This study identified significant clustering of cases in Pamekasan and Pasuruan using the heatmap methodology with 15 combinations of radii and cluster density. The proportion of total cases in clusters increased with heatmap radius and ranged from 3 to almost 100%. The proportion of population (in clusters) targeted for PEP decreased with heatmap radius from > 100 to 3%. Moreover, our analysis showed that the heatmap tool is practical. A substantial percentage of the leprosy cases in 2017 and 2018 was localized in the identified clusters established in previous years (21% when using the 500 m and low-density cluster setting, and almost 90% of the leprosy cases of 2017 and 2018 using the 2000 m cluster setting). This would imply that between 21 and 90% of the leprosy cases living in targeted clusters might be prevented in the next years.

We found a considerable higher NCDR in the northern subdistricts in Pamekasan and Pasuruan indicating that more transmission of M. leprae is taking place in these subdistricts. Individuals would have a higher risk to develop leprosy in these subdistricts and therefore may need to be targeted with PEP interventions first. If the new cases would be evenly distributed throughout the whole area, i.e., if there were small or no differences in NCDR between subunits, the entire area should be considered as a target area.

Our findings showed a more clustered distribution of leprosy cases in Pasuruan than in Pamekasan (Morans’ I value 0.44 and 0.27 respectively). Also, the proportion of total cases in clusters in Pasuruan is higher overall than in Pamekasan for clusters based on high density, except for the 500 m radius. The strength of clustering may determine whether a higher or lower radius should be selected to determine clusters that would be targeted for prophylactic interventions. When the distribution of cases is more diffuse, it would be more effective to define clusters using cluster settings with larger radii and low density clustering. In areas with a focused distribution of cases, cluster settings with low radii and moderate to high-density clustering are recommended. In general, smaller clusters or a small total cluster area may be preferred, as they are operationally easier to manage. However, choosing for smaller clusters also means that the proportion of contacts targeted with PEP among those who may benefit from PEP will also be smaller.

The importance of more accurate information on spatial heterogeneous distribution of disease and endemicity level at sub-district or village level is recognized by program managers of neglected tropical diseases as an added value to determine the target populations for preventive interventions [36, 37]. For example, schistosomiasis and soil-transmitted helminths show a heterogeneous distribution with large clusters of cases located near infested water and soil, respectively. Since the whole population in these areas is considered to be at risk, a population-wide strategy (i.e., mass drug administration) is recommended in that area [37]. Leprosy also shows a heterogeneous distribution but with small clusters of cases. Therefore, a cluster-based PEP strategy targeting only those individuals that might have been in contact with a leprosy patient is considered more effective than targeting the whole population in the district.

In this study, we considered two contact-based PEP strategies, (I) providing PEP to 20 contacts per leprosy case, and (II) providing PEP to 100 individuals per leprosy case, and one population-wide PEP strategy, (III) providing PEP to the total population in clusters. Contact-based strategies include tracing and screening contacts of a leprosy case for leprosy signs and symptoms. Those who have no leprosy or other contraindications receive PEP. Strategy I, wherein 20 close contacts (e.g., household, neighbours, and social contacts) are screened has shown to be effective and feasible in a large study [5]. In very high endemic areas, however, this strategy may not be sufficient to significantly reduce the transmission because a much larger proportion of the population could be considered a contact. Increasing the number of contacts or a population-wide strategy may be more effective. Strategy II has not been studied yet, but a modeling study showed that a larger reduction in incidence could be achieved if more contacts were included for screening and PEP [6]. Strategy III would resemble a blanket or population strategy in high risk areas. A study by Bakker (2005) showed a significant decline in incidence in the first three years after providing PEP to all eligible persons on three islands using a blanket approach compared to the island where only close contacts received PEP and the control island [38]. The choice of PEP strategy also depends on available resources. We calculated that the total number of individuals requiring PEP in the two districts ranged from 580 to 22,740 using strategy I, from 2900 to 113,700 using strategy II, and from 256 to 877,413 using strategy III. With limited resources (i.e., small budget and limited trained health staff) strategy I is more suitable, while strategy II or III should only be considered if sufficient resources are available. All three strategies target the cases in clusters, but the contacts of cases outside a cluster should also be targeted with PEP as recommended by the WHO guidelines (at least the household contacts) [4].

We observed that the proportion of population targeted for PEP exceeded 100% in five clusters settings with a small radius (i.e., ≤ 1000 m) for strategy I and II because the identified cluster area is relatively small and covers small populations. Therefore, the calculated number of individuals targeted for PEP may exceed the total population size in these small clusters. This implies that certain cluster settings are not suitable to facilitate PEP strategies that have a fixed number of contacts or individuals per index (i.e., strategy I or II). In this case, the program manager could also consider targeting the total population in the cluster only (i.e., strategy III). Another option is to use a cluster setting with a larger radius (> 1000 m) and lower density, which would result in a larger cluster area and population.

Based on this study, program managers may use the heatmap methodology to develop a practical guideline to determine target populations with PEP. An example of how such a guideline could be set up can be found in Additional file 1: File. S3. To develop such a guideline, the following three components should be available. Firstly, a dataset of the GPS locations of leprosy patients at household level (i.e., exact location of resident or within 10–20 m of the resident) to identify more accurate clusters. GPS coordinates at village level (i.e., centre of village with total number of cases in the village) can also be used but will result in more aggregated clusters. GPS locations at a higher level are not preferred because it will result in large clusters. Secondly, the location and population data of villages to calculate the population density per village and proportion of population targeted for PEP. In this study, the proportion of population is based on the density per km2 as calculated for the whole district because the population data at a subunit level was not available or complete. In the most urban or remote areas the density per km square will differ considerably and therefore, the proportions to be targeted in these clusters are less accurate and not comparable. When population data per village are available the proportions will be more accurate. Thirdly, an estimation should be at hand of the resources available in the area, either in terms of funding and/or in terms of trained health staff.

The hotspot analysis used in this study has proven to be a practical method to identify clusters of cases of disease and determine the target populations for interventions. Our sensitivity analysis showed that between 21 and 90% of the cases of the next years fall in a defined cluster. This may indicate that in high-endemic areas with a stable leprosy incidence, clusters will remain in the same areas over the next years [22]. Interventions should therefore be prioritized in these clusters.

A possible limitation of our approach is that the cut-off values to define low, moderate, and high-density clustering were chosen arbitrarily. Alternatively, in a study to identify hotspots of malaria cases for each season in Myanmar, the median density was used given a fixed radius to identify clusters [39]. We did not use the median density value because we varied the radius (500 to 2500 m), which would have resulted in a different median density value for each radius. Since our aim was to directly compare the implication of choices regarding radii and density, we selected three cut-off values of density that would be simple and meaningful for a policymaker. Also, our approach has only been used in the context of two high-endemic districts in Indonesia and may not completely apply to other (foreign) areas. For example, depending on the size of districts, one may need to increase or decrease radii to identify clusters of reasonable size. Nevertheless, the general concept of this approach may apply to all contexts.

Another consideration is that we did not take into account urban and rural areas and assumed that the population is evenly distributed in a district, whereas, in reality, this is not the case. This also could partly explain why in small clusters the proportion targeted with PEP exceeds 100%. If the actual population per village or city is known a more accurate estimate of the target population can be made. Also, the distance between leprosy cases may be different in urban and rural areas. Therefore, program managers may need to consider different cluster settings, for example, a small radius in urban areas and a large radius in very remote areas.

By admin

https://muehlenbar.de/wp-includes/slot-online/

https://the-chef.co/sbobet/

Slot Gacor Terbaru

Link Slot Gacor

Sbobet

Situs Slot Gacor

Slot Gacor 2022

Login Sbobet

Daftar Sbobet

https://www.dcosmeticclinics.com.au/wp-includes/sbobet/

https://thetastesoflife.com/wp-includes/sbobet/

https://www.townshipofsugargrove.com/wp-includes/slot-gacor/

https://texasmamaboutique.com/wp-includes/slot-gacor/

https://bizu-me.com/wp-includes/slot-gacor/

https://tiketa.co.za/wp-includes/slot-gacor/

situs slot gacor

slot gacor gampang menang

slot gacor terbaru

daftar sbobet

slot bonus newmember

link sbobet

sbobet login