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Jan Hendrik Richardus

Publications and source records attributed to Jan Hendrik Richardus.

12 recordsLinked to original sources
PubMed2007

Risk selection and targeted interventions in community-based control of chlamydia.

PURPOSE OF REVIEW: To describe recent developments in the community-based approach of high-risk groups for Chlamydia trachomatis infection, and to discuss the assessment of impact of selective systematic screening on the transmission of C. trachomatis in the community. RECENT FINDINGS: Two large home-based screening programs in Europe have recently shown that systematic postal screening for C. trachomatis infection is feasible, but certain high-risk groups are poor participators. This underscores the need for risk selection and targeted approaches. A prediction rule has been developed which can assist in identifying high-risk groups and can be used as a tool for (self) selection for screening. The Internet has been shown to be a promising medium to promote chlamydia testing. School-based programs also succeed in including high-risk groups in screening programs. Recently developed dynamic simulation models, which take into account transmission of C. trachomatis, can assist in the development and evaluation of targeted screening strategies. SUMMARY: Chlamydia will not likely be controlled by one standard approach. Risk selection strategies need further development and different systematic approaches at the community level, including postal screening, school-based screening, and the Internet may produce the desired public health effect of decreasing morbidity and reducing the transmission of C. trachomatis in the community.

Chlamydia Infections↗
PubMed2006

A pertussis outbreak associated with social isolation among elderly nuns in a convent.

The pertussis incidence during an outbreak in a convent in The Netherlands in 1992 was higher among 75 retired (unvaccinated) nuns (60%) than among 24 staff members (8%) and was higher among 9 nuns with only a convent career (100%) than among 66 nuns who had a career outside of the convent (55%). The pertussis incidence increased with duration of social isolation but not with age.

Aged↗
PubMed2006

Spatial analysis of hemorrhagic fever with renal syndrome in China.

BACKGROUND: Hemorrhagic fever with renal syndrome (HFRS) is endemic in many provinces with high incidence in mainland China, although integrated intervention measures including rodent control, environment management and vaccination have been implemented for over ten years. In this study, we conducted a geographic information system (GIS)-based spatial analysis on distribution of HFRS cases for the whole country with an objective to inform priority areas for public health planning and resource allocation. METHODS: Annualized average incidence at a county level was calculated using HFRS cases reported during 1994-1998 in mainland China. GIS-based spatial analyses were conducted to detect spatial autocorrelation and clusters of HFRS incidence at the county level throughout the country. RESULTS: Spatial distribution of HFRS cases in mainland China from 1994 to 1998 was mapped at county level in the aspects of crude incidence, excess hazard and spatial smoothed incidence. The spatial distribution of HFRS cases was nonrandom and clustered with a Moran's I = 0.5044 (p = 0.001). Spatial cluster analyses suggested that 26 and 39 areas were at increased risks of HFRS (p < 0.01) with maximum spatial cluster sizes of < or = 20% and < or = 10% of the total population, respectively. CONCLUSION: The application of GIS, together with spatial statistical techniques, provide a means to quantify explicit HFRS risks and to further identify environmental factors responsible for the increasing disease risks. We demonstrate a new perspective of integrating such spatial analysis tools into the epidemiologic study and risk assessment of HFRS.

China↗
PubMed2006

Needlestick injury and accidental exposure to blood: the need for improving the hepatitis B vaccination grade among health care workers outside the hospital.

To describe the characteristics of needlestick injuries occurring to health care workers outside the hospital, a new case report form was implemented and analyzed after 12 months. A total of 144 incidents were reported. Of the needlestick injuries in nursing assistants, 84% involved an insulin needle or pen. Thirty-five percent of all health care workers and 47% of the nursing assistants were not vaccinated against hepatitis B. Hepatitis B vaccination grade in health care workers outside the hospital should be improved, in particular among nursing assistants.

Blood-Borne Pathogens↗
PubMed2006

Prediction of Chlamydia trachomatis infection: application of a scoring rule to other populations.

BACKGROUND: Active case finding is crucial to reduce transmission and consequences of Chlamydia trachomatis (CT) infections. We previously proposed the use of a prediction rule for CT infection for selective screening of high-risk individuals in a population. To support such an application, the prediction rule needs to be validated in other populations. METHODS: We studied participants aged 15 to 29 years in a population-based study in Amsterdam (n = 1,788) and an outreach screening project among high-risk youth in Rotterdam (n = 172). Validity was indicated by discriminative ability (area under the receiver operating characteristic curve [AUC]) and by calibration, which was visualized in plots and tested with the Hosmer-Lemeshow (H-L) goodness-of-fit test. Cutoffs of predicted risk were examined for their effect on sensitivity and the fraction of participants that would need to be screened. RESULTS: Discriminative ability was reasonable both for the Amsterdam study (AUC 0.66; 95% confidence interval [CI], 0.58-0.74) and for the Rotterdam study (AUC 0.68; 95% CI, 0.58-0.79). The observed CT prevalence was lower than predicted in Amsterdam (H-L P = 0.02) and nonsignificantly higher in Rotterdam (H-L P = 0.20). By screening 77% of the Amsterdam population, 93% of the cases would have been detected, whereas in the Rotterdam study, no cases would be missed by screening 75%. CONCLUSION: The chlamydia prediction rule showed a reasonable external validity in two studies. These findings support the use of the rule as a tool for selective chlamydia screening, although only a limited fraction of participants can be excluded when a high sensitivity is required.

Adolescent↗
PubMed2006

Risk of introduction of poliovirus into a Dutch Cape Verdian community during an outbreak of poliovirus in Cape Verde, 2000.

OBJECTIVE: To assess the risk of introduction of polio virus in a Cape Verdian community of Rotterdam, during the polio epidemic in Cape Verde in 2000. METHODS: All 225 insufficiently vaccinated 0-14-year-old Cape Verdian children (n=4188) and a random sample of 285 out of all 15-30-year-old Cape Verdians (n=5074) in Rotterdam were surveyed to assess travel behaviour and vaccination coverage. Faecal specimens were collected and sewage samples taken in neighbourhoods with a sizable Cape Verdian population for testing of polio virus. RESULTS: During the polio epidemic in Cape Verde, 10% of insufficiently vaccinated children aged 0-14 years and 17% of adults aged 15-30 years living in Rotterdam reported travelling to Cape Verde. 94.6% of Cape Verdians in Rotterdam aged 0-14 years were sufficiently vaccinated against polio, but 9 of 91 insufficiently vaccinated children had travelled to Cape Verde during the epidemic. Of those aged 15-30 years, 10% were not vaccinated against polio. In the faeces of 80 insufficiently vaccinated individuals aged 0-14 years and in 74 adults aged 15-30 years, no poliovirus was detected. Samples of sewage from six sites were negative for poliovirus. CONCLUSION: No evidence of poliovirus infection was found in the Cape Verde population in Rotterdam despite extensive travel to the Cape Verde during the outbreak.

Adolescent↗
PubMed2005

Reinfections, persistent infections, and new infections after general population screening for Chlamydia trachomatis infection in the Netherlands.

OBJECTIVES: The objectives of this study were to determine the rate of new infections and reinfections or persistent infections with Chlamydia trachomatis to define appropriate screening intervals and to identify risk factors for reinfection. DESIGN: This was a cross-sectional study among a subsample of participants in a population-based screening. SETTING: This study was conducted in urban and rural areas in The Netherlands. PARTICIPANTS: A total of 21,000 15- to 29-year-old women and men were invited for home-based urine testing. One year after the study, a subsample of 299 participants were offered retesting. MAIN OUTCOME MEASURES: The authors studied the rate of infection with C. trachomatis. Serovar determination was used to potentially discriminate between new infections and reinfections or persistent infections. RESULTS: Nine C. trachomatis infections were found among 187 responders (4.8% confidence interval, 1.7-7.9). The prevalence was 10.4% (5 of 48) in previous positives and 2.9% (4 of 139) in negatives. Three of 5 repeatedly positive participants were infected with a different C. trachomatis serovar. CONCLUSIONS: Our study indicates that infected persons found in a systematic, population-based screening should be re-screened within 1 year. Optimal screening intervals still need to be determined.

Adolescent↗
PubMed2004

Steroid prophylaxis for prevention of nerve function impairment in leprosy: randomised placebo controlled trial (TRIPOD 1).

OBJECTIVE: To determine whether addition of low dose prednisolone to multidrug treatment can prevent reaction and nerve function impairment in leprosy. DESIGN: Multicentre, double blind, randomised, placebo controlled, parallel group trial. SETTING: Six centres in Bangladesh and Nepal. PARTICIPANTS: 636 people with newly diagnosed multibacillary leprosy. INTERVENTION: Prednisolone 20 mg/day for three months, with tapering dose in month 4, plus multidrug treatment, compared with multidrug treatment alone. MAIN OUTCOME MEASURES: Signs of reaction, impairment of sensory and motor nerve function, and nerve tenderness needing full dose prednisolone at four months and one year. RESULTS: Prednisolone had a significant effect in the prevention of reaction and nerve function impairment at four months (relative risk 3.9, 95% confidence interval 2.1 to 7.3), but this was not maintained at one year (relative risk 1.3, 0.9 to 1.8). Fewer events occurred in the prednisolone group at all time points up to 12 months, but the difference at 12 months was small. Subgroup analysis showed a difference in response between people with and without impairment of nerve function at diagnosis. CONCLUSIONS: The use of low dose prophylactic prednisolone during the first four months of multidrug treatment for leprosy reduces the incidence of new reactions and nerve function impairment in the short term, but the effect is not sustained at one year. The presence of nerve function impairment at diagnosis may influence the response to low dose prednisolone.

Adolescent↗
PubMed2004

Referral of chronic hepatitis B patients from primary to specialist care: making a simple guideline work.

BACKGROUND/AIMS: To evaluate a guideline selecting patients at the primary care level for referral to a specialist, to identify bottlenecks and subsequently implement and evaluate improvements. METHODS: Retrospective patient files analysis and a prospective cohort study. The study was conducted in Municipal Public Health Service (PHS), University Medical Center. Patients diagnosed with chronic hepatitis B virus (HBV) infection were referred to the PHS. Improvement of bottlenecks were identified in the referral chain, based on the guideline. Number of patients receiving correct advice, number of patients reaching the hospital for specialist care, time between notification of the PHS and final arrival in the hospital. RESULTS: The guideline for the referral of chronic HBV patients appeared to be appropriate, although one-third of the selected patients was not seen by the specialist. After the intervention more HBV patients (76 versus 61%) received correct advice from the PHS, and the number of HBV patients seen by the specialist increased by 18%. CONCLUSIONS: The referral guideline works, yet we could improve the efficiency of the guideline increasing the proportion of eligible patients reaching specialist care. In countries where mandatory reporting of HBV infections exists this guideline can be adapted to local health systems.

Cohort Studies↗
PubMed2002

Birth weight and perinatal mortality: a comparison of "optimal" birth weight in seven Western European countries.

BACKGROUND: Previous studies have suggested that a population's entire birth weight distribution may be shifted towards higher or lower birth weights, and that optimal birth weight may be lower in populations with a lower average birth weight. We evaluated this hypothesis for seven western European countries. METHODS: We obtained data on all singleton births (N = 1,372,092) and extended perinatal deaths (stillbirths plus neonatal deaths; N = 7,900) occurring in Finland, Sweden, Norway, Denmark, Scotland, the Netherlands, and Flanders (Belgium) in 1993-1995. We assessed whether countries differed in the mode of their birth weight distribution and in the birth weight associated with the lowest perinatal mortality, and then correlated the two. RESULTS: Substantial international differences were found in the mode of the birth weight distribution, which ranged between 3384 gm in Flanders and 3628 gm in Finland. The position of the minimum of the perinatal mortality curve also differed considerably, ranging between 3755 gm in Flanders and 4305 gm in Norway. There was a strong relation between the two: for every 100 gm increase in modal birth weight, optimal birth weight was 170 gm higher (95% confidence interval = 104-236 gm). CONCLUSIONS: Our results confirm those of previous studies that compared two populations. To improve the identification of small babies at high risk of perinatal death, population-specific standards for birth weight should be developed and used.

Birth Weight↗