Should outbreak response immunization be recommended for measles outbreaks in middle- and low-income countries? An update.

Measles caused mortality in >164,000 children in 2008, with most deaths occurring during outbreaks. Nonetheless, the impact and desirability of conducting measles outbreak response immunization (ORI) in middle- and low-income countries has been controversial. World Health Organization guidelines published in 1999 recommended against ORI in such settings, although recently these guidelines have been reversed for countries with measles mortality reduction goals

Measles vaccination in humanitarian emergencies: a review of recent practice

<p>Abstract</p> <p>Background</p> <p>The health needs of children and adolescents in humanitarian emergencies are critical to the success of relief efforts and reduction in mortality. Measles has been one of the major causes of child deaths in humanitarian emergencies and further contributes to mortality by exacerbating malnutrition and vitamin A deficiency. Here, we review measles vaccination activities in humanitarian emergencies as documented in published literature. Our main interest was to review the available evidence focusing on the target age range for mass vaccination campaigns either in response to a humanitarian emergency or in response to an outbreak of measles in a humanitarian context to determine whether the current guidance required revision based on recent experience.</p> <p>Methods</p> <p>We searched the published literature for articles published from January 1, 1998 to January 1, 2010 reporting on measles in emergencies. As definitions and concepts of emergencies vary and have changed over time, we chose to consider any context where an application for either a Consolidated Appeals Process or a Flash Appeal to the UN Central Emergency Revolving Fund (CERF) occurred during the period examined. We included publications from countries irrespective of their progress in measles control as humanitarian emergencies may occur in any of these contexts and as such, guidance applies irrespective of measles control goals.</p> <p>Results</p> <p>Of the few well-documented epidemic descriptions in humanitarian emergencies, the age range of cases is not limited to under 5 year olds. Combining all data, both from preventive and outbreak response interventions, about 59% of cases in reports with sufficient data reviewed here remain in children under 5, 18% in 5-15 and 2% above 15 years. In instances where interventions targeted a reduced age range, several reports concluded that the age range should have been extended to 15 years, given that a significant proportion of cases occurred beyond 5 years of age.</p> <p>Conclusions</p> <p>Measles outbreaks continue to occur in humanitarian emergencies due to low levels of pre-existing population immunity. According to available published information, cases continue to occur in children over age 5. Preventing cases in older age groups may prevent younger children from becoming infected and reduce mortality in both younger and older age groups.</p

Challenges in measuring measles case fatality ratios in settings without vital registration

Measles, a highly infectious vaccine-preventable viral disease, is potentially fatal. Historically, measles case-fatality ratios (CFRs) have been reported to vary from 0.1% in the developed world to as high as 30% in emergency settings. Estimates of the global burden of mortality from measles, critical to prioritizing measles vaccination among other health interventions, are highly sensitive to the CFR estimates used in modeling; however, due to the lack of reliable, up-to-date data, considerable debate exists as to what CFR estimates are appropriate to use. To determine current measles CFRs in high-burden settings without vital registration we have conducted six retrospective measles mortality studies in such settings. This paper examines the methodological challenges of this work and our solutions to these challenges, including the integration of lessons from retrospective all-cause mortality studies into CFR studies, approaches to laboratory confirmation of outbreaks, and means of obtaining a representative sample of case-patients. Our experiences are relevant to those conducting retrospective CFR studies for measles or other diseases, and to those interested in all-cause mortality studies

Measles deaths in Nepal: estimating the national case–fatality ratio

OBJECTIVE: To estimate the case-fatality ratio (CFR) for measles in Nepal, determine the role of risk factors, such as political instability, for measles mortality, and compare the use of a nationally representative sample of outbreaks versus routine surveillance or a localized study to establish the national CFR (nCFR). METHODS: This was a retrospective study of measles cases and deaths in Nepal. Through two-stage random sampling, we selected 37 districts with selection probability proportional to the number of districts in each region, and then randomly selected within each district one outbreak among all those that had occurred between 1 March and 1 September 2004. Cases were identified by interviewing a member of each and every household and tracing contacts. Bivariate analyses were performed to assess the risk factors for a high CFR and determine the time from rash onset until death. Each factor's contribution to the CFR was determined through multivariate logistic regression. From the number of measles cases and deaths found in the study we calculated the total number of measles cases and deaths for all of Nepal during the study period and in 2004. FINDINGS: We identified 4657 measles cases and 64 deaths in the study period and area. This yielded a total of about 82 000 cases and 900 deaths for all outbreaks in 2004 and a national CFR of 1.1% (95% confidence interval, CI: 0.5-2.3). CFR ranged from 0.1% in the eastern region to 3.4% in the mid-western region and was highest in politically insecure areas, in the Ganges plains and among cases < 5 years of age. Vitamin A treatment and measles immunization were protective. Most deaths occurred during the first week of illness. CONCLUSION: To our knowledge, this is the first CFR study based on a nationally representative sample of measles outbreaks. Routine surveillance and studies of a single outbreak may not yield an accurate nCFR. Increased fatalities associated with political insecurity are a challenge for health-care service delivery. The short period from disease onset to death and reduced mortality from treatment with vitamin A suggest the need for rapid, field-based treatment early in the outbreak

Measles outbreak in South Africa, 2003 - 2005

OBJECTIVES: Measles was virtually eliminated in South Africa following control activities in 1996 / 7. However, from July 2003 to November 2005, 1 676 laboratory-confirmed measles cases were reported in South Africa. We investigated the outbreak's cause and the role of HIV. DESIGN: We traced laboratory-confirmed case-patients residing in the Johannesburg metropolitan (JBM) and O R Tambo districts. We interviewed laboratory- or epidemiologically confirmed case-patients or their caregivers to determine vaccination status and, in JBM, HIV status. We calculated vaccine effectiveness using the screening method. SETTING: Household survey in JBM and O R Tambo districts. OUTCOME MEASURES: Vaccine effectiveness, case-fatality rate, and hospitalisations. RESULTS: In JBM, 109 case-patients were investigated. Of the 57 case-patients eligible for immunisation, 27 (47.4%) were vaccinated. Fourteen (12.8%) case-patients were HIV infected, 46 (42.2%) were HIV uninfected, and 49 (45.0%) had unknown HIV status. Among children aged 12 - 59 months, vaccine effectiveness was 85% (95% confidence interval (CI) : 63, 94) for all children, 63% for HIV infected, 75% for HIV uninfected, and 96% for children with unknown HIV status. (Confidence intervals were not calculated for sub-groups owing to small sample size.) In O R Tambo district, 157 case-patients were investigated. Among the 138 case-patients eligible for immunisation, 41 (29.7%) were vaccinated. Vaccine effectiveness was 89% (95% CI 77, 95). CONCLUSIONS: The outbreak's primary cause was failure to vaccinate enough of the population to prevent endemic measles transmission. Although vaccine effectiveness might have been lower in HIV-infected than in uninfected children, population vaccine effectiveness remained high

Microbial Etiology of Travelers' Diarrhea in Mexico, Guatemala, and India: Importance of Enterotoxigenic Bacteroides fragilis and Arcobacter Species ▿

This study examined established enteric pathogens, Arcobacter species and enterotoxigenic Bacteroides fragilis (ETBF), in 201 U.S. and European travelers with acute diarrhea acquired in Mexico, Guatemala, and India. Arcobacter butzleri and ETBF were detected in 8% and 7% of diarrhea cases, respectively

Mechanism of Nonlinear Optical Enhancement and Supramolecular Isomerism in 1D Polymeric Zn(II) and Cd(II) Sulfates with Pyridine-4-aldoxime Ligands

Interaction of zinc(II) and cadmium(II) sulfates with pyridine-4-aldoxime (4-pyao) and pyridine-4-amidoxime (4-pyamo) ligands resulted in four 1D metal-organic materials (MOMs) with identical composition, [M(SO 4)A2(H2O)2]n, where M = Zn(II), A = 4-pyao for 1, M = Cd(II), A = 4-pyao for 2, M = Zn(II), A = 4-pyamo for 3, M = Cd(II), A = 4-pyamo for 4, and mononuclear [Zn(SO4)(4- pyamo)2(H2O)3] 5. New coordination polymers represent the mixed-ligand supramolecular isomers different by the twisting of two pyridine-4-oxime ligands in the metal coordination environments, and crystallizing in the different space groups. Conformational preferences and nonlinear optical properties of the 4-pyao and 4-pyamo complexes were investigated using density functional theory. Spectral properties of 1-3 have been also evaluated. The solid-state emission of 1D polymers 1-3 appears to be ligand-based, as the positions of the emission maxima remain practically unchanged from free ligand to complexes. The enhancement of luminescence and two-photon absorption in polymers in comparison with the pure ligands is attributed to the chelation of the ligand to the metal center. The detailed mechanism of this enhancement upon complex formation is analyzed and can be used in future design of metal-organic nonlinear optical materials. © 2014 American Chemical Society