A comparison study of measles antibody between two doses vaccination at 9, 18 months and single dose at 9 months in children 4-6 years old

BACKGROUND

The authors have added the second dose of measles vaccine to children aged 18 months since 1997 because of the measles outbreaks in Nan province in 1993-1994.

OBJECTIVE

To compare measles antibody level between two doses vaccination at 9, 18 months and single dose at 9 months in children at the age of 4 to 6 years old.

MATERIAL AND METHOD

A cross sectional serological study in children 4 to 6 years old was performed between August 2008 and August 2009 at three hospitals in Nan and Phrae provinces. The subjects were divided into two groups, 1) 100 children in Nan provincial hospital received two doses of measles vaccination at the age of 9 and 18 months and 2) 91 children received single dose measles vaccination at the age of 9 months, 41 from Phrae provincial hospital and 50 from Weingsa district hospital. Blood samples were drawn for measles antibody measurement by ELISA assays at Virus Research Institute, National Institute of Health, Thailand.

RESULTS

The mean measles antibody level in children 4 to 6 years old in both groups was a satisfactory high level, 1,887.67 and 1,621.02 mIU/ml in single and two doses vaccination respectively, which were not statistically significant (p = 0.431). The higher level in single dose group could be explained by the average age being younger than the two doses group by one year (4 years 2 months vs. 5 years 4 months). Therefore, the waning immunity in younger age group is suspected to be less than the older age group. The rate of protective measles antibody level (> or = 255 mIU/ml) was significantly higher in the two doses group than the single dose, 87% compared to 76% (p = 0.046), which represented primary vaccine failure at the age 4 to 6 years of 13% and 24%, respectively.

CONCLUSION

The authors suggest that a second dose of measles vaccine at the age of 18 months be administered to decrease the number of primary vaccine failure from 24% to 13%. Further studies in the same age group and in different areas are required to confirm these findings.

Perinatal death pattern in the four districts of Thailand: findings from the Prospective Cohort Study of Thai Children (PCTC)

OBJECTIVE

To determine the magnitude and investigate causes of perinatal deaths of a cohort of the Prospective Cohort Study of Thai Children.

MATERIAL AND METHOD

A semi-structured verbal autopsy questionnaire and review of medical records were used to ascertain the causes of deaths during the perinatal period in four districts of Thailand.

RESULTS

The total numbers of 3,522 babies (with 28 pairs of twins) were born from 3,494 pregnant women. The perinatal mortality rate was 10.69 per 1,000 total births, the stillbirth rate was 6.75 per 1,000 births, and the early neonatal mortality rate was 3.97 per 1,000 live-births. About 37.8% of the perinatal deaths were agreed to by two pediatricians and a neonatologist as preventable. About 90% of the preventable stillbirths occurred in the antepartum period.

CONCLUSION

Findings from the present study indicates that to further reduce the perinatal death rate, attention should be focused on reducing the stillbirths by a quality antenatal care.

Measles antibody in mothers and infants 0-2 years and response to measles vaccine at the age of 9 and 18 months

BACKGROUND

Despite the declining trends in measles cases corresponding to an increase in routine measles immunization coverage, measles outbreaks occur in some isolated areas in Nan province, northern Thailand. The primary reason for these outbreaks is inadequate vaccine coverage. Another reason is primary vaccine failure.

OBJECTIVES

To study maternal and cord blood measles antibody, the kenetic change of infant measles antibody from 0-9 months and the response to measles vaccine at the age of 9 and 18 months.

MATERIAL AND METHOD

A prospective cohort study for measles antibody of 1,010 mothers and infants 0-2 years was done between April 1999 and March 2001 at three hospitals in Nan province. Consecutive blood samples were drawn for measles antibody measurement by ELISA assays at Virus Research Institute, National Institute of Health, Thailand. The demographic data of mothers and infants were recorded at each visit.

RESULTS

Maternal and cord blood measles antibody were high and the authors found a higher level in cord blood than in maternal level. Measles antibody level in infants declined significantly from the age of 4 months (246.4 +/- 364.2 mlU/L) to their lowest level at the age of 9 months (17.7 +/- 197.1 mlU/L).

CONCLUSION

After the first dose of 9-month measles vaccination, the authors found the seroconversion rate of 82.2 percent. The seroconversion rate was significantly higher to 99.6 percent after the second dose at 18 months old.

Phenylketonuria detected by the neonatal screening program in Thailand

Neonatal screening for phenylketonuria (PKU) was introduced as a pilot project in Thailand from 1992--1995, and mass screening was started in 1996 by the Department of Medical Sciences, Ministry of Public Health. Blood samples were collected by heelprick on filter paper either at 48 hours of life or before discharge from the hospital. Elevated blood phenylalanine was identified by screening with the Guthrie method, then followed by the fluorometric method: All infants with a phenylalanine level equal to or greater than 4 mg/dl were recalled and retested using the fluorometric method and confirmed by plasma amino acid analysis and urinary pterins for tetrahydrobiopterin deficiency. A total of 1,062,676 newborns were screened from October 1992--March 2001, with 5 cases confirmed with PKU. The incidence was 1 in 212,535. All patients have been treated with low phenylalanine diet. The results of this study confirm the benefit of early detection and treatment of PKU through the screening program.

Pneumonia in mechanically ventilated patients in Nan Hospital intensive care unit

A study on ventilator-associated pneumonia was done in the I.C.U., Nan Hospital from April 1991 to March 1992. Of the 536 patients, 40 had pneumonia (7.5%). One half of the cases with pneumonia were on mechanical ventilation for 3-7 days. The incidence rate of pneumonia was 17.5, 6.5, 2.5 and 0 per cent in paediatric, medical, surgical and gynaecologic patients. Nine patients died of pneumonia. Low birth weight was the commonest predisposing factor of death along with prolonged ventilatory support and resistant bacteria. Breaching of aseptic and nursing care techniques was also observed.