Estimated cumulative incidence of pandemic (H1N1) influenza among pregnant women during the first wave of the 2009 pandemic

Background

Hospitalization and lab confirmed cases of H1N1 have been reported during the first wave of the 2009 pandemic but these are not accurate measures of influenza incidence in the population. We estimated the cumulative incidence of pandemic (H1N1) influenza among pregnant women in the province of Manitoba during the first wave of the 2009 pandemic.

Methods

Two panels of stored frozen serum specimens collected for routine prenatal screening were randomly selected for testing before (March 2009, n = 252) and after (August 2009, n = 296) the first wave of the pandemic. A standard hemagglutination inhibition assay was used to detect the presence of IgG antibodies against the pandemic (H1N1) 2009 virus. The cumulative incidence of pandemic (H1N1) influenza was calculated as the difference between the point prevalence rates in the first and second panels.

Results

Of the specimens collected in March, 7.1% were positive for the IgG antibodies (serum antibody titre ≥ 1:40). The corresponding prevalence was 15.7% among the specimens collected in August. The difference indicated a cumulative incidence of 8.6% (95% confidence interval [CI] 3.2%–13.7%). The rate differed geographically, the highest being in the northern regions (20.8%, 95% CI 7.9%–31.8%), as compared with 4.0% (95% CI 0.0%–11.9%) in Winnipeg and 8.9% (95% CI 0.0%–18.8%) in the rest of the province.

Interpretation

We estimated that the cumulative incidence of pandemic (H1N1) influenza among pregnant women in Manitoba during the first wave of the 2009 pandemic was 8.6%. It was 20.8% in the northern regions of the province.During the first wave of the pandemic (H1N1) 2009, the province of Manitoba was more severely affected than almost any other Canadian province.¹ Pregnant women in particular had higher rates of laboratory-confirmed infection and of severe illness.² However, the number of laboratory-confirmed cases is not an accurate measure of the incidence of influenza in the population. The number and geographic distribution of confirmed cases are influenced by differences in access to medical care, physicians’ practices and other factors.³We estimated the cumulative incidence of pandemic (H1N1) influenza among pregnant women in the province of Manitoba during the first wave of the 2009 pandemic. We did this by measuring the point seroprevalence in random samples of pregnant women presenting for routine prenatal screening before and after the first wave.     

Strobilanthes crispus attenuates renal carcinogen, iron nitrilotriacetate (Fe-NTA)-mediated oxidative damage of lipids and DNA

This study was aimed to evaluate the effect of Strobilanthes crispus extract for possible protection against lipid peroxidation and DNA damage induced by iron nitrilotriacetate (Fe-NTA) and hydrogen peroxide (H₂O₂). Fe-NTA is a potent nephrotoxic agent and induces acute and subacute renal proximal tubular necrosis by catalyzing the decomposition of H₂O₂-derived production of hydroxyl radicals, which are known to cause lipid peroxidation and DNA damage. Incubation of postmitochondrial supernatant and/or calf thymus DNA with H₂O₂ (40 mM) in the presence of Fe-NTA (0.1 mM) induces lipid peroxidation and DNA damage to about 2.3-fold and 2.9-fold, respectively, as compared to control (P < 0.05). In lipid peroxidation protection studies, S. crispus treatment showed a dose-dependent inhibition (45–53% inhibition, P < 0.05) of Fe-NTA and H₂O₂ induced lipid peroxidation. Similarly, in DNA damage protection studies, S. crispus treatment also showed a dose-dependent inhibition (18–30% inhibition, P < 0.05) of DNA damage. In addition, the protection was closely related to the content of phenolic compounds as evident by S. crispus extract showing the value of 124.48 mg/g total phenolics expressed as gallic acid equivalent (GAE, mg/g of extract). From these studies, it is concluded that S. crispus inhibits peroxidation of membrane lipids and DNA damage induced by Fe-NTA and H₂O₂ and possesses the potential to be used to treat or prevent degenerative diseases where oxidative stress is implicated.     

The tyrosine kinase p56lck is essential in coxsackievirus B3-mediated heart disease

Infections are thought to be important in the pathogenesis of many heart diseases. Coxsackievirus B3 (CVB3) has been linked to chronic dilated cardiomyopathy, a common cause of progressive heart disease, heart failure and sudden death. We show here that the sarcoma (Src) family kinase Lck (p56lck) is required for efficient CVB3 replication in T-cell lines and for viral replication and persistence in vivo. Whereas infection of wild-type mice with human pathogenic CVB3 caused acute and very severe myocarditis, meningitis, hepatitis, pancreatitis and dilated cardiomyopathy, mice lacking the p56lck gene were completely protected from CVB3-induced acute pathogenicity and chronic heart disease. These data identify a previously unknown function of Src family kinases and indicate that p56lck is the essential host factor that controls the replication and pathogenicity of CVB3.     

Evaluation of Two Influenza Surveillance Systems in South Africa

Background

The World Health Organisation recommends outpatient influenza-like illness (ILI) and inpatient severe acute respiratory illness (SARI) surveillance. We evaluated two influenza surveillance systems in South Africa: one for ILI and another for SARI.

Methodology

The Viral Watch (VW) programme has collected virological influenza surveillance data voluntarily from patients with ILI since 1984 in private and public clinics in all 9 South African provinces. The SARI surveillance programme has collected epidemiological and virological influenza surveillance data since 2009 in public hospitals in 4 provinces by dedicated personnel. We compared nine surveillance system attributes from 2009–2012.

Results

We analysed data from 18,293 SARI patients and 9,104 ILI patients. The annual proportion of samples testing positive for influenza was higher for VW (mean 41%) than SARI (mean 8%) and generally exceeded the seasonal threshold from May to September (VW: weeks 21–40; SARI: weeks 23–39). Data quality was a major strength of SARI (most data completion measures >90%; adherence to definitions: 88–89%) and a relative weakness of the VW programme (62% of forms complete, with limited epidemiologic data collected; adherence to definitions: 65–82%). Timeliness was a relative strength of both systems (e.g. both collected >93% of all respiratory specimens within 7 days of symptom onset). ILI surveillance was more nationally representative, financially sustainable and expandable than the SARI system. Though the SARI programme is not nationally representative, the high quality and detail of SARI data collection sheds light on the local burden and epidemiology of severe influenza-associated disease.

Conclusions

To best monitor influenza in South Africa, we propose that both ILI and SARI should be under surveillance. Improving ILI surveillance will require better quality and more systematic data collection, and SARI surveillance should be expanded to be more nationally representative, even if this requires scaling back on information gathered.     

The Effect of Lactococcus lactis subsp. lactis PTCC 1403 on the Growth Performance,Digestive Enzymes Activity,Antioxidative Status,Immune Response,and Disease Resistance of Rainbow Trout (Oncorhynchus mykiss)

The effect of Lactococcus lactis subsp. lactis strain PTCC 1403 as a potential probiotic was investigated on the growth, hematobiochemical, immune responses, and resistance to Yersinia ruckeri infection in rainbow trout. A total of 240 fish were distributed into 12 fiberglass tanks representing four groups (× 3 replicates). Each tank was stocked with 20 fish (average initial weight: 11.81 ± 0.32 g) and fed L. lactis subsp. lactis PTCC 1403 at 0 (control, T0), 1 × 10⁹ (T1), 2 × 10⁹ (T2), and 3 × 10⁹ (T3) CFU/g feed for 8 weeks. The results showed enhanced protein efficiency ratio and reduced feed conversion ratio in the fish-fed T2 diet. Further, fish-fed T2 and T3 diets showed a significantly higher survival rate than the control (p < 0.05). Trypsin, lipase, and protease activities were increased in fish-fed L. lactis subsp. lactis PTCC 1403 compared to the control (p < 0.05). Fish fed with a T2 diet showed significantly (p < 0.05) lower glucose content than other groups. The blood lysozyme activity and IgM showed significantly (p < 0.05) higher values in fish-fed T2 and T3 diets than in other groups. The antioxidative responses were increased in fish-fed T2 and T3 diets (p < 0.05). After 7 days post-Y. ruckeri challenge, the cumulative mortality rate showed the lowest value in fish fed with T1 and T2 diets, while the highest value was recorded in the control group. In conclusion, the results revealed beneficial effects of L. lactis subsp. lactis PTCC 1403 on the feed efficiency, immune response, and resistance to Y. ruckeri infection in rainbow trout.

     

Th1/Th2 cytometric bead array can discriminate cytokine secretion from endogenously activated cells in pulmonary disease, recent and remote infection in tuberculosis

Differential T cell trafficking through the blood compartment towards infected foci may be occurring in different stages of tuberculosis disease and infection. The aim of the present study was to identify cytokine signatures in the blood compartment in tuberculosis patients with pulmonary disease (PTB=19), recently exposed household contacts (HC=27) and nonexposed community controls (EC=37). Diluted (1:10) whole blood was cultured for 2 days and cytokine secretion was assessed using Cytometric Bead Array (Th1/Th2 kit II; BD Biosciences) which included IL-2, TNF-α, IFN-γ (Type1/T1), IL-4, IL-6 and IL-10 (Type2/T2). All T1/T2 cytokines were elevated in PTB (AUROC>0.9) while HC showed selective elevation of IL-6 (AUROC>0.7) compared to EC. Principal component analysis (PCA) extracted two groupings with Eigen values >1; IL-6 separated into the second component for PTB, HC and EC. After rotation, IFN-γ was correlated with the first component for PTB and EC and the second component for HC indicating an absence of T1/T2 dichotomy. Therefore endogenous cytokine signatures may indicate differential T cell trafficking in different stages of tuberculosis infection and disease.     

Role of organic soil amendments with some non-conventional plant additives on the growth of eggplant and their role against Meloidogyne incognita infection

The effects of four waste residues from castor (Ricinus communis L.), rocket (Eruca sativa Mill.), linseed (Linum usitatissimum L.) and wheat germ (Triticum aestivum L.) crops oil extraction as soil amendments at three rates (on base lower rate, recommended rate and higher rate), in comparison with the nematicide Nemacur 10% G were evaluated in greenhouse conditions (25 ± 5°C) at the National Research Center, Egypt, during two successive seasons on the physiological influence on the eggplant and on the infection by the root-knot nematode Meloidogyne incognita. All the tested treatments significantly reduced the numbers of juveniles in soil or in roots, number of galls, egg-masses, gall and egg-mass indices and the rate of nematode build-up. Significant differences in the nematode stages were found within and between treatments. The percentage reduction in the nematode stages was greater with the use of wheat germ mill residues (WGMR) compound followed by castor seed mill residues (CAMR) compound, rocket seed mill residues (RSMR) and Nemacur 10% G. The application of linseed mill residues (LSMR) was the least effective in reducing the nematode stages. Regarding infected plants, all the evaluated amendments achieved significant increases in the almost shoot and root growth variables, total contents of photosynthetic pigments, phenolics and carbohydrates when compared with nematode inoculated and untreated plants. As for healthy plants, it is clear that all the doses of WGMR compound and the highest doses (3.75%, w/w) of the other additives had pronounced effect on the growth parameters and phenolic content of dry leaves of the eggplant. In addition, all the treatments increased photosynthetic pigments and carbohydrates content of the eggplant. These results indicate that some seed mill residues may be used as natural nematicides in controlling M. incognita nematode and improving the growth and some chemical composition of the eggplant.     

Coexistence of a C4 grass and a leaf succulent shrub in an arid ecosystem. The relationship between rooting depth, water and nitrogen

Here we aim to demonstrate that in arid environments the competitive balance between species can be determined by niche separation with either nitrogen or water as the relevant niche axis. To do this we sampled roots <2 mm in diameter for 5 soil pits equidistant between two coexisting species, a shrub and a grass. Using stable carbon and nitrogen isotope ratios of fine roots we determine both photosynthetic pathway and rooting depth. We also examine the distribution of soil moisture and nitrogen relative to root biomass. Our results for root biomass and stable isotope ratios of fine roots demonstrate both niche separation and competition for resources. Root biomass is highest at the top of the profile where soil nitrogen is highest and soil moisture is lowest. We conclude that while there is competition for resources in the middle of the profile, competition is mitigated by photosynthetic pathway. The facultative CAM shrub grows whenever the soil at the surface is wet enough. The C₄ photosynthetic pathway of the grass is more nitrogen and water use efficient making it better adapted to the low nitrogen in the middle of the profile and low summer rainfall.