Will We Have a Cohort of Healthcare Workers Full Vaccinated against Measles, Mumps, and Rubella?

Healthcare workers are a population exposed to several infectious diseases, and an immunization programme is essential for the maintenance of good vaccination coverage to protect workers and patients. A population of 10,653 students attending degree courses at Padua Medical School (medicine and surgery, dentistry and health professions) was screened for vaccination coverage and antibody titres against rubella, mumps, and measles. The students were subdivided into five age classes according to their date of birth: those born before 1980, between 1980 and 1985, between 1986 and 1990, between 1991 and 1995, and after 1995. Vaccination coverage was very low in students born before 1980, but the rate of positive antibody titre was high due to infection in infancy. Increasing date of birth showed increased vaccination coverage. In contrast, immune coverage was high for rubella (more than 90%) but not for mumps and measles (approximately 80%). An "anomaly" was observed for mumps and measles in the cohort born between 1991 and 1995, probably due to the trivalent vaccine formulation. Students born after 1990 showed vaccination coverage that exceeded 90%. It is therefore very likely that we will have a future generation of healthcare workers with optimal vaccination coverage.

Significance of anti-HB levels below 10 IU/L after vaccination against hepatitis B in infancy or adolescence: an update in relation to sex.

Hepatitis B vaccination (three-dose series) induces long-term immunity, but it is not uncommon to find antibody levels below 10 IU/L long after vaccination. However, the majority of the subjects with low antibody levels have a prompt response to a booster dose. A population of 10,294 students at Padua University Medical School, who were subjected to hepatitis B vaccination during infancy or adolescence according to the law, was tested for the presence of anti-HBs, usually during the first year of matriculation. Among the students offered a booster dose, 1,030 were vaccinated, and the antibody titre was re-tested. The present research provides further evidence from a larger number of students (1,030) that an anti-HB level higher than 2 IU/L is predictive of a prompt response to a booster. There are also differences related to sex. The results clearly confirm that an antibody titre equal to or greater than 2 IU/L is enough to prompt a response after a booster dose, even several years after the initial vaccination cycle, and to predict effective immune protection. The length of the interval between the booster/post-booster analyses increases the probability of finding a low response to the booster; furthermore, females show a more rapid response to the booster than males. The importance for healthcare workers of measuring the antibody titre four weeks after a booster is highlighted, and the results suggest that females have a better response than males to booster vaccination.

Maintaining Maternal and Child Health Services During the Ebola Outbreak: Experience from Pujehun, Sierra Leone.

BACKGROUND: During the Ebola outbreak the overall confidence of the population in the national health system declined in Sierra Leone, with a reduction in the use of health services. The objective of this study is to provide information on understanding of how Ebola impacted maternal and child health services in Sierra Leone. Data come from an operational setting which is representative of the communities affected by the outbreak. METHODS: By integrating hospital registers and contact tracing form data with healthcare workers and local population interviews, the transmission chain was reconstructed. Data on the utilization of maternal and neonatal health services were collected from the local district's Health Management Information System. The main measures put in place to control the Ebola epidemic were: the organization of a rapid response to the crisis by the local health authorities; triage, contact tracing and quarantine; isolation, clinical management and safe burials; training and community sensitization. RESULTS: A total of 49 case patients were registered between July and November 2014 in the Pujehun district. Hospitalization rate was 89%. Overall, 74.3% of transmission events occurred between members of the same family, 17.9% in the community and 7.7% in hospital. The mean number of contacts investigated per case raised from 11.5 in July to 25 in September 2014. The 2014 admission trend in the pediatric ward shows a decrease after beginning of June: the reduction was almost significant in the period July-December (p 0.05). The admission in the maternity ward showed no statistical differences in comparison with the previous year (p 0.07). Also the number of deliveries appeared to be similar to the previous year, without significant variations (p 0.41). CONCLUSION: The Ebola outbreak reduced the number of patients at hospital level in Pujehun district. However, the activities undertaken to manage Ebola, reduced the spread of infection and the impact of the disease in mothers and children. A number of reasons which may explain these results are presented and discussed.

The 2014 Ebola virus disease outbreak in Pujehun, Sierra Leone: epidemiology and impact of interventions.

BACKGROUND: In July 2014, an outbreak of Ebola virus disease (EVD) started in Pujehun district, Sierra Leone. On January 10th, 2015, the district was the first to be declared Ebola-free by local authorities after 49 cases and a case fatality rate of 85.7%. The Pujehun outbreak represents a precious opportunity for improving the body of work on the transmission characteristics and effects of control interventions during the 2014-2015 EVD epidemic in West Africa. METHODS: By integrating hospital registers and contact tracing form data with healthcare worker and local population interviews, we reconstructed the transmission chain and investigated the key time periods of EVD transmission. The impact of intervention measures has been assessed using a microsimulation transmission model calibrated with the collected data. RESULTS: The mean incubation period was 9.7 days (range, 6-15). Hospitalization rate was 89%. The mean time from the onset of symptoms to hospitalization was 4.5 days (range, 1-9). The mean serial interval was 13.7 days (range, 2-18). The distribution of the number of secondary cases (R 0 = 1.63) was well fitted by a negative binomial distribution with dispersion parameter k = 0.45 (95% CI, 0.19-1.32). Overall, 74.3% of transmission events occurred between members of the same family or extended family, 17.9% in the community, mainly between friends, and 7.7% in hospital. The mean number of contacts investigated per EVD case raised from 11.5 in July to 25 in September 2014. In total, 43.0% of cases were detected through contact investigation. Model simulations suggest that the most important factors determining the probability of disease elimination are the number of EVD beds, the mean time from symptom onset to isolation, and the mean number of contacts traced per case. By assuming levels and timing of interventions performed in Pujehun, the estimated probability of eliminating an otherwise large EVD outbreak is close to 100%. CONCLUSIONS: Containment of EVD in Pujehun district is ascribable to both the natural history of the disease (mainly transmitted through physical contacts, long generation time, overdispersed distribution of secondary cases per single primary case) and intervention measures (isolation of cases and contact tracing), which in turn strongly depend on preparedness, population awareness, and compliance. Our findings are also essential to determine a successful ring vaccination strategy.

Occupational blood and body fluid exposure of university health care workers.

BACKGROUND: Occupational exposure to bloodborne pathogens caused by percutaneous injuries or mucosal contamination is common in hospital settings. METHODS: Reports of exposures to human blood and body fluids from Padua university health care workers since 2004 to 2006 and compliance with follow-up after injury according to the patients' source were analyzed. RESULTS: The injury reports were 497. The residents in surgery and anesthesiology were significantly more injured than others, and the compliance with follow-up was low: from 26.3% (hepatitis B virus) to 40% (hepatitis C virus) with a positive source, less than 30% with a negative source, as far as 40% with an unknown source. No seroconversion was observed in subjects completing the follow-up. CONCLUSION: We suspect underestimation of injury reports and low compliance with the follow-up requests that health care workers adhere to the protocols and follow the standard procedures to prevent exposures to bloodborne pathogens.

Immunity against infectious diseases: predictive value of self-reported history of vaccination and disease.

OBJECTIVE: To determine whether self-reported history of disease and/or vaccination is predictive of immunity against hepatitis B, varicella, rubella, mumps, and measles. DESIGN: The seroprevalence of viral antibodies and the predictive value of a self-report questionnaire were determined for 616 paramedical students who matriculated into Padua Medical School (Padua, Italy) during 2003-2005. RESULTS: The majority of subjects (86.9%) remembered being vaccinated against hepatitis B but had no recollection of disease. Among vaccinees, 1.5% showed markers of previous infection, 6.7% tested negative for anti-hepatitis B virus surface antigen (anti-HBsAg) antibodies, and 91.8% tested positive for anti-HBsAg. Self-reported vaccination history had a positive predictive value of 93.2% for test results positive for immunity against hepatitis B. Immunity against varicella (93.7% of subjects) and rubella (95.5%) was high, compared with immunity against mumps (79.9%) and measles (83.1%). In addition, results of tests for detection of immunity against mumps and measles were equivocal for more than 7% of subjects, probably because their vaccination regimen was not completed. Self-reported histories of varicella disease and rubella disease and vaccination had high positive predictive values (greater than 98% each) for testing positive for antiviral antibodies, compared with self-reported histories of mumps disease and vaccination and measles disease and vaccination; however, high positive predictive values were observed for self-reported histories of mumps only (92.0%) and measles only (94.7%). CONCLUSIONS: The self-report questionnaire used in this study did not accurately predict immunity against 5 transmittable but vaccine-preventable diseases. A complete serological evaluation of healthcare workers, followed by vaccination of those with negative or equivocal results of serological tests, is an appropriate measure to decrease the risk of infection in this population.

Prevalence of childhood exanthematic disease antibodies in paramedical students: need of vaccination.

The immunity to common childhood exanthematic diseases such as varicella, rubella, mumps and measles was evaluated in 1024 students of the degree courses of health professions at Padua University Medical School. Subjects were subdivided according to gender and age (25 years old or less, and older than 25 years). Results showed that the prevalence of positive antibodies (IgG) to varicella and rubella (94.1 and 94.5%, respectively) was significantly higher (p<0.001) than mumps (78.6%) and measles (86.3%). In addition, measles showed a significant higher prevalence than mumps (p<0.001). Prevalence of positive antibodies to rubella in females (97.4%) was significantly higher (p<0.001) than males (87.5%), but only if aged 25 years or less. Furthermore, males older than 25 years were significantly more immune (p<0.001) to measles (93.0%) than younger ones (84.3%). A vaccination strategy was applied but compliance was less than 50%; in addition, about 40.0% of vaccinated subjects eluded control after vaccination. Seroconversion after vaccine appeared high for rubella, mumps and measles (92.3, 88.9 and 88.1%, respectively), but low for varicella (43.8%).