title: Morbidity assessment of Opisthorchis viverrini infection in rural Laos: I. Parasitological, clinical, ultrasonographical and biochemical findings.
abstract: BACKGROUND
  Infections with the food-borne trematode Opisthorchis viverinni are common in Southeast Asia. In Lao PDR alone, two million people are supposed to be infected. Opisthorchiasis may cause severe liver disease, eventually leading to cholangiocarcinoma. The objective of this study is to assess the eating habits, complaints, symptoms, signs and ultrasonographical findings in three different areas of Savannakhet Province.
  
  
  METHODS
  Study participants were recruited in Lahanam village in the flood-prone lowland of, Sonkhone district, Savannakhet Province (group A); in Non Somboon village, a community located on a hilly plateau in the same district (group B); and in staff of Savannakhet Province Hospital, Savannakhet town (group C). Eating habits, complaints and symptoms were recorded by standardized structured questionnaires. Participants were thoroughly examined clinically, and ultrasonography was performed. O. viverrini eggs were looked for in stool and in duodenal fluid. An array of biochemical and haematological parameters potentially related to liver disease was determined. Group A consisted of 45, group B of 31 and group C of 18 individuals.
  
  
  RESULTS
  Eating habits were similar in the three groups, except that participants from group C tended to consume less high-risk types of fish dishes and more frequently ate beef and pork. Average intensity of infection (eggs per gram of stool) was low, but significantly higher in group A than in group B and C (p < 0.001). Medical history and complaints were similar in the three groups. Ultrasonography did not reveal any bile duct pathology. The only pathological finding was a slight elevation of ASAT and gamma-GT in a few participants in groups A and B.
  
  
  CONCLUSIONS
  The study shows that eating habits favouring the infection with O. viverrini are common in south Laos. Although the average intensity of infection was low, there was a significant difference between the groups, paralleling slightly different eating habits. Clinically, this corresponded to a paucity of liver disease-associated complaints and signs. The low intensity of infection probably explains why no alterations of bile ducts were detectable by ultrasonography.
authors.affiliation: Institute of Microbiology and Hygiene, Charité University Medicine, Berlin, Germany.
authors.forename: Hermann
authors.initials: H
authors.lastname: Feldmeier
authors.affiliation: Specialist Practice for Internal Medicine, Hamburg, Germany.
authors.forename: Miklos
authors.initials: M
authors.lastname: Hazay
authors.affiliation: Graduate School of Health Sciences, Niigata University, Niigata, Japan.
authors.forename: Megumi
authors.initials: M
authors.lastname: Sato
authors.affiliation: Malaria, Parasitology and Entomology Section, Savannakhet Province, Lao PDR.
authors.forename: Pongvongsa
authors.initials: P
authors.lastname: Tiengkham
authors.affiliation: Graduate School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan.
authors.forename: Futoshi
authors.initials: F
authors.lastname: Nishimoto
authors.affiliation: Research Institute for Humanity and Nature, Kyoto, Japan.
authors.forename: Hongwei
authors.initials: H
authors.lastname: Jiang
authors.affiliation: Savannakhet Provincial Hospital, Savannakhet Province, Lao PDR.
authors.forename: Vatsana
authors.initials: V
authors.lastname: Sopraseuth
authors.affiliation: Graduate School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Moji