Abstract
Objective: To determine the odds ratio and population attributable fraction associated with food and environmental risk factors for acute toxoplasmosis in pregnancy.
Design: Case-control study.
Setting: Six large European cities.
Participants: Pregnant women with acute infection (cases) detected by seroconversion or positive for anti-Toxoplasma gondii IgM were compared with pregnant women seronegative for toxoplasma (controls).
Main outcome measures: Odds ratios for acute infection adjusted for confounding variables; the population attributable fraction for risk factors.
Results: Risk factors most strongly predictive of acute infection in pregnant women were eating undercooked lamb, beef, or game, contact with soil, and travel outside Europe and the United States and Canada. Contact with cats was not a risk factor. Between 30% and 63% of infections in different centres were attributed to consumption of undercooked or cured meat products and 6% to 17% to soil contact.
Conclusions: Inadequately cooked or cured meat is the main risk factor for infection with toxoplasma in all centres. Preventive strategies should aim to reduce prevalence of infection in meat, improve labelling of meat according to farming and processing methods, and improve the quality and consistency of health information given to pregnant women.
Sources of toxoplasma infection in pregnant women: European multicentre case-control study
- A J C Cook, lecturer in veterinary epidemiologya,
- R E Gilbert, senior lecturer in clinical epidemiology (r.gilbert{at}ich.ucl.ac.uk)b,
- W Buffolano, consultant paediatricianc,
- J Zufferey, head of serology laboratoryd,
- E Petersen, head of parasitology departmente,
- P A Jenum, assistant directorf,
- W Foulon, consultant obstetriciang,
- A E Semprini, postgraduate technicianh,
- D T Dunn, senior lecturer in statistics the European Research Network on Congenital Toxoplasmosis.b
- a Department of Farm Animal and Equine Medicine and Surgery, Royal Veterinary College, University of London, North Mimms, Hertfordshire AL9 7TA,
- b Department of Paediatric Epidemiology and Biostatistics, Institute of Child Health, London WC1N 1EH,
- c Università Degli Studi di Napoli Federico II Department of Paediatrics, 80131 Naples, Italy,
- d Institute of Microbiology, 1011 Lausanne-CHUV, Switzerland,
- e Statens Serum Institut, DK 2300, Copenhagen S, Denmark,
- f Department of Bacteriology, National Institute of Public Health, PB 4404 Torshov, N-0403 Oslo, Norway,
- g Department of Gynaecology and Obstetrics, Academisch Ziekenhuis, Free University of Brussels, Belgium,
- h Department of Obstetrics and Gynaecology, Ospedale San Paolo, Milan, Italy
- St George's Hospital and Medical School, London SW17 0QT
- Correspondence to: R E Gilbert
Abstract
Objective: To determine the odds ratio and population attributable fraction associated with food and environmental risk factors for acute toxoplasmosis in pregnancy.
Design: Case-control study.
Setting: Six large European cities.
Participants: Pregnant women with acute infection (cases) detected by seroconversion or positive for anti-Toxoplasma gondii IgM were compared with pregnant women seronegative for toxoplasma (controls).
Main outcome measures: Odds ratios for acute infection adjusted for confounding variables; the population attributable fraction for risk factors.
Results: Risk factors most strongly predictive of acute infection in pregnant women were eating undercooked lamb, beef, or game, contact with soil, and travel outside Europe and the United States and Canada. Contact with cats was not a risk factor. Between 30% and 63% of infections in different centres were attributed to consumption of undercooked or cured meat products and 6% to 17% to soil contact.
Conclusions: Inadequately cooked or cured meat is the main risk factor for infection with toxoplasma in all centres. Preventive strategies should aim to reduce prevalence of infection in meat, improve labelling of meat according to farming and processing methods, and improve the quality and consistency of health information given to pregnant women.
Commentary: Congenital toxoplasmosis—further thought for food
- Richard Holliman, consultant and reader in clinical microbiology
- a Department of Farm Animal and Equine Medicine and Surgery, Royal Veterinary College, University of London, North Mimms, Hertfordshire AL9 7TA,
- b Department of Paediatric Epidemiology and Biostatistics, Institute of Child Health, London WC1N 1EH,
- c Università Degli Studi di Napoli Federico II Department of Paediatrics, 80131 Naples, Italy,
- d Institute of Microbiology, 1011 Lausanne-CHUV, Switzerland,
- e Statens Serum Institut, DK 2300, Copenhagen S, Denmark,
- f Department of Bacteriology, National Institute of Public Health, PB 4404 Torshov, N-0403 Oslo, Norway,
- g Department of Gynaecology and Obstetrics, Academisch Ziekenhuis, Free University of Brussels, Belgium,
- h Department of Obstetrics and Gynaecology, Ospedale San Paolo, Milan, Italy
- St George's Hospital and Medical School, London SW17 0QT
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