Experimental Transmission of African Swine Fever (ASF) Low Virulent Isolate NH/P68 by Surviving Pigs

African swine fever (ASF) has persisted in Eastern Europe since 2007, and two endemic zones have been identified in the central and southern parts of the Russian Federation. Moderate- to low-virulent ASF virus isolates are known to circulate in endemic ASF-affected regions. To improve our knowledge of virus transmission in animals recovered from ASF virus infection, an experimental in vivo study was carried out. Four domestic pigs were inoculated with the NH/P68 ASF virus, previously characterized to develop a chronic form of ASF. Two additional in-contact pigs were introduced at 72 days post-inoculation (dpi) in the same box for virus exposure. The inoculated pigs developed a mild form of the disease, and the virus was isolated from tissues in the inoculated pigs up to 99 dpi (pigs were euthanized at 36, 65, 99 and 134 dpi). In-contact pigs showed mild or no clinical signs, but did become seropositive, and a transient viraemia was detected at 28 days post-exposure (dpe), thereby confirming late virus transmission from the inoculated pigs. Virus transmission to in-contact pigs occurred at four weeks post-exposure, over three months after the primary infection. These results highlight the potential role of survivor pigs in disease maintenance and dissemination in areas where moderate- to low-virulent viruses may be circulating undetected. This study will help design better and more effective control programmes to fight against this disease.

Development of BCG Scar and Subsequent Morbidity and Mortality in Rural Guinea-Bissau

BACKGROUND

Previous studies have found that BCG vaccination has nonspecific beneficial effects on child survival, especially among children who developed a BCG scar. These studies have mostly been done in settings with a high scar frequency. In rural Guinea-Bissau, many children do not develop a scar; we tested the hypothesis that among BCG-vaccinated children, a vaccination scar was associated with lower mortality and fewer hospital admissions.

METHODS

During 2009-2011, children <5 years of age in villages followed by Bandim Health Project's demographic surveillance system had their scar status assessed at semiannual visits. We compared mortality and hospital admission rates of scar-positive and scar-negative BCG-vaccinated children during 6 months of follow-up in Cox proportional hazards models.

RESULTS

Among 15 911 BCG-vaccinated children, only 52% had a scar. There were 106 non-injury-related deaths among scar-positive children and 137 among scar-negative children. The mortality rate ratio (MRR) was 0.74 (95% confidence interval [CI], .56-.96) overall; 0.48 (95% CI, .26-.90) in infancy, 0.69 (95% CI, .45-1.05) in the second year of life, and 0.89 (95% CI, .61-1.31) in the third-fifth year of life. The association between scar positivity and lower mortality differed significantly by cause of death and was strongest for respiratory infections (MRR, 0.20 [95% CI, .07-.55]). There were 99 hospital admissions among scar-positive children and 125 admissions among scar-negative children, resulting in an incidence rate ratio of 0.74 (95% CI, .60-.92).

CONCLUSIONS

Among BCG-vaccinated children in a setting with low scar prevalence, having a scar is associated with lower mortality and morbidity. BCG scar prevalence may be an important marker of vaccination program quality.

Implementation of multivariate techniques for the selection of volatile compounds as indicators of sensory quality of raw beef

This study was performed in order to select volatile compounds to predict the off-odour and overall assessment of raw beef's freshness Maronesa breed, using multivariate analysis. M. longissimus dorsi packed in vacuum and MAP (70 % O2/20 % CO2/10 % N2) stored at 4 ºC were examined for off-odour perception as well as the overall assessment of freshness at 10 and 21 days post mortem. The results achieved in this study demonstrated that the selected volatile compounds could be considered as volatile indicators of beef spoilage, enclosing information for discrimination of Maronesa beef samples in sensory classes of odour corresponding to unspoiled and spoiled levels. Fifty-four volatile compounds were detected. A significant increase of aldehydes, ketones and alcohols were observed during storage in MAP. 2 and 3-methylbutanal, 2 and 3-methylbutanol, 1-pentanol, 1-hexanol, 2,3-octanedione, 3,5-octanedione, octanal and nonanal were suggested as indicators of beef spoilage. 3-methylpentane was considered as a marker in the first stages of spoilage in beef, decreasing during storage. Data were examined using PCR and PLSR models for different optimal subsets of volatile compounds. The simplicity and usefulness of the technique in using 0/1 data in preserving high levels of accuracy was also prevalent. The powerful analytical methodologies for reducing variables and the choice of optimal subsets could be advantageous in both basic research and the routine quality control of chilled beef.

Baker's yeast (Saccharomyces cerevisiae) antigen in obese and normal weight subjects

Baker's yeast (Saccharomyces cerevisiae) and its cell wall components have been used as one of the alternatives to antibiotic growth promoters in the feed industry. Antibodies to cell wall mannan of this yeast (ASCA) have been traditionally used in the study of Crohn's disease (CD). We applied ASCA in relation to obesity. This study aims (i) to determine the concentration of ASCA (immunoglobulin A [IgA] and immunoglobulin G [IgG]) in obese compared with normal weight individuals and (ii) to determine if there is a correlation between ASCA concentrations, obesity indices and C-reactive protein. Forty obese individuals (body mass index [BMI] > 35 kg m(-2) ) and 18 healthy (BMI < 25 kg m(-2) ) volunteers participated in this case-control study. Binding activity of serum IgA and IgG to the cell wall mannan of S. cerevisiae was measured by enzyme-linked immunosorbent assay. More than one-third of the obese individual (35%) showed elevated titres of ASCA compared with the control group (5%). This antibody was positively associated with weight (P = 0.01), BMI (P = 0.02) and waist circumference (P = 0.02), but not with C-reactive protein. It seems that ASCA are not only specific for CD but are also associated with obesity. S. cerevisiae or a related antigen may play a role in the matrix of this complex condition.

BCG coverage and barriers to BCG vaccination in Guinea-Bissau: an observational study

BACKGROUND

BCG vaccination is recommended at birth in low-income countries, but vaccination is often delayed. Often 20-dose vials of BCG are not opened unless at least ten children are present for vaccination ("restricted vial-opening policy"). BCG coverage is usually reported as 12-month coverage, not disclosing the delay in vaccination. Several studies show that BCG at birth lowers neonatal mortality. We assessed BCG coverage at different ages and explored reasons for delay in BCG vaccination in rural Guinea-Bissau.

METHODS

Bandim Health Project (BHP) runs a health and demographic surveillance system covering women and their children in 182 randomly selected village clusters in rural Guinea-Bissau. BCG coverage was assessed for children born in 2010, when the restricted vial-opening policy was universally implemented, and in 2012-2013, where BHP provided BCG to all children at monthly visits in selected intervention regions. Factors associated with delayed BCG vaccination were evaluated using logistic regression models. Coverage between intervention and control regions were evaluated in log-binomial regression models providing prevalence ratios.

RESULTS

Among 3951 children born in 2010, vaccination status was assessed for 84%. BCG coverage by 1 week of age was 11%, 38% by 1 month, and 92% by 12 months. If BCG had been given at first contact with the health system, 1-week coverage would have been 35% and 1-month coverage 54%. When monthly visits were introduced in intervention regions, 1-month coverage was higher in intervention regions (88%) than in control regions (51%), the prevalence ratio being 1.74 (1.53-2.00). Several factors, including socioeconomic factors, were associated with delayed BCG vaccination in the 2010-birth cohort. When BCG was available at monthly visits these factors were no longer associated with delayed BCG vaccination, only region of residence was associated with delayed BCG vaccination.

CONCLUSION

BCG coverage during the first months of life is low in Guinea-Bissau. Providing BCG at monthly vaccination visits removes the risk factors associated with delayed BCG vaccination.

Use of conventional PCR and smear microscopy to diagnose pulmonary tuberculosis in the Amazonian rainforest area

The diagnostic usefulness of Ziehl-Neelsen (ZN)-stained sputum smears combined with conventional polymerase chain reaction (ZN/PCR) to amplify IS6110 region DNA extracted from ZN slides was evaluated. The objective was to verify if this association could improve tuberculosis (TB) diagnosis in patients at remote sites. The study was carried out in 89 patients with culture-confirmed pulmonary TB as defined by the Brazilian Manual for TB Treatment. The participants were recruited in a reference unit for TB treatment in Rondônia, a state in the Amazonian area in northern Brazil. ZN, PCR, and culture performed in the sputum samples from these patients were analyzed in different combinations (i.e., ZN plus PCR and ZN plus culture). The prevalence rates of pulmonary TB in these patients were 32.6 and 28.1% considering culture and ZN/PCR, respectively. The sensitivity and specificity of ZN/PCR were 86 and 93%, respectively. ZN/PCR was able to detect more TB cases than ZN alone. This method could offer a new approach for accurate tuberculosis diagnosis, especially in remote regions of the world where culture is not available.

The non-specific effects of vaccines and other childhood interventions: the contribution of INDEPTH Health and Demographic Surveillance Systems

Most childhood interventions (vaccines, micronutrients) in low-income countries are justified by their assumed effect on child survival. However, usually the interventions have only been studied with respect to their disease/deficiency-specific effects and not for their overall effects on morbidity and mortality. In many situations, the population-based effects have been very different from the anticipated effects; for example, the measles-preventive high-titre measles vaccine was associated with 2-fold increased female mortality; BCG reduces neonatal mortality although children do not die of tuberculosis in the neonatal period; vitamin A may be associated with increased or reduced child mortality in different situations; effects of interventions may differ for boys and girls. The reasons for these and other contrasts between expectations and observations are likely to be that the immune system learns more than specific prevention from an intervention; such training may enhance or reduce susceptibility to unrelated infections. INDEPTH member centres have been in an ideal position to document such additional non-specific effects of interventions because they follow the total population long term. It is proposed that more INDEPTH member centres extend their routine data collection platform to better measure the use and effects of childhood interventions. In a longer perspective, INDEPTH may come to play a stronger role in defining health research issues of relevance to low-income countries.

A randomized trial of an early measles vaccine at 4½ months of age in Guinea-Bissau: sex-differential immunological effects

Background

After measles vaccine (MV), all-cause mortality is reduced more than can be explained by the prevention of measles, especially in females.

Objective

We aimed to study the biological mechanisms underlying the observed non-specific and sex-differential effects of MV on mortality.

Methods

Within a large randomised trial of MV at 4.5 months of age blood samples were obtained before and six weeks after randomisation to early MV or no early MV. We measured concentrations of cytokines and soluble receptors from plasma (interleukin-1 receptor agonist (IL-1Ra), IL-6, IL-8, IL-10, tumor necrosis factor (TNF)-α, monocyte chemoattractant protein (MCP)-1, soluble urokinase-type plasminogen activator receptor), and secreted cytokines (interferon-γ, TNF-α, IL-5, IL-10, IL-13, IL-17) after in vitro challenge with innate agonists and recall antigens. We analysed the effect of MV in multiple imputation regression, overall and stratified by sex. The majority of the infants had previously been enrolled in a randomised trial of neonatal vitamin A. Post hoc we explored the potential effect modification by neonatal vitamin A.

Results

Overall, MV versus no MV was associated with higher plasma MCP-1 levels, but the effect was only significant among females. Additionally, MV was associated with increased plasma IL-1Ra. MV had significantly positive effects on plasma IL-1Ra and IL-8 levels in females, but not in males. These effects were strongest in vitamin A supplemented infants. Vitamin A shifted the effect of MV in a pro-inflammatory direction.

Conclusions

In this explorative study we found indications of sex-differential effects of MV on several of the plasma biomarkers investigated; in particular MV increased levels in females, most strongly in vitamin A recipients. The findings support that sex and micronutrient supplementation should be taken into account when analysing vaccine effects.

Trial Registration

clinicaltrials.gov number NCT 00168545

Measles virus antibody responses in children randomly assigned to receive standard-titer edmonston-zagreb measles vaccine at 4.5 and 9 months of age, 9 months of age, or 9 and 18 months of age

The World Health Organization recommends administration of measles vaccine (MV) at age 9 months in low-income countries. We tested the measles virus antibody response at 4.5, 9, 18, and 24 months of age for children randomly assigned to receive standard-titer Edmonston-Zagreb MV at 4.5 and 9 months, at 9 months, or at 9 and 18 months of age. At 4.5 months of age, 75% had nonprotective measles virus antibody levels. Following receipt of MV at 4.5 months of age, 77% (316/408) had protective antibody levels at 9 months of age; after a second dose at 9 months of age, 97% (326/337) had protective levels at 24 months of age. In addition, the response at both 9 and 24 months of age was inversely correlated with the antibody level at receipt of the first dose of MV, and the second dose of MV, received at 9 months of age, provided a significant boost in antibody level to children who had low antibody levels. In the group of 318 children who received MV at 9 months of age, with or without a second dose at 18 months of age, 99% (314) had protective levels at 24 months of age. The geometric mean titer at 24 months of age was significantly lower in the group that received MV at 4.5 and 9 months of age than in the group that received MV at 9 months of age (P = .0001). In conclusion, an early 2-dose MV schedule was associated with protective measles virus antibody levels at 24 months of age in nearly all children. Clinical Trials Registration. NCT00168558.

Immunization with the Leishmania infantum recombinant cyclophilin protein 1 confers partial protection to subsequent parasite infection and generates specific memory T cells

Control of zoonotic visceral leishmaniosis can be achieved using several available drugs. These drugs present high toxicity and require longer treatment regimens which complicate compliance to the treatment. Other control measures directed to the vector or the reservoirs are useful tools to restrain the spreading of this disease but the effects are transitory. A safe, affordable and efficient vaccine conferring long lasting immunity should be the most cost effective way of controlling zoonotic visceral leishmaniosis. The present study aims at characterizing a cyclophilin protein 1 of Leishmania infantum (LiCyP1) and investigating whether recombinant LiCyP1 (LirCyP1) is able to confer protection against infection by evaluating viable parasite load and the generation of specific CD4(+) and CD8(+) effector and central memory T cells in rodent model. LiCyP1 is present in the cytoplasm of L. infantum amastigotes and promastigotes. Immunization of BALB/c mice with LirCyP1 confers high protection to L. infantum infection, causing a marked reduction in parasite replication in the liver and spleen. Furthermore, helper and cytotoxic memory T cell subsets able to specifically recognize parasite antigens expanded in immunized and in challenged mice. CD4(+) T cell subpopulation of intermediate phenotype (CD62L(high)CD127(low)) of challenging mice also presented an accentuated expansion after the recall. This study demonstrated that LirCyP1 confers partial protection to L. infantum infection, promoting the generation of a desired long lasting immunity. LirCyP1 can be considered a potential candidate for the design of a vaccine against zoonotic visceral leishmaniosis.

High- and moderate-intensity aerobic exercise and excess post-exercise oxygen consumption in men with metabolic syndrome

Physical activity is central in prevention and treatment of metabolic syndrome. High-intensity aerobic exercise can induce larger energy expenditure per unit of time compared with moderate-intensity exercise. Furthermore, it may induce larger energy expenditure at post-exercise recovery. The aim of this study is to compare the excess post-exercise oxygen consumption (EPOC) in three different aerobic exercise sessions in men with metabolic syndrome. Seven men (age: 56.7 ± 10.8) with metabolic syndrome participated in this crossover study. The sessions consisted of one aerobic interval (1-AIT), four aerobic intervals (4-AIT), and 47-min continuous moderate exercise (CME) on separate days, with at least 48 h between each test day. Resting metabolic rate (RMR) was measured pre-exercise and used as baseline value. EPOC was measured until baseline metabolic rate was re-established. An increase in O2 uptake lasting for 70.4 ± 24.8 min (4-AIT), 35.9 ± 17.3 min (1-AIT), and 45.6 ± 17.3 min (CME) was observed. EPOC were 2.9 ± 1.7 L O2 (4-AIT), 1.3 ±  .1 L O2 (1-AIT), and 1.4 ± 1.1 L O2 (CME). There were significant differences (P < 0.001) between 4-AIT, CME, and 1-AIT. Total EPOC was highest after 4-AIT. These data suggest that exercise intensity has a significant positive effect on EPOC in men with metabolic syndrome.

Old Fragments of Forest Inside an Urban Area Are Able to Keep Orchid Bee (Hymenoptera: Apidae: Euglossini) Assemblages? The Case of a Brazilian Historical City

Retention of habitat fragments within the urban matrix can provide critical resources for the maintenance of regional biodiversity while still providing socio-economic value. Euglossini bees are important components in a community as they are important pollinators for economically valuable plants as well as hundreds of orchid species. However, some species are very sensitive to environmental impacts like urbanization. This study presents the role of antique urban fragments in a historical city in Brazil and compares it with a conservation area on the aspects of orchid bee assemblage, such as richness, composition, and abundance. Four fragments inside the city of Ouro Preto and three inside Parque Estadual do Itacolomi (PEIT) were sampled for Euglossini bees. Sorensen similarity index was used to compare community composition. The Mantel test was applied to verify the hypothesis that an urban center is a barrier for the mobility of the individuals. Fourteen Euglossini species from the region were registered. Close to 75% of the sampled bees were collected from the PEIT sampling areas. The fragments presented differences in Euglossini richness and abundance. A majority of the sampled fragments were dominated by the Eulaema cingulata Fabricius, Eulaema nigrita Lepeletier, and Euglossa securigera Dressler species. We found differences on community composition between the fragments localized in PEIT and those located in the urban center. The data suggest that there is a possible flux of individuals between the sampled fragments. The various small forest fragments in Ouro Preto, primarily in backyards, may also serve as stepping stones between sampled fragments.

Measles antibody levels after vaccination with Edmonston-Zagreb and Schwarz measles vaccine at 9 months or at 9 and 18 months of age: a serological study within a randomised trial of different measles vaccines

Standard-titre Schwarz (SW) and Edmonston-Zagreb (EZ) measles vaccines (MV) are both used in the routine immunisation programme. Within a trial of different strains of MV, we examined antibody responses in both one-dose and two-dose schedules when the first dose was administered at 9 months.

SETTING AND METHODS

The trial was conducted in an urban area in Guinea-Bissau where we have had a health and demographic surveillance system and studied strategies to prevent measles infection since 1978. In the present study, children were randomised to SW or EZ as the first MV and furthermore randomised to a second dose of the same MV or no vaccine at 18 months of age. We obtained blood samples from 996 children at baseline; post-vaccination blood samples were collected at 18 and 24 months of age to assess measles antibody levels after one or two doses of MV.

RESULTS

At age 18 months all had responded to the first dose and only 1% (8/699) of the children had non-protective antibody levels irrespective of vaccine type. SW was associated with significantly higher levels of measles antibodies (geometric mean titre (GMT)=2114 mIU/mL (95%CI 1153-2412)) than EZ (GMT=807 mIU/mL (722-908)) (p=0.001). Antibody concentration was significantly higher in girls than in boys after EZ but not after SW. Antibody levels were higher in the rainy than the dry season. There was no clear indication that a booster dose at 18 months increased the antibody level at 24 months of age.

CONCLUSIONS

Maternal antibody levels have declined significantly in recent years and 99% had protective levels of measles antibody following primary MV at 9 months of age. It is unlikely that measles prevention and child health will be improved by increasing the age of MV as currently recommended.