Tetanus antibody levels among adolescent girls in developing countries

Neonatal and maternal tetanus infections remain an important cause of death in many countries. Few studies have reported tetanus toxoid antibody levels of adolescent girls. As part of the Expanded Programme on Immunization most girls receive up to 3 injections in early childhood, and many subsequently do not receive booster vaccinations until pregnant. We determined (by ELISA) tetanus antibody seropositivity in adolescent girls from Malawi (in 1996), Nigeria (in 1993) and Pakistan (in 1996), and response to tetanus vaccination in adolescent girls from Pakistan. Geometric mean titres (GMT, IU/mL) were 0.94 in 117 Malawian, 0.32 in 154 Nigerian and 1.08 in 162 Pakistani girls. In Nigeria, 54.7% of adolescents were seronegative, of whom 26.8% had a history of unsafe abortion. In Malawi and Pakistan all girls were seropositive and in Pakistan, following a booster vaccination, titres increased 3-fold, with a lower response in older girls. The results indicated that adequate childhood immunization is likely to provide protective levels through adolescence. Booster vaccination in late childhood/early adolescence should protect the majority of women throughout their reproductive lives. This practice would reduce the risks of girls exposed to infection through unsafe abortions, and may be the best option for countries seeking to improve their vaccination schedule, especially where tetanus vaccine coverage in pregnant women is unacceptably low.

Lack of protection against vertical transmission of HIV-1 by interferons produced during pregnancy in a cohort from East African republic of Malawi

Interferons (IFNs) associated with pregnancy were studied for their possible role in inhibition of vertical transmission of the human immunodeficiency virus type 1 (HIV-1). A study group was composed of 43 HIV-1-positive mothers, of whom 15 transmitted the virus to the offspring and 28 did not. The control group included 48 HIV-1-negative mother-infant pairs. The IFN-alpha was detected only sporadically in the maternal sera from the groups of transmitters (27%), nontransmitters (21%), and controls (19%). The average levels of IFN-alpha were low, 16.3 +/- 2.5 pg/ml, 21.4 +/- 9.9 pg/ml, and 21.3 +/- 9.4 pg/ml among the transmitters, nontransmitters, and control subjects, respectively. In the cord blood, IFN-alpha was detected only on two occasions among transmitters, and on a single occasion in the control group. IFN-beta was absent from both maternal and cord blood in the study group, and found to be present in one case in the control group simultaneously in the maternal and fetal sera. In the placentas, on the other hand, both type I and II IFNs were expressed universally in the villous trophoblast, and IFN-alpha and -beta in the stromal macrophages as well. In one case among transmitters, no IFNs were detected; nevertheless, no significant difference with respect to nontransmitters could be confirmed. Our data suggest that although the placental IFNs have an antiviral potential, they are not sufficient to suppress transmission of HIV from mother to infant.

A community based study of vitamin A and vitamin E status of adolescent girls living in the Shire Valley, Southern Malawi

OBJECTIVE

To assess vitamin A and E status and anaemia in non-pregnant Malawian adolescent girls.

DESIGN

A cross-sectional study in rural village communities in the Shire Valley, Southern Malawi.

SUBJECTS

Adolescent girls, n = 118, aged between 10 and 19 y, 112 of whom were unmarried.

METHODS

Socio-demographic information was collected by questionnaire, heights and weights were measured. Vitamin A was assessed by the Modified Relative Dose Response (MRDR) test, in addition to serum retinol values. Blood samples were collected 4-5 h after administration of 3,4-didehydroretinyl acetate. Retinol and alpha-tocopherol levels were measured by HPLC. Serum retinol results for non-pregnant girls were compared with values for 43 adolescent pregnant girls which were available from a previous study.

RESULTS

26.6% of non-pregnant girls had serum retinol values < 0.70 micromol/L; 40.2% had an MRDR ratio > 0.060. In 59.3%, serum tocopherol levels were < 11.5 micromol/L and the tocopherol/cholesterol ratio was < 2.2 in 23.9%. 11.3% had a haemoglobin > or = 12 g/dl. Vitamin A levels were significantly related to age, and younger girls were more likely to be deficient. Significant correlations were found between serum retinol, MRDR values and serum tocopherol. Girls with a low body mass index for age had tocopherol cholesterol ratios < 2.2. Low serum retinol values occurred significantly more often in stunted girls (P=0.01). Serum retinol values of adolescent pregnant girls were significantly lower than those of non-pregnant adolescents (P=0.002).

CONCLUSIONS

Vitamin A and E deficiency and anaemia were common in adolescent non-pregnant girls, and thought to partly result from increased growth requirements. Girls who become pregnant at an early age are at risk of depletion of their nutritional reserves. Measures to reduce nutritional deficiencies before the first pregnancy are needed.