Children and Disasters

Issue #18: March 2, 2015

NEWS

  • THE EBOLA EPIDEMIC – Ebola case counts now total 23,694 (suspected, probable, and confirmed) with 9,589 deaths in the countries with widespread transmission during the 2014-5 epidemic. Last month’s totals were 21,689 cases with 8,626 deaths. While this is a good reduction from exponential spread late in 2014, imagine the sense of crisis if the present West Africa transmission rates pertained to the US. Among the endemic countries, infection control is best in Liberia. Sporadic cases continue to occur at a fairly constant rate in some communities in Sierra Leone and Guinea where contact tracing is incomplete. New reports indicate a very high child mortality rate of 80% in those younger than 5 years and 95% for those younger than 1 year, probably due to the lack of intensive nursing for those too young to feed themselves. Costs of infection control and disease treatment programs in West Africa continue to be enormous, and the rainy season beginning in April threatens to make the work less efficient. Meanwhile, costs of preparing for infection control within American healthcare facilities has also strained budgets, and federal support for these efforts remains uncertain. Expert consensus guidelines for pediatric critical care of Ebola patients in resource rich countries include input from the National Center for Disaster Preparedness.
  • MEASLES – The 2015 measles outbreak in the US totals 154 cases through February 20. This is a tiny proportion of the almost 200,000 worldwide cases in 2014, currently most prevalent in China, the Philippines, and Vietnam. Measles also continues to be endemic in Europe where over 22,000 cases in 7 countries were reported in 2014-5. Global travel to endemic areas highlights the ongoing risk for those American communities where immunization rates are low. In the US, nonmedical exemption for measles immunization continues to be responsible for risk. Vaccine-exempted individuals have 22 to 35 times greater likelihood of contracting measles than immunized children.
  • MIDDLE EAST RESPIRATORY SYNDROME – During February, a new surge in cases of MERS caused by a coronavirus has been reported in the Middle East, especially Saudi Arabia (74 cases in 2015, including 6 in healthcare workers). The source of transmission may be camels or camel products, as well as nosocomial spread within the healthcare system. With a fatality rate of approximately 40% of identified cases, the illness behaves like the SARS outbreak of 2003-4, also caused by a coronavirus. The current increase in MERS cases parallels the seasonal trends of 2014. MERS is currently a disease of adults, although it is not clear whether this is due to age specific pathophysiology or age related differences in exposure. MERS, spread by the airborne route as well as by contact and droplet transmission, has the potential to be far more contagious in the healthcare setting than Ebola, which is spread only by direct contact and droplet mechanisms.
  • DROUGHT UPDATES – A survey of Californians indicates that 60% support voluntary reductions in water use, while one-third favor mandatory water rationing. In southeast Brazil, severe drought is forcing intermittent interruption in the water supply to Sao Paulo. New solar powered reverse osmosis water purification plants are being built in drought stricken areas of Pakistan.

TOOLS

  • NEW YORK CITY PANEL ON CLIMATE CHANGE – 2015 report.
  • COUNTERMEASURES FOR ACUTE RADIATION SYNDROME – A number of promising radiation countermeasures are currently under development, seven of which have received US FDA investigational new drug status for clinical investigation. Four of these agents, CBLB502, Ex-RAD, HemaMax and OrbeShield, are progressing with large animal studies and clinical trials. G-CSF has high potential and well-documented therapeutic effects in countering myelosuppression and may receive full licensing approval by the US FDA in the future.

SCIENCE

  • TOXIC STRESS – Exposure of children to chronic stress at a developmentally vulnerable age may have long lasting adverse health effects. Preliminary studies have begun to suggest pathophysiologic mechanisms. A series of ice storms in Quebec during January 1998 interrupted power to 1.4 million households for periods lasting as long as 6 weeks. Exposure to this event has been utilized by researchers as an experimental model to study the long lasting consequences of stress. Previous studies have shown that children born to women who were pregnant during these ice storms suffer long lasting adverse physical, behavioral, motor, and cognitive effects. Now a small new study of 34 of those children explores a possible molecular mechanism that may be associated with the functional consequences of prenatal maternal stress. DNA provides the genetic code for the basic information, the genome, controlling functions of all of an individual’s cells. In addition, “epigenetic” mechanisms influence cell function. When a cell experiences certain stimuli, molecular modifications of that cell’s DNA provide the cell with a long lasting “memory” of its experience that may modify the cell’s subsequent function. One epigenetic process, the addition of a methyl chemical group to a nucleotide of DNA, modifies expression of the gene that has been chemically marked. As a result of DNA methylation, expression of the gene is usually suppressed or silenced. Some epigenetic mechanisms may provide a biologically useful adaptation. Others may contribute to disease states. Researchers at McGill University isolated T cell lymphocytes from blood samples of adolescents born to pregnant mothers exposed to stress during the 1998 Quebec ice storm. They studied changes in DNA methylation across the entire genome of these lymphocytes. The findings: DNA methylation patterns differed in adolescents whose mothers reported “negative” prenatal experiences during the period of stress, compared with those whose mothers were “neutrally or positively” affected by the stress. Genes associated with many biologically important pathways appeared to be affected. Interpretation: The large number of genes studied across a very small sample of subjects warrants expert scrutiny of the statistical analysis. Do biological events during prenatal maternal stress affect the developing fetus? Or is subsequent postnatal parental behavior the important determinant of subsequent childhood effects? The small sample size and the multiplicity of variables preclude answering such questions on the basis of available data. Epigenetic changes in brain neurons would be even more interesting, but of course are unavailable for study. Nevertheless, possible links between epigenetic changes and functional effects suggest mechanisms for future study. Many questions are suggested, including identification and mechanisms of developmentally enhanced vulnerability to stress, as well as interventions to mitigate the adverse effects.
  • GLOBAL BURDEN OF DISEASE – For children younger than 5 years, diarrheal disease (especially rotavirus), lower respiratory infection (especially pneumococcus, followed by H influenzae type B, respiratory syncytial virus, and influenza), neonatal disorders, malaria, and injuries are leading causes of death.
  • TETRAVALENT DENGUE VACCINE IN CHILDREN – Dengue is a mosquito-borne viral illness endemic in tropical and subtropical regions. Despite vector control efforts, transmission rates have not declined. Four serotypes of the virus cause disease, and for individuals with a second infection with a different serotype, severe disease is more likely, presumably due to an enhanced, but nonprotective inflammatory response. Thus, an effective vaccine must protect against all four serotypes. A clinical trial of a tetravalent vaccine demonstrates efficacy of 61% (42-77% for different serotypes), 96% efficacy against severe disease, and 80% efficacy against hospitalization.

Edited by: Dr. Bob Kanter

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