Serodiagnosis of toxoplasmosis in Bahrain

OBJECTIVE: We report here an analysis of results of anti-Toxoplasma immunoglobulin M (IgM) and immunoglobulin G (IgG) measurements reported from the Central Laboratory of Bahrain over a period of 3 years and 9 months.

METHODS: This study included all blood samples received at the Salmaniya Medical Complex, Manama, Bahrain serology laboratory for the determination of Toxoplasma-specific antibodies during the period of January 2000 to September 2003. A total of 4,739 specimens were assayed for IgG and 1,947 for IgM.

RESULTS: An overall seropositivity of 21.8% for IgG and 10.3% for IgM antibodies were found with no gender differences for either IgG or IgM. In addition, no statistically significant positivity rate differences (p=0.723) were observed between Bahrainis and non-Bahraini residents. The prevalence of Toxoplasma gondii (T. gondii)-specific IgG amongst post partum women was 15.8% and 6.3% for IgM, while for women of child-bearing age IgG was higher at 22.3% and 11.6% for IgM. The IgG seropositivity in neonates (<1 month old) was 16.5%, decreasing to 9.3% in preschool children, while for IgM, it was 3.7% at birth increasing to 7.3% in the preschool group. The IgG seroprevalence increased within the first 15 years of life, and leveled thereafter, for IgM however, it was low at birth and increased within the first 12 months of life then leveled-off at the age of 20-40 to approximately 11-14%, with a further increase after 40 years to 17%.

CONCLUSION: The seropositivity rates of T. gondii in the samples examined during the present study fall within the range of other Gulf Cooperative Council countries. True prevalence in the general population may actually be lower.