain of liver (87.1%), eosinophillia (63.5%), plodding (26.1%), fever (39.8%), digestive disorder (20.1 %) and. positive stool examination with Fasciola egg (16.9%). Most of the symptoms were decreased and disappeared within 1 month after treatment except for pain of up-liver in some patients that lasted longer and disappeared within 6 to 12 months after treatment. The cure rate was 92.9% for 1 month after treatment, 95.2% for 3 months after treatment and 100% for 6 months after treatment. Ultrasound prejudice in liver decreased and disappeared 80.9% for 1 month, 92.6% for 3 months, 96.3% for 6 months and 100% for 12 months after treatment. Eosin returned to normal of 90.7% for 6 months and 100% for 12 months after treatment. ELISA test with F. gigantica antigen become negative of 89.4% for 6 months and 100% for 12 months. GOT, GPT, urea and creatinin test were not pathologically changed during 1 month using triclabendazole. Side effects of triclabendazole were inconsiderable and disappeared without medical treatment. Triclabendazole may be recommended in treatment of fascioliasis in Vietnam with doses of 10 or 20 mg/kg/ body.

Trombiculidae distribution associated to tsutsugamushi in Quang Ninh province

During 2000-2002, 449 tsutsugamusi patients were admitted to the Dong Bi hospital. They came mainly from Dong Bi town, districts of Dong trieu and Yen Hung and earn Pha town. The disease occurred sporadically during the year but more frequently found between May and October. The surveys were made in the endemic areas and 14 species of trombiculidae have been found as: L(L.) deliense, L.(L) fulleri, E hirsti, E. wichmanni, A(Lau.) indica, N. gallinarum, N. posekanyi, G.(W.) chinensis, G.(W.) pacifica, G.(W) isonichia, G.(W.) micropelta, G.(W) parapacifica, G.(W.) rustica and G. ( G.) mirabilis. For of them identified to be vectors are: L.(L.) deliense, A.( Lau.) indica, G.(W.) chinensis, G.(W.) parapacifica. Those parasite species were found in mice in almost all the surveyed sites, especially in the places with more tsutsugamusi patients. The patients were admitted to hospital with such clinical signs as biting spots (94.2%), fever (100%), peripheral glands (98.7%) and rash (52.2). Three regimens determined effective in treatment of tsutsugamusi are: (1) chloramphenicol: 30-50mg/kg/24hours/ 2-3 times x 5-7 days; (2) tetraxycline: 30-40mg!kg/24hours/2-3 times x 5-7 days, and doxycyclin 4mg!kg/24hours x 3-5 days.

Two epidemics of Trichinellosis Tuan Giao district of Lai Chau province

Twenty two people were confirmed infected with trichinellosis after eating a raw pork dish "Lap" in a weeding party organized on 220d November 2001 in the Quai To commune (Tuan Giao district of northwest province of Lai Chau). The pork fish "Lap" was prepared from a local pig. Later, 20 other people were also found infected with the same disease after eating "Lap" made of a local pig in a funeral party held on 2151 September 2004 in the same place. Symptoms were nearly simultaneously appeared in those people within 1-2 weeks (in average 10.3 days). They were fever (100%), muscle pain (100%), walking with difficulty (100%), swallowing with difficulty (90.5%), edema (92.9%), weight loss (90.5%), itch (85.7%), abnormal speaking (54.8%), breathless (64.3%), diarrhea (50.0%), and blood stool (4.8%). Two patients (4.8%) died. The patients were aged from 21 to 65 year old with most infection rate between 31-50 years old, most of which were men.