Implementation of an outbreak response vaccination campaign with typhoid conjugate vaccine - Harare, Zimbabwe, 2019.

Introduction: Typhoid fever is a public-health problem in Harare, the capital city of Zimbabwe, with seasonal outbreaks occurring annually since 2010. In 2019, the Ministry of Health and Child Care (MOHCC) organized the first typhoid conjugate vaccination campaign in Africa in response to a recurring typhoid outbreak in a large urban setting. Method: As part of a larger public health response to a typhoid fever outbreak in Harare, Gavi approved in September 2018 a MOHCC request for 340,000 doses of recently prequalified Typbar-TCV to implement a mass vaccination campaign. To select areas for the campaign, typhoid fever surveillance data from January 2016 until June 2018 was reviewed. We collected and analyzed information from the MOHCC and its partners to describe the vaccination campaign planning, implementation, feasibility, administrative coverage and financial costs. Results: The campaign was conducted in nine high-density suburbs of Harare over eight days in February-March 2019 and targeted all children aged 6 months-15 years; however, the target age range was extended up to 45 years in one suburb due to the past high attack rate among adults. A total of 318,698 people were vaccinated, resulting in overall administrative coverage of 85.4 percent. More than 750 community volunteers and personnel from the MOHCC and the Ministry of Education were trained and involved in social mobilization and vaccination activities. The MOHCC used a combination of vaccination strategies (i.e., fixed and mobile immunization sites, a creche and school-based strategy, and door-to-door activities). Financial costs were estimated at US$ 2.39 per dose, including the vaccine and vaccination supplies (US$ 0.79 operational costs per dose excluding vaccine and vaccination supplies). Conclusion: A mass targeted campaign in densely populated urban areas in Harare, using the recently prequalified typhoid conjugate vaccine, was feasible and achieved a high overall coverage in a short period of time.

Salmonella infections associated with mung bean sprouts: epidemiological and environmental investigations.

We investigated an outbreak of Salmonella Enteritidis (SE) infections linked to raw mung bean sprouts in 2000 with two case-control studies and reviewed six similar outbreaks that occurred in 2000-2002. All outbreaks were due to unusual phage types (PT) of SE and occurred in the United States (PT 33, 1, and 913), Canada (PT 11b and 913), and The Netherlands (PT 4b). PT 33 was in the spent irrigation water and a drain from one sprout grower. None of the growers disinfected seeds at recommended concentrations. Only two growers tested spent irrigation water; neither discarded the implicated seed lots after receiving a report of Salmonella contamination. We found no difference in the growth of SE and Salmonella Newport on mung beans. Mung bean sprout growers should disinfect seeds, test spent irrigation water, and discontinue the use of implicated seed lots when pathogens are found. Laboratories should report confirmed positive Salmonella results from sprout growers to public health authorities.

Towards Q-PCR of pathogenic bacteria with improved electrochemical double-tagged genosensing detection.

A very sensitive assay for the rapid detection of pathogenic bacteria based on electrochemical genosensing has been designed. The assay was performed by the PCR specific amplification of the eaeA gene, related with the pathogenic activity of Escherichia coli O157:H7. The efficiency and selectivity of the selected primers were firstly studied by using standard Quantitative PCR (Q-PCR) based on TaqMan fluorescent strategy. The bacteria amplicon was detected by using two different electrochemical genosensing strategies, a highly selective biosensor based on a bulk-modified avidin biocomposite (Av-GEB) and a highly sensitive magneto sensor (m-GEC). The electrochemical detection was achieved in both cases by the enzyme marker HRP. The assay showed to be very sensitive, being able to detect 4.5 ng microl(-1) and 0.45 ng microl(-1) of the original bacterial genome after only 10 cycles of PCR amplification, when the first and the second strategies were used, respectively. Moreover, the electrochemical strategies for the detection of the amplicon showed to be more sensitive compared with Q-PCR strategies based on fluorescent labels such as TaqMan probes.

ANALYSIS OF BAROREFLEX FUNCTION BY MEANS OF MATHEMATICAL MODEL.

Re-evaluation of all functions of baroreflex by means of a simple mathematical model of circulation was the aim of the present study. The following states are modelled: 1. Rest. 2. Immediately after baroreceptor denervation. 3. Several days after denervation. 4. Physical exercise before denervation. 5. Physical exercise several days after denervation. Despite the same cardiac contractility and the same vasodilatation in working muscles as before denervation the cardiac output is by one third lower after baroreceptor denervation. In conclusion, a model simulation revealed the common regulation of blood pressure and blood volume by baroreflex and kidneys as a primary function of baroreflex.

Comparison of primers for the detection of pathogenic Escherichia coli using real-time PCR.

AIMS: To evaluate PCR primers for the detection of pathogenic Escherichia coli in a real-time PCR assay and determine their utility in produce irrigation water testing. METHODS AND RESULTS: Three previously published PCR primer sets and one set designed for this study were tested for their ability to produce amplification products for several pathogenic E. coli serotypes from whole cells as template. Two of the previously published primer sets were chosen for real-time PCR detection limit determination. The coneaeA and PEH detection limit of E. coli O157:H7 was 10(0) and 10(1) CFU rxn(-1) in sterile water respectively. To detect E. coli O157:H7 in sprout irrigation water, the water required dilution due to PCR inhibitors. The detection limit of the coneaeA and PEH was 10(1) and between 10(2) and 10(3) CFU rxn(-1) in diluted sprout irrigation water respectively. CONCLUSIONS: The primer set coneaeA was able to produce an amplification product from each E. coli serotype, except O128:H7 and most sensitive for real-time PCR detection of pathogenic E. coli in diluted sprout irrigation water. SIGNIFICANCE AND IMPACT OF THE STUDY: The necessity of a dissociation analysis to distinguish positive samples from those with fluorescence of random dsDNA generation for real-time PCR in a complex background was established.

Comparison of primers for the detection of Salmonella enterica serovars using real-time PCR.

AIMS: To evaluate the specificity and sensitivity of PCR primers for the detection of Salmonella enterica in a real-time PCR assay using pure cultures. METHODS AND RESULTS: Unenriched whole cells in sterile water were used as template for each PCR. SYBR Green dye was used for the nonspecific detection of dsDNA. The real-time PCR detection limits of five previously published primer sets used in conventional PCR applications were not below 3 x 10(3) CFU per reaction (rxn). A new primer set, Sen, was designed, which detected Salm. enterica Newport down to 6 CFU rxn(-1) in one case, and gave an average detection limit of 35 CFU rxn(-1) over three separate runs. CONCLUSIONS: Primers originally designed for end-point PCR did not have adequate specificity or sensitivity compared with those specifically designed for real-time PCR. SIGNIFICANCE AND IMPACT OF THE STUDY: This study emphasizes the importance of evaluating real-time PCR primer sets in pure cultures prior to testing in field samples. This study will benefit other researchers in selecting an appropriate primer set for real-time PCR detection of Salm. enterica.

Malignant solitary fibrous tumor of the tongue.

Solitary fibrous tumor is a generally benign spindle-cell neoplasm that has been predominantly described in the visceral pleura and other serosal sites and is extremely rare in the head and neck area. We report the first known case of malignant solitary fibrous tumor of the tongue in a 57-year-old female patient who experienced rapid growth of a longstanding right anterior tongue mass, with associated dysphagia and dysarthria. Magnetic resonance imaging was suggestive of a low-flow vascular malformation not requiring preoperative embolization. The patient underwent partial peroral glossectomy for the excision of the tumor. Final pathology, however, was consistent with solitary fibrous tumor, characterized as malignant by histopathologic criteria, and the patient was returned for re-excision of the close surgical margins. The patient has experienced symptomatic improvement, and she remains free of recurrence 12 months later. All reports of solitary fibrous tumors of the oral cavity and 3 reports of the tongue tumors described in the literature to date represent benign lesions. To our knowledge, this is the first report of a malignant solitary fibrous tumor of the tongue. Presentation, differential diagnosis, criteria for malignancy, treatment, and possible prognostic implications of this rare entity are discussed.

Differences in attachment of Salmonella enterica serovars and Escherichia coli O157:H7 to alfalfa sprouts.

Numerous Salmonella enterica and Escherichia coli O157:H7 outbreaks have been associated with contaminated sprouts. We examined how S. enterica serovars, E. coli serotypes, and nonpathogenic bacteria isolated from alfalfa sprouts grow on and adhere to alfalfa sprouts. Growth on and adherence to sprouts were not significantly different among different serovars of S. enterica, but all S. enterica serovars grew on and adhered to alfalfa sprouts significantly better than E. coli O157:H7. E. coli O157:H7 was essentially rinsed from alfalfa sprouts with repeated washing steps, while 1 to 2 log CFU of S. enterica remained attached per sprout. S. enterica Newport adhered to 3-day-old sprouts as well as Pantoea agglomerans and 10-fold more than Pseudomonas putida and Rahnella aquatilis, whereas the growth rates of all four strains throughout seed sprouting were similar. S. enterica Newport and plant-associated bacteria adhered 10- to 1,000-fold more than E. coli O157:H7; however, three of four other E. coli serotypes, isolated from cabbage roots exposed to sewage water following a spill, adhered to sprouts better than E. coli O157:H7 and as well as the Pseudomonas and Rahnella strains. Therefore, attachment to alfalfa sprouts among E. coli serotypes is variable, and nonpathogenic strains of E. coli to be used as surrogates for the study of pathogenic E. coli may be difficult to identify and should be selected carefully, with knowledge of the biology being examined.

Differences in growth of Salmonella enterica and Escherichia coli O157:H7 on alfalfa sprouts.

Sprout producers have recently been faced with several Salmonella enterica and Escherichia coli O157:H7 outbreaks. Many of the outbreaks have been traced to sprout seeds contaminated with low levels of human pathogens. Alfalfa seeds were inoculated with S. enterica and E. coli O157:H7 strains isolated from alfalfa seeds or other environmental sources and sprouted to examine growth of these human pathogens in association with sprouting seeds. S. enterica strains grew an average of 3.7 log(10) on sprouting seeds over 2 days, while E. coli O157:H7 strains grew significantly less, an average of 2.3 log(10). The initial S. enterica or E. coli O157:H7 inoculum dose and seed-sprouting temperature significantly affected the levels of both S. enterica and E. coli O157:H7 on the sprouts and in the irrigation water, while the frequency of irrigation water replacement affected only the levels of E. coli O157:H7. Colonization of sprouting alfalfa seeds by S. enterica serovar Newport and E. coli O157:H7 strains transformed with a plasmid encoding the green fluorescent protein was examined with fluorescence microscopy. Salmonella serovar Newport colonized both seed coats and sprout roots as aggregates, while E. coli O157:H7 colonized only sprout roots.

Structural modification and cryopreservation of porcine heart valves for xenotransplantation with reduced immunity.

BACKGROUND AND AIM OF THE STUDY: In order to provide valved xenografts with reduced immunity, yet durability comparable with that of homografts, a method for endothelial cell removal was developed. METHODS: Adult porcine valved pulmonary conduits were isolated, washed and incubated in trypsin-EDTA solution. The endothelial cells were flushed free with a stream of culture medium, and the xenografts cryopreserved. Grafts were thawed after three months, and evaluated structurally. RESULTS: Macroscopic inspection of the grafts revealed no cracks or other morphological damage. Light microscopy revealed mildly edematous changes, and the elastic layers appeared to be preserved. Incubation with trypsin-EDTA solution consistently removed the entire endothelial layer, without obvious damage to the underlying tissues. CONCLUSION: With care and appropriate timing, the xenograft endothelium can be selectively removed, leaving the underlying tissue intact. This process may allow further structural manipulations to improve the durability of these grafts.

Outcome and risk factors in octogenarians undergoing open-heart surgery.

BACKGROUND AND AIM OF THE STUDY: Increasing numbers of elderly (aged > 80 years) patients are being referred for cardiac surgery, and results for coronary artery bypass grafting (CABG) are generally better than for combined CABG and valve replacement. METHODS: During the past 55 months, 77 octogenarians underwent cardiac intervention in our institution. Forty-five patients (mean age 82.5 years) underwent CABG alone; surgery was elective in 33% of patients and 2.7 +/- 1.0 grafts per patient were performed. Thirty-two patients (mean age 82.4 years) underwent combined CABG and valve surgery (28 aortic, four mitral); 2.1 +/- 0.8 grafts per patient were performed and 65% of cases were emergencies. RESULTS: In patients undergoing CABG alone, the operative mortality rate was 2% and rose to 4% (n = 2) at the end of follow up. Mean NYHA functional class improved significantly from 3.5 +/- 0.5 to 1.4 +/- 0.3 after surgery (p < 0.05) and most patients reported marked improvement in their quality of life. In CABG + valve surgery patients, the operative mortality rate was 6% (n = 2) and reached 18% by the end of follow up. In these patients the complication rate was 24% and mean hospitalization stay 11.0 +/- 2.9 days, while mean NYHA functional class improved from 3.4 +/- 0.6 to 1.2 +/- 0.5. Data analysis revealed that mitral regurgitation combined with coronary artery disease (p < 0.03) and prolonged cross-clamping time (p < 0.01) were the most important independent factors for mortality. CONCLUSION: This study confirms that, in selected elderly patients, combined CABG and cardiac surgery can achieve good postoperative results.

A one-way valved atrial septal patch: a new surgical technique and its clinical application.

Patients who undergo surgical repair of congenital heart defects, characterized by a hypoplastic right ventricle or high pulmonary vascular resistance, are at high risk for the development of postoperative right heart failure. This risk may discourage the surgical team from carrying out a biventricular or complete repair in such patients. To reduce the risk for right heart failure, we developed a one-way, valved, atrial septal patch to serve as an artificial one-way foramen ovale and tested it in an animal model. By permitting right-to-left shunt, this device decompresses the failing right ventricle and maintains systemic cardiac output. The device has been used in 15 patients divided into three different groups: group 1 (n = 8), patients with a hypoplastic right ventricle and pulmonic stenosis or atresia, seven of whom underwent a biventricular repair; group 2 (n = 5), patients with evidence of pulmonary disease after longstanding left-to-right shunt caused by a correctable atrial or ventricular septal defect, all of whom had a complete repair; group 3, two patients with acute right heart failure in whom the device was used as a last option of treatment to wean them from cardiopulmonary bypass. This article presents our data in regard to the use of the one-way, valved, atrial septal patch and the indications for its clinical use.

Non-syntenic amplification of MDM2 and MYCN in human neuroblastoma.

Amplification of the MYCN gene is a well documented genetic alteration of aggressively growing human neuroblastomas. Through cytogenetic studies we have identified neuroblastoma cell lines which, in addition to amplified MYCN, carry amplified DNA not harbouring MYCN. In situ hybridization of biotinylated total genomic DNA to metaphase chromosomes of normal human lymphocytes by reverse genomic hybridization revealed the amplified DNA to be derived from chromosome 12 band q13-14. Subsequent filter analyses showed a 20- to 40-fold amplification of the MDM2 gene, located at 12q13-14, both in three cell lines and in an original tumor, in addition to amplified MYCN. As the apparent consequence of amplification abundant MDM2 protein was present, a part of which was complexed with p53.

Role of protease inhibition in myocardial preservation following ischemia and reperfusion.

Aprotinin, a naturally occurring protease inhibitor, in concentrations of 10(6) KIU/L was found to have no effect on myocardial performance in normally perfused isolated rat hearts, before ischemia. Given during the preischemic period, the drug had a significant protective effect on the reperfused hearts, following cardioplegic ischemia: better contractility upon reperfusion (p < 0.011), faster decline of the ischemic contracture, higher coronary flow (p < 0.025), lower AV-difference (p < 0.05), and lower CPK levels (p < 0.01).

A one-way, valved, atrial septal patch in the management of postoperative right heart failure. An animal study.

Patients who undergo surgical repair of congenital heart defects that are characterized by hypoplastic right ventricle or pulmonary hypertension are at high risk for the development of postoperative right heart failure. To minimize this risk, a new one-way, valved, atrial septal patch was developed that serves as an artificial one-way foramen ovale. The feasibility of this device was tested in five dogs in which reversible right heart failure had been induced. Use of the one-way valved patch significantly improved right ventricular performance and reduced right ventricular hydrostatic pressures. The interatrial pressure gradient was reduced from 10 +/- 3.5 mm Hg during right heart failure to 4.4 +/- 1.4 mm Hg. When the device was opened, cardiac output increased significantly. This hemodynamic improvement was achieved at the expense of systemic arterial desaturation, which was, however, well tolerated. When the state of right heart failure was reversed, the one-way valved patch spontaneously closed, allowing no interarterial shunting. The results of this experimental trial suggest that this device can play a useful role in selected patients in whom postoperative right heart failure can be anticipated after surgical repair of certain congenital heart defects.

Aprotinin improves myocardial recovery after ischemia and reperfusion. Effects of the drug on isolated rat hearts.

The effects of aprotinin, a protease inhibitor, on the ischemic and nonischemic isolated rat heart was investigated with the use of the modified Langendorff model. During phase I of the study, hearts were perfused with either low-dose aprotinin (10(5) KIU/L), high-dose aprotinin (10(6) KIU/L), or normal saline solution added to modified Krebs-Henseleit solution. No statistically significant differences in contraction amplitude, contractility, coronary flow, and wet/dry heart weight ratio were observed among the three groups of hearts. In phase II, hearts were exposed to a 40-minute period of global ischemia at 31 degrees C. Ischemic arrest was induced by warm cardioplegia. Before ischemia and during cardioplegia, hearts were perfused with either aprotinin 10(6) KIU/L (n = 10) or normal saline solution (n = 10) for 30 minutes. On reperfusion, recovery of hearts treated with aprotinin was significantly better than that of control hearts, as reflected by better contractility (analysis of variance, p = 0.011), higher coronary flow (p < 0.025), and lower creatine kinase levels (p < 0.05). No statistically significant differences in contraction amplitude were observed between the two groups. When the effect of ischemia within each group of hearts was analyzed, the preserving effect of aprotinin was even more pronounced. In the control group, ischemia caused a decrease in contractility (p < 0.025) and a decrease in oxygen consumption (p = 0.006); by contrast, in the aprotinin group the preischemic values were maintained. Accordingly, we conclude that aprotinin at concentrations up to 10(6) KIU/L has no deleterious effect on normally perfused hearts and has a significant protective effect on the ischemic heart when used in high doses in the preischemic period.

Conjoined double internal mammary artery grafting.

Double internal mammary artery (IMA) grafting to the coronary arteries was performed on 82 patients. In ten of them one IMA was used as a free graft, and was proximally connected to the other ("conjoined" double IMA), the indications being insufficient supply of adequate veins, diseased aortic wall, availability of only a short right IMA segment for free grafting, occluded left subclavian artery, and when distal and scattered lesions of relatively important vessels had to be bypassed. Additional sequential IMA anastomoses were performed in four patients and an additional sequential vein graft in a fifth. All patients became angina-free postoperatively and have remained so during observation up to 16 months. Recatheterization studies were performed in six patients and in all of them the IMA-to-IMA (n = 6) and distal anastomoses (n = 26) were patent. Conjoined double IMA grafting is an important option available to the cardiac surgeon for management of selected patients with coronary artery disease.

The effect of vitamin D3 deficiency on the isolated chick heart: hemodynamic, P-31 NMR and membrane studies.

The purpose of this study was to investigate whether vitamin D3 deficiency affects the cardiac function of chick hearts directly or whether the influence is secondary through the hormone's effect on serum calcium levels. To this end, three experimental groups were studied: (a) the control group of vitamin D3 supplemented chicks, Ds, (b) vitamin D3 deficient chicks, Dd, and (c) vitamin D3 supplemented hypocalcemic chicks raised on decreased calcium levels, Dh. The three groups were compared by checking hemodynamic, metabolic and membrane parameters. Total and ionized serum calcium concentrations in the Dh and Dd groups were found to be lower than in the Ds group. Perfusion of the isolated hearts with solutions containing various calcium concentrations (1, 1.5 and 2.5 mM) induced enhanced contractility levels, the magnitude of which was dependent on the difference between the in vivo and perfusate calcium levels. Thus, the inotropic effect was similar and more enhanced for the two hypocalcemic groups. The differences in hemodynamic behaviour could not be explained by variations in the levels of the high energy compounds and acidity, since similar ATP, creatine phosphate and intracellular pH levels were detected for both Ds and Dd groups. However, membrane studies revealed an increase in the number of slow calcium channels for the two hypocalcemic groups and this may be the possible mechanism for the differences in the contractile activity. In conclusion, our study strongly suggests that the effects of vitamin D3 on the heart is mediated only indirectly through its effect on serum calcium levels.

Sperm motility index: a new parameter for human sperm evaluation.

OBJECTIVE: The study was performed to evaluate the correlation between sperm motility index, a novel parameter of semen quality, and routine semen analysis parameters by microscopic evaluation. DESIGN: Sperm motility index was measured by an electro-optical device, the Sperm Quality Analyzer (United Medical Systems Inc., Santa Ana, CA). Human semen samples covering the whole span of qualities were analyzed prospectively and simultaneously by both methods. SETTING: Samples were collected from patients referred to university hospital infertility clinics. PATIENTS, PARTICIPANTS: Nine hundred sixty-eight semen samples of 812 patients and healthy men were analyzed. MAIN OUTCOME MEASURE(S): Sperm motility index is a measurement of optical density fluctuations caused by motile cells; therefore, a positive correlation was anticipated between its values and semen motility parameters. RESULTS: Sperm motility index values demonstrated statistically significant correlation with motile cell concentration, total cell concentration, and percent motile cells. They were also shown to reliably represent semen quality assessment obtained by two experienced andrologists. CONCLUSIONS: The sperm motility index provides a reliable and objective reflection of semen motility parameters and quality.