Efficacy of the Tent-Pole Technique in Horizontal Ridge Augmentation

Abstract Objective: To evaluate the efficacy of the technique for ridge augmentation prior to implant placement. Material and Methods: Six patients with nine sites presenting an initial ridge width of smaller than 4 mm were included in this study. The tent-pole technique (combination of osteosynthesis screws measuring 1.5 mm in diameter, ABBM, and resorbable collagen membrane) was applied at defect sites. After eight months of healing time, implants were placed in the treated sites. The primary outcomes (radiographic initial ridge width, re-entry ridge width, ridge width gain) were measured by cone-beam computed tomography in reference buccopalatal cross-sections and the secondary outcomes (clinical parameters) were recorded by a digital caliper at the first and second stages. Results: After grafting, the radiographic ridge width increased by 3.02 ± 1.11 mm (1.57-4.75 mm) at 2 mm below the crest and 3.32 ± 1.70 mm (0.23-5.66 mm) at 6 mm below the crest significantly (p< 0.05). For clinical results, the mean horizontal dimension gain was 3.21 ± 1.04 mm (1.83-4.57 mm), while the mean reduction in dimension was 0.38 ± 0.33 mm. These results were statistically significant (p<0.05). Uneventful healing and no infections or membrane exposure were recorded at all sites during the study process. Three of nine (33.33%) defect sites required additional bone grafting. Conclusion: The tent-pole technique is an effective method for increasing the horizontal ridge dimension, minimizing postoperative complications, and facilitating subsequent implant placement.

Cost of Hospitalization for Foodborne Diarrhea: A Case Study from Vietnam

Vietnam is undergoing a rapid social and economic developments resulting in speedy urbanization, changes in methods for animal production, food marketing systems, and food consumption habits. These changes will have major impacts on human exposures to food poisoning. The present case study aimed to estimate hospitalization costs of foodborne diarrhea cases in selected health facilities in Vietnam. This is a facility-based cost-of-illness study conducted in seven health facilities in Northern Vietnam. All suspect cases of foodborne diarrhea, as diagnosed by doctors, who admitted to the studied health facilities during June-August, 2013 were selected. Costs associated with hospitalization for foodborne diseases were estimated from societal perspective using retrospective approach. We included direct and indirect costs of hospitalization of foodborne diarrhea cases. During the study period, 87 foodborne diarrhea cases were included. On average, the costs per treatment episode and per hospitalization day for foodborne diarrhea case were US$ 106.9 and US$ 33.6 respectively. Indirect cost (costs of times to patient, their relatives due to the patient's illness) made up the largest share (51.3%). Direct medical costs accounted for 33.8%; direct non-medical costs (patient and their relatives) represented 14.9%. Cost levels and compositions varied by level of health facilities. More attentions should be paid on prevention, control of foodborne diarrhea cases in Vietnam. Ensuring safety of food depends on efforts of everyone involved in food chain continuum, from production, processing, and transport to consumption.

Patterns of Health Expenditures and Financial Protections in Vietnam 1992-2012

Health financing has been considered as an important building block of a health system and has a key role in promoting universal health coverage in the Vietnam. This paper aims to describe the pattern of health expenditure, including total health expenditure and composition of health expenditure, over the last two decades in Vietnam. The paper mainly uses the data from Vietnam National Health Account and Vietnam Living Standards Survey. We also included data from other relevant published literature, reports and statistics about health care expenditure in Vietnam. The per capita health expenditure in Vietnam increased from US$ 14 in 1995 to US$ 86 in 2012. The total health expenditure as a share of GDP also rose from 5.2% in 1995 to 6.9% in 2012. Public health expenditure as percentage of government expenditure rose from 7.4% in 1995 to nearly 10% in 2012. The coverage of health insurance went up from 10% in 1995 to 68.5% in 2012. However, health financing in Vietnam was depending on private expenditures (57.4% in 2012). As a result, the proportion of households with catastrophic expenditure in 2012 was 4.2%. The rate of impoverishment in 2012 was 2.5%. To ensure equity and efficient goal of health system, policy actions for containing the health care out-of-pocket payments and their poverty impacts are urgently needed in Vietnam.

Current Status of Taeniasis and Cysticercosis in Vietnam

Several reports on taeniasis and cysticercosis in Vietnam show that they are distributed in over 50 of 63 provinces. In some endemic areas, the prevalence of taeniasis was 0.2-12.0% and that of cysticercosis was 1.0-7.2%. The major symptoms of taeniasis included fidgeted anus, proglottids moving out of the anus, and proglottids in the feces. Clinical manifestations of cysticercosis in humans included subcutaneous nodules, epileptic seizures, severe headach, impaired vision, and memory loss. The species identification of Taenia in Vietnam included Taenia asiatica, Taenia saginata, and Taenia solium based on combined morphology and molecular methods. Only T. solium caused cysticercosis in humans. Praziquantel was chosen for treatment of taeniasis and albendazole for treatment of cysticercosis. The infection rate of cysticercus cellulosae in pigs was 0.04% at Hanoi slaughterhouses, 0.03-0.31% at provincial slaughterhouses in the north, and 0.9% in provincial slaughterhouses in the southern region of Vietnam. The infection rate of cysticercus bovis in cattle was 0.03-2.17% at Hanoi slaughterhouses. Risk factors investigated with regard to transmission of Taenia suggested that consumption of raw meat (eating raw meat 4.5-74.3%), inadequate or absent meat inspection and control, poor sanitation in some endemic areas, and use of untreated human waste as a fertilizer for crops may play important roles in Vietnam, although this remains to be validated.

Paragonimus and Paragonimiasis in Vietnam: an Update

Paragonimiasis is a food-borne parasitic zoonosis caused by infection with lung flukes of the genus Paragonimus. In Vietnam, research on Paragonimus and paragonimiasis has been conducted in northern and central regions of the country. Using a combination of morphological and molecular methods, 7 Paragonimus species, namely P. heterotremus, P. westermani, P. skrjabini, P. vietnamensis, P. proliferus, P. bangkokenis and P. harinasutai, have been identified in Vietnam. Of these, the first 3, P. heterotremus, P. westermani and P. skrjabini, are known to infect humans in other countries. However, in Vietnam, only P. heterotremus, found in some northern provinces, has been shown to infect humans. Even nowadays, local people in some northern provinces, such as Lai Chau and Yen Bai, are still suffering from P. heterotremus infection. In some provinces of central Vietnam, the prevalence and infection intensity of P. westermani metacercariae in freshwater crabs (the second intermediate hosts) are extremely high, but human cases have not been reported. Likewise, although P. skrjabini was found in Thanh Hoa Province, its pathogenicity to humans in Vietnam still remains uncertain. The results of molecular phylogenetic analyses of Vietnamese Paragonimus species provides new insights on the phylogeny and taxonomy of the genus Paragonimus. Comprehensive molecular epidemiological and geobiological studies on the genus in Vietnam and adjacent countries are needed to clarify the biodiversity and public health significance of the lung flukes.

Foodborne Trematode Metacercariae in Fish from Northern Vietnam and Their Adults Recovered from Experimental Hamsters

The prevalence of foodborne trematode (FBT) metacercariae was investigated in fish from 2 localities of northern Vietnam in 2004-2005. Freshwater fish (9 species) were collected from local markets in Hanoi City (n=76) and Nam Dinh Province (n=79), and were examined for FBT metacercariae using the artificial digestion technique. Adult flukes were obtained from hamsters experimentally infected with the metacercariae at day 8 post-infection. Three (Haplorchis pumilio, Centrocestus formosanus, and Procerovum varium) and 6 (Haplorchis taichui, H. pumilio, C. formosanus, P. varium, Stellantchasmus falcatus, and Heterophyopsis continua) species of FBT metacercariae were detected in the 2 regions, respectively. Overall, among the positive fish species, H. pumilio metacercariae were detected in 104 (80.0%) of 130 fish examined (metacercarial density per infected fish; 64.2). C. formosanus metacercariae were found in 37 (40.2%) of 92 fish (metacercarial density; 14.7). P. varium metacercariae were detected in 19 (63.3%) of 30 fish (Anabas testudineus and Mugil cephalus) (metacercarial density; 247.7). S. falcatus metacercariae were found in all 10 M. cephalus examined (metacercarial density; 84.4). H. continua metacercariae (2 in number) were detected in 1 fish of Coilia lindmani. Morphologic characteristics of the FBT metacercariae and their experimentally obtained adults were described. The results have demonstrated that various FBT species are prevalent in northen parts of Vietnam.

An Outbreak of Trichinosis with Molecular Identification of Trichinella sp. in Vietnam

The 5th outbreak of trichinosis occurred in a mountainous area of North Vietnam in 2012, involving 24 patients among 27 people who consumed raw pork together. Six of these patients visited several hospitals in Hanoi for treatment. Similar clinical symptoms appeared in these patients within 5-8 days after eating infected raw pork, which consisted of fever, muscle pain, difficult moving, edema, difficult swallowing, and difficult breathing. ELISA revealed all (6/6) positive reactions against Trichinella spiralis antigen and all cases showed positive biopsy results for Trichinella sp. larvae in the muscle. The larvae detected in the patients were identified as T. spiralis (Vietnamese strain) by the molecular analysis of the mitochondrial cytochrome c oxidase subunit III (cox3) gene.

Virulence factors in Escherichia coli isolated from calves with diarrhea in Vietnam

This study was conducted to determine the prevalence and characteristics of pathogenic Escherichia (E.) coli strains from diarrheic calves in Vietnam. A total of 345 E. coli isolates obtained from 322 diarrheic calves were subjected to PCR and multiplex PCR for detection of the f5, f41, f17, eae, sta, lt, stx1, and stx2 genes. Of the 345 isolates, 108 (31.3%) carried at least one fimbrial gene. Of these 108 isolates, 50 carried genes for Shiga toxin and one possessed genes for both enterotoxin and Shiga toxin. The eae gene was found in 34 isolates (9.8%), 23 of which also carried stx genes. The Shiga toxin genes were detected in 177 isolates (51.3%) and the number of strains that carried stx1, stx2 and stx1/stx2 were 46, 73 and 58, respectively. Among 177 Shiga toxin-producing E. coli isolates, 89 carried the ehxA gene and 87 possessed the saa gene. Further characterization of the stx subtypes showed that among 104 stx1-positive isolates, 58 were the stx1c variant and 46 were the stx1 variant. Of the 131 stx2-positive strains, 48 were stx2, 48 were stx2c, 11 were stx2d, 17 were stx2g, and seven were stx2c/stx2g subtypes. The serogroups most prevalent among the 345 isolates were O15, O20, O103 and O157.

Gastric and colo-rectal cancer mortality in Viet Nam in the years 2005-2006.

BACKGROUND: The International Collaborative Epidemiological Study of Host and Environmental Factors for Stomach and Colorectal Cancers in Southeast Asian Countries (SEACs) has been conducted in Viet Nam from 2003 to 2008 on a case-control basis. For further effective primary prevention, we examined gastric and colorectal cancer mortality nationwide in eight regions of Viet Nam in 2005-06. METHODS: Both demographic data and lists of all deaths in 2005-06 were obtained from all 10,769 commune health stations in Viet Nam. Five indicators included name, age, sex, date of death and cause of death was collected for each case. We selected only communes having the list of deaths with clear cause for each case and crude mortality rate for all causes from 300-600/100,000 as published by the Ministry of Health for a reasonable accuracy and completeness. Obtained data for all causes, all cancers, stomach and colorectal cancer deaths as well as demographic information were processed using Excel software and exported to STATA 8.0 for estimation of world age-standardized cancer mortality rates per 100,000. RESULTS: Data were available for 1,246 gastric cases, (819 male and 427 female) with age-standardized mortality rates from 12.7 to 31.3 per 100,000 in males and from 5.9 to 10.3 per 100,000 in females in the 8 regions of the country. For colorectal cancers, 542 cases (268 male and 274 female) gave mortality rates from 4.0 to 11.3 per 100,000 in males and from 3.0 to 7.8 per 100,000 in females. DISCUSSION: Stomach cancer mortality in males in the region of North East in the North Viet Nam (2005-06) was higher than that in Japan (2002) (31.3 versus 28.7 per 100,000) while colorectal cancer in Viet Nam was lower. While prevalence of Helicobacter pyloris infection in Viet Nam was from 70-75% in both males and females, the stomach cancer rate in males was significantly higher than in females, 31.3 versus 6.8 per 100,000, suggesting an influence of other environmental risk factors. Whether protective factors are operating against colorectal cancer in Viet Nam now needs to be explored.

The first poison control center in Vietnam: experiences of its initial years.

Poisoning is a sparsely studied but major health problem in Vietnam. In this hospital-based retrospective study, the medical records of all cases of poisoning admitted to the Poison Control Center in Hanoi from 1999 to 2003 were carefully reviewed. A total of 1,836 poisoning emergencies were recorded. The female:male ratio was approximately 1:1. The largest number of poisoned patients was found in the age-group 15-24 years. A vast majority of the toxic exposures (74.1%) occurred at the patients' homes. Suicidal poisoning constituted about one third of all cases. The most commonly involved toxic agents consisted of the heterogeneous group "food poisoning" (35.1%), pharmaceuticals (33.8%), toxins from poisonous animals, mostly snake bites (12.6%), and pesticides (9.1%). On admission, two thirds of the patients had mild symptoms (Poisoning Severity Score, PSS grade 1), while more than a quarter displayed pronounced clinical signs of poisoning (PSS grades 2-4). The most frequently used poisoning-specific treatments were gastric lavage (30.2%) and administration of activated charcoal (35.4%) and cathartics (34.2%). Intensive care measures, such as mechanical ventilation and dialysis, were applied less frequently, in 6.5% and 1.7%, respectively. Specific antidotes were given in 5.2% of the cases. The total number of fatalities was 21 (1.1%) and 10 patients were discharged with a neurological sequela. Hypnotic pharmaceuticals (mainly barbiturates), heroin, and pesticides were involved in a majority of the fatalities. These data provide an important basis for poisoning prevention efforts in developing countries\such as Vietnam.

Leucocyte and lymphocyte count in cases of bird flu infection in Thailand.

Bird flu or avian flu is a new emerging Infectious disease. The H5N1 virus has not only affected the fowls but also the human beings. Severe disease with high mortality in humans in Vietnam and Thailand are reported. This mini-study was undertaken in order to document the Impact of bird flu infection on leucocyte and lymphocyte counts among patients of Thailand. This study was designed as a descriptive retrospective study. A literature review on the papers concerning human bird flu in Thailand was performed. According to this study, there are 6 cases covering 12 Thai patients with confirmed diagnosis of bird flu. However, the complete data were available on only 6 patients. The reported leucocyte count ranges from 1,200 cells/cmm to 5,680 cells/cmm and the lymphocyte count ranges from 454 cells/ cmm to 1,440 cells/cmm. The average leucocyte and lymphocyte counts equalled to 3,230.0 +/- 1,552.7 cells/cmm and 748.7 +/- 348.5 cells/cmm, respectively. According to this study, low lymphocyte count is common. This can support the previous observation for the lymphocyte suppression effect of H5N1 virus.

Seroprevalence of Toxoplasma gondii antibody in Vietnamese villagers.

Toxoplasmosis caused by Toxoplasma gondii is a protozoan infection found worldwide. It usually produces non-specific symptoms, but in pregnant women and immunocompomised individuals, it may cause severe and fatal illness. Many serological studies have been done in various parts of the world, but information is lacking for Vietnam. A seroprevalence study of T gondii antibodies in Vietnamese villagers (n = 650) was performed using the Sabin-Feldman dye test. The average seroprevalence was 4.19% (95% CI = 1.78-4.62), including 6.36% (95% CI = 3.22-11.09), 4.73% (95% CI = 1.92-9.50) and 1.09% (95% CI = 0.23-3.15) from Nghe An, Lao Cai and Tien Giang provinces, respectively. This study confirmed the low prevalence of toxoplasmosis in Vietnam similar to other countries in the region. Further studies are necessary in order to provide a complete picture for the country.

Nutritional Status and the Characteristics Related to Malnutrition in Children Under Five Years of Age in Nghean, Vietnam / 예방의학회지

OBJECTIVES: This study was conducted to assess the nutritional status and characteristics related to malnutrition in children less than five years of age in Nghean, Vietnam. METHODS: In this study, which was conducted in November 2007, 650 child-mother pairs were selected using a two-stage cluster sampling methodology. A structured questionnaire was then administered to the mothers in their home settings. Anthropometric measurement was then used to determine if children were underweight (weight-for-age), wasting (weight-for-height) and stunting (height-for-age) based on reference data from the National Center for Health Statistics (NCHS)/World Health Organization (WHO). Logistic regression analysis was then used to describe the hierarchical relationships between potential risk factors and malnutrition. RESULTS: The mean Z-scores for weight-for-age, heightfor-age and weight-for-height were -1.46 (95% CI=-1.57, -1.35), -1.44 (95% CI=-1.56, -1.32) and -0.71 (95% CI=-0.82, -0.60), respectively. Of the children included in this study, 193 (31.8%) were underweight, 269 (44.3%) were stunting and 72 (11.9%) were wasting. Region of residence, the mother's level of education and occupation, household size, number of children in the family, weight at birth and duration of exclusive breastfeeding were found to be significantly related to malnutrition. CONCLUSIONS: The findings of this study indicate that malnutrition is still an important problem among children less than five years of age in Nghean, Vietnam. In addition, maternal, socio-economic and environment factors were found to be significant factors for malnutrition among children under five.

Prevalence of Zoonotic Metacercariae in Two Species of Grouper, Epinephelus coioides and Epinephelus bleekeri, and Flathead Mullet, Mugil cephalus, in Vietnam

Fishborne zoonotic metacercariae have not been reported from brackish water and marine fish from Vietnam waters although these parasites are common in the country's freshwater fish. Both wild-caught and cultured grouper (Epinephelus coioides and Epinephelus bleekeri), and mullet (Mugil cephalus) from brackish and marine waters locate in Khanh Hoa province in central coastal Vietnam were examined, and found positive for zoonotic trematode metacercariae. From grouper, Heterophyopsis continua and Procerovum varium were recovered. The prevalence of H. continua ranged from 2.0 to 6.0% and that for P. varium ranged from 11.6 to 15.8%. Mullet were infected with Pygidiopsis summa and H. continua both of these species are new records for Vietnam. The prevalence of P. summa in mullet was generally high, ranging from 17.6 to 75.5%, and was significantly higher than the prevalence of H. continua (2.5 to 32.4%). There were no significant differences in the prevalence of metacercariae between grouper from natural or cultured habitats, indicating that the highest risk of infection occurs in the wild-caught state prior to their placement in culture. Further, there was no difference in metacercarial prevalence between the 2 species of grouper. Infected wild-caught seed were only observed from January to October. Monthly variation in prevalence suggests seasonal variation in mullet infections occurs in this region with the highest transmission taking place from October to December. Basic investigations on the ecology and epidemiology of these intestinal flukes need to be carried out to determine their significance as a public health problem and the aspects of their biology that may be vulnerable to control interventions.

Cancer mortality pattern in Viet Nam.

BACKGROUND: Health information in general and cancer information in particular in Viet Nam is an basic data for decisions related to health planning prevent against cancer. However, very limited database of cancer information bas been available to date. The aim of the present study was to examine cancer mortality pattern nationwide in Viet Nam. METHODS: Descriptive cancer epidemiology was designed for the present study. Both demographic data and list of all deaths during the two years period, 2005-06, were obtained from all 10,769 commune health stations. Five indicators included name, age, sex, date of death and cause of death was collected for each case. A guideline to report demographic data of each commune and information of each case who has been lived at least 6 months in their commune was prepared in the designed form and sent by express mail service to all the heads of 10,769 commune health stations throughout country. The data comprises all cancer mortality records at the commune-level for the period 2005-06. All obtained data of cancer deaths as well as demographic information was computed using Excel software. The Excel data was exported to STATA 8.0 for cancer analysis. Cancer case was coded following ICD-10. RESULTS: To date, 94.6% of the 10,769 communes (from the 638 of 671 districts within the 64 provinces) have forwarded the required data and we currently have approximately 93,719 cancer deaths for the 2 years period. Number of person-year was 76,726,873 in 2005 and 77,902,688 in 2006. Number of cancer deaths was 45,413 (29,189 males and 16,224 females) in 2005 and 48,306 (31,447 males and 16,859 females) in 2006. Male to female ratios were 1.8 and 1.9 in 2005 and 2006, respectively. Three most common cancer sites numbered of 61,079 (65% of all 93,719 cancer deaths) included 25,410 liver cancer; 22,209 lung cancer; and 13,460 stomach cancer. Among both males and females, liver cancer was ranked in the first most common (31,04% and 19.91%), followed by lung cancer (26.69% and 18.21%) and stomach (14.42% and 14.26%). Among females, cervix and other female genital cancers were ranked in the four most common (9.13%) and breast cancer was about 5.69%. CONCLUSIONS: Participated proportion of nationwide administration units and population was over 90% to report about 93,719 deaths from cancer that suggested that cancer has been highly concerned by social as well as people due to a number of thousand life lost. This condition will accept well primary cancer prevention at commune level in Viet Nam to eliminate the ancient disease of cancer in human.

Population-based cancer survival in sites in Viet Nam.

BACKGROUND: Very few population-based cancer survival studies have been performed in Viet Nam. The aim of the present study was to estimate observed and relative cancer survival rates in populations of Phu Tho, Hanoi and Hue city. METHODS: A retrospective-cohort study was performed for all 12 districts of Phu Tho province (semi-highland area in the north), eight districts of Hanoi city (Capital) and four districts of Hue city in central area). Seven indicators were collected for each case of cancer death: name, age, sex, date of the first diagnosis having cancer, date of death, the cause of death and full address. Two steps were done. Firstly, we collected name, age, sex, date of death, the cause of death and full address; secondly, we collected date of the first diagnosis having cancer by a household visit by trained interviewer. Survival time was calculated from the date of death minus the date of diagnosis for each case of cancer. Observed survival rates for 1-year, 2-years, 3-years, 4-years and 5-years were estimated by the form of survival number multiplied by 100 then corrected for the registered number of cancer cases. For relative survival rates, the observed survival rates were corrected for the general population survival rate. RESULTS: Males and females combined, for all cancer sites, 1-year, 2-year, 3-year, 4-year and 5-year observed and relative survival rates were 23.8%-23.9%, 8.5%-8.5%, 3.8%-3.8%, 2.6%-2.6%, 1.7%-1.7%, respectively. The highest one-year relative cancer survival rate was seen in the capital, Hanoi city (49,8%), followed by Hue city in the central area (24,7%), and the lowest in Phu Tho, north-semi-highland (21.8%). CONCLUSIONS: The better cancer survival in Hanoi than in Phu Tho province, as well as the results overall, point to a need for greater efforts in early detection and treatment, especially in rural areas.

Survey for zoonotic liver and intestinal trematode metacercariae in cultured and wild fish in An Giang Province, Vietnam

Although Vietnam has a high risk of fishborne zoonotic trematode (FZT) infections for humans, little information exists on the epidemiology of these infections in the country's fish. Because of the importance of cultured catfish and snakehead production in An Giang province, a major production area in the Mekong Delta of Vietnam, a survey for FZTs was carried out in randomly selected fish farms between June 2005 and March 2006. For comparison, wild fish from the same area were also surveyed. A total of 852 cultured fish from 4 districts were collected and examined by pepsin digestion to determine their FZT infection status. In Tra catfish, the prevalence of all types of metacercariae was 2.6%, of which the prevalence of Haplorchis pumilio was 0.7%. The overall prevalence of metacercariae in wild fish was 30.6%, of which 10.3% harbored zoonotic species: H. pumilio (2.8%) and Procerovum sp. (5.6%). The prevalence of Opisthorchis metacercariae, which were diagnosed as O. viverrini, was 1.9%. No metacercariae were found in cultured snakehead fish, although wild-caught snakehead fish had a FZT prevalence of 10.3%: 5.1% were O. viverrini; 2.6% H. pumilio; and 2.6% were Procerovum sp. These are the first reports of H. pumilio, Procerovum sp., and O. viverrini metacercariae in Vietnamese fish. These results indicate that consumption of improperly prepared fish represents a significant risk of acquiring FZTs in this south Vietnam region.

Survey for zoonotic liver and intestinal trematode metacercariae in cultured and wild fish in An Giang Province, Vietnam

Although Vietnam has a high risk of fishborne zoonotic trematode (FZT) infections for humans, little information exists on the epidemiology of these infections in the country's fish. Because of the importance of cultured catfish and snakehead production in An Giang province, a major production area in the Mekong Delta of Vietnam, a survey for FZTs was carried out in randomly selected fish farms between June 2005 and March 2006. For comparison, wild fish from the same area were also surveyed. A total of 852 cultured fish from 4 districts were collected and examined by pepsin digestion to determine their FZT infection status. In Tra catfish, the prevalence of all types of metacercariae was 2.6%, of which the prevalence of Haplorchis pumilio was 0.7%. The overall prevalence of metacercariae in wild fish was 30.6%, of which 10.3% harbored zoonotic species: H. pumilio (2.8%) and Procerovum sp. (5.6%). The prevalence of Opisthorchis metacercariae, which were diagnosed as O. viverrini, was 1.9%. No metacercariae were found in cultured snakehead fish, although wild-caught snakehead fish had a FZT prevalence of 10.3%: 5.1% were O. viverrini; 2.6% H. pumilio; and 2.6% were Procerovum sp. These are the first reports of H. pumilio, Procerovum sp., and O. viverrini metacercariae in Vietnamese fish. These results indicate that consumption of improperly prepared fish represents a significant risk of acquiring FZTs in this south Vietnam region.

Risk factors for anemia in Vietnam.

Anemia is a significant public health problem in Vietnam, but representative national data and comprehensive risk factors analysis are lacking. The objectives of this study were to: 1) determine the distribution and severity of anemia in Vietnam, and 2) to assess potential risk factors for anemia. Nine thousand five hundred fifty households in 53 provinces were covered using a stratified two-stage cluster survey carried out in 1995. Selected household members were interviewed; intestinal helminthes were tested in non-pregnant women by Kato-Katz technique; hemoglobin concentrations were measured with Hemocue. Data were weighted and analyzed by survey procedures using SAS 9.0. Overall, 60% of children under 2 years old, 53% of pregnant women, 40% of non-pregnant women and 15.6% of men were anemic. Hookworm infection was the strongest factor associated with anemia (OR = 1.7; 2.9 and 4.5 for 11,999, 2,000-3,999 and > or = 4,000 hookworm egg counts, respectively) and accounted for 22% of anemia. Hookworm intensity was significantly associated with hemoglobin level; for each 1,000 egg increase, hemoglobin was reduced by 2.4 g/l. Living in different ecological zones, eating < 1 serving of meat/ week, and farming were significantly associated with anemia in women and children. Other risk factors in women included having > 3 children and having a child < 24 months old. In men, no variables were found significantly associated with anemia.

Intestinal helminth infections among reproductive age women in Vietnam: prevalence, co-infection and risk factors.

Intestinal helminth infections are a significant public health problem for Vietnamese women, but prevalence and risk factor data are scarce. The objectives of this paper were to (1) determine the prevalence of helminth infections among women; (2) investigate interactions among intestinal helminth species in individuals and (3) identify risk factors that contribute to intestinal helminth infections. In a nationwide survey conducted in 1995, 9550 households in 53 provinces were covered using a stratified two-stage cluster survey. Stool specimens were examined by Kato-Katz technique. Of 5,127 women, 76% were infected with one or more helminth species, 36% with hookworm, 59% with Ascaris lumbricoides and 28% with Trichuris trichiura. A. lumbricoides and T. trichiura were more likely to be concurrent than expected by chance. There was significant interaction between prevalence and intensity of infection in all three species. All three helminth species were more common in certain ecologic zones than others. Hookworm infection was associated with farming [Odd ratio (OR) = 2.1] and lack of a closed latrine (OR = 2.0), A. lumbricoides with use of untreated feces as fertilizer (OR = 1.2) and coinfection with T. trichiura (OR = 2.1) and T trichiura with A. lumbricoides co-infection (OR = 2.1). Our findings suggest that reproductive-age women, especially rural farmers, should be included among the high priority groups for helminth control programs through mass chemotherapy and improving sanitation.