Vitamin A supplements and mortality related to measles: a randomised clinical trial.

One hundred and eighty children admitted with measles were randomly allocated to receive routine treatment alone or with additional large doses of vitamin A (200,000 IU orally immediately and again the next day). Baseline characteristics of the two groups were virtually identical for age, severity of measles, and vitamin A and general nutritional states. In 91% of the children serum vitamin A concentrations were less than 0.56 mumol/l. Of the 88 subjects given vitamin A supplements, six (7%) died; of the 92 controls, 12 (13%) died (p = 0.13). This difference in mortality was most obvious for children aged under 2 years (one death out of 46 children receiving supplements versus seven deaths out of 42 controls; p less than 0.05) and for cases complicated by croup or laryngotracheobronchitis. Mortality was several times higher in marasmic than in better nourished children, regardless of study allocation (p less than 0.01).     

Low titers of measles antibody in mothers whose infants suffered from measles before eligible age for measles vaccination

Background

Mink enteritis virus (MEV) causes a highly contagious viral disease of mink with a worldwide distribution. MEV has a linear, single-stranded, negative-sense DNA with a genome length of approximately 5,000 bp. The VP2 protein is the major structural protein of the parvovirus encoded by the vp2 gene. VP2 is highly antigenic and plays important roles in determining viral host ranges and tissue tropisms. This study describes the bionomics and vp2 gene analysis of a mutated strain, MEV-DL, which was isolated recently in China and outlines its homologous relationships with other selected strains registered in Genbank.

Results

The MEV-DL strain can infect F81 cells with cytopathic effects. Pig erythrocytes were agglutinated by the MEV-DL strain. The generation of MEV-DL in F81 cells could infect mink within three months and cause a disease that was similar to that caused by wild-type MEV. A comparative analysis of the vp2 gene nucleotide (nt) sequence of MEV-DL showed that this was more than 99% homologous with other mink enteritis parvoviruses in Genbank. However, the nucleotide residues at positions 1,065 and 1,238 in the MEV-DL strain of the vp2 gene differed from those of all the other MEV strains described previously. It is noteworthy that the mutation at the nucleotide residues position 1,238 led to Asp/Gly replacement. This may lead to structural changes. A phylogenetic tree and sequence distance table were obtained, which showed that the MEV-DL and ZYL-1 strains had the closest inheritance distance.

Conclusions

A new variation of the vp2 gene exists in the MEV-DL strain, which may lead to structural changes of the VP2 protein. Phylogenetic analysis showed that MEV-DL may originate from the ZYL-1 strain in DaLian.     

BCG vaccination and cancer mortality

Summary The mortality rate from leukemia and other neoplastic diseases for the years 1957–1969 was compared in 85,356 BCG-vaccinated newborns at Cook County Hospital, Chicago, and 534,870 nonvaccinated population in Chicago (all black). All cases of cancer deaths under 20 years of age in the black population of Chicago were obtained from death certificates at the Chicago Board of Health. The total black population 20 years of age and under was determined by demographic means from the Chicago Board of Health birth records, adjusted for deaths under the period of study. There were 13 deaths among the vaccinated for a rate of 1.17/100,000/year and 306 deaths among the nonvaccinated for a rate of 4.39/100,000/year. The difference was statistically highly significant (p<0.001). This was a reduction of 74% in the vaccinated group as compared to the nonvaccinated. There were no deaths from malignancies in the under 1 year of age group in the vaccinated, but a drop in the rates to 50% or less in the later age groups (except 10–14 years) in the vaccinated as compared to the nonvaccinated. Thus revaccination at given intervals (1–2 years) is recommended. The National Cancer Institute checked death reports due to cancer elsewhere in the country in our vaccinated population. To reduce the possibility of error, deaths due to trauma in the two groups were determined. No differences in the rates were found. The major categories of neoplasms for this age group were (1) leukemia, (2) central nervous system, (3) lymphoma, and (4) bone and connective tissue. This was a retrospective study. Statistically designed, controlled studies may provide definite conclusions.     

Quantifying density-independent mortality of temperate tree species

Forest resilience to climate change is a topic of national concern as our standing assets and future forests are important to our livelihood. Many tree species are predicted to decline or disappear while others may be able to adapt or migrate. Efforts to quantify and disseminate the current condition of forests are urgently needed to guide management and policy. Here, we develop a new indicator to summarize raw density-independent mortality of forested stands by species from the last decade of the 20th century to the first decade of the 21st century using forest inventory data. We define density-independent mortality to be stand mortality by species due to processes unrelated to natural mortality from succession or stand maturation, which is marked by overall increase in tree girth at the expense of density of individuals. We assess trends for 22 species on national forests in two U.S. states, Washington and Oregon. Populations of some species including timber species have no or low overall levels of density-independent mortality (Juniperus occidentalis, Abies procera, Thuja plicata, Tsuga heterophylla, Pinus ponderosa, and Pseudotsuga menziesii). In contrast, other species demonstrate unsustainable levels of density-independent mortality (Pinus monticola, Arbutus menziesii, Pinus albicaulis, Abies lasiocarpa, Taxus brevifolia, Pinus contorta, Abies grandis, Picea englemanii, and Larix occidentalis). Additionally, the net potential for unsustainable levels of density-independent mortality in standing populations does not necessarily warrant concern when examined across species for our study area and time period; however, when examined by species, the number of species in decline exceeds the number of species where mortality can be generally attributed to endogenous self-thinning. We argue that this work can aid management and policy decisions and our understanding of complex vegetation dynamics in a changing climate. Application of the indicator at larger spatial scales and in conjunction with data on migration and establishment may be used to address questions such as, how can we make cost-effective management decisions to ensure long-term sustainability of tree species and forests? Tree species distributions across the landscape are complex systems, and raw characterization of current trends occurring in forest inventories is important especially given the uncertainty associated with the modeling and prediction of complex systems such as tree species.     

Reduced childhood mortality after standard measles vaccination at 4-8 months compared with 9-11 months of age.

OBJECTIVE--To evaluate the impact on mortality of standard Schwarz measles immunisation before 9 months of age. DESIGN--Children vaccinated in 1980-3 at 4-5, 6-8, and 9-11 months of age were followed to migration, death, or the age of 5 years. SETTING--One urban district and nine villages in two rural areas of Guinea-Bissau. SUBJECT--307 children vaccinated at 4-8 months and 256 at 9-11 months. MAIN OUTCOME MEASURES--Mortality from 9 months to 5 years of age for children immunised at 4-5, 6-8, and 9-11 months. RESULTS--Mortality was significantly lower in children vaccinated at 6-8 months than at 9-11 months (mortality ratio = 0.63, (95% confidence interval 0.41 to 0.97), p = 0.047). As vaccination was provided in semiannual or annual campaigns it is unlikely that age at vaccination reflected a selection bias. The trend was the same in all three study areas. Improved survival after early immunisation was not related to better protection against measles infection. With a Cox multivariate regression model to adjust for age, sex, season at risk, season at birth, measles infection, and region, children vaccinated at 4-8 months had a mortality ratio of 0.61 (0.40 to 0.92, p = 0.020) compared with children vaccinated at 9-11 months. Reimmunised children tended to have lower mortality than children who received only one vaccine (0.59 (0.28 to 1.27, p = 0.176)). CONCLUSION--Standard measles vaccination before 9 months is not associated with higher childhood mortality than is the currently recommended strategy of immunising from 9 months, and it may reduce mortality. This has implications for measles immunisation strategy in developing countries.     

A discrete-time model with vaccination for a measles epidemic.

A discrete-time, age-independent SIR-type epidemic model is formulated and analyzed. The effects of vaccination are also included in the model. Three mathematically important properties are verified for the model: solutions are nonnegative, the population size is time-invariant, and the epidemic concludes with all individuals either remaining susceptible or becoming immune (a property typical of SIR models). The model is applied to a measles epidemic on a university campus. The simulated results are in good agreement with the actual data if it is assumed that the population mixes nonhomogeneously. The results of the simulations indicate that a rate of immunity greater than 98% may be required to prevent an epidemic in a university population. The model has applications to other contagious diseases of SIR type. Furthermore, the simulated results of the model can easily be compared to data, and the effects of a vaccination program can be examined.     

Infant and child mortality in Bangladesh

Socioeconomic differences and trends in infant and child mortality in Bangladesh are examined using data from the 1975 World Fertility Survey and 1979 Contraceptive Prevalence Survery. There is evidence of some recent decline in infant mortality and child mortality. Logit analysis of infant and child mortality indicates that sociodemographic variables such as mother's education, recent period, or higher birth orders, has significant independent effects upon the reduction of infant and child mortality. Other variables such as fetal loss, father's education, or land ownership had no consistent significant effect. On the other hand the effect of urban residence on infant and child mortality was positive after the control of sociodemographic variables. Mere concentration on the supply of modern medical services may bring limited returns unless they are reinforced by appropriate social changes, in particular those affecting the socioeconomic status of women. Educated mothers are likely to belong to higher income households, have better knowledge of how to care for children, and can bring more resources to the care of a sick child.     

Has mortality related to alcohol decreased in Sweden?

In Sweden sales of alcohol dropped 17% from 1976 to 1982. Similarly, comparison of data from 1979 and 1982 shows that the mortality from cirrhosis of the liver declined appreciably, by 28% in men and 29% in women. During 1979-82 mortality from pancreatitis also declined noticeably, by 30% in men and 36% in women. By contrast, no decrease occurred in mortality from alcoholic psychosis, alcoholism, or alcohol intoxication. The decrease in mortality from cirrhosis of the liver and pancreatitis is probably explained by a decrease in the consumption of alcohol among an important subgroup of high consumers of alcohol. The lack of a decrease in mortality from alcoholic psychosis, alcoholism, and alcohol intoxication may be because such diagnoses are often made in socially deteriorated, more dependent alcoholic subjects who have not been able to reduce their consumption.     

Factors affecting infant and child mortality

This paper examines the determinants of infant and child mortality variations in Jordan, Yemen, Egypt, and Tunisia using data from WFS surveys. The analysis considers biological correlates of mortality--mother's age, birth order, birth interval, and previous infant loss--and several social factors--mother's and father's education, mother's residence, father's occupation, and mother's work experience since marriage. The estimates for the 4 countries show large variations in the mortality rates and an expected pattern of declining infant and child mortality during the period of 20 years prior to the survey. Further, the proportionate decline in child mortality in each country was generally greater than the proportionate decline in infant mortality. A persistent pattern of higher child mortality for females than for males is found, suggesting preferential care and treatment of male offspring. The higher mortality risk is found for infants born to very young and very old mothers, with short previous birth intervals, of higher birth orders, and where the previous infant had died. Among the socioeconomic characteristics, the education of the mother and rural-urban residence are found to affect infant survival. In childhood, among the demographic factors, only birth interval shows a significant effect on mortality. The risk of child mortality decreases considerably with the increase in the birth interval. The analysis of the effect of breastfeeding on mortality, although based on limited information, clearly shows the beneficial effect of breastfeeding on the infant's survival, especially during the early months of life. For all countries, the mortality rate for the non-breastfeeders is substantially higher than for the breastfeeders even when the effect of the other covariates is controlled.