Invasion of Tropical Montane Cities by Aedes aegypti and Aedes albopictus (Diptera: Culicidae) Depends on Continuous Warm Winters and Suitable Urban Biotopes

We provide the first evidence of a recent invasion of Aedes aegypti (Linnaeus in Hasselquist, 1762) and Aedes albopictus (Skuse 1894), followed by dengue virus, in tropical montane cities in south-eastern Brazil, Mariana, and Ouro Preto, at mid and high altitudes, respectively. Long-term temperature variation, dengue public data, and sampling of immature and adult mosquitoes (ovitraps and mosquitraps) in contrasting habitats were used to explain the distribution of Aedes in what in these two cities. From 1961 to 2014, the annual temperature increased significantly due to increases in winter temperatures. In the 1990s/2000s, the winter temperature was 1.3°C warmer than in the 1960s, when it varied from 21.2 to 18.9°C. After 2007, the winter temperatures increased and ranged from 21.6 to 21.3°C. The first autochthonous dengue cases in Mariana and Ouro Preto were in 2007, followed by few occurrences until in 2012, when the mean numbers increased three-fold, and peak at 2013. The continuous 'warmer winter' may have trigged the Aedes invasion. Aedes species benefited from higher winter temperatures, which was an important driver of their invasion of the state of Minas Gerais in the 1980s and, more recently, in the remaining montane urban habitats in this region. In both 2009 and 2011, we found more Aedes in Mariana than Ouro Preto, and more Ae. albopictus in green areas and Ae. aegypti in houses, the expected pattern for well-established populations.

A perspective on the need and current status of efficient sex separation methods for mosquito genetic control

Major efforts are currently underway to develop novel, complementary methods to combat mosquito-borne diseases. Mosquito genetic control strategies (GCSs) have become an increasingly important area of research on account of their species-specificity, track record in targeting agricultural insect pests, and their environmentally non-polluting nature. A number of programs targeting Aedes and Anopheles mosquitoes, vectors of human arboviruses and malaria respectively, are currently being developed or deployed in many parts of the world. Operationally implementing these technologies on a large scale however, beyond proof-of-concept pilot programs, is hampered by the absence of adequate sex separation methods. Sex separation eliminates females in the laboratory from male mosquitoes prior to release. Despite the need for sex separation for the control of mosquitoes, there have been limited efforts in recent years in developing systems that are fit-for-purpose. In this special issue of Parasites and Vectors we report on the progress of the global Coordinated Research Program on “Exploring genetic, molecular, mechanical and behavioural methods for sex separation in mosquitoes” that is led by the Insect Pest Control Subprogramme of the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture with the specific aim of building efficient sex separation systems for mosquito species. In an effort to overcome current barriers we briefly highlight what we believe are the three main reasons why progress has been so slow in developing appropriate sex separation systems: the availability of methods that are not scalable, the difficulty of building the ideal genetic systems and, finally, the lack of research efforts in this area.

Black patients with chronic hepatitis C have a lower sustained viral response rate than non-Blacks with genotype 1, but the same with genotypes 2/3, and this is not explained by more frequent dose reductions of interferon and ribavirin*

In previous hepatitis C virus (HCV) treatment studies, Black patients not only had a lower sustained viral response (SVR) rate to interferon and ribavirin (RBV) than non-Black patients but also a higher frequency of HCV genotype 1 (GT-1) infection. The aim of this community-based study was to determine whether Black patients have a lower SVR rate independent of genotype. We prospectively enrolled 785 patients (24.8% Black, 71.5% White, 3.7% others) who received interferon alpha-2b 3 MU three times weekly + RBV 1000-1200 mg/day for 24 weeks (GT-2/3) or 48 weeks (GT-1). Black patients were more commonly infected with GT-1 (86.8%vs 64.8%, P < 0.001) and less frequently had an SVR compared with non-Black patients (8.4%vs 21.6%, P < 0.001). Within GT-1, Black patients had a lower SVR rate than non-Black patients (6.1%vs 14.1%, P = 0.004) but not within GT-2/3 (50.0%vs 36.5%, P = 0.47). Black patients had lower baseline haemoglobin levels (14.8 vs 15.3 g/dL, P < 0.001) and neutrophil counts (2900 vs 4100/mm(3), P < 0.001) and required more frequent dose reductions of RBV (29.8%vs 18.5%, P < 0.001) and interferon (4.7%vs 1.6%, P = 0.012). However, dose reductions were not associated with lower SVR rates while early treatment discontinuations were (2.9%vs 25.7%, P < 0.001). Independent predictors of SVR were GT-1 [odds ratio (OR) 0.33; 95% confidence interval (CI) 0.20-0.55; P < 0.001], Black race (OR 0.45; 95% CI 0.22-0.93; P = 0.030), and advanced fibrosis, stages 3 + 4 (OR 0.53; 95% CI 0.31-0.92; P = 0.023). In conclusion, Black patients infected with HCV GT-1 (but not GT-2/3) have a lower SVR rate than non-Black patients. This is not explained by their lower baseline haemoglobin levels and neutrophil counts that lead to higher rates of ribavirin and interferon dose reductions.

Should noncardiac chest pain be treated empirically? A cost-effectiveness analysis

BACKGROUND

Chest pain is a common clinical problem, but up to 30% of patients who present with chest pain lack coronary disease. Subsequent investigation often reveals an esophageal source for the pain, with gastroesophageal reflux disease identified most frequently. Controversy exists regarding whether to establish the cause or to empirically treat as reflux.

OBJECTIVE

To assess the cost-effectiveness of empirical treatment in patients with noncardiac chest pain.

METHODS

Decision analysis was used to compare a strategy of empirical treatment as reflux using an H-blocker or proton pump inhibitor with initial investigation for gastrointestinal causes over a period of up to 16 weeks and over a period of more than a year. The prototype patient was an outpatient with chest pain and a normal coronary angiogram. Gastrointestinal investigations included an upper gastrointestinal tract series, endoscopy, manometry, 24-hour pH monitoring, and provocation tests. The main outcome measure was direct medical costs per case treated from a third-party payer perspective.

RESULTS

Total medical costs were $2,187 per case treated for the initial investigation arm and $849 for the empirical treatment arm in the 8- to 16-week model. One-way sensitivity analyses revealed that the model was robust; the treatment arm was less expensive in all cases. At just over a year empirical treatment remained dominant.

CONCLUSIONS

An initial therapeutic trial with antisecretory agents for patients with noncardiac chest pain is cost-effective compared with investigation for gastrointestinal causes in the short term of weeks, with cost savings persisting beyond a year.

Vitamin E supplementation and in vivo immune response in healthy elderly subjects. A randomized controlled trial

OBJECTIVE

To determine whether long-term supplementation with vitamin E enhances in vivo, clinically relevant measures of cell-mediated immunity in healthy elderly subjects.

DESIGN

Randomized, double-blind, placebo-controlled intervention study.

SETTING AND PARTICIPANTS

A total of 88 free-living, healthy subjects at least 65 years of age.

INTERVENTION

Subjects were randomly assigned to a placebo group or to groups consuming 60, 200, or 800 mg/d of vitamin E for 235 days.

MAIN OUTCOME MEASURES

Delayed-type hypersensitivity skin response (DTH); antibody response to hepatitis B, tetanus and diphtheria, and pneumococcal vaccines; and autoantibodies to DNA and thyroglobulin were assessed before and after supplementation.

RESULTS

Supplementation with vitamin E for 4 months improved certain clinically relevant indexes of cell-mediated immunity in healthy elderly. Subjects consuming 200 mg/d of vitamin E had a 65% increase in DTH and a 6-fold increase in antibody titer to hepatitis B compared with placebo (17% and 3-fold, respectively), 60-mg/d (41% and 3-fold, respectively), and 800-mg/d (49% and 2.5-fold, respectively) groups. The 200-mg/d group also had a significant increase in antibody titer to tetanus vaccine. Subjects in the upper tertile of serum alpha-tocopherol (vitamin E) concentration (>48.4 micromol/L [2.08 mg/dL]) after supplementation had higher antibody response to hepatitis B and DTH. Vitamin E supplementation had no effect on antibody titer to diphtheria and did not affect immunoglobulin levels or levels of T and B cells. No significant effect of vitamin E supplementation on autoantibody levels was observed.

CONCLUSIONS

Our results indicate that a level of vitamin E greater than currently recommended enhances certain clinically relevant in vivo indexes of T-cell-mediated function in healthy elderly persons. No adverse effects were observed with vitamin E supplementation.

Gastric emptying and first-pass metabolism of ethanol in elderly subjects with and without atrophic gastritis

BACKGROUND

Oral ethanol intake results in lower blood ethanol concentrations than intravenous administration of the same dose of ethanol. This first-pass metabolism is thought to be due to gastric metabolism of ethanol via alcohol dehydrogenase and also to hepatic first-pass metabolism.

METHODS

Since a loss of gastric mucosa may decrease first-pass metabolism of ethanol, this metabolism was studied in 10 elderly subjects (6 women and 4 men) with atrophic gastritis and bacterial overgrowth and in 17 control subjects with normal gastric secretory function. Atrophic gastritis was verified by means of the serum pepsinogen I to pepsinogen II ratio and the hypochlorhydria occurring after pentagastrin stimulation. Bacterial overgrowth was assessed by bacteria. In addition, gastric emptying rates of ethanol solution with technetium-99m sulfur colloid were calculated from scintigraphic images. Furthermore, gastric biopsy specimens were taken from 12 female patients with atrophic gastritis and from 12 controls for determination of alcohol dehydrogenase activity.

RESULTS

Neither gender (female versus male, 28 +/- 5% versus 42 +/- 5%), atrophic gastritis (normal versus atrophic gastritis, 35 +/- 4% versus 32 +/- 6%), nor tetracycline treatment in atrophic gastritis subjects (before versus after, 32 +/- 6% versus 41 +/- 5%) had a statistically significant effect on the first-pass metabolism of ethanol in the elderly. Gastric alcohol dehydrogenase activity was significantly lower in atrophic gastritis subjects than in controls (p < 0.01). A significant correlation was found between the first-pass metabolism of ethanol in healthy controls and gastric half-emptying time (p = 0.032).

CONCLUSIONS

We conclude from these data that the rate of gastric emptying modulates first-pass metabolism of ethanol in elderly individuals.

Alternate-day prednisone in the maintenance immunosuppressive therapy after orthotopic liver transplantation

Glucocorticoids have been an important part of maintenance immunosuppressive therapy following orthotopic liver transplantation (OLT). However, long-term daily glucocorticoid use is associated with a high incidence of unpleasant side effects. In an effort to minimize side effects while maintaining adequate immunosuppression, we have treated 48 adult patients with low dose alternate-day prednisone, 15 mg q.o.d. Pre-OLT diagnoses included primary biliary cirrhosis (16 patients), alcoholic liver disease (8 patients), sclerosing cholangitis (8 patients), cryptogenic cirrhosis and/or non-A, non-B hepatitis (11 patients), acute hepatic failure (3 patients), and hepatocellular carcinoma and bile duct carcinoma (1 patient each). Conversion to alternate-day prednisone was attempted when patients were clinically stable and the daily prednisone dose was 15 mg. The average interval between OLT and beginning of the conversion to alternate-day prednisone was 38 weeks. The mean time for conversion to alternate-day prednisone was 35 weeks, but decreased as more experience was gained. The mean follow-up was 106 weeks. Cushingoid side effects diminished in all. In 47 of the 48 patients, there were no clinical laboratory or histologic changes suggestive of rejection after the initiation of alternate-day prednisone. A single episode of rejection occurred during the taper. This episode responded promptly to increased glucocorticoid therapy, and the patient was easily converted to alternate-day prednisone at a later date. There was no increase in concurrent immunosuppressives dosage after the conversion. Alternate-day prednisone is effective and safe for chronic immunosuppression after OLT in patients receiving cyclosporine and azathioprine.

Magnetic resonance cholangiography

Magnetic resonance cholangiography (MRC) can be performed with data from a routine imaging protocol, without the need for additional pulse sequences or special equipment. We studied three patients with obstructive jaundice who underwent magnetic resonance imaging (MRI) of the liver. T2-weighted fat suppressed fast spin-echo sequences were processed with a maximum intensity projection algorithm to create three-dimensional images of the dilated portions of the biliary tree. Results were correlated with endoscopic retrograde cholangiopancreatography and computed tomography. These images compared favorably with those acquired on scanners in which special breath-holding gradient echo protocols are used.

Survival of yogurt-containing organisms and Lactobacillus gasseri (ADH) and their effect on bacterial enzyme activity in the gastrointestinal tract of healthy and hypochlorhydric elderly subjects

The effect of the live bacterial yogurt cultures, namely Streptococcus thermophilus and Lactobacillus bulgaricus, and a mucosal adhering strain of Lactobacillus gasseri (ADH) on small intestinal and fecal bacterial characteristics was examined in 10 elderly subjects with atrophic gastritis and 23 elderly normal volunteers (11 received yogurt and 12 received ADH). Neither S thermophilus nor L bulgaricus was recovered from the stomach or small intestine of subjects fed yogurt or pasteurized yogurt. ADH was recovered from gastric or small intestinal aspirates in three of four subjects and in the stools of four of five subjects diagnosed with atrophic gastritis. In 11 of 12 normal subjects, ADH was isolated from stools. There was a significant reduction in fecal bacterial enzyme activity in both normal volunteers and subjects with atrophic gastritis after being fed with viable ADH. Adherent strains of bacteria such as ADH are likely to survive passage through the gastrointestinal tract and thus have greater metabolic effects.

Effect of hypochlorhydria due to omeprazole treatment or atrophic gastritis on protein-bound vitamin B12 absorption

OBJECTIVE

To investigate the effects of hypochlorhydria and acidic drink ingestion on protein-bound vitamin B12 absorption in elderly subjects.

METHODS

Absorption of protein-bound vitamin B12 was examined in elderly normal subjects (n = 8), and in hypochlorhydric subjects due to omeprazole treatment (n = 8) or with atrophic gastritis (n = 3). Subjects underwent absorption tests of protein-bound vitamin B12 ingested with water, cranberry juice and 0.1 N hydrochloric acid.

RESULTS

Protein-bound vitamin B12 absorption was lower in the omeprazole-treated group (0.50%) compared to the normal group (1.21%; p < 0.001). With cranberry juice ingestion, the omeprazole-treated group showed an increase in absorbed protein-bound vitamin B12 (p = 0.025). With dilute hydrochloric acid ingestion, there was a further increase in vitamin B12 absorption (p < 0.001).

CONCLUSION

Omeprazole causes protein-bound vitamin B12 malabsorption, and ingestion of an acidic drink improves protein-bound vitamin B12 absorption.

Bacterial overgrowth without clinical malabsorption in elderly hypochlorhydric subjects

BACKGROUND/AIMS

Bacterial overgrowth of the small intestine commonly occurs in association with hypochlorhydria caused by atrophic gastritis or during treatment with omeprazole. The purpose of this study was to determine the clinical significance of bacterial overgrowth on small intestinal absorption and permeability and to evaluate the reliability of noninvasive breath tests to detect bacterial overgrowth in subjects with hypochlorhydria.

METHODS

Seventeen healthy, elderly subjects with atrophic gastritis or omeprazole treatment (40 mg/day) and documented bacterial overgrowth were studied.

RESULTS

There was no evidence of fat malabsorption (72-hour fecal fat) or clinically significant carbohydrate malabsorption (25 g D-xylose and fecal pH) in any subject. The ratio of lactulose to mannitol excreted was normal in both atrophic gastritis and omeprazole-treated groups. Three subjects in each group had abnormally high alpha 1-antitrypsin clearances. Lactulose (10 g) and glucose (80 g) hydrogen breath tests were only abnormal in 1 out of 17 subjects, whereas the 1 g [14C]D-xylose test was abnormal in 6 out of 17 subjects.

CONCLUSIONS

Bacterial overgrowth caused by atrophic gastritis or omeprazole treatment is typically not associated with clinically significant fat or carbohydrate malabsorption. Noninvasive breath tests for bacterial overgrowth are not reliable in subjects with hypochlorhydria.