A cocoon immunisation strategy against pertussis for infants: does it make sense for Ontario?

Pertussis deaths occur primarily among infants who have not been fully immunised. In Ontario, Canada, an adult booster dose was recently added to the publicly funded immunisation programme. We applied number-needed-to-treat analyses to estimate the number of adults that would need to be vaccinated (NNV) to prevent pertussis disease, hospitalisation and death among infants if a cocoon strategy were implemented. NNV=1/(P(M) X R) + 1/(P(F) X R), where P(M),P(F) (proportion of infants infected by mothers, fathers) were sourced from several studies. Rates of disease, hospitalisation or death (R) were derived from Ontario's reportable disease data and Discharge Abstract Database. After adjusting for under-reporting, the NNV to prevent one case, hospitalisation or death from pertussis was between 500-6,400, 12,000-63,000 and 1.1-12.8 million, respectively. Without adjustment, NNV increased to 5,000-60,000, 55,000-297,000 and 2.5-30.2 million, respectively. Rarer outcomes were associated with higher NNV. These analyses demonstrate the relative inefficiency of a cocoon strategy in Ontario, which has a well-established universal immunisation programme with relatively high coverage and low disease incidence. Other jurisdictions considering a cocoon programme should consider their local epidemiology.

Mammographic density and its interaction with other breast cancer risk factors in an Asian population.

BACKGROUND: Joint effects of mammographic density and other risk factors on breast cancer risk remain unclear. METHODS: From The Singapore Breast Screening Project, we selected 491 cases and 982 controls. Mammographic density was measured quantitatively. Data analysis was by conditional logistic regression. RESULTS: Density was a significant risk factor, adjusting for other factors. Density of 76-100% had an odds ratio of 5.54 (95% CI 2.38-12.90) compared with 0-10%. Density had significant interactions with body mass index and oral contraceptive use (P=0.02). CONCLUSIONS: Percent density increases breast cancer risk in addition to effects of other risk factors, and modifies the effects of BMI and OCs.

Effect of childbirth after treatment on long-term survival from breast cancer.

BACKGROUND: This study quantified long-term absolute and relative mortality risks of survivors of breast cancer with subsequent childbirth. METHODS: The Singapore Birth Register (n = 319,437), Swedish Multi-Generation Register (n = 11 million) and population-based cancer registries were linked to identify 492 women with childbirth after breast cancer. For these women, cumulative mortality risks and standardized mortality ratios (SMRs) were calculated and compared with those of 8529 women aged less than 40 years with breast cancer without subsequent childbirth, and with those predicted by Adjuvant! Online. RESULTS: Women with subsequent childbirth had a lower 15-year cumulative overall mortality rate than other women with breast cancer (16.8 (95 per cent confidence interval (c.i.) 13.3 to 20.9) versus 40.7 (39.5 to 41.9) per cent), but a higher relative mortality risk than the background population (SMR 13.6, 95 per cent c.i. 10.6 to 17.3). Mortality risks decreased significantly with increasing interval between diagnosis and subsequent childbirth. Mean 10-year cumulative mortality risks of women with subsequent childbirth were within the range of 10-year mortality predicted by Adjuvant! Online for women with T1 N0 tumours in otherwise perfect health. CONCLUSION: This study reinforced the view that pregnancy after breast cancer is not detrimental to survival. However, women who gave birth after this diagnosis had substantially higher mortality risks than young women in the general population. This information may be a valuable addition to routine mortality estimates.

24-Hour observational ward management of diabetic patients presenting with hypoglycaemia: a prospective observational study.

BACKGROUND: A 24 h observational ward was set up in the study hospital emergency department (ED) in September 2005 to manage a group of patients with specific conditions including hypoglycaemia that require only short focused inpatient care. AIM: To evaluate the efficacy and safety of the management of hypoglycaemia in the observational ward via criteria of successful discharge of patients from the observational ward within 24 h and the recurrence of hypoglycaemia after discharge. METHODS: Hypoglycaemic patients admitted to the observational ward had their treatment and evaluation performed within 24 h. A protocol based on current available literature was formulated. Data were collected prospectively and included patient demographics, the duration and type of diabetes mellitus, current medications and treatment given. Patients were discharged only after a set of strict discharge criteria was fulfilled, and were followed up by telephone interviews at 7 and 28 days after discharge. RESULTS: A total of 203 patients were recruited. Of these, 170 (83.7%) patients were discharged and 33 (16.3%) were transferred to an inpatient team for a longer period of treatment. The median length of stay in the observational ward was 23.0 h. Of the 170 patients discharged, 151 (88.8%) were contacted at 7 and 28 days after discharge. Six patients had symptoms of recurrent hypoglycaemia, two of whom reattended the ED and had to be admitted. The remaining four patients had mild symptoms that were self-managed at home. Two other patients reattended for conditions not related to hypoglycaemia. Nineteen patients could not be contacted, but there was no record of any reattendances at the ED among this group of patients. CONCLUSION: There are currently no recommendations regarding the length of stay in hospital for patients with severe hypoglycaemia. This study shows that selected patients can be treated effectively and safely in a 24 hour observational ward.

Patient satisfaction in an observation unit: the Consumer Assessment of Health Providers and Systems Hospital Survey.

BACKGROUND: The growing demand for inpatient beds in Singapore has led Tan Tock Seng Hospital to set up an observation medicine unit where patients are monitored and discharged within a 24-h period. METHODS: Using the Consumer Assessment of Health Providers and Systems (CAHPS) Hospital Survey, this descriptive study examines the satisfaction levels of patients admitted into an observation unit, in particular the communication between patients and doctors and nurses. The anonymous surveys were either self-administered by the patients or by the research assistant or nurses. RESULTS: 271 patients completed the survey, with 96% of patients satisfied with the politeness (ie, treating them with courtesy and respect, listening carefully to them) of the medical staff. More highly educated patients were more satisfied with the communication between the doctors or nurses, compared with less educated patients (p<0.05). However, less educated patients gave a higher rating of their observation unit stay than more educated patients (p<0.05). CONCLUSION: With patient satisfaction becoming increasingly important as an indicator of the quality of care in the present healthcare environment, doctors and nurses should seek to improve their communication with their patients so as to ensure that patients are satisfied and receive quality care.

Adherence and efficacy of an external teat sealant to prevent new intramammary infections in the dry period.

The efficacy and adherence of an external teat sealant applied at drying off was evaluated in 2 studies between 1997 and 1999. At drying off, 2 quarters were randomized to receive intramammary dry-cow antibiotic therapy, and the remaining 2 quarters were treated with either a single or double application of external teat sealant. Approximately 3 d before calving, all teats that had been dipped at drying off were redipped in a single coating of teat sealant. Adherence of the teat sealant was scored for the first 2 wk after drying off, and physical traits of the teat skin and teat ends were recorded. Quarter milk samples were collected 1 wk before drying off, at drying off, 0 to 7 d, and 14 to 21 d postcalving. Somatic cell counts were determined from quarter samples taken at d 7 and 14 to 21 d after calving. Data were analyzed from 172 dry periods of 162 cows. The mean time of sealant adherence following drying off application was 3 +/- 0.13 d. Double sealant application significantly increased the duration of adherence by 0.67 d. Teats that had teat sealant applied twice at drying off and that had up to 3 d of adherence had the lowest linear score (LS) at 14 to 21 d (1.89 +/- 0.31) of all quarters. The LS of quarters that received antibiotic therapy only was 2.27 +/- 0.19. The majority of intramammary infections identified at drying off were caused by the minor pathogens, coagulase-negative staphylococci and Corynebacterium bovis (51 and 23%, respectively). The results from this study indicate that duration of sealant adherence to the teat-end should be considered when evaluating the impact of teat sealant treatment at drying off on the level of infection after calving. Double sealant application, cooler seasons, and longer teat lengths were associated with a significant increase in the duration of sealant adherence to the teat-end.

Herd management factors that affect duration and variation of adherence of an external teat sealant.

During 1998 and 1999, a purposive sample of Ontario dairy herds was enrolled in a study to examine management factors associated with adherence of an external teat sealant. A total of 74 herds were recruited that had previously complied with a provincial Sentinel Herd mastitis study. All herds were sent a management survey and a commercially available external teat sealant product. The sealant was applied to all cows in first lactation or greater that were scheduled to go dry. Adherence of the teat sealant was scored on a scale of 1 to 5 (1 = sealant completely removed) for the first 12 d following dry off. Complete data were analyzed from 806 cows in 48 herds (mean of 17 cows/herd). Mean duration of adherence of the teat sealant was 4 d (range 1 to 7 d). Of the management factors recorded, only changing the feed to reduce milk production prior to drying off was significantly associated with 0.78-d prolonged adherence. No factors related to dry cow housing, bedding material, or floor surface were associated with the duration of adherence. The variance around the duration of adherence was examined. The median variance of adherence was 3.0 d(2), which was equivalent to a standard deviation of 2.6 d. Herds in which dry cows were housed in tie-stall barns, and the herds that used a penicillin and novobiocin combination dry cow antibiotic had the greatest variation. We concluded that modifying the ration to reduce milk production enhanced adherence of an external teat sealant. Teat-end preparation prior to application of the teat sealant is an important factor to consider when choosing to adopt this dry period mastitis prevention strategy. This study demonstrates that beyond cow- and quarter-level factors, herd management factors can influence the duration and variation of sealant adherence experienced among different herds.

Spinal epidural leiomyoma occurring in an HIV-infected man. Case report.

A case of spinal epidural leiomyoma is reported in a 52-year-old man infected with the human immunodeficiency virus (HIV). The tumor arose in the epidural region at the T-3 vertebral level, and the patient presented with radicular pain in the right T-3 dermatome. While soft-tissue tumors such as Kaposi's sarcoma and lymphomas have been well documented in association with HIV infection, this is the first reported case of primary spinal leiomyoma. Isolated cases of leiomyomas and leiomyosarcomas in unusual locations have been reported, notably in pediatric HIV-positive patients, perhaps indicating a causal relationship. This case may represent further evidence of such an association.

Characterization of a novel ranavirus isolated from grouper Epinephelus tauvina.

A large icosahedral virus was isolated from diseased grouper Epinephelus tauvina. The virus grew well in several cultured fish cell lines, with stable and high infectivity after serial passages in grouper cell line (GP). The virus was sensitive to both acid and heat treatments. Virus replication was inhibited by 5-iodo-2-deoxyuridine (IUDR), indicative of a DNA-containing genome. The virus infectivity was reduced with ether treatment, suggesting that the virus was lipid-enveloped. Electron micrographs showed abundant cytoplasmic icosahedral virons in the virus-infected GP cells. The size of the intracellular nucleocapsid was 154 nm between the opposite sides, or 176 nm between the opposite vertices with an inner electron-dense core of 93 nm. Virus particles were released through budding from plasma membranes with a size of 200 nm in diameter. SDS-PAGE of purified virus revealed 20 structural protein bands and a major capsid protein (MCP) of 49 kDa. A DNA fragment of approximately 500 nucleotides was successfully amplified by polymerase chain reaction (PCR) using the primers from conserved regions of the MCP gene of frog virus 3 (FV3), the type species of Ranavirus. Subsequent multiple alignment and phylogenetic analysis showed that the newly isolated grouper virus was closely related to largemouth bass virus (LMBV), FV3 and Regina ranavirus (RRV). Our data suggests that the virus isolate is a novel member of genus Ranavirus, family Iridoviridae. We tentatively name the virus as Singapore grouper iridovirus (SGIV). SGIV was able to cause serious systemic disease capable of killing 96% of grouper fry.

The pathology of systemic iridoviral disease in fish.

Iridoviruses have been associated with severe disease and economic loss in farmed food fish and ornamental fish, with mortality often reported to reach 50% or more. In the present study, three tropical marine food fish species and four tropical freshwater ornamental fish species with systemic iridovirus infections were examined histopathologically and ultrastructurally. Light microscopy consistently revealed pale to intensely basophilic hypertrophied virus-infected cells in spleen, kidney and intestine from all seven species. Ultrastructural examination showed changes in the vascular endothelium overlying hypertrophied virus-infected cells suggestive of pressure necrosis. Viral isolation was improved by the use of fibroblastic cell lines. This, together with the sub-endothelial location of infected cells in all infected species examined, suggests that systemic iridoviruses are mesotheliotropic.