Burden of influenza-associated deaths in the Americas, 2002-2008

BACKGROUND

Influenza disease is a vaccine-preventable cause of morbidity and mortality. The Pan American Health Organization (PAHO) region has invested in influenza vaccines, but few estimates of influenza burden exist to justify these investments. We estimated influenza-associated deaths for 35 PAHO countries during 2002-2008.

METHODS

Annually, PAHO countries report registered deaths. We used respiratory and circulatory (R&C) codes from seven countries with distinct influenza seasonality and high-quality mortality data to estimate influenza-associated mortality rates by age group (0-64, 65-74, and ≥ 75 years) with a Serfling regression model or a negative binomial model. We calculated the percent of all R&C deaths attributable to influenza by age group in these countries (etiologic fraction) and applied it to the age-specific mortality in 13 countries with good mortality data but poorly defined seasonality. Lastly, we grouped the remaining 15 countries into WHO mortality strata and applied the age and mortality stratum-specific rate of influenza mortality calculated from the 20 countries. We summed each country's estimate to arrive at an average total annual number and rate of influenza deaths in the Americas.

RESULTS

For the 35 PAHO countries, we estimated an annual mean influenza-associated mortality rate of 2·1/100,000 among <65-year olds, 31·9/100 000 among those 65-74 years, and 161·8/100,000 among those ≥ 75 years. We estimated that annually between 40,880 and 160,270 persons (mean, 85,100) die of influenza illness in the PAHO region.

CONCLUSION

Influenza remains an important cause of mortality in the Americas.

Incidence of influenza-associated mortality and hospitalizations in Argentina during 2002-2009

BACKGROUND

We estimated rates of influenza-associated deaths and hospitalizations in Argentina, a country that recommends annual influenza vaccination for persons at high risk of complications from influenza illness.

METHODS

We identified hospitalized persons and deaths in persons diagnosed with pneumonia and influenza (P&I, ICD-10 codes J10-J18) and respiratory and circulatory illness (R&C, codes I00-I99 and J00-J99). We defined the influenza season as the months when the proportion of samples that tested positive for influenza exceeded the annual median. We used hospitalizations and deaths during the influenza off-season to estimate, using linear regression, the number of excess deaths that occurred during the influenza season. To explore whether excess mortality varied by sex and whether people were age <65 or ≥ 65 years, we used Poisson regression of the influenza-associated rates.

RESULTS

During 2002-2009, 2411 P&I and 8527 R&C mean excess deaths occurred annually from May to October. If all of these excess deaths were associated with influenza, the influenza-associated mortality rate was 6/100,000 person-years (95% CI 4-8/100,000 person-years for P&I and 21/100,000 person-years (95% CI 12-31/100,000 person-years) for R&C. During 2005-2008, we identified an average of 7868 P&I excess hospitalizations and 22,994 R&C hospitalizations per year, resulting in an influenza-associated hospitalization rate of 2/10,000 person-years (95% CI 1-3/10,000 person-years) for P&I and 6/10,000 person-years (95% CI 3-8/10,000 person-years) for R&C.

CONCLUSION

Our findings suggest that annual rates of influenza-associated hospitalizations and death in Argentina were substantial and similar to neighboring Brazil.

Global health security and the International Health Regulations

Global nuclear proliferation, bioterrorism, and emerging infections have challenged national capacities to achieve and maintain global security. Over the last century, emerging infectious disease threats resulted in the development of the preliminary versions of the International Health Regulations (IHR) of the World Health Organization (WHO). The current HR(2005) contain major differences compared to earlier versions, including: substantial shifts from containment at the border to containment at the source of the event; shifts from a rather small disease list (smallpox, plague, cholera, and yellow fever) required to be reported, to all public health threats; and shifts from preset measures to tailored responses with more flexibility to deal with the local situations on the ground. The new IHR(2005) call for accountability. They also call for strengthened national capacity for surveillance and control; prevention, alert, and response to international public health emergencies beyond the traditional short list of required reporting; global partnership and collaboration; and human rights, obligations, accountability, and procedures of monitoring. Under these evolved regulations, as well as other measures, such as the Revolving Fund for vaccine procurement of the Pan American Health Organization (PAHO), global health security could be maintained in the response to urban yellow fever in Paraguay in 2008 and the influenza (H1N1) pandemic of 2009-2010.

Strategy to enhance influenza surveillance worldwide

The emergence of a novel strain of influenza virus A (H1N1) in April 2009 focused attention on influenza surveillance capabilities worldwide. In consultations before the 2009 outbreak of influenza subtype H1N1, the World Health Organization had concluded that the world was unprepared to respond to an influenza pandemic, due in part to inadequate global surveillance and response capacity. We describe a sentinel surveillance system that could enhance the quality of influenza epidemiologic and laboratory data and strengthen a country's capacity for seasonal, novel, and pandemic influenza detection and prevention. Such a system would 1) provide data for a better understanding of the epidemiology and extent of seasonal influenza, 2) provide a platform for the study of other acute febrile respiratory illnesses, 3) provide virus isolates for the development of vaccines, 4) inform local pandemic planning and vaccine policy, 5) monitor influenza epidemics and pandemics, and 6) provide infrastructure for an early warning system for outbreaks of new virus subtypes.

[Technological development: a weak link in vaccine innovation in Brazil]

In very recent years, the federal government has launched important initiatives mean to strengthen science, technology, and innovation in Brazil and thus enhance the results of technological innovation in key areas of the country's economy. Yet these initiatives have not been enough to reduce Brazil's heavy dependence on goods and technology from more developed nations. The article describes the current state of vaccination, production, and technological development of vaccines both internationally and nationally. Some thoughts are also offered on the complexity of vaccine innovation and the various stages whose completion is essential to the whole process of technological development. An analysis is made of the parameters and factors involved in each stage; technical requirements for facilities and equipment; good manufacturing practice guidelines; organizational, infrastructural, and managerial needs; and the lengthy time periods adn high costs entailed in these activities.

Time course of vinblastine-induced autophagocytosis and changes in the endoplasmic reticulum in murine pancreatic acinar cells: a morphometric and biochemical study

The time course of the vinblastine(-sulfate; 10 mg/kg body weight, single injection)-induced enlargement and subsequent regression of the autolysosomal compartment was studied by electron microscopic morphometrical and cell biochemical methods in order to gain information concerning some key problems of this major route of intralysosomal degradation of the cell's endogenous macromolecules and structures. Detailed analysis of the dynamics of the total autophagic vacuole (AV) compartment and its different subcompartments (early, advanced, late, and fused AVs), as well as of changes of rough-surfaced endoplasmic reticulum (RER) showed: 1. Pancreatic acinar cells react to vinblastine biphasically, i.e. two expansion phases of the AV compartment, the first in the 0 to 90 min and the second in the 2 to 8 h post-injectional periods, were detected. 2. Fusions of AVs are not inhibited by vinblastine, at least during the second expansion phase when cytoplasmic volume fraction (CVF) of fused AVs steadily increased until the 12th h. Fusion of early, advanced and late AVs or composition of fused complex vacuoles (AVc) are somehow regulated, as the proportion of the three AV stages from the CVF of AVc, was maintained constant throughout the second expansion phase. 3. Stimulation of autophagosome formation and resulting substrate overload seems to be the primary mode of action by which vinblastine causes the enormous expansion of the autolysosomal compartment. 4. Degranulation of the rough-surfaced endoplasmic reticulum (RER) membranes occurs in a biphasic fashion, similarly to the volume and surface changes of the AV compartment, thus supporting our previous hypothesis, that labilization or change of RER may have a role in the formation of autophagosomes. 5. Vinblastine-induced autophagocytosis is a selective process, as mitochondria, Golgi elements and zymogen granules are very much underrepresented, whereas RER is more than twice overrepresented in the volume of early AVs, when compared to their volume fraction in the whole cytoplasm. 6. Immunogold electron microscopy revealed the presence of ubiquitinylated proteins in advanced and late, but not in early AVs.

L-arginine is unlikely to exert neuroendocrine effects in humans via the generation of nitric oxide

There is now considerable evidence that nitric oxide is an important neuroregulatory agent, but there has been very little investigation of its possible role in neuroendocrine mechanisms in humans. We have investigated the effects of two nitric oxide precursors, L-arginine and molsidomine, under basal conditions on the pituitary hormones growth hormone (GH), prolactin, luteinizing hormone, follicle-stimulating hormone, thyrotrophin, adrenocorticotrophin (ACTH) and vasopressin, and also on serum cortisol; we have also studied the effect of L-arginine on circulating prolactin, ACTH and cortisol in normal human subjects under hypoglycaemic stress. L-Arginine stimulated both GH and prolactin release under basal conditions but had no effect on the other hormones studied, while the nitric oxide donor molsidomine showed no effect on any hormone studied. L-Arginine potentiated the hypoglycaemia-stimulated release of ACTH but did not influence the rise in GH. The current studies suggest that the effects of L-arginine on the stimulation of GH and prolactin release are unlikely to be mediated via the generation of nitric oxide.

Somatostatin infusion suppresses GH secretory burst frequency and mass in normal men

In attempting to elucidate the neuroendocrine mechanisms that regulate pulsatile growth hormone (GH) secretion, we measured serum GH concentrations by an ultrasensitive immunofluorometric method in blood collected every 10 min for 8 h in 11 young healthy male volunteers (age range 21-31 yr) before and during somatostatin (SS) administration (an iv bolus dose of 350 micrograms followed by a continuous infusion at the rate of 6 micrograms.kg-1.h-1, which increases the circulating SS levels to approximately 570 pg/ml). Pulsatile GH secretion was analyzed using the computer-assisted pulse detection program cluster method and deconvolution analysis. The area and frequency of GH peaks were significantly reduced during SS infusion compared with basal values, but detectable pulsatile episodes were still present. These data suggest that, in adult males, SS controls pulsatile GH secretion and can decrease the mass and frequency of GH secretory bursts.

Effect of exogenous growth hormone administration on endogenous growth hormone secretion induced by a met-enkephalin analog

Exogenous growth hormone (hGH) administration in humans attenuates the endogenous growth hormone (GH) response to some pharmacological stimuli; in particular, pretreatment with hGH completely blocks the serum GH response to growth hormone-releasing hormone. In order to evaluate the mechanism(s) whereby opiods induce GH secretion in man, we gave the following treatments to six healthy male volunteers: (a) IV saline; (b) a met-enkephalin analog G-DAMME 250 micrograms IV as a bolus at time 0'; (c) hGH 2 IU as an IV bolus at time -180'; (d) G-DAMME as above, preceded by hGH as above. In our study, G-DAMME stimulated GH secretion both basally (peak 17.9 +/- 6.0 ng/ml) and, to a lesser extent, after hGH pretreatment (6.0 +/- 2.7 ng/ml). Since in our study G-DAMME was able to partially overcome the inhibitory effect of hGH administration, it is suggested that opioids act through an inhibition of somatostatin release and not through a GHRH-dependent pathway. However, an additional direct effect of hGH on pituitary somatotrophes cannot be excluded.

[Hospital day-surgery: comparative evaluation of 3 general anesthesia techniques]

For the voluntary interruption of pregnancy, three anaesthetic techniques have been compared being a random assigned to three groups of 40 patients. Induction of anaesthesia was based on fentanyl 0.005 mg/kg+midazolam 0.2 mg/kg or fentanyl 0.005 mg/kg = propofol 2.5 mg/kg or ketamina 0.5 mg/kg+propofol 2.0 mg/kg. Anaesthesia was maintained delivering in spontaneous-assisted ventilation N2O 70% in O2. In addition to the intraoperative conditions, quality and rapidity of some neurofunctional aspects of the recovery have been evaluated using the Steward Score and the Coin Counting Test respectively. Our data suggest fentanyl-propofol association as the safest one as regards the needs of one-day surgery.

Opioid peptide and alpha-adrenoceptor pathways in the regulation of the pituitary-adrenal axis in man

Opioid peptides are well established as potent inhibitors of the pituitary-adrenal axis, while alpha 1-adrenoceptor drugs have recently been shown to stimulate this axis: both classes of agents appear to work principally above the level of the pituitary, most probable directly on the hypothalamus. There is also evidence that these drugs interact in their control of pituitary-adrenal function, although the specific hypothalamic releasing hormone involved has remained unclear. We have therefore carried out a study into the interaction of methoxamine, an alpha 1-adrenoceptor agonist and naloxone, an opioid antagonist, together with human corticotrophin-releasing hormone (CRH), in a group of healthy volunteers in order to establish the mode of action of these drugs. The following drugs were administered to a group of seven healthy male subjects in a randomized double-blind manner: methoxamine (6 micrograms/kg per min over 3 h); naloxone (10 mg bolus); human CRH (100 micrograms bolus); methoxamine plus CRH; naloxone plus CRH; methoxamine plus naloxone; saline (control). Plasma ACTH and serum cortisol were measured at intervals in each subject, and blood pressure and pulse rate recorded with each sample. Both CRH and naloxone produce a marked rise in ACTH and cortisol, peaking at approximately 45 min after infusion. In combination, the drugs produced a peak response in plasma ACTH at the same time, but its magnitude was greater than that after either drug alone. Methoxamine produced a rise in plasma ACTH which was maximal at approximately 75 min, as well as a peak rise in serum cortisol at 120 min.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of captopril, an inhibitor of the converting enzyme on naloxone induced secretion of ACTH and LH in man

It has been previously shown that endogenous opioid peptides suppress human ACTH and gonadotropins secretion via hypothalamic mechanism. Since the angiotensin converting enzyme can participate in the metabolism of opioid peptides, this study examined the action of Captopril, an angiotensin converting enzyme inhibitor, on corticotropin and gonadotropin (LH and FSH) release induced by the opiate antagonist naloxone in man. Seven male hypertensive volunteers (aged 30-52) were treated with A) saline; B) naloxone 8 mg iv as a bolus followed by an iv infusion of 4 mg/h; C) naloxone as above after pretreatment with captopril 150 mg/day for 15 days; D) captopril alone. Naloxone significantly stimulated ACTH and LH secretion when compared with the saline infusion. This stimulating effect was taken as an indirect evidence for a tonic opioid inhibition on pituitary hormones release. The pre-medication with captopril significantly enhanced the ACTH and LH response to the opiate antagonist naloxone, but captopril alone did not modify ACTH and LH values when compared to saline. The results would suggest that captopril interferes with the opioid regulation of human ACTH and LH secretion probably by blocking the proteolytic degradation of opioid peptides.

Dynamics of vinblastine-induced autophagocytosis in murine pancreatic acinar cells: influence of cycloheximide post-treatments

Accumulation of autophagic vacuoles (AVs) was monitored by electron microscopic morphometry in murine pancreatic acinar cells during the 5-hr period after a single injection of vinblastine (VBL). The expansion of the autophagic compartment (AC) occurred in two waves. AVs accumulated in the first 90 min and regressed in the next hour, but thereafter AC expanded again, and 5 hr following the VBL injection, as much as 5.3% of the cytoplasmic volume was found sequestered into the AC. The high rates of accumulation of AVs indicated that VBL stimulated AV formation (segregation) during both expansion phases. To have a deeper insight into the dynamics of the process segregational inhibitor cycloheximide (CHI) was given 1 and 3 hr after VBL and the subsequent regression of the AC and its subcompartments (i.e., early, advanced, and late AVs) were measured during the next 90 min. We found that regression of AVs was fast in the first expansion and slowed down in the second expansion phase during which only early AVs regressed. CHI proved to be a fast and effective inhibitor of autophagic segregation, whether it was given before, simultaneously, or after the VBL injection. The aforementioned results argue for a dual mode of action of VBL (i.e., a prompt stimulation of segregation and a delayed retardation of AV maturation). The two effects of the alkaloid prevail differently along the time course. A further analysis of the behavior of the AC subcompartments showed that CHI perhaps inhibits segregational step(s) occurring prior to the actual formation of the autolysosomes.

Calcium oxalate nephrolithiasis: an easy way to detect an imbalance between promoting and inhibiting factors

Calcium oxalate stone formation depends on both urine oversaturation with calcium oxalate--which in turn depends mainly on oxalate excretion--and the excretion of inhibitors; the possibility that a ratio of these variables might differentiate stone-formers from stone-free subjects was explored, 24-h urine samples from 20 control subjects and 53 idiopathic calcium oxalate stone-formers receiving a standard diet were studied. A further group of 2-h urine samples (from 7 to 9 a.m.). collected after a overnight fast from 16 non-stone and 24 stone-forming persons on a normal diet, were also examined. The ratio 'oxalate/citrate X acid mucopolysaccharides; (Ox/Cit X AMPs) seems capable of differentiating more than 80% of stone-formers from non-stone-formers using both 24- and 2-h urine collection.

Clinical and endocrinological investigations on superovulation induced in heifers by human menopausal gonadotrophin

After an i.v. injection of human menopausal gonadotrophin (hMG), three components of the disappearance time in heifers were found for immunoreactive LH (half-life 13.8--1020 min) and immunoreactive FSH (half-life 21.3--1090 min). When heifers were treated daily with hMG from Days 9, 10 or 11 of the cycle for 3 or 5 days, a total dose of 1350 i.u. FSH induced 10.2 +/- 2.5 (mean +/- s.d.) corpora lutea (CL) in 6 animals and 13 persistent follicles in 4 animals, while a total dose of 2100 i.u. FSH induced 14.3 +/- 1.5 CL in 6 heifers and there were no persistent follicles. Nine heifers treated with a single i.m. injection of 1500 i.u. PMSG exhibited 11.4 +/- 8.6 CL with 17 persistent follicles in 7 animals. Progesterone concentrations rose significantly faster and the oestradiol drop was more rapid after oestrus in heifers treated with hMG than in those treated with PMSG. These results demonstrate that stimulation of the ovarian follicles of heifers is more homogeneous when hMG is used.

Improved method to induce superovulation in cattle using Human Menopausal Gonadotropin (HMG)

In a previous preliminary study, HMG (Pergonal 500 -Serono Italy) was favourably used to induce superovulation in heifers. In the present work, the results of further clinical and endocrinological investigations using another treatment schedule are reported. Both friesian heifers and lactating friesian cows, starting from the 9th-11th day of the cycle, received i.m. two ampoules of Pergonal 500 (75 i.u. FSH and 75 i.u. LH per ampoule) at 0, 12, 24, 36 hours and one ampoule at 48, 60, 72, 84, 96 and 108 hours. At the 72nd hour, all donors received 2 ml of Estrumate (I.C.I.) and, at estrus, 1000 i.u. of HCG (Profasi, Serono) 24 hours apart. Both clinical and endocrinological results showed that all animals responded well to the superovulatory stimulus. No donor gave less than two transferable embryos. The mean number of ovulations (11.66 and 10.36 for heifers and cows respectively), the low individual variability, the low number of persistent follicles, the rate of transferable embryos (67%) and the rapid spontaneous restoration of estrous cycles show that the schedule adopted induced satisfactory superovulation of both heifers and cows in embryo transfer practice.