2,449 research outputs found
Measurements of carbonaceous aerosols at urban and remote marine sites
Concentrations of total carbon (TC) and black carbon (BC) in ambient air at Delhi (urban site) and over Indian Ocean (remote marine) were determined as a part of INDOEX programme. Over Indian Ocean, the TC and BC concentrations varied from 1.81 to 10.05 μg/m3 and 0.13 to 1.36 μg/m3 respectively during FFP-98. During the same season at Delhi, the TC and BC ranged from 7.50 to 40.27 μg/m3 and 0.49 to 2.84 μg/m3 respectively. In addition, at Delhi, the TC and BC concentrations were noticed very low during the monsoon season. However, the percentage BC during monsoon season was very high compared to winter season. High concentrations of TC were observed due to high organic carbon (OC) which might be due to biomass burning of various kinds. Similar to Delhi, near Indian coast, the concentration of OC was very high while towards ITCZ and across ITCZ, OC content was relatively lower
Eff ect of pentavalent rotavirus vaccine introduction on hospital admissions for diarrhoea and rotavirus in children in Rwanda: a time-series analysis
Background In May, 2012, Rwanda became the fi rst low-income African country to introduce pentavalent rotavirus
vaccine into its routine national immunisation programme. Although the potential health benefi ts of rotavirus
vaccination are huge in low-income African countries that account for more than half the global deaths from
rotavirus, concerns remain about the performance of oral rotavirus vaccines in these challenging settings.
Methods We conducted a time-series analysis to examine trends in admissions to hospital for non-bloody diarrhoea in
children younger than 5 years in Rwanda between Jan 1, 2009, and Dec 31, 2014, using monthly discharge data from
the Health Management Information System. Additionally, we reviewed the registries in the paediatric wards at six
hospitals from 2009 to 2014 and abstracted the number of total admissions and admissions for diarrhoea in children
younger than 5 years by admission month and age group. We studied trends in admissions specifi c to rotavirus at one
hospital that had undertaken active rotavirus surveillance from 2011 to 2014. We assessed changes in rotavirus
epidemiology by use of data from eight active surveillance hospitals.
Findings Compared with the 2009–11 prevaccine baseline, hospital admissions for non-bloody diarrhoea captured by
the Health Management Information System fell by 17–29% from a pre-vaccine median of 4051 to 2881 in 2013 and
3371 in 2014, admissions for acute gastroenteritis captured in paediatric ward registries decreased by 48–49%, and
admissions specifi c to rotavirus captured by active surveillance fell by 61–70%. The greatest eff ect was recorded in
children age-eligible to be vaccinated, but we noted a decrease in the proportion of children with diarrhoea testing
positive for rotavirus in almost every age group.
Interpretation The number of admissions to hospital for diarrhoea and rotavirus in Rwanda fell substantially after
rotavirus vaccine implementation, including among older children age-ineligible for vaccination, suggesting indirect
protection through reduced transmission of rotavirus. These data highlight the benefi ts of routine vaccination against rotavirus in low-income settings
A Preliminary Assessment of Rotavirus Vaccine Effectiveness in Zambia
BACKGROUND: Diarrhea is the third leading cause of child death in Zambia. Up to one-third of diarrhea cases resulting in hospitalization and/or death are caused by vaccine-preventable rotavirus. In January 2012, Zambia initiated a pilot introduction of the Rotarix live, oral rotavirus vaccine in all public health facilities in Lusaka Province.
METHODS: Between July 2012 and October 2013, we conducted a case-control study at 6 public sector sites to estimate rotavirus vaccine effectiveness (VE) in age-eligible children presenting with diarrhea. We computed the odds of having received at least 1 dose of Rotarix among children whose stool was positive for rotavirus antigen (cases) and children whose stool was negative (controls). We adjusted the resulting odds ratio (OR) for patient age, calendar month of presentation, and clinical site, and expressed VE as (1 - adjusted OR) × 100.
RESULTS: A total of 91 rotavirus-positive cases and 298 rotavirus-negative controls who had under-5 card-confirmed vaccination status and were ≥6 months of age were included in the case-control analysis. Among rotavirus-positive children who were age-eligible to be vaccinated, 20% were hospitalized. Against rotavirus diarrhea of all severity, the adjusted 2-dose VE was 26% (95% confidence interval [CI], -30% to 58%) among children ≥6 months of age. VE against hospitalized children ≥6 months of age was 56% (95% CI, -34% to 86%).
CONCLUSIONS: We observed a higher point estimate for VE against increased severity of illness compared with milder disease, but were not powered to detect a low level of VE against milder disease
Household Transmission of Rotavirus in a Community with Rotavirus Vaccination in Quininde, Ecuador
Background: We studied the transmission of rotavirus infection in households in peri-urban Ecuador in the vaccination era.
Methods: Stool samples were collected from household contacts of child rotavirus cases, diarrhea controls and healthy controls following presentation of the index child to health facilities. Rotavirus infection status of contacts was determined by RT-qPCR. We examined factors associated with transmissibility (index-case characteristics) and susceptibility (householdcontact
characteristics).
Results: Amongst cases, diarrhea controls and healthy control household contacts, infection attack rates (iAR) were 55%, 8% and 2%, (n = 137, 130, 137) respectively. iARs were higher from index cases with vomiting, and amongst siblings. Disease ARs were higher when the index child was ,18 months and had vomiting, with household contact ,10 years and those sharing a room with the index case being more susceptible. We found no evidence of asymptomatic infections leading to disease transmission.
Conclusion: Transmission rates of rotavirus are high in households with an infected child, while background infections are rare. We have identified factors associated with transmission (vomiting/young age of index case) and susceptibility (young age/sharing a room/being a sibling of the index case). Vaccination may lead to indirect benefits by averting episodes or reducing symptoms in vaccinees
Population-based incidence of intussusception and a case-control study to examine the association of intussusception with natural rotavirus infection among Indian children
Background: A rotavirus vaccine previously licensed in the United States was withdrawn because it caused intussusception. Data on background intussusception rates in developing countries are required to plan pre- and postlicensure safety studies for new rotavirus vaccines. Also, it is unclear whether natural rotavirus infection is associated with intussusception. Methods: Passive surveillance for intussusception in a large, well-defined, poor, urban population in Delhi, India, was conducted in 2 phases. Intussusception was confirmed by ultrasonography or surgery. Fecal samples obtained from patients with intussusception at study hospitals (irrespective of their residence in study areas) and healthy control subjects were tested for rotavirus with use of enzyme immunoassay. If available, resected intestinal tissue samples were tested for rotavirus with use of immunohistochemistical analysis and reverse-transcription polymerase chain reaction. Results: The incidence of intussusception requiring hospitalization was 17.7 cases per 100,000 infant-years of follow-up (95% confidence interval, 5.9-41.4 cases per 100,000 infant-years). Detection rates of rotavirus in stool samples did not differ significantly between case patients and control subjects (4 of 42 case patients vs 6 of 92 control subjects), and no evidence of rotavirus was detected in any of the 22 patients with intussusception for whom intestinal tissue samples were available. Conclusions: The incidence of intussusception among Indian infants appears to be lower than that reported in other middle- and high-income countries. Natural rotavirus infection does not appear to be a major cause of intussusception in Indian infants
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