Validation of hemoglobin estimation using Hemocue.

OBJECTIVE: This piece of work is an attempt to compare Hemocue and Cyanmethemoglobin methods for hemoglobin estimation. METHODS: In 100 apparently healthy children of 1-6 years of age, Hb was estimated using Hemocue and cyanmethemoglobin methods from finger prick blood sample. The results obtained by the two methods were compared using appropriate statistical methods. RESULTS: Mean +/- SD values for hemoglobin (g/dl) were 9.33 +/- 2.719 by Hemocue and 8.14 +/- 2.448 by cyanmethemoglobin method. When assessed by Hemocue method the proportion of children with anemia was 66% while it was 88% with cyanmethemoglobin method. The sensitivity of Hemocue method was 0.75 and specificity 1.0 considering cyanmethemoglobin method as gold standard. The corresponding values by cyanmethemoglobin method for a given Hemocue value fell within the Mean difference +/- 2 SD with correlation coefficient being r = 0.922. Despite the good association, the two methods agreed, the magnitude of difference being -1.19 g/dl (CI: -1.40 to -0.98) thus suggesting an overestimate of hemocue values ranging from 10 to 15%. A correction factor was arrived for converting Hb values obtained by Hemocue method to arrive at the expected value by the reference method, this factor being 0.389 + 0.831 Hb (Hemocue). CONCLUSION: As there are limitations expressed for both the methods in accurately estimating Hb, it is difficult to decide whether one is an overestimate or the other an underestimate. By virtue of the principle involved in estimating Hb, cyanmethemoglobin method may be taken as an indirect indicator of iron status. However, it is not clear whether such a principle is involved in estimating Hb by Hemocue. Therefore, these two methods need to be further validated against a sensitive and specific indicator for iron status like circulating transferrin receptor to decide which of the methods can be used to accurately determine the prevalence of iron deficiency anemia in the community.

Association of tumour necrosis factor alpha & malnutrition with outcome in children with acute bacterial meningitis.

BACKGROUND & OBJECTIVES: Tumour necrosis factor alpha (TNF alpha) is implicated in the pathogenesis of acute bacterial meningitis (ABM). However, we do not know if the nutritional status influences the concentration of TNF alpha in the CSF in children with ABM. The present study evaluates the association between malnutrition and TNF alpha detectability in CSF and the outcome from ABM in children. METHODS: A total of 120 children aged 1-5 yr diagnosed as ABM, based on the standard criteria of CSF changes were recruited for the study. A CSF sample was collected at the time of admission. TNF alpha was measured by ELISA and CSF culture was done by standard technique. Nutritional status was assessed by anthropometry. Outcome was measured by clinical examination. RESULTS: Of the 120 children, 20 died, 36 developed complications and 64 children recovered without sequelae. TNF alpha was detectable in 94 (78.3%) CSF samples, with a range of 32 to 1714 pg/ml. TNF alpha detectability was not associated with either nutritional status or with death and sequelae. However, death and sequelae were significantly (P = 0.01) associated with malnutrition. INTERPRETATION & CONCLUSION: CSF TNF alpha was not associated with nutritional status. However, malnutrition was associated with adverse outcome due to ABM in children.

Post-vaccination scenario of measles: a retrospective analysis.

BACKGROUND: Routine vaccination against measles was introduced in India during 1985-86 through the Universal Immunization Programme. Its effect on the current prevalence of measles is not known. METHODS: Information on the total number of patients admitted and deaths due to measles from January 1982 to December 1997 were obtained from the records of the Institute of Tropical Medicine, Hyderabad, the only infectious diseases hospital in the city. Details on age, sex, number of complications, duration of hospital stay, vaccination status and information on vitamin A administration in the hospital were collected from the case records. RESULTS: A total of 20,926 cases of measles were admitted from 1982 to 1997. There was a 69% reduction in hospital admissions from the pre-vaccination to the post-vaccination period, and deaths due to measles decreased by 90%. Over the years, a rise in the age of children admitted with measles was observed. Boys were admitted more frequently to the hospital (p < 0.001) than girls. All the children showed one or more complications. From 1992 onwards, vitamin A was administered to 45.4% of the children admitted. CONCLUSION: A significant reduction was observed in the number of cases admitted to the hospital as well as deaths due to measles. Apart from the effect of the vaccination programme, this could also be due to increased awareness and availability of better health care facilities in the hospital and peripheral health clinics. Administration of vitamin A to children with measles as recommended by the World Health Organization needs to be implemented. A significant increase in the number of older children (> 5 years) with no significant reduction in the infants affected by measles indicates inadequate vaccine coverage and accumulation of susceptible older children.

Effect of administration of 200,000 IU of vitamin A to women within 24 hrs after delivery on response to PPV administered to the newborn.

OBJECTIVE: To explore the effect of maternal supplementation of vitamin A on the immune response to oral polio vaccine in breastfed infants. DESIGN: Randomized controlled trial. SETTING: Hospital based. METHODS: One hundred mothers having uncomplicated deliveries randomly received either 200,000 IU vitamin A orally (Experimental) or placebo (Control). All the newborns were given a dose of oral polio vaccine within 72 hours after birth and were breastfed. Type specific neutralizing antibodies to polio viruses in test sera diluted from 1:4 to 1:512 and serum retinol levels were determined from the cord blood and at the age of 6 weeks. Breast milk retinol levels were determined at 3, 10, 30, 45 and 90 days of lactation. RESULTS: Seroconversion to OPV and geometric means of antibody titers to the three types of polio viruses were comparable between the groups of infants belonging to the experimental and control mothers. Breast milk retinol levels were significantly higher in the experimental group upto 45-90 days of lactation. Majority of the infants at birth had serum retinol levels < 15 micrograms/dl which improved significantly by 6 weeks irrespective of the maternal supplementation status. CONCLUSIONS: Maternal vitamin A supplementation soon after delivery improves vitamin A intakes of breastfed infants during the first 3 months and has no interference with the seroconversion to a neonatal dose of OPV. OPV administered to newborn in turn has no adverse effect on the vitamin A status of the breastfed infants.

Enhancement in seroconversion to measles vaccine with simultaneous administration of vitamin A in 9-months-old Indian infants.

The mutual interactions of measles vaccine and vitamin A dose when administered simultaneously to 9 month old infants are explored in this study. One hundred healthy infants of 9 months of age received EZ strain of measles vaccine in the routine immunization clinic along with either 100,000 IU of vitamin A or a placebo orally. Blood samples were collected before and 4 weeks after intervention. They were coded and analysed for serum retinol and Hemagglutination Inhibition (HI) antibodies to measles. Ninety five per cent of the infants were seronegative to measles prior to vaccination with a seroconversion rate of 63% in the control group and a significantly higher percent of 83.7% in the experimental group (P < 0.01). Seroconversion was not related to initial serum retinol levels in either of the groups. 42% of infants had serum retinol levels less than 20 ug/dl before administration of the vaccine and both the groups showed improvement in vitamin A status following intervention, the increase being significant in the experimental group (from 22.4 +/- 1.32 to 26.0 +/- 1.07; P < 0.05). The results indicate that majority of the infants at 9 months of age were seronegative to measles. Seroconversion to measles vaccine in the routine immunization clinics was low. Simultaneous administration of vitamin A and measles vaccine had beneficial effects on vitamin A status as well as seroconversion rates to the vaccine in 9 months old infants.

Measles & malnutrition.

Measles is an important acute childhood viral infection having severe consequences on the nutritional status. The adverse nutritional effects of measles are experienced by both the well-nourished and the malnourished children. However, the severe nutritional deficiencies like kwashiorkor/marasmus are precipitated only in children who are already malnourished. As high as 3-4 per cent of children with measles suffered from these clinical nutritional syndromes in their post-measles period. Though malnutrition is widespread among Asian children also, measles appears to run a milder course with low mortality rates in developing Asian countries, as compared to African children. The associated secondary infections which apparently complicate the primary illness in malnourished children might be responsible for higher mortality and could be due to socioeconomic and environmental causes that are associated with poverty and malnutrition rather than due to malnutrition or measles per se. Measles related blindness is of multifactorial aetiology. While acute measles triggers corneal ulceration through viral proliferation in the cornea, nutritional keratomalacia is often the cause of blindness in the post-measles period. Measles vaccination is the major preventive measure. However, timely use of local antibiotic therapy to the eyes and administration of vitamin A supplements offer protection to the child who already has measles. Response of malnourished children to live attenuated measles vaccine has been found to be safe and effective. Neither malnutrition nor tuberculosis which are widespread among malnourished children of developing countries appear to be contraindications for measles vaccination. Thus, the beneficial effects of the measles vaccination should be fully exploited by adequate supply of potent vaccine and coverage of all susceptible children.

Zinc status of Indian children.

Zinc is a trace metal essential for human health and its deficiency is found to cause severe growth retardation in children. Information on the zinc status of Indian children is meagre perhaps due to lack of a reliable parameter. However, in view of the role of zinc in promoting growth, it has become common practice to prescribe zinc supplements to young children and newborns, particularly preterm infants. It is now clearly established that zinc confers no additional benefits to an individual with adequate zinc status while it can potentially lead to harmful effects by disturbing the milieu of other trace metals in the body. Estimation of thymulin levels in circulation is found to be a sensitive indicator of zinc status and using this parameter we found that apparently normal children have adequate zinc status. Children suffering from severe protein energy malnutrition however had very low levels of the hormone besides low leukocyte and plasma zinc levels indicating zinc deficiency. Such children showed improvement in their zinc status when zinc supplements were provided along with rehabilitation diets. Pregnant women and term newborns showed no evidence of zinc deficiency. Preterm infants had higher leukocyte zinc levels during early infancy and the breast milk of their mothers also had higher zinc content which could cater to the higher requirements of the rapidly growing preterm infant. All breast-fed infants showed decline in the zinc status gradually over the initial 4 months of life and regained adequate zinc status after appropriate weaning. These studies thus do not support the view of routine zinc supplements to pregnant women or children. However, Infants solely fed formula milk from birth had significantly impaired zinc status till the time of weaning. The functional significance of severe zinc inadequacy in such infants needs to be established.

A direct ELISA technique to detect antibodies against polioviruses.

A direct ELISA test was developed to detect circulating antibodies specific to poliovirus types 1, 2 and 3. Specificity of the test was established by using known polio negative and positive sera. The assay was compared with the standard microneutralization test using sera from polio and non polio cases vaccinated and unvaccinated subjects and standard positive sera obtained from WHO/EPI (Geneva). The reproducibility of the results was tested using different batches of the antigen prepared from Sabin strain of poliovirus supplied by ERC Bombay and from Sabin strain of virus obtained from WHO/EPI. ELISA was found to be as sensitive as microneutralization test in detecting seronegatives and was found to be specific to polio by giving negative results with non polio cases. ELISA is thus a rapid and simple method that may be useful for mapping seroepidemiology of poliomyelitis and as a tool for effective surveillance of the disease by offering rapid diagnosis in acute cases.

An outbreak of poliomyelitis in Andhra Pradesh (South India).

An outbreak of poliomyelitis that occurred in the year 1992 in Telangana region of Andhra Pradesh, South India was investigated to understand the reasons for persistence of poliomyelitis in the general population and for the outbreak in Andhra Pradesh in particular. The study comprised of a detailed investigation of epidemiological and clinical features, serology and vaccination status and a case control study to calculate vaccine efficacy by matched pair analysis. The outbreak occurred after a relative quiescence of 3 years. The age group of the patients ranged from 2 months to 5 years, 26.5% being infants and 70.2% being children between 1 and 5 years. The outbreak was mainly caused by Type 1 poliovirus. Vaccine efficacy was found to be 70%. Antibody response was not high in cases. Seventy six per cent of the children with poliomyelitis were unvaccinated. Ignorance of the mothers and family interference were the main causes for not vaccinating the children. The study indicates the need to increase the vaccination coverage and inclusion of children upto 5 years in the programme. Absence of vaccination is the major risk factor for the outbreak. The persistence of poliomyelitis in older children, low antibody response and suboptimal vaccine efficacy point out the problem of achieving control with OPV in tropical countries and suggest the need for alternate strategies. Better health education strategies need to be developed.

Nutritional modulation of immunity to infection.

PEM of varying grades constitutes an important nutritional deficiency disorder of young children. Several immune mechanisms are found to be impaired in severely malnourished children thus making them victims of the vicious cycle of infection and malnutrition. Early impairment of neutrophil function triggers the vicious cycle and this emphasizes the need for prevention and early treatment of acute infections in children. Often based on the observations made in severely malnourished children, doubts have been expressed about the success of vaccination programmes in communities where malnutrition is widespread. But the humoral and cell mediated immune responses which are essential for adequate response to the various vaccines are found to be satisfactory among the undernourished children who constitute the major segment of the beneficiaries of such programmes in the communities. These observations help in strongly recommending the implementation of vaccination programmes in such communities and thus prevent severe malnutrition. Severe malnutrition, though often amenable for rehabilitation in the hospital, however, leaves certain permanent immunological sequelae and thus prevention of severe PEM in young children is important.

BCG vaccination in malnourished child population.

The efficacy of BCG vaccination is still a subject of controversy. In the present study the protective role of BCG vaccination, the influence of nutritional status and justification for revaccination in children were investigated. Of the 504 preschool children suffering from tuberculosis who were registered for the study, 345 children did not receive BCG vaccine while the others had it during early infancy. Vaccinated children showed a significantly greater tendency to localise the tubercular lesions while most of the unvaccinated children suffered from progressive forms of the infection. Vaccination had similar effects even when there was associated malnutrition. Age did not seem to influence the severity of the disease in unvaccinated children while older children (greater than 3 yrs) had a greater tendency to localise the lesion in the vaccinated group. These data do not support the proposal of administering a booster dose of BCG to children who were vaccinated during early infancy.

Need for protection against rubella in India.

Reports from different parts of India highlight the existence of Rubella leading to fetal malformations and wastage. However, the need for routine immunization to control rubella has not been duly recognized. In the present study the prevalence of rubella was determined in different age groups of the population by estimating IgG antibodies to rubella virus using ELISA kit obtained from Diamedix. Two hundred and seventy four pairs of maternal blood samples were collected. Samples were also obtained from one hundred and thirty nine children aged 1-15 years and assayed for rubella antibodies. The sample was read as positive if the Elisa unit/ml was 15 EU/ml. The results showed that 94.9% of mothers and 94.1% of cord blood samples showed seropositivity. Children between 1 and 5 years showed the lowest seropositivity of 69.2% which gradually increased to reach near 95% levels by 15 years. These observations indicate the prevalence of rubella in children and thus suggest the need to protect susceptible women of reproductive age group.

Specific immune responses in typhoid fever & after TAB vaccination.

The specific immune responses to Salmonella typhi were investigated in 131 patients suffering from typhoid fever and 34 healthy individuals after TAB vaccination. A proportion of individuals failed to develop either specific humoral or cell mediated immune responses. About 5 per cent of the patients with natural infection and nearly 9 per cent of the vaccine recipients failed to develop both the responses. Frequent reinfection and carrier state, and lack of absolute protection following TAB vaccination could be due to the inability of a proportion of naturally infected and TAB vaccinated individuals to mount sufficient specific immune responses, due to the same mechanism.