Risk reduction of severe outcomes in vaccinated COVID-19 cases: an analysis of surveillance data from Estonia, Ireland, Luxembourg and Slovakia, January to November 2021

Despite high COVID-19 vaccine coverage in the EU/EEA, there are increasing reports of SARS-CoV-2 infections and hospitalisations in vaccinated individuals. Using surveillance data from Estonia, Ireland, Luxembourg and Slovakia (January-November 2021), we estimated risk reduction of severe outcomes in vaccinated cases. Increasing age remains the most important driver of severity, and vaccination significantly reduces risk in all ages for hospitalisation (adjusted relative risk (aRR): 0.32; 95% confidence interval (CI): 0.26-0.39) and death (aRR: 0.20; 95% CI: 0.13-0.29).

Initial assessment of the COVID-19 vaccination's impact on case numbers, hospitalisations and deaths in people aged 80 years and older, 15 EU/EEA countries, December 2020 to May 2021

Prioritisation of elderly people in COVID-19 vaccination campaigns aimed at reducing severe outcomes in this group. Using EU/EEA surveillance and vaccination uptake, we estimated the risk ratio of case, hospitalisation and death notifications in people 80 years and older compared with 25-59-year-olds. Highest impact was observed for full vaccination uptake 80% or higher with reductions in notification rates of cases up to 65% (IRR: 0.35; 95% CI: 0.13-0.99), hospitalisations up to 78% (IRR: 0.22; 95% CI: 0.13-0.37) and deaths up to 84% (IRR: 0.16; 95% CI: 0.13-0.20).

Influenza vaccine uptake among healthcare workers and residents in public health care facilities in Ireland over nine influenza seasons (2011-2012 to 2019-2020)

The influenza vaccine is free to all healthcare workers (HCWs) working in hospitals and long-term/residential health care facilities in Ireland. To evaluate influenza vaccine uptake, the Health Service Executive-Health Protection Surveillance Centre surveyed HCWs each season between 2011-2012 and 2019-2020. The national HCW uptake target was 40% for the first six seasons and was increased to 75% for the 2019-2020 season. Data on seasonal influenza vaccine uptake among HCWs employed in these healthcare settings were obtained using web-based surveys sent to occupational or management contact points. Data on numbers of staff vaccinated by Health Service Executive (HSE) professional staff grade and numbers eligible for vaccination in each grade were provided. Since the 2017-2018 season, a point prevalence survey for residents to assess influenza vaccine uptake has also been undertaken in long-term/residential care facilities (LTCFs) and aggregate data submitted, initially using a desktop spreadsheet survey tool, but later using web-based survey tools; these surveys were undertaken to investigate how uptake differed between HCWs and residents, both long-term and short-term. Participation by healthcare facilities and influenza vaccine uptake by both HCWs and LTCF-residents in these surveys increased over the nine seasons. Uptake among HCWs employed in publicly-funded hospitals increased from 18.1% (2011-2012) to 58.9% (2019-2020). Uptake in publicly-funded LTCFs increased from 17.8% (2011-2012) to 45.5% (2019-2020). Overall, uptake among hospital nursing staff was lowest among all staff categories for most seasons, but increased from 12.4% in 2011-2012 to 58.1% in 2019-2020. In all seasons since 2011-2012, medical/dental, management/administrative or health and social care professional staff reported the highest uptake values in public LTCFs. Of the three annual point prevalence surveys between 2017-2018 and 2019-2020, all showed high overall uptake among long-term residents (between 88.9% and 89.4%), and a lower and wider uptake range among respite residents (between 57.5% and 66.5%).

Seroepidemiological and phylogenetic characterization of neurotropic enteroviruses in Ireland, 2005-2014

Enteroviruses (EVs) are associated with a broad spectrum of clinical presentation, including aseptic meningitis (AM), encephalitis, hand, foot and mouth disease, acute flaccid paralysis, and acute flaccid myelitis. Epidemics occur sporadically and are associated with increased cases of AM in children. The present study describes the seroepidemiological analysis of circulating EVs in Ireland from 2005 to 2014 and phylogenetic characterization of echovirus 30 (E-30), enterovirus A71 (EV-A71), and enterovirus D68 (EV-D68). EV VP1 genotyping was applied to viral isolates and clinical samples, including cerebrospinal fluid (CSF), and those isolates that remained untypeable by neutralising anti-sera. An increase in AM cases from 2010 to 2014 was associated with an E-30 genogroup variant VII and sequences clustered phylogenetically with those detected in AM outbreaks in France and Italy. EV-D68 viral RNA was not detected in CSF samples and no neurological involvement was reported. Three EV-A71 positive CSF samples were identified in patients presenting with AM. A phylogenetic analysis of respiratory-associated EV-D68 and EV-A71 cases in circulation was performed to determine baseline epidemiological data. EV-D68 segregated with clades B and B(1) and EV-A71 clustered as subgenogroup C2. The EV VP1 genotyping method was more sensitive than neutralising anti-sera methods by virus culture and importantly demonstrated concordance between EV genotypes in faecal and CSF samples which should facilitate EV screening by less invasive sampling approaches in AM presentations.

Reporting of Acute Flaccid Paralysis in Children under 15 years of age: Improving Surveillance, January 2009 - December 2014

Acute Flaccid Paralysis (AFP) surveillance, including case investigation and specimen collection is a gold standard method for poliomyelitis surveillance. The expected annual non-polio AFP rate <15 years of age in Ireland is = 1/100 000 population. This study reviewed all cases of AFP reported to the Irish Paediatric Surveillance Unit and the Health Protection Surveillance Centre between January 2009 and December 2014 and compared reporting rates with the expected incidence rate annually. We assessed quality of surveillance data in terms of completeness of investigation for each case reported. Forty-three AFP cases in children <15 years were notified; 35 of which were confirmed. Guillain-Barre Syndrome (GBS) accounted for 48.6% (n=17) of AFP notifications. In 2014, the expected annual AFP target rate was reached. This study identified possible under-reporting of AFP paediatric cases in Ireland between 2009-2013. Completeness of investigations has improved over time, but requires further work.

A prolonged outbreak of invasive meningococcal disease in an extended Irish Traveller family across three Health Service Executive (HSE) areas in Ireland, 2010 to 2013

Between March 2010 and November 2013 eight laboratory-confirmed cases of serogroup B, invasive meningococcal disease (IMD) were identified in an extended Irish Traveller family across three Health Service Executive (HSE) areas of Ireland. Cases were aged between 5 and 46 months, and were either a cousin or sibling of another case. All eight cases survived. Chemoprophylaxis was given to relevant nuclear family members and close contacts on each occasion, but failed to prevent further cases. Neisseria meningitidis isolates from six cases were highly related, belonging to the ST-41/44 clonal complex, and shared the porA designation 7–2,4. In November 2013, the outbreak control team recommended that directly observed ciprofloxacin chemoprophylaxis be administered simultaneously to the extended family, and that the four component meningococcal B (4CMenB) vaccine be administered to family members aged 2 months to 23 years inclusive and relevant close contacts of the eighth case. Subsequently these recommendations were implemented at three regional clinics. Additionally pharyngeal swabs (n=112) were collected to assess carriage rates of N. meningitidis in this extended family. Pharyngeal carriage of N. meningitidis was detected in 15 (13%) family members. From the epidemiological investigation and carriage study overcrowding was the most likely risk factor identified in this outbreak. To date, the combination of directly observed ciprofloxacin chemoprophylaxis and use of 4CMenB vaccine have controlled the outbreak with no further cases diagnosed.

Underreporting of viral encephalitis and viral meningitis, Ireland, 2005-2008

Viral encephalitis (VE) and viral meningitis (VM) have been notifiable infectious diseases under surveillance in the Republic of Ireland since 1981. Laboratories have reported confirmed cases by detection of viral nucleic acid in cerebrospinal fluid since 2004. To determine the prevalence of these diseases in Ireland during 2005–2008, we analyzed 3 data sources: Hospital In-patient Enquiry data (from hospitalized following patients discharge) accessed through Health Intelligence Ireland, laboratory confirmations from the National Virus Reference Laboratory, and events from the Computerised Infectious Disease Reporting surveillance system. We found that the national surveillance system underestimates the incidence of these diseases in Ireland with a 10-fold higher VE hospitalization rate and 3-fold higher VM hospitalization rate than the reporting rate. Herpesviruses were responsible for most specified VE and enteroviruses for most specified VM from all 3 sources. Recommendations from this study have been implemented to improve the surveillance of these diseases in Ireland.

Seasonal influenza vaccine uptake in HSE-funded hospitals and nursing homes during the 2011/2012 influenza season

Annual seasonal influenza vaccine is recommended for all health care workers (HCWs) in Ireland. For the 2011/2012 influenza season, information was collected on influenza vaccination uptake among HCWs employed in Health Service Executive (HSE)-funded hospitals (primarily acute) and of nursing homes (NHs) and also among NH long-term and short-term respite care residents. Forty-five hospitals (80%) and 120 NHs (75%) provided uptake data. Nationally, influenza vaccine uptake among hospital employed HCWs was estimated to be 18% and 14% among HCWs in NHs; in NHs vaccine uptake among long-term care residents was estimated to 88%. These findings highlight the continued low uptake among HCWs of all categories and demonstrate the need for sustained measures to improve uptake rates.

Transmission of endemic ST22-MRSA-IV on four acute hospital wards investigated using a combination of spa, dru and pulsed-field gel electrophoresis typing

The transmission of meticillin-resistant Staphylococcus aureus (MRSA) between individual patients is difficult to track in institutions where MRSA is endemic. We investigated the transmission of MRSA where ST22-MRSA-IV is endemic on four wards using demographic data, patient and environmental screening, and molecular typing of isolates. A total of 939 patients were screened, 636 within 72 h of admission (on admission) and 303 >72 h after admission, and 1,252 environmental samples were obtained. Isolates were typed by spa, dru and pulsed-field gel electrophoresis (PFGE) typing. A composite dendrogram generated from the three sets of typing data was used to divide isolates into 'dendrogram groups' (DGs). Ten percent of patients (92/939) were MRSA-positive; 7 % (44/636) on admission and 16 % (48/303) >72 h after admission (p = 0.0007). MRSA was recovered from 5 % of environmental specimens (65/1,252). Most isolates from patients (97 %, 85/88) and the environment (97 %, 63/65) exhibited the ST22-MRSA-IV genotype. Four DGs (DG1, DG4, DG16 and DG17) accounted for 58 % of ST22-MRSA-IV isolates from patients. Epidemiological evidence suggested cross-transmission among 44/92 patients (48 %) but molecular typing confirmed probable cross-transmission in only 11 instances (13 %, 11/88), with the majority of cross-transmission (64 %; 7/11) occurring on one ward. In the setting of highly clonal endemic MRSA, the combination of local epidemiology, PFGE, spa and dru typing provided valuable insights into MRSA transmission.

Evaluation of screening risk and nonrisk patients for methicillin-resistant Staphylococcus aureus on admission in an acute care hospital

BACKGROUND

Screening for methicillin-resistant Staphylocccus aureus (MRSA) is advocated as part of control measures, but screening all patients on admission to hospital may not be cost-effective.

OBJECTIVE

Our objective was to evaluate the additional yield of screening all patients on admission compared with only patients with risk factors and to assess cost aspects.

METHODS

A prospective, nonrandomized observational study of screening nonrisk patients ≤72 hours of admission compared with only screening patients with risk factors over 3 years in a tertiary referral hospital was conducted. We also assessed the costs of screening both groups.

RESULTS

A total of 48 of 892 (5%) patients was MRSA positive; 28 of 314 (9%) during year 1, 12 of 257 (5%) during year 2, and 8 of 321 (2%) during year 3. There were significantly fewer MRSA-positive patients among nonrisk compared with MRSA-risk patients: 4 of 340 (1%) versus 44 of 552 (8%), P ≤ .0001, respectively. However, screening nonrisk patients increased the number of screening samples by 62% with a proportionate increase in the costs of screening. A backward stepwise logistic regression model identified age > 70 years, diagnosis of chronic pulmonary disease, previous MRSA infection, and admission to hospital during the previous 18 months as the most important independent predictors to discriminate between MRSA-positive and MRSA-negative patients on admission (94.3% accuracy, P < .001).

CONCLUSION

Screening patients without risk factors increased the number of screenings and costs but resulted in few additional cases being detected. In a hospital where MRSA is endemic, targeted screening of at-risk patients on admission remains the most efficient strategy for the early identification of MRSA-positive patients.

Childhood cancer in Ireland: a population-based study

BACKGROUND

Population-based studies of childhood cancer incidence, survival and mortality make an important contribution to monitoring the successful implementation of new treatment guidelines and to understanding the epidemiology of these diseases.

METHODS

We analysed incidence and survival data for cancers diagnosed in children under 15 years of age in the Republic of Ireland during 1994-2000 (the first 7 years of National Cancer Registry coverage), and longer term mortality trends.

RESULTS

World age-standardised incidence rates in Ireland averaged 142 cases per million children per year, slightly higher than the European average and slightly lower than the US average, although differences varied by diagnostic group. Observed 5-year survival in Ireland (79% overall) was slightly higher than European and US averages, and was significantly higher for acute non-lymphocytic leukaemia (67%) and (compared with the USA) significantly lower for Hodgkin lymphoma (83%). No significant increases in incidence rates were evident from the available 7 years' data, either overall or for particular diagnostic groups. Rates of childhood cancer mortality have declined markedly since the 1950s.

CONCLUSIONS

Data presented here are in line with other developed countries and suggest major improvements in treatment and consequent survival.

Prostate cancer mortality predictions for Ireland up to 2015

The objective of this analysis was to predict average world age-standardized mortality rates per person-years (100,000 person-years) and numbers of prostate cancer deaths in Ireland for the years 2005, 2010 and 2015. Poisson linear and log-linear regression models of Irish prostate cancer mortality data for the years 1950-2002 were used to predict trends for the whole population, for men aged 0-64 and 50-74 years. The prostate cancer world age-standardized mortality rate in 2015 is predicted to remain unchanged from the average recorded in 1998-2002, while, because of population growth, the number of deaths is predicted to increase. In persons under 65 years of age, the world age-standardized mortality rate is expected to increase, but the number of deaths in this age group is expected to nearly double between 2002 and 2015. Similarly, the world age-standardized mortality rate for men aged 50-74 years is predicted to rise with the number of deaths in this age group expected to increase sharply. The historical evidence predicts a small increase of age-adjusted prostate cancer mortality rates in Ireland and only in the age groups of 0-64 and 50-74 years in the next 10 years, along with a continuing marked increase in number of deaths due to demographic change.

Cumulative cancer mortality risk and potential years of life lost to 64 years of age in Ireland, 1953–2002

Premature cancer mortality trends were examined by reviewing cumulative mortality risk ('cumulative risk' hereafter) and potential years of life lost (PYLL) up to and including 64 years of age between 1953 and 2002 in Ireland. Trends were assessed quantitatively by Joinpoint analysis of both measures (with PYLL expressed as an age-standardized rate). The age of 64 years was used for these summary measures to reflect the focus of the Irish Government's cancer strategy on cancer in the under-65 population. Some differences emerged when ranking the significant types of cancer using cumulative risk and PYLL values. In general, however, the two methods generated similar overall trends, although PYLL rates tended to show steeper or longer-term declines, presumably reflecting the greater weight given to deaths at younger ages. Most cancers have, in recent years, shown a downward, or levelling-off of, trend for both sexes. The only exceptions were significant increases for oesophageal cancer in men (both measures), and prostate cancer (cumulative risk), cervical cancer (PYLL rate) and lymphoma in both sexes (cumulative risk). Rankings based on both cumulative risk and PYLL showed that male lung cancer is still the leading cause of premature death from cancer in Ireland, despite recent falls in mortality rates. Breast cancer has consistently been the leading cause of premature cancer death in women since the 1950s. Stomach cancer was once the second leading cause of premature cancer death in women, but since the 1960s it has been replaced by lung cancer. Ovarian cancer, having had a middle ranking for many years has, since the early 1990s, become the third leading cause of premature cancer death for women.

Mortality predictions for esophageal, stomach, and pancreatic cancer, Ireland, up to 2015

BACKGROUND AND AIM OF THE STUDY

An analysis was undertaken to predict numbers of esophageal, stomach, and pancreatic cancer deaths and their World age standardized mortality rates (WASMRs) per 100,000 person years (100,000 PY-1) in Ireland for the years 2005, 2010 and 2015.

METHODS

Linear and log-linear Poisson regression models were applied to 1950-2002 Irish cancer mortality data.

RESULTS

By 2015, esophageal cancer WASMR for males is expected to rise to 9.1 100,000 PY-1, but for females to fall to 2.3 100,000 PY-1. In women under 65 yr, the WASMR is expected to decline to 0.8 100,000 PY-1 but to increase to 3.6 100,000 PY-1 in men. The stomach cancer WASMR for males is predicted to decrease to 5.3 100,000 PY-1 and for females to 2.9 100,000 PY-1. In males under 65 yr, the WASMR is predicted to fall to 1.7 100,000 PY-1 and to 1.0 100,000 PY-1 in women. The male WASMR for pancreatic cancer is predicted to decrease to 5.9 100,000 PY-1 and to 4.7 100,000 PY-1 in women. In men under 65 yr, the WASMR is predicted to drop to 1.7 100,000 PY-1 and to fall in women to 1.2 100,000 PY-1.

CONCLUSIONS

Apart from male esophageal cancer, the findings would indicate that declines in Irish WASMRs for these three cancer types are expected to occur by 2015.

Mortality predictions for Ireland, 2001-2015: cancers of the breast, ovary, and cervix and Corpus uteri

Linear and log-linear Poisson regression models of Irish breast, ovarian, and cervical and corpus uterine cancer mortality data for the years 1953-2000 were used to predict European age standardized mortality rates (EASMRs) per 100,000 person years and numbers of deaths for the period 2001-2015. Rates for the whole population and for those under 65 are expected to fall from their current levels for breast and corpus uterine cancers but not for ovarian and cervical uterine cancers. EASMRs for postmenopausal women aged between 55 and 69 years are predicted to fall for breast, ovarian, and cervical and corpus uterine cancers. The continuing expansion of the Irish female population is the primary reason why the numbers of deaths arising from breast, ovarian, and cervical uterine cancer are predicted to increase in all of the above age groups. It is not exactly clear why the numbers of corpus uterine cancer deaths are expected to continue to decline, but it may be a matter of improvement in overall death-certificate coding or their diagnoses as cervical cancer deaths.

Mortality predictions for colon and anorectal cancer for Ireland, 2003-17

OBJECTIVE

Colorectal cancer mortality predictions for Ireland are presented for all ages and for the age group 0-64 years.

METHODS

Log and log-linear Poisson regression modelling was fitted to colorectal cancer mortality data for each year between 1950 and 2002 to predict average European age standardized mortality rates (EASMRs) per 100,000 person years (100,000 PY(-1)) and average numbers of deaths.

RESULTS

EASMRs for colon cancer are predicted to fall to 17.3 100,000 PY(-1) (95%PI 14.4, 20.2) in men and to 8.4 100,000 PY(-1) (95%PI 6.9, 10.2) in women by 2013-17. EASMRs for anorectal cancer are also predicted to fall to 8.0 100,000 PY(-1) (95%PI 6.6, 9.5) in men and to 3.0 100,000 PY(-1) (95%PI 2.3, 3.8) in women by this time. Truncated EASMRs for colon cancer for those aged between 0 and 64 years are predicted over the next 15 years to fall from their current levels to 4.4 100,000 PY(-1) (95%PI 3.0, 5.8) in men and to 2.3 100,000 PY(-1) (95%PI 1.5, 3.2) in women. For anorectal cancer, truncated EASMRs for those aged between 0 and 64 years are also predicted over the next 15 years to fall from their current levels to 2.9 100,000 PY(-1) (95%PI 2.0, 3.8) in men and to 0.9 100,000 PY(-1) (95%PI 0.4, 1.3) in women.

CONCLUSIONS

Ireland currently has one of the highest colorectal mortality rates in the developed world but recent downward trends, the advent of new screening tests and well targeted public health promotion programmes may lead to further reductions.

A population-based study of skin cancer incidence and prevalence in renal transplant recipients

BACKGROUND

Cancers occurring following solid organ transplantation are a rapidly growing public health concern. Defining the extent of the problem has been limited by surveillance systems with incomplete registration of cases and the paucity of reliable national incidence data.

OBJECTIVES

To determine the incidence of all cancers following renal transplantation and to make a detailed examination of trends and patterns associated with postrenal transplant skin cancers.

METHODS

Integration of data from the national renal transplant database and the national cancer registry in Ireland enabled accurate determination of the number of renal transplant recipients (RTRs) with skin cancers and other malignancies in the time period 1 January 1994 to 31 December 2001.

RESULTS

We demonstrated a biphasic increase in skin cancer incidence following renal transplantation, determined by the age at transplantation. There was a steady increase in risk for older RTRs (age 50+ years) from year 2 post-transplant, whereas the increased risk in younger RTRs (age < 50 years) occurred later but much more significantly, reaching 200 times the risk for an age-matched nontransplanted population by year 6 post-transplant. The number of nonmelanoma skin cancers (NMSCs) registered in RTRs accounted for 1% of all NMSCs registered nationally over the study period. The standardized incidence rates for invasive NMSC (33-fold increase) and in situ carcinoma of the skin (65-fold increase) were significantly increased (P < 0.05). The risk for invasive squamous cell carcinoma (SCC) was increased 82-fold compared with the nontransplanted population. Male RTRs were at particular risk of invasive SCC at sun-exposed sites such as the scalp and the external ear. Risk of malignant melanoma and Kaposi sarcoma were also increased relative to the nontransplanted population.

CONCLUSIONS

This comprehensive national study illustrates how rates of skin cancer in Irish RTRs have influenced the national incidence of skin cancer. The high incidence of SCC, basal cell carcinoma and Bowen's disease in the early post-transplant period for older patients and the cumulative risk in younger patients with increased duration of transplantation highlight the importance of implementing early and continued cancer surveillance regimens post-transplant.

Lung cancer mortality predictions for Ireland 2001-2015 and current trends in North Western Europe

PURPOSE AND METHODOLOGY: Poisson regression models of Irish lung cancer mortality data for the years 1954-2000 were used to predict European age standardized mortality rates (EASMRs) and numbers of deaths for the period 2001-2015. Predictions for the whole population and for the age group 0-64 years were the main focus of this analysis. The models employed in this analysis were written for the STATA 6.0 STATISTICAL PACKAGE FOR WINDOWS. Linear models were applied, in general, to upward trends and log-linear models to downward trends.

RESULTS

For males of all ages, EASMRs are expected to fall significantly from 59.7 per 100,000 person years (100,000 PY(-1)) in 2000 to 47.2 in the period 2011-2015. Female EASMRs are expected to fall from 28.3 100,000 PY(-1) in 2000 to 27.8 in 2011-2015. The EASMR for males under 65 years of age is predicted to continue its decline from 20.6 100,000 PY(-1) in 2000 to 11.7 in 2011-2015. The rate for females in this same age group is predicted to decline from 10.7 100,000 PY(-1) in 2000 to 7.0 in 2001-2015. Recent lung cancer trends In Ireland were also compared to other countries in North Western Europe.

The epidemiology of infectious syphilis in the Republic of Ireland

In response to the increasing numbers of syphilis cases reported among men having sex with men (MSM) in Dublin, an Outbreak Control Team (OCT) was set up in late 2000. The outbreak peaked in 2001 and had largely ceased by late 2003. An enhanced syphilis surveillance system was introduced to capture data from January 2000. Between January 2000 and December 2003, 547 cases of infectious syphilis were notified in Ireland (415 were MSM). Four per cent of cases were diagnosed with HIV and 15.4% of cases were diagnosed with at least one other STI (excluding HIV) within the previous 3 months. The mean number of contacts reported by male cases in the 3 months prior to diagnosis was 4 (range 0-8) for bisexual contacts and 6 for homosexual contacts (range 1-90). Thirty one per cent of MSM reported having had recent unprotected oral sex and 15.9% of MSM reported having had recent unprotected anal sex. Sixteen per cent of cases reported having had sex abroad in the three months prior to diagnosis. The results suggest that risky sexual behaviour contributed to the onward transmission of infection in Dublin. The outbreak in Dublin could be seen as part of a European-wide outbreak of syphilis. The rates of co-infection with HIV and syphilis in Ireland are comparable with rates reported from other centres. There is a need to improve surveillance systems in order to allow real time evaluation of interventions and ongoing monitoring of infection trends.

The public health importance of Ascaris lumbricoides

Numerous studies have shown that anthelminthic treatment can be effective in improving growth rates when given to malnourished children with ascariasis. Recent investigations have also indicated that Ascaris infections can affect mental processing in some school children. Poor socio-economic conditions are among the key factors linked with higher prevalences of ascariasis, as are defaecation practices, geophagia, cultural differences relating to personal and food hygiene, occupational necessity, agricultural factors, housing style, social class and gender. Chemotherapy is currently the major tool used for the strategic control of ascariasis as a short-term goal. In the long term, improvements in hygiene and sanitation are thought to aid long-term control considerably. Targeted treatment, especially when aimed at schoolchildren, has been a major focus of recent control efforts in some areas. Universal treatment reaches more people and thus decreases further aggregate morbidity, especially in nutritionally vulnerable preschool-age children. Selective treatment requires technical effort to identify heavily infected individuals; acceptance by the community may vary in less educated populations when some individuals receive treatment and others do not. Child-targeted treatment may be more cost-effective than population treatment in reducing the number of disease cases and, in high transmission areas, expanding coverage of a population can be a more cost-effective strategy than increasing the frequency of treatment.

B-cell epitope mapping within the MA16 antigenic sequence found in Eimeria acervulina merozoites and sporozoites

Overlapping heptapeptides derived from the MA16 Eimeria acervulina antigenic sequence (Castle et al., 1991) were synthesised on polypropylene pins ('pepskan' technique, Cambridge Research Biochemicals, UK). Binding of antibodies from chickens and rabbits infected and immunised respectively with various species of Eimeria oocysts (E. acervulina, E. tenella, E praecox, E. necatrix and E. maxima), was examined using the coated pins as the solid phase of an enzyme immunoassay (EIA). Antigenicity of the overlapping synthetic heptapeptides was then analysed using a number of algorithms based on the amino acid sequence to predict secondary protein structure, hydrophilicity, acrophilicity and chain flexibility profiles. The antigenicity of this sequence appears to be quite different from that found for the E. tenella GX3264 antigenic sequence (Bhogal et al., 1992) whose profile was similarly examined (Talebi and Mulcahy, 1994) using the same rabbit and chicken anti-Eimeria oocyst sera.

Mapping for B-cell epitopes in the GX3262 antigenic sequence derived from Eimeria tenella sporulated oocysts

Polypropylene pins were impregnated with synthetic overlapping heptapeptides based on the GX3262 Eimeria tenella antigenic sequence (Miller et al., 1989). Using these coated pins as the solid phase of an enzyme immunoassay (EIA), binding of sera from chickens and rabbits infected and immunised respectively with five different species of Eimeria were examined. Antibody reactions to the individual heptapeptides were then analysed by a number of criteria based on the amino acid sequence including hydropathy, chain flexibility and secondary structure.

Eczema and hay fever in schoolchildren

In a questionnaire survey of 2,813 children aged 4 to 19 years, eczema prevalence was 7.8% but rose to 21.3% in those with asthma. The prevalence was 5.9% in non-asthmatics. The hay fever prevalence was 12.3% but rose to 36% in those with asthma. The prevalence was 8.9% in non-asthmatics. Hay fever was more common in urban than rural children, but there was no town/country difference for eczema.

Asthma and wheeze in schoolchildren

In a questionnaire survey of 2813 children aged 4 to 19 years 11.9% reported asthma compared to 4.4% in 1983-4: a rise of 170% over 9 years. The asthma prevalence was 8.35% in girls and 14.8% in boys. The prevalence of wheeze in the past 12 months was 12% in girls and 18.9% in boys. The wheeze prevalence values for 9 year olds were similar to those found in a recent study in Galway. 40.8% of those reporting wheeze in the previous 12 months did not report asthma. This suggests under diagnosis, ineffective communication of the diagnosis to the parents or denial of the diagnosis. 79% of those with asthma reported wheeze and 10.7% reported cough but no wheeze ('cough variant asthma'), emphasising the importance of cough as an indicator of asthma in these children.

Sero-epidemiology of toxocariasis in school children

The seroprevalence of toxocariasis was investigated in 2129 school children ranging in age from 4 to 19 years. Infection, as measured by titre, was found to be high compared to values obtained from children in other countries, with 31% having a titre of > or = 1:50 and 3.1% having titres of > or = 1:800. Relationships between seroprevalence and host factors including age, sex and location, and risk factors including geophagia, thumbsucking and pet ownership were explored. Age was found to be a significant factor in relation to infection with Toxocara. Males were significantly more infected than females, as were the inhabitants of rural schools versus urban schools. The percentage of seropositive children varied widely from school to school. Geophagia and pet ownership were found to be significantly associated with toxocariasis. Logistic regression analysis was used to model the relative contribution of these factors to infection with Toxocara. While this analysis identified factors which were highly significantly associated with Toxocara titre, the odds ratios were generally low indicating the low specificity of the model.

The effects of freezing on the viability of Toxocara canis and T. cati embryonated eggs

Suspensions of embryonated (L2) Toxocara canis and T. cati eggs were maintained under freezing conditions in order to study the impact on their long term viability. The eggs had been removed from the uteri of adult Toxocara spp. worms and the suspended in a 0.4% formalin solution before being frozen in 20 ml plastic tubes in the freezer compartment of a domestic refrigerator. Assessment of embryonated egg viability over a period of 34 days was conducted by microscopic examination under a high light intensity. Embryonated T. cati eggs were found to exhibit a greater resistance to freezing than those of T. canis. A difference in the size, design of the egg shell or the metabolism of the larval form may have accounted for the observed differences in the percentage viabilities over time between the two species of Toxocara.

Epidemiology of Toxocara spp. in stray dogs and cats in Dublin, Ireland

A survey was undertaken to study the epidemiology of Toxocara spp. in 350 dogs and 181 cats. A prevalence of 82.6% was recorded for Toxocara canis and 42% for T. cati. The distribution of parasite burdens in both dogs and cats was overdispersed. The highest parasite prevalence rates and burdens were found in hosts of 12 to 24 weeks of age. No Toxocara parasites were found in cats between 0 to 4 weeks old. There was no significant difference in parasite prevalence between male and female dogs or between male and female cats. The relationships between host age and sex with parasite prevalence, burden and length are discussed. Female T. canis worms with mature ova and those with immature ova differed significantly with regard to their length. The relationship between the length of mature T. canis female worms and the proportion of body length occupied by the uterus was highly significant.

Prevalence of Toxocara canis ova in public playgrounds in the Dublin area of Ireland

A total of nine playground sites in Dublin city and county were surveyed from which 228 samples were removed. Of these samples, 15% were positive for Toxocara canis ova and a mean egg density of 1.4 ova/100 g was calculated. Two types of playground sites were identified and that the level of toxocaral contamination was found to be greater in 'neighbourhood playgrounds' than in 'adventure playgrounds'. There was no significant difference in the number of positive samples taken from sites both inside and outside these playgrounds. No evidence of Toxocara cati ova was found. Only one sample was positive for Toxascaris leonina ova. Over 50% of the T. canis ova identified were infective. The findings in this study suggest that the sample's moisture content contributes to the long term survival of infective Toxocara ova in the environment. A recovery rate of 69.8% was achieved with a modified version of the flotation method.