10 research outputs found
A simple model to quantitatively account for periodic outbreaks of the measles in the Dutch Bible Belt
In the Netherlands there has been nationwide vaccination against the measles since 1976. However, in small clustered communities of orthodox Protestants there is widespread refusal of the vaccine. After 1976, three large outbreaks with about 3000 reported cases of the measles have occurred among these orthodox Protestants. The outbreaks appear to occur about every twelve years. We show how a simple Kermack-McKendrick-like model can quantitatively account for the periodic outbreaks. Approximate analytic formulae to connect the period, size, and outbreak duration are derived. With an enhanced model we take the latency period in account. We also expand the model to follow how different age groups are affected. Like other researchers using other methods, we conclude that large scale underreporting of the disease must occur
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Think globally, act locally: the role of local demographics and vaccination coverage in the dynamic response of measles infection to control
The global reduction of the burden of morbidity and mortality owing to
measles has been a major triumph of public health. However, the continued
persistence of measles infection probably not only reflects local variation in progress
towards vaccination target goals, but may also reflect local variation in
dynamic processes of transmission, susceptible replenishment through births
and stochastic local extinction. Dynamic models predict that vaccination
should increase the mean age of infection and increase inter-annual variability
in incidence. Through a comparative approach, we assess national-level patterns
in the mean age of infection and measles persistence. We find that
while the classic predictions do hold in general, the impact of vaccination on
the age distribution of cases and stochastic fadeout are mediated by local
birth rate. Thus, broad-scale vaccine coverage goals are unlikely to have the
same impact on the interruption of measles transmission in all demographic settings.
Indeed, these results suggest that the achievement of further measles
reduction or elimination goals is likely to require programmatic and vaccine
coverage goals that are tailored to local demographic conditions
Effect of stress on birth weight in two Johannesburg populations
The effect of stress on birth weight was assessed In mothers delivering at JohaMesburg (predominantly white) and Baragwanath (exclusively black) Hospitals. The Social Readjustment Rating Scale of Holmes and Rahe was used to assign maternal stress scores established during an Interview conducted within 36 hours of delivery. Only mothers without medical problems who had delivered liveborn Infants were Included. Maternal age, obstetric history, smoking history and stresses present during the 12 months preceding delivery were recorded. Of 535 Johannesburg and 662 Baragwanath mothers studied, 48% and 55% respectively reported significant stresses. Anelysis of the two groups revealed that for the Johannesburg mothers, smoking, cumulative stress score and previous preterm birth were Important determinants of birth weight. Of the stress factors studied, marital separation and death of a spouse were significantly associated with a lower birth weight. For Baragwanath mothers the major determinants of low birth weight were maternal age, loss of income through being dismissed from work, or having to leave school as a consequence of the pregnancy
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Genomic analysis of recombinant Sabin clinical isolates
Recombination in Poliovirus vaccine strains is a very frequent phenomenon. In this report 23 polio/Sabin strains isolated from healthy vaccinees or from VAPP patients after OPV administration, were investigated in order to identify recombination sites from 2C to 3D regions of the poliovirus genome. RT-PCR, followed by Restriction Fragment Length Polymorphism (RFLP) screening analysis were applied in four distant genomic regions (5' UTR, VP1, 2C and 3C-3D) in order to detect any putative recombinant. The detected recombinants were sequenced from 2C to the end of the genome (3' UTR) and the exact recombination sites were determined with computational analysis. Five of the 23 isolated strains were recombinant in one genomic region, two of them in 2C, isolates EP16:S3/S2, EP23:S3/S1, two in 3D isolates EP6:S2/S1, EP12:S2/S1 and one in 3A isolate EP9:S2/Sl. Point mutations were found in strains EP3, EP6, EP9 and EP12. Recombination specific types and sites re-occurrence along with point mutations are discussed concerning the polioviruses evolution
Vaccine derived bi- and multi-recombinant Sabin strains
A retrospective analysis of five Sabin intertypic recombinant strains, isolated from human feacal specimens during the time period 1978-1985 in Greece, was performed by RT-PCR, Restriction Fragment Length Polymorphism (R.F.L.P.) and sequencing. Of the studied strains, three (EPA, EPB, EPC) were found to be bi-recombinant Sabin3/Sabin2/Sabin3 (S3/S2/S3), one strain was characterized as a probable S3/S2- CAV18 or CAV21-S2/S1 multi-recombinant (EDP11) and one was identified as a tripartite one S3/S2/S1 (EDP12). Samples EPA, EPB and EPC presented a common recombination junction in the 2C genomic region. Moreover, strains EPA and EPB shared also the second recombination site in the 3D genomic region, whereas the second recombination of EPC was also determined in 3D but in a different nucleotide position. Strains EDP11 and EDP12 presented both identical recombination motifs and recombination sites. The first was detected in the 2C genomic region and the second in the 3D region. Strain EDP11 presented an interesting feature since a sequence of 120 nucleotides seems to have derived from a member of human enteroviruses species C (CAV18 or CAV21). This finding is of great importance, considering that this strain (EDP11) was isolated from an area and time period, where no Coxsackie A virus or poliovirus epidemics occurred. Our study underlines the role of specific positions and motifs of the poliovirus genomic sequences involved in recombination events and prompts that Coxsackie A viruses belonging to human enterovirus species C (genetically closely related to PV) are considered as the possible counterparts of the recombination. © 2007 Springer Science+Business Media, LLC
The health of the Roma people: a review of the published literature
BACKGROUND—The Roma people originated in northern India and have been known in Europe for nearly a thousand years. For much of that time they have been the subjects of discrimination and oppression, culminating in the extermination of half a million Roma in the Nazi death camps. While it is widely believed that the health of Roma people is often poorer than the majority population, these inequalities remain largely unresearched.
METHODS—Published literature on the health of the Roma people was identified using Medline. Opinion pieces were excluded, as were papers relating to anthropometry and to genetic markers. The resultant papers were analysed by country of study and by disease type or care group.
RESULTS—Some 70% of papers identified related to just three countries; Spain and the Czech and Slovak Republics. Much literature concentrates upon communicable disease or reproductive health. The limited evidence suggests increased morbidity from non-communicable disease, but there is little published on this topic. Evidence on health care, though fragmentary, suggests poorer access to health services and uptake of preventative care.
DISCUSSION—Published research on the health needs of the Roma population is sparse. The topics that have received attention suggest a focus on concepts of contagion or social Darwinism, indicating a greater concern with the health needs of the majority populations with which they live. There is a need for both further research into the health of Roma people; with particular emphasis on non-communicable disease; and also for interventions that improve Roma health. Such research must, however, be handled with sensitivity, recognising the social and political context of the society concerned.
Keywords: gypsies; inequalities; ethnicity; social exclusio