Nguyen Thi My
Thanh, Nguyen Thi Phuong Lan,
Tran Thi My Trinh, Nguyen Ngoc
Anh Thu
Pasteur Institute in Ho Chi Minh City
The use of ELISA in the study of Vi
antibodies in serum has been carried out in many groups of adults living in
various parts of Vietnam.
Preliminary results showed that the normal levels of Vi antibody in the
subjects living in non-endemic areas (Ho Chi Minh city, Lam Dong) are lower
than those of the people in endemic areas (Dong Thap, Tien Giang): Ho Chi Minh
city 6.33 EU/ml; Lam Dong 7.78 EU/ml; Dong Thap 9.62EU/ml; Tien Giang
10.0EU/ml. At the same time we measured the level of Vi antibody in a group of
patients having acute typhoid fever and a group of persons having contact with
typhoid patients, including household members and neighbours. The Vi antibody
level in the group of patients was higher than normal (26.85 EU/ml), but still
lower than that in the group of persons having contact with the patients (38.85
EU/ml). The high level of Vi antibody in patients had no diagnostic
significance. In fact, there were some healthy persons having very high Vi
concentrations (about 100 EU/ml). The different background levels of Vi
antibody will allow us to evaluate the immune status to typhoid fever of
various parts of Vietnam. The serological method using ELISA will be an
effective means for us to perform further studies, such as in the screening of Salmonella typhi carrriers to serve the
public health.