Mother-to-child transmission of human T-cell lymphotropic virus type I (HTLV-I) in Jamaica: association with antibodies to envelope glycoprotein (gp46) epitopes.

To study mother-to-child transmission of HTLV-I in Jamaica, we screened antenatal patients in Kingston, Jamaica, from 1983 to 1985. Of 2,329 women, 81 (3.5%) were HTLV-I seropositive. Two to three years later, 36 seropositive mothers were recontacted, and blood was drawn from them and their children. All sera were tested for HTLV-I antibodies, and mother's sera were additionally tested for HTLV-I whole-virus antibody titer, syncytium-inhibition neutralizing antibody titer, and titers to six synthetic peptides from the HTLV-I envelope glycoprotein gp46. Seventeen of 74 (23%) [95% confidence interval (CI) 15-34%] children were seropositive. HTLV-I transmission was associated with breast-feeding duration > 6 months [relative risk (RR) 3.2; CI 0.4-22.1], maternal age > 30 years (RR 2.8; CI 1.0-7.8), and higher maternal whole-virus antibody titer (RR 3.3; CI 1.3-8.5). After controlling for higher whole-virus antibody titer, transmission remained associated with higher titer of neutralizing antibody and higher titer of antibody to the peptide sp4a1, corresponding to amino acids 196-209 of the gp46 envelope glycoprotein. We conclude that mother-to-child transmission of HTLV-I in Jamaica is associated with longer duration of breast-feeding, older age, and higher HTLV-I antibody titer, in particular to a certain immunogenic portion of the gp46 envelope glycoprotein.

Durability of passive measles antibody in Jamaican children.

Measles antibody titres were determined by haemagglutination inhibition and by neutralization in 221 sets of serum collected from delivering mothers, umbilical cords, and infants when about six months of age. Radio-immunoassay was also used to measure antibody in 120 sera. Total IgG concentration was determined in the infant sera. All mothers had measles antibody and the mean titre was high. At the time of birth, measles antibody had been further concentrated in the infant. Nevertheless, many children lost protective titres before six months of age. The rate of loss was correlated with the infant's total serum IgG so that high IgG levels at six months correlated with rapid loss of measles-specific antibody. It is suggested that in homes where sanitation is poor, antibody is made to many agents at an early age. To maintain physiological balance, homeostatic mechanisms then increase the rate of catabolism of all IgG, including that passively acquired. In keeping with its stage of sanitary development, vaccination in Jamaica can profitably be given earlier than in the United States, but it must be later than in many African countries.

Comparison of low and high sodium and potassium content in oral rehydration solutions.

PIP: Oral rehydration solutions (ORS) with low and high sodium or potassium contents were compared in 84 infants aged 3-15 months with dehydration caused by acute watery diarrhea. In randomized, double-blind trials, the ORS contained (in mmol/liter): glucose, 110; HCO3, 30; K, 10; Na, 60 (low) or 90 (high), or, in a second trial, the high Na formula plus 20 vs. 35 mEq/liter of K and extra oral water, given in the ratio of 2 bottles (240 ml) of ORS followed by 1 bottle of plain water (the 2:1 regimen). The balance technique was used to measure net absorption. Of the 84 infants, only 1 required intravenous therapy. During the first 6 hours of therapy, mean sodium absorption was significantly lower in the low Na group, and hyponatremia was more common. A few high Na group infants receiving no extra oral water had transient mild asymptomatic hypernatremia. Mean K absorption from 0-6 hours was significantly higher in the high K group, and they had no hypokalemia after oral rehydration; in contrast, 33% of the low K infants had hypokalemia. High Na ORS in the 2:1 regimen caused no electrolyte abnormalites, yielded better sodium absorption, and was usable in all age groups and for all diarrheas. High K ORS corrected K deficits better than the low K ORS. An increase in potassium concentration above that in the currently recommended ORS formula should be considered.^ieng

Early deaths in Jamaican children with sickle cell disease.

In Jamaican children with homozygous sickle cell (SS) disease diagnosed at birth two-year survival was 87%, compared with 95% in children with sickle cell-haemoglobin C (CS) disease, and 99% in normal controls. Death among those with SS disease occurred most often between the ages of 6 and 12 months. Principal causes were acute splenic sequestration and pneumococcal infection. Neonatal diagnosis of haemoglobinopathies must be followed by close observation if mortality is to be reduced by early diagnosis and treatment of these complications.