Vitamin A status of children in Sri Lanka.

A representative country-wide rural nutrition status survey determined the extent and distribution of vitamin A deficiency in Sri Lanka in children 6 through 71 months of age. Trained paramedical personnel recorded the presence or absence of selected ophthalmological signs and symptoms associated with vitamin A deficiency in 13,450 children. The results of the country-wide clinical survey indicate that a vitamin A deficiency problem of public health importance may exist in two of 15 health areas. Serum vitamin A levels were determined on 346 survey children from two of 15 health areas and compared with clinical findings for these areas. The lowest mean serum vitamin A, 26.3 microgram/100 ml, occurred in children with clinical eye findings. A high prevalence of clinical eye findings, 34%, and the low mean serum vitamin A value, 28.2 microgram/100 ml, were found in the group of chronically undernourished children--children who are less than 90% of their expected height for age. The survey results enabled planned redirection of the distribution of vitamin A capsules to preschool children in Sri Lanka to areas shown to have the highest prevalences of ophthalmological signs and symptoms and/or the highest prevalence of chronic undernutrition.

Infant mortality and childhood nutritional status among Afghan refugees in Pakistan.

In 1984 and again in 1985, systematic surveys were undertaken to evaluate infant mortality and childhood nutritional status among the Afghan refugee population in Pakistan. The entire Afghan refugee population under the administration of the United Nations High Commissioner for Refugees was sampled. Infant mortality rates were estimated to be 156 per 1000 for 1984 and 119 per 1000 for 1985. A decline was also suggested in neonatal mortality rates from 61 per 1000 for 1984 to 46 per 1000 for 1985. For neither infant nor neonatal mortality was the difference statistically significant. Improvements were seen in the percentage of children who died before their fifth birthday (22.5% in 1984 and 18.8% in 1985), in the percentage of children who were malnourished (3.5% in 1984 and 2.3% in 1985), and an increase in the percentage of children above the WHO/NCHS/CDC weight-for-height reference median (26% in 1984 and 35% in 1985). Diarrhoea was the most frequently reported cause of death for both years and was a particularly important cause of death among one-year-old children. In 1985, measles was related to 24% of the deaths and neonatal tetanus to 9% of the deaths, an increase from 8% for measles and 6% for tetanus in 1984.

PIP: Female health visitors interviewed 1512 families in 1984 and 1566 families in 1985 dispersed among Afghan refugee camps in the provinces of the Northwest Frontier Province (NWFP), Baluchistan, and Punjab in Pakistan in Pashto, the language of most of the refugees. The refugees came to Pakistan as a result of civil war in Afghanistan. Infant mortality fell from 156-119/1000, but the difference was insignificant. The researchers believed the consistent direction of the differences to be real, however. A 3.7% increase in the percentage of children who lived to age 5 and a 9% increase in children above the standard weight for height median occurred between 1984-1985. Further 1.2% fewer children were malnourished in 1985 than 1984. Moreover no children in either year were 70% of the median. These improvements coincided with a shift from tents to permanent dwellings; more livestock, vegetable gardens, enclosed water supplies, and, in near urban camps, electricity. Despite these improvements and readily available oral rehydration salts, diarrhea still was the major cause of death, especially for 1 year old children. In addition, no change occurred in the percentage of children who had diarrhea 1 week before the interview between the 2 years. Vaccine preventable deaths increased between 1984-1985. Specifically, neonatal deaths from tetanus rose from 22-28%. Further 10 children died from measles in 1984 whereas 27 did in 1985. 24% of children in 1985 had measles. In 1985, researchers estimated previous access to immunizations by the presence of a BCG vaccine scar. 45% in NWFP and Punjab had the scar while only 26% in Baluchistan had a scar. Moreover infant mortality in Baluchistan was 2 times that of the other 2 provinces. In conclusion, relief workers should implement control measures in Afghan refugee camps that reduce neonatal and infant mortality.

Impact of multiple injections on immunization rates among vulnerable children.

BACKGROUND: In 1997, the Advisory Committee on Immunization Practices (ACIP) recommended a switch from oral polio vaccine (OPV) to inactivated polio vaccine (IPV) for the first two infant doses. The ACIP also recommended use of diphtheria, tetanus, and acellular pertussis vaccine (DTaP) for infants. These recommendations resulted in two additional injections at the 2- and 4-month immunization visits. This study evaluates the implementation of new IPV and DTaP immunization recommendations and their impact on immunization coverage levels. METHODS: Immunization coverage was assessed in public clinics in three urban areas before and after the recommendations. One pre- and three post-recommendation cohorts were followed to 12 months of age. RESULTS: Almost all (> or = 88%) infants in the pre-recommendation cohort received OPV, DTP, and only one or two injections. Almost all (> or = 78%) infants in the post-recommendation cohorts received IPV, DTaP, and three or four injections. The percentage of infants in the post-recommendation cohorts up-to-date for immunizations at 12 months of age was slightly higher than those in the pre-recommendation cohort. CONCLUSIONS: Providers rapidly switched from OPV and DTP to IPV and DTaP. Coverage at 12 months of age was higher among IPV/DTaP recipients than among OPV/DTP recipients. Provider and parent acceptance of four injections at a visit was high. The recent pneumococcal conjugate vaccine recommendations potentially add a fifth injection at 2 and 4 months of age. Acceptance or rejection of five injections by providers and parents needs early assessment.

Current epidemiology of pertussis in the United States.

The incidence of pertussis in the United States decreased rapidly during the 20th century, with the most impressive decreases resulting from the widespread use of DTP vaccine since the late 1940's. As a result of immunization laws, vaccine coverage levels against pertussis at school entry have been greater than 95% since 1980. National surveillance for pertussis done by the Centers for Disease Control (CDC) consists of two parts: a weekly telephone reporting system and a written case report system providing more detailed demographic, clinical, and laboratory information. In addition, data on secondary spread of pertussis among household contacts of reported cases were available on a small proportion of reported cases during 1979-1983. During the period 1980-1986, a total of 17,396 cases of pertussis was reported to CDC by weekly telephone reports. The annual incidence of reported pertussis rose during this period from 0.5 cases per 100,000 population to 1.7/100,000. Infants less than 12 months of age had the highest average annual incidence, estimated at 32 cases per 100,000. Children 1-4 years of age accounted for 25% of all cases but had an average annual incidence only 1/7th that of infants. The incidence rates for all age groups increased consistently between 1982 and 1986. The most impressive relative increases occurred among older adolescents and persons 20 years of age and older. In 1986, 10% of reported cases were in this age group compared to only 5% in 1982. Rates of hospitalization and complications such as pneumonia, seizures, and encephalopathy associated with pertussis were highest in children less than 6 months of age and declined progressively with increasing age.(ABSTRACT TRUNCATED AT 250 WORDS)

Outbreaks of pertussis in the United States: the Wisconsin experience.

To identify risk factors for pertussis in older age groups and to examine the effectiveness of erythromycin therapy and prophylaxis in reducing secondary spread, epidemiologic investigations of two outbreaks involving teenagers and adults were conducted. The first outbreak occurred in 1984 among residents of a facility for developmentally disabled persons (median age 17 years). Rates of culture-and/or serologically confirmed infection ranged from 6% to 91% in exposed wards (42% overall), with transmission continuing over a five-month period. Although residents age 10-19 years experienced the highest rates of infection, they were also more likely to be exposed compared with residents in other age groups. Infection rates were significantly lower on wards where erythromycin treatment and prophylaxis were initiated less than 2 weeks after onset of illness in the index case (overall attack rate = 16% vs. 75% in wards where more than 4 weeks had elapsed; p less than .0001). Early treatment with erythromycin was also effective in reducing pertussis severity. The second outbreak occurred over a six-month period among residents of a 3-county area in central Wisconsin in 1985, with adults accounting for 38% of 161 culture-positive cases. Exposure outside the home was the most important predictor of community-acquired infection (p less than .001), with adolescents being at higher risk than persons in other age groups (odds ratio 3.2; p less than .001).(ABSTRACT TRUNCATED AT 250 WORDS)

Naturally acquired measles immunity in Nepal and Sri Lanka.

Serological surveys of naturally acquired measles antibodies in children 6--72 months of age were done in Nepal and Sri Lanka. The prevalences of naturally acquired measles immunity are compared by age groups with serological studies done in other countries. Suggestions are made regarding age ranges for measles vaccination programs.

Assessment of vital statistics and surveillance data for monitoring tetanus mortality, United States, 1979-1984.

Reported tetanus cases and tetanus deaths have declined substantially since widespread implementation of tetanus immunization. However, preventable morbidity and mortality continue to occur. During 1979-1984, 74-95 cases of tetanus were reported annually to the Centers for Disease Control (CDC) and 20-31 deaths were reported annually by the National Center for Health Statistics (NCHS). To evaluate further the health impact of tetanus, the authors assessed the completeness of national tetanus mortality data. They reviewed tetanus case report forms received at CDC from the states and NCHS multiple-cause-of-death tapes for 1979-1984. CDC reports recorded 129 deaths and NCHS mortality tapes 197 deaths. Year of death, state, age, and sex were used to match CDC and NCHS deaths, identifying 78 deaths reported to both sources. Using the methodology of Chandra Sekar and Deming, the authors estimated the actual number of tetanus deaths for 1979-1984 to be 326 (95% confidence interval 291-361). Based on this estimate, the completeness of reporting to CDC was 40%, to NCHS 60%, and to the combined systems 76%. To evaluate the reasons for underreporting, the authors contacted 14 states that had reported greater than or equal to 10 cases of tetanus to CDC during 1979-1984 to obtain death certificates for all tetanus deaths and additional information on all tetanus cases. Thirteen states submitted 108 death certificates for review. Coding and other systematic errors did not explain the low reporting efficiency. Failure to list tetanus as a cause of death on the death certificate was the primary reason for nonreporting of tetanus deaths to NCHS. These results suggest that NCHS tetanus mortality data may not be as complete as previously assumed and that tetanus mortality, and probably morbidity, are higher than previous reports have indicated.

Microtiter determination of measles hemagglutination inhibition antibody with filter papers.

Epidemiological studies of measles and measles immunization frequently require determination of measles antibody status. In developing countries, where venipuncture is frequently unacceptable and where refrigerated storage of serum specimens is often unavailable, microtiter techniques not requiring refrigeration are required. We developed a filter paper technique that measures measles hemagglutination inhibition antibody and meets these criteria. Comparison of separately collected venous blood and peripheral blood collected on filter paper demonstrated 97% agreement in terms of presence or absence of antibody. In 30 of 32 measles specimens, 94% of titers were the same or varied by less than 2 twofold dilutions.

Decision analysis and polio immunization policy.

Dr. Salk's comments on our paper fall into four major categories: our use of the techniques of decision analysis, the assumptions we used, the fact that we did not include individual and social values in the model, and the way in which vaccine policies are developed in the United States. We believe that the methods were used correctly, that the assumptions we used are defensible, and that our conclusions were both appropriate and appropriately worded. We explicitly did not include individual and social values since we were addressing the scientific and epidemiologic issues rather than ethical and moral issues. Vaccine policy development in the United States is carried out in public forums with opportunity for presentation of all sides of an issue.

Use of IgM-hepatitis A antibody testing. Investigating a common-source, food borne outbreak.

An outbreak of hepatitis, type A, affecting 30 employees of a large metropolitan department store was investigated using traditional case findings, a food preference questionnaire, and case-control methods. In addition, the new serological tests for IgM and IgG antibody to hepatitis A virus (anti-HAV) were employed to establish a serological diagnosis of hepatitis A infection, to define the control group, and to identify the index case, an asymptomatic food handler. Twenty-five of 25 cases tested had IgM anti-HAV, whereas none of 73 controls and one of 46 food handlers were IgM anti-HAV positive. This test eliminated three suspect cases that were diagnosed as hepatitis but that had atypical epidemiologic features. Epidemiologic and serological analysis confirmed the association of illness with eating in the employees' cafeteria and eating cold sandwiches.

Nutritional status of preschool children in Togo, 1976-77.

Survey teams visited 163 rural villages and 41 urban quarters in Togo and collected data on weight, height, arm circumference, age, and pedal oedema from 6120 children aged 6-72 months. Haemoglobin levels were determined for one-fifth of the survey children. When 80% of the reference median weight-for-height was used as the cut-off point, the prevalence of acute undernutrition was 2.0%. When 90% of the reference median height-for-age was used as the cut-off point, the prevalence of chronic undernutrition was 19.1%. The prevalence of both types of undernutrition was significantly higher in the northern rural regions, with the lowest prevalence in the urban areas. The prevalence of anaemia was 58.6%, with the highest prevalence in the northern regions. Anthropometric data on socioeconomically privileged preschool children were collected and compared with those for the survey children and the reference population. The socioeconomically privileged preschool group of Togolese children had a nutritional status substantially better than that of the survey children and nearly equivalent to that of the American reference population. The survey method was economical in terms of money, time, and personnel. The methodology employed rapidly provided objective data on the extent and distribution of protein-energy undernutrition and anaemia in the preschool children of Togo.

History of convulsions and use of pertussis vaccine.

Data on 2062 reports from the Monitoring System for Adverse Events Following Immunization, Centers for Disease Control (CDC), were analyzed to compare the risk of a personal or family history of convulsions in children who had a neurologic adverse event after receipt of diphtheria-tetanus-pertussis (DTP) vaccine with those who had a nonneurologic adverse event. Children with a neurologic event after DTP vaccine had a 7.2 times higher risk for personal history of convulsions (95% confidence limits 4.5 to 11.5) and a 4.5 times higher risk for family history of convulsions (95% confidence limits 3.1 to 6.7) than did children with an adverse event that did not affect the nervous system. Children with either a febrile or nonfebrile convulsion after receipt of DTP were significantly more likely to have a personal history of convulsions than children with a nonneurologic adverse event (P less than 0.0001). Children with a febrile convulsion after receipt of DTP but not children with nonfebrile convulsions were significantly more likely to have a family history of convulsions than those with a nonneurologic adverse event. It is recommended that pertussis vaccination be deferred in children with a personal history of a convulsion until it can be determined that an evolving neurologic disorder is not present. If such disorders are found, these children should be given the combined pediatric diphtheria and tetanus toxoids (DT) vaccine to complete the series.

Family history of convulsions and use of pertussis vaccine.

To evaluate the risk of neurologic events after vaccination with diphtheria-tetanus-pertussis (DTP) vaccine, we used data from the Centers for Disease Control Monitoring System for Adverse Events Following Immunization to compare the family history of convulsions in persons reporting neurologic events with that in persons reporting nonneurologic events; these events have an onset within 3 days of immunization with DTP vaccine, given either alone or with oral poliovirus vaccine. Persons reporting neurologic events were 6.4 times more likely to report a prior personal history of convulsions than those reporting nonneurologic events (95% confidence interval 4.7 to 8.8), and were 2.4 times more likely to report a history of convulsions in first-degree family members, that is, siblings or parents (95% confidence interval 1.7 to 3.4). Similar risks were noted for subgroup analyses controlling for type of event (febrile vs nonfebrile convulsion), age at immunization, source of report, number of previous doses of DTP vaccine, and day of onset. Because the Centers for Disease Control monitoring system receives reports on a nonrandom sample of all adverse events after immunization, selection bias could not be ruled out. On the basis of these data, we conclude that children with a family history of seizures are at increased risk of neurologic events, primarily febrile convulsions, after DTP vaccination. However, this increase in risk may reflect a nonspecific familial tendency for convulsions rather than a specific vaccine effect. Considering the rare occurrence of neurologic events after DTP vaccination, the generally benign outcome of febrile convulsions (which make up the majority of these neurologic events), and the possible increased risk of pertussis in the general population if the estimated 5% to 7% of persons with a first-degree family history of convulsions were exempted from pertussis vaccination, we further conclude that a history of convulsions in siblings or parents should not be a contraindication to pertussis vaccination. Special care in the prevention of postvaccination fever may be warranted in children with a family history of seizures.

Nutritional status of children in Nepal, 1975.

Using a random start, fixed interval method of population proportionate sampling, the survey teams visited 219 villages in rural Nepal and collected data on height, weight, and age from 6501 preschool children. During training and at specific times during the survey, systematic standardization methods were utilized to improve the quality of the collected data. Using 80% of the reference median weight-for-height as the cut-off point, the prevalence of acute undernutrition was 6.7%. Using 90% of the reference median height-for-age as the cut-off point, the prevalence of chronic undernutrition was 52%. The prevalence of chronic undernutrition was significantly higher in the hilly areas. Mean haemoglobin values of blood samples collected from one-fifth of the survey population increased with age with no difference between hill and terai areas. A Nepal urban elite population was measured for comparison. The survey method used indicators that are economical in terms of money, time, and personnel and that provide objective data on the extent and distribution of protein/energy undernutrition and of low haemoglobin values in preschool children.

Live or inactivated poliomyelitis vaccine: an analysis of benefits and risks.

Using decision analysis we evaluated the benefits and risks of continued primary reliance on oral poliomyelitis vaccine (OPV) compared to use of inactivated poliovirus vaccine (IPV). We followed a hypothetical cohort of 3.5 million children from birth to age 30 assuming 95 per cent coverage with 98 per cent effective vaccine. Primary reliance on IPV would result in more cases of paralytic poliomyelitis as well as more susceptibles remaining in the population than would be expected with continuing OPV use (74.1 vs 10.0 cases and 5.9 per cent vs 1.1 per cent susceptibles, respectively). However, with OPV use, most cases of paralysis seen would be associated with the vaccine. Our analysis supports a continuation of current US policy placing primary reliance on OPV but the conclusion is heavily dependent on assumptions of risk of exposure to wild virus in the United States. Major declines in risk of exposure to wild virus could alter the balance significantly.