628 research outputs found
Use of cumulative incidence of novel influenza A/H1N1 in foreign travelers to estimate lower bounds on cumulative incidence in Mexico
Background: An accurate estimate of the total number of cases and severity of illness of an emerging infectious disease is
required both to define the burden of the epidemic and to determine the severity of disease. When a novel pathogen first
appears, affected individuals with severe symptoms are more likely to be diagnosed. Accordingly, the total number of cases
will be underestimated and disease severity overestimated. This problem is manifest in the current epidemic of novel
influenza A/H1N1.
Methods and Results: We used a simple approach to leverage measures of incident influenza A/H1N1 among a relatively
small and well observed group of US, UK, Spanish and Canadian travelers who had visited Mexico to estimate the incidence
among a much larger and less well surveyed population of Mexican residents. We estimate that a minimum of 113,000 to
375,000 cases of novel influenza A/H1N1 have occurred in Mexicans during the month of April, 2009. Such an estimate
serves as a lower bound because it does not account for underreporting of cases in travelers or for nonrandom mixing
between Mexican residents and visitors, which together could increase the estimates by more than an order of magnitude.
Conclusions: We find that the number of cases in Mexican residents may exceed the number of confirmed cases by two to
three orders of magnitude. While the extent of disease spread is greater than previously appreciated, our estimate suggests
that severe disease is uncommon since the total number of cases is likely to be much larger than those of confirmed cases
International Health Regulations—What Gets Measured Gets Done
Focus on goals and metrics for 4 core capacities illustrates 1 approach to implementing IHR
Little Evidence for Genetic Susceptibility to Influenza A (H5N1) from Family Clustering Data
The apparent clustering of human cases of influenza A (H5N1) among blood relatives has been considered as evidence of genetic variation in susceptibility. We show that, by chance alone, a high proportion of clusters are expected to be limited to blood relatives when infection is a rare event
Precisely tracking childhood death
Little is known about the specific causes of neonatal and
under-five childhood death in high-mortality geographic regions
due to a lack of primary data and dependence on inaccurate
tools, such as verbal autopsy. To meet the ambitious new
Sustainable Development Goal 3.2 to eliminate preventable child
mortality in every country, better approaches are needed to
precisely determine specific causes of death so that prevention
and treatment interventions can be strengthened and focused.
Minimally invasive tissue sampling (MITS) is a technique that
uses needle-based postmortem sampling, followed by advanced
histopathology and microbiology to definitely determine cause of
death. The Bill & Melinda Gates Foundation is supporting a
new surveillance system called the Child Health and Mortality
Prevention Surveillance network, which will determine cause of
death using MITS in combination with other information, and
yield cause-specific population-based mortality rates,
eventually in up to 12-15 sites in sub-Saharan Africa and south
Asia. However, the Gates Foundation funding alone is not enough.
We call on governments, other funders, and international
stakeholders to expand the use of pathology-based cause of death
determination to provide the information needed to end
preventable childhood mortality
Poultry-handling Practices during Avian Influenza Outbreak, Thailand
With poultry outbreaks of avian influenza H5N1 continuing in Thailand, preventing human infection remains a priority. We surveyed residents of rural Thailand regarding avian influenza knowledge, attitudes, and practices. Results suggest that public education campaigns have been effective in reaching those at greatest risk, although some high-risk behavior continues
Streptococcus pneumoniae and Haemophilus influenzae type b Carriage, Central Asia
A study of children was conducted in 3 Central Asian Republics. Approximately half of the Streptococcus pneumoniae isolates were serotypes included in available vaccine formulations. Approximately 6% of children carried Haemophilus influenzae type b (Hib). Using pneumococcal and Hib conjugate vaccines may decrease illness in the Central Asian Republics
Seasonal Patterns of Invasive Pneumococcal Disease
Pneumococcal infections increase each winter, a phenomenon that has not been well explained. We conducted population-based active surveillance for all cases of invasive pneumococcal disease in seven states; plotted annualized weekly rates by geographic location, age, and latitude; and assessed correlations by time-series analysis. In all geographic areas, invasive pneumococcal disease exhibited a distinct winter seasonality, including an increase among children in the fall preceding that for adults and a sharp spike in incidence among adults each year between December 24 and January 7. Pneumococcal disease correlated inversely with temperature (r –0.82 with a 1-week lag; p<0.0001), but paradoxically the coldest states had the lowest rates, and no threshold temperature could be identified. The pattern of disease correlated directly with the sinusoidal variations in photoperiod (r +0.85 with a 5-week lag; p<0.0001). Seemingly unrelated seasonal phenomena were also somewhat correlated. The reproducible seasonal patterns in varied geographic locations are consistent with the hypothesis that nationwide seasonal changes such as photoperiod-dependent variation in host susceptibility may underlie pneumococcal seasonality, but caution is indicated in assigning causality as a result of such correlations
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