Measles elimination - Is it achievable? Lessons from an immunisation coverage survey

Objectives. To detennine routine measles coverage at district level and to explore reasons for immunisation failure in Mpumalanga Province, South Africa.Design. An adaptation of the World Health Organisation (WHO) Expanded Programme on Immunisation (EFl) cluster sampling method was used to make a random selection of 30 clusters in each of 21 health districts, 630 clusters in total. Seven individuals from the age group 12 - 23 months were randomly selected from each cluster and immunisation status and source were transcribed from their child health records. Where no immunisations were administered, reasons provided by parents or guardians were recorded.Setting. Mpumalanga Province, South Africa.Results. The weighted valid population coverage with measles vaccine for children aged 12 - 23 months in Mpumalanga Province was 71.1% (95% confidence interval 64.9 - 78.5%); this was the lowest of all EPI antigens. There was marked heterogeneity in measles coverage across the province, with a coefficientof variation of 22.2%. Districts with the lowest coverage shared borders with neighbouring provinces. District measles coverage was highly positively correlated with diphtheria, pertussis and tetanus (DPT3) coverage (r = 0.960, P = 0.000). There was a strong negative correlation between ranked measles campaign coverage and routine measles immunisation coverage. Obstacles to immunisation accounted· for nearly half (49%) of all reasons for immunisation failure, while lack of information and lack of motivation accounted for 30% and 22%, respectively.Conclusions. Survey results highlight the need for supplementary immunisation, including non-selective campaigns, if Mpumalanga is to achieve the South African goal of measles elimination by 2002. The value of determining district resolution coverage in order to identify areas with low measles coverage requiring supplementary intervention was also demonstrated. A strong negative correlation between routine and campaign coverage deserves further study in other settings

Editorial

Sentinal malaria surveillance - More than a research too

Historical data and modern methods reveal insights in measles epidemiology: a retrospective closed cohort study

OBJECTIVES Measles was endemic in England during the early 1800s; however, it did not arrive in Australia until 1850 whereas other infectious diseases were known to have arrived much earlier-many with the First Fleet in 1788-leading to the question of why there was a difference. DESIGN Ships surgeons' logbooks from historical archives, 1829-1882, were retrospectively reviewed for measles outbreak data. Infectious disease modelling techniques were applied to determine whether ships would reach Australia with infectious measles cases. SETTING Historical ship surgeon logbooks of measles outbreaks occurring on journeys from Britain to Australia were examined to provide new insights into measles epidemiology. PRIMARY AND SECONDARY OUTCOME MEASURES Serial intervals and basic reproduction numbers (R(0)), immunity, outbreak generations, age-distribution, within-family transmission and outbreak lengths for measles within these closed cohorts. RESULTS Five measles outbreaks were identified (163 cases). The mean serial interval (101 cases) was 12.3 days (95% CI 12.1 to 12.5). Measles R(0) (95 cases) ranged from 7.7-10.9. Immunity to measles was lowest among children ≤10 years old (range 37-42%), whereas 94-97% of adults appeared immune. Outbreaks ranged from 4-6 generations and, before 1850, were 41 and 38 days in duration. Two outbreaks after 1850 lasted longer than 70 days and one lasted 32 days. CONCLUSIONS Measles syndrome reporting in a ship surgeon's logs provided remarkable detail on prevaccination measles epidemiology in the closed environment of ship voyages. This study found lower measles R(0) and a shorter mean clinical serial interval than is generally reported. Archival ship surgeon log books indicate it was unlikely that measles was introduced into Australia before 1850, owing to high levels of pre-existing immunity in ship passengers, low numbers of travelling children and the journey's length from England to Australia.g BP was supported by a Master of Applied Epidemiology scholarship from the Australian Government and a Hunter Medical Research Institute Research Fellowshi

Seismic methods in mineral exploration and mine planning: A general overview of past and present case histories and a look into the future.

Due to high metal prices and increased difficulties in finding shallower deposits, the exploration for and exploitation of mineral resources is expected to move to greater depths. Consequently, seismic methods will become a more important tool to help unravel structures hosting mineral deposits at great depth for mine planning and exploration. These methods also can be used with varying degrees of success to directly target mineral deposits at depth. We review important contributions that have been made in developing these techniques for the mining industry with focus on four main regions: Australia, Europe, Canada, and South Africa. A wide range of case studies are covered, including some that are published in the special issue accompanying this article, from surface to borehole seismic methods, as well as petrophysical data and seismic modeling of mineral deposits. At present, high-resolution 2D surveys mostly are performed in mining areas, but there is a general increasing trend in the use of 3D seismic methods, especially in mature mining camps

Clinical Performance of an Automated Reader in Interpreting Malaria Rapid Diagnostic Tests in Tanzania.

Parasitological confirmation of malaria is now recommended in all febrile patients by the World Health Organization (WHO) to reduce inappropriate use of anti-malarial drugs. Widespread implementation of rapid diagnostic tests (RDTs) is regarded as an effective strategy to achieve this goal. However, the quality of diagnosis provided by RDTs in remote rural dispensaries and health centres is not ideal. Feasible RDT quality control programmes in these settings are challenging. Collection of information regarding diagnostic events is also very deficient in low-resource countries. A prospective cohort of consecutive patients aged more than one year from both genders, seeking routine care for febrile episodes at dispensaries located in the Bagamoyo district of Tanzania, were enrolled into the study after signing an informed consent form. Blood samples were taken for thick blood smear (TBS) microscopic examination and malaria RDT (SD Bioline Malaria Antigen Pf/PanTM (SD RDT)). RDT results were interpreted by both visual interpretation and DekiReaderTM device. Results of visual interpretation were used for case management purposes. Microscopy was considered the "gold standard test" to assess the sensitivity and specificity of the DekiReader interpretation and to compare it to visual interpretation. In total, 1,346 febrile subjects were included in the final analysis. The SD RDT, when used in conjunction with the DekiReader and upon visual interpretation, had sensitivities of 95.3% (95% CI, 90.6-97.7) and 94.7% (95% CI, 89.8--97.3) respectively, and specificities of 94.6% (95% CI, 93.5--96.1) and 95.6% (95% CI, 94.2--96.6), respectively to gold standard. There was a high percentage of overall agreement between the two methods of interpretation. The sensitivity and specificity of the DekiReader in interpretation of SD RDTs were comparable to previous reports and showed high agreement to visual interpretation (>98%). The results of the study reflect the situation in real practice and show good performance characteristics of DekiReader on interpreting malaria RDTs in the hands of local laboratory technicians. They also suggest that a system like this could provide great benefits to the health care system. Further studies to look at ease of use by community health workers, and cost benefit of the system are warranted

A retrospective analysis of the change in anti-malarial treatment policy: Peru

<p>Abstract</p> <p>Background</p> <p>National malaria control programmes must deal with the complex process of changing national malaria treatment guidelines, often without guidance on the process of change. Selecting a replacement drug is only one issue in this process. There is a paucity of literature describing successful malaria treatment policy changes to help guide control programs through this process.</p> <p>Objectives</p> <p>To understand the wider context in which national malaria treatment guidelines were formulated in a specific country (Peru).</p> <p>Methods</p> <p>Using qualitative methods (individual and focus group interviews, stakeholder analysis and a review of documents), a retrospective analysis of the process of change in Peru's anti-malarial treatment policy from the early 1990's to 2003 was completed.</p> <p>Results</p> <p>The decision to change Peru's policies resulted from increasing levels of anti-malarial drug resistance, as well as complaints from providers that the drugs were no longer working. The context of the change occurred in a time in which Peru was changing national governments, which created extreme challenges in moving the change process forward. Peru utilized a number of key strategies successfully to ensure that policy change would occur. This included a) having the process directed by a group who shared a common interest in malaria and who had long-established social and professional networks among themselves, b) engaging in collaborative teamwork among nationals and between nationals and international collaborators, c) respect for and inclusion of district-level staff in all phases of the process, d) reliance on high levels of technical and scientific knowledge, e) use of standardized protocols to collect data, and f) transparency.</p> <p>Conclusion</p> <p>Although not perfectly or fully implemented by 2003, the change in malaria treatment policy in Peru occurred very quickly, as compared to other countries. They identified a problem, collected the data necessary to justify the change, utilized political will to their favor, approved the policy, and moved to improve malaria control in their country. As such, they offer an excellent example for other countries as they contemplate or embark on policy changes.</p

A structured framework for improving outbreak investigation audits

Outbreak investigation is a core function of public health agencies. Suboptimal outbreak investigation endangers both public health and agency reputations. While audits of clinical medical and nursing practice are conducted as part of continuous quality improvement, public health agencies rarely make systematic use of structured audits to ensure best practice for outbreak responses, and there is limited guidance or policy to guide outbreak audit. A framework for prioritising which outbreak investigations to audit, an approach for conducting a successful audit, and a template for audit trigger questions was developed and trialled in four foodborne outbreaks and a respiratory disease outbreak in Australia. The following issues were identified across several structured audits: the need for clear definitions of roles and responsibilities both within and between agencies, improved communication between agencies and with external stakeholders involved in outbreaks, and the need for development of performance standards in outbreak investigations - particularly in relation to timeliness of response. Participants considered the audit process and methodology to be clear, useful, and non-threatening. Most audits can be conducted within two to three hours, however, some participants felt this limited the scope of the audit. The framework was acceptable to participants, provided an opportunity for clarifying perceptions and enhancing partnership approaches, and provided useful recommendations for approaching future outbreaks. Future challenges include incorporating feedback from broader stakeholder groups, for example those of affected cases, institutions and businesses; assessing the quality of a specific audit; developing training for both participants and facilitators; and building a central capacity to support jurisdictions embarking on an audit. The incorporation of measurable performance criteria or sharing of benchmark performance criteria will assist in the standardisation of outbreak investigation audit and further quality improvement

Effect of Artemether-Lumefantrine Policy and Improved Vector Control on Malaria Burden in KwaZulu–Natal, South Africa

BACKGROUND: Between 1995 and 2000, KwaZulu–Natal province, South Africa, experienced a marked increase in Plasmodium falciparum malaria, fuelled by pyrethroid and sulfadoxine-pyrimethamine resistance. In response, vector control was strengthened and artemether-lumefantrine (AL) was deployed in the first Ministry of Health artemisinin-based combination treatment policy in Africa. In South Africa, effective vector and parasite control had historically ensured low-intensity malaria transmission. Malaria is diagnosed definitively and treatment is provided free of charge in reasonably accessible public-sector health-care facilities. METHODS AND FINDINGS: We reviewed four years of malaria morbidity and mortality data at four sentinel health-care facilities within KwaZulu–Natal's malaria-endemic area. In the year following improved vector control and implementation of AL treatment, malaria-related admissions and deaths both declined by 89%, and outpatient visits decreased by 85% at the sentinel facilities. By 2003, malaria-related outpatient cases and admissions had fallen by 99%, and malaria-related deaths had decreased by 97%. There was a concomitant marked and sustained decline in notified malaria throughout the province. No serious adverse events were associated causally with AL treatment in an active sentinel pharmacovigilance survey. In a prospective study with 42 d follow up, AL cured 97/98 (99%) and prevented gametocyte developing in all patients. Consistent with the findings of focus group discussions, a household survey found self-reported adherence to the six-dose AL regimen was 96%. CONCLUSION: Together with concurrent strengthening of vector control measures, the antimalarial treatment policy change to AL in KwaZulu–Natal contributed to a marked and sustained decrease in malaria cases, admissions, and deaths, by greatly improving clinical and parasitological cure rates and reducing gametocyte carriage

Using the SaTScan method to detect local malaria clusters for guiding malaria control programmes

Mpumalanga Province, South Africa is a low malaria transmission area that is subject to malaria epidemics. SaTScan methodology was used by the malaria control programme to detect local malaria clusters to assist disease control planning. The third season for case cluster identification overlapped with the first season of implementing an outbreak identification and response system in the area. SaTScan™ software using the Kulldorf method of retrospective space-time permutation and the Bernoulli purely spatial model was used to identify malaria clusters using definitively confirmed individual cases in seven towns over three malaria seasons. Following passive case reporting at health facilities during the 2002 to 2005 seasons, active case detection was carried out in the communities, this assisted with determining the probable source of infection. The distribution and statistical significance of the clusters were explored by means of Monte Carlo replication of data sets under the null hypothesis with replications greater than 999 to ensure adequate power for defining clusters. SaTScan detected five space-clusters and two space-time clusters during the study period. There was strong concordance between recognized local clustering of cases and outbreak declaration in specific towns. Both Albertsnek and Thambokulu reported malaria outbreaks in the same season as space-time clusters. This synergy may allow mutual validation of the two systems in confirming outbreaks demanding additional resources and cluster identification at local level to better target resources. Exploring the clustering of cases assisted with the planning of public health activities, including mobilizing health workers and resources. Where appropriate additional indoor residual spraying, focal larviciding and health promotion activities, were all also carried out