Blood pressure patterns in Nigerian adolescents.

The study was designed to define the mean blood pressure level of adolescents in the city of Ibadan and to establish the relationship between blood pressure and age, sex, weight, height, skinfold thickness, pulse and parental socio-economic class or educational level in an urban adolescent population. All pupils attending two schools located in 2 different socio-economic areas of Ibadan, a city in Western Nigeria, were recruited into the study. Mean Systolic Blood Pressures (SBP) were 111.3 +/- 12.4 mm for males and 112.5 +/- 12.2 mm for females (P < 0.04). The Mean Diastolic Blood Pressures (DBP) were 60.2 +/- 9.7 in males and 70.7 +/- 10.0 in females (P < 0.003). Mean SBP and DBP increased with age in the 2 groups and in both sexes. Adolescents aged 16-19 years had higher blood pressures than those aged 12-15 years (P < 0.001). There were positive significant correlations between body mass index (BMI), pulse and blood pressure. Mean Systolic and Diastolic Pressures were higher in children from the lower socio-economic group and the differences were significant in females (P < 0.001). Similarly higher percentage prevalences of SBP and DBP above 95th percentile were found in adolescents from the lower socio-economic group and the differences were statistically significant (P < 0.05 and P < 0.001 respectively). The findings confirm that age, sex, body mass and socio-economic background all have an influence on the blood pressure levels of Nigerian adolescents.

Iron deficiency anaemia in Nigerian infants.

Hematological parameters and the iron status of 50 randomly selected infants who were attending the research infant welfare clinic of the Institute of Child Health, Ibadan (ICHI), for routine immunization were studied. Investigations included estimations of packed cell volume (PCV), haemoglobin (Hb), serum iron (Fe), unsaturated iron-binding capacity (UIBC) and total iron-binding Capacity (TIBC). Forty percent of the infants had PCVs below 0.32, 48% had Hbs below 10 g/dl and 27% had mean corpuscular volume (MVC) less that 70fl. Thirty-seven percent of the children had serum Fe below 3.58 mmol/l, but only 4% had UIBC above 320 mmol/l. Fifty-two percent had Transferin Saturation Index (TSI) below 10%. Eighteen percent had MCV below 70fl associated with TSI below 10% and 67% of these had Hbs below 10 g/dl. The prevalence of iron deficiency anaemia in infants as shown in this study is very high. The ill effects of iron deficiency in childhood have been well documented. It is suggested that screening for anaemia should be offered at 9 months as part of a Child Survival Programme and that infants found to be anaemic should be treated. However, for cost-effectiveness and taking into consideration the high prevalence rate of iron deficiency in this age group, it might be preferable to give iron and weekly prophylactic antimalarias routinely to infants aged 9 to 15 months in lieu of screening.

Routine screening for sickle cell haemoglobinopathy by electrophoresis in an infant welfare clinic.

The experience of a Nigerian infant welfare clinic in offering sickle cell haemoglo-binopathy (SCH) screening by electrophoresis to its clinic population over a 12-year period is reported. Overall 10,115 children were screened. Homozygous haemoglobin S was detected in 3.1% and haemoglobin S + C in 1.1%. Carriers of the sickle cell gene (haemoglobin A + S) comprised 23.7% of the children screened. Gene frequencies for the A, S and C genes were 0.814, 0.155 and 0.031 respectively. The gene frequencies of the S and C genes were higher than those reported in infants and under-five children from other parts of Nigeria. Screening for sickle cell haemoglobinopathy in the first year of life through infant welfare clinics and 'well-baby' clinics as described in this report is suggested as a viable approach to the problems of detection (and genetic counselling) of SCH in developing countries with their scant resources. The advantages and limitations of this approach are discussed.

Safety and efficacy of yellow fever vaccine in children less thanone-year-old.

In a clinical trial of stabilized yellow fever vaccine from Institute Pasteur in 77 children aged seven to eight months, fever was the most significant immediate and delayed side effect. Fever occurred in 12 (15.6%) children with in 48 hours of vaccination while it occurred in 10 (12.9%) children within ten days of vaccination. Other recorded side effects were pain at innoculation site in four (5.2%) children and vomiting in one (1.3%) child. Temperature recorded in 20 of the 22 febrile episodes ranged from 37.8 degrees C to 38.6 degrees C. One of the two patients who had temperatures of 39 degrees C and above had malaria parasites in her blood film. All episodes of fever except one responded to antipyretic. There was no episode of febrile convulsion and no feature suggestive of encephalitis. Of the 20 children who had neutralization test carried out against yellow fever virus six weeks after vaccination, the test was positive in post vaccination sera of 12 (60%) children whose pre-vaccination sera were negative. Two others showed evidence of partial protection. Although the seroconversion rate of 60% is less than reported in adults and older children, the result of this study shows that yellow fever vaccine is safe and fairly effective in infants. It is our suggestion that if a larger trial confirms our findings, the vaccine may be incorporated into the expanded programme on immunization (EPI) to be given at the age of seven months after completion of diptheria, tetanus, pertussis and poliomyelitis vaccinations and before measles vaccination is due.

Serum immunoglobulin concentration in Nigerian infants.

Serum immunoglobulin (Ig) G, M and A were determined at 3-monthly intervals during the first year of life in 35 healthy Nigerian infants. The neonatal IgG values were high, but dropped rapidly by 3 months to about 37% of the neonatal value, and thereafter rose steadily. The neonatal IgM values dropped slightly (10%) by 3 months and then rose steadily to reach a level above the neonatal value after 1 year. IgA was not detected in most of the children during the neonatal period, but where it was detected and was measurable, the values were very low and then rose steadily until the age of 1 year. There was a suggestion that the pattern of immunoglobulin in infancy might be influenced by the level of maternal education.

Serum immunoglobulins in Nigerian neonates.

Serum immunoglobulins G, M and A levels were studied in 187 Nigerian neonates. Estimations were done by the radial immunodifusion method of Mancini. Immunoglobulin G shows a fall in value in the first few days of life to about 62% of the value in the last days of the neonatal period. There is however a gradual increase in the level of IgM to about double at the end of the neonatal period. IgA level remained relatively constantly low throughout this period. The effect of maternal education on the levels of immunoglobulins of their neonates was also investigated. This had a positive influence at the secondary educational level, affecting only the IgG and IgA.

Immunity in malaria: depression of delayed hypersensitivity reaction in acute Plasmodium falciparum infection.

The effect of acute Plasmodium falciparum malaria infection on the cell-mediated immune response of 30 Nigerian children attending the General Out-patient (GOP) Clinic of the University College Hospital, Ibadan, Nigeria, was assessed in a controlled study. Delayed-type hypersensitivity skin reaction to five tuberculin units (5 TU) of purified protein derivative (PPD) was used as an indicator of cell-mediated immunity. The results showed marked depression of delayed hypersensitivity reaction to PPD in 27 (90%) of the malarious children, compared with four (16%) of the 25 control healthy subjects (P less than 0.0005). This depression was observed despite evidence of previous BCG vaccination in 38 (69.1%) of the 55 children in the study. The possible clinical significance of these observations in tropical paediatric practice, and the immunopathological implications, are discussed.

A comparison of two methods of milk sampling for calculating the fat intake of breast-fed babies.

Fat intake at a breast feed was estimated by either sampling milk intermittently during the feed using a thin latex nipple shield ('shield method') or by expressing samples before and after the feed ('expression method'). These sampling techniques were compared within 30 mother/infant pairs using a randomized cross-over design. Mean fat intake estimated by the expression method was significantly greater than that estimated by the shield method (first breast P less than 0.0001, second breast P less than 0.002). This finding was partly explained by a significantly lower mean milk intake when the nipple shield was used, but the higher fat content of expressed milk samples compared to samples obtained during suckling also played a part. Use of the nipple shield confirmed that breast-milk fat content does not change in a predictable way during a feed. Nevertheless, for practical purposes, the advantages of studying changes in milk composition during the feed have to be set against the potential restrictive effect of the nipple shield system when it is used to sample intermittently during the feed.

Plasma transport proteins in rehabilitated protein-energy malnourished children in Nigeria.

Blood levels of prealbumin, retinol-binding protein, ceruloplasmin and transferrin were monitored during the rehabilitation of thirty protein-energy malnourished children. The children aged between six and fifty-four months were rehabilitated on an out-patient basis and fed locally prepared good quality food while the mothers were given nutrition education coupled with health education. The initial mean anthropometric values and plasma transport protein levels were significantly lower in these children when compared with values obtained from 10 apparently healthy children presenting with no signs or symptoms suggestive of any form of malnutrition. At the end of the rehabilitation period, there was no significant difference in plasma transport protein levels between the previously malnourished children and the normal controls although the malnourished children still demonstrated significant weight deficit.

Biracial study of arterial pressures in the first and second decades of life.

The blood pressures of young Black and White American schoolchildren were measured and compared with those of Nigerian children of similar ages. Both diastolic and systolic pressures were consistently higher in the Nigerian children than in the Americans, both Black and White. The White children had the lowest pressures at each age. The mean weights and heights at each age were not significantly different in the three groups. Although the blood pressure of African children was higher than that of Black Americans, mean adult pressures are known to be similar in both groups. This suggests that the difference in childhood pressures must be due more to environmental factors than to genetic ones.

Arthropod-borne viral infections of man in Nigeria, 1964-1970.

During the years 1964 to 1970, 171 arboviruses of 15 different types were isolated from humans in Nigeria. Isolation rates were highest in 1969, and lowest in 1965 and 1967. Monthly arbovirus activity was highest in the rainy season months of June, July and August and lowest in the dry months of January and February. Viruses were isolated from all age groups, with the majority from children one to four years old. The viruses isolated in largest numbers were chikungunya and yellow fever, which caused epidemics in 1969, and dengue types 1 and 2 and Tataguine, which are endemic in Ibadan. Bwamba virus was isolated in 1964 and 1969, and Bunyamwera group viruses were encountered for the first time in 1969. Other viruses recovered less frequently were Zika, Igbo-Ora (an agent related to o'nyong-nyong), two viruses related to the Uganda mosquito virus Ug MP 359, Dugbe, Thogoto, Lebombo and Shuni. Several of these are new agents and have not previously been isolated from man. Clinical details are presented where available.