1921
Volume 99, Issue 6
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645

Abstract

Abstract.

In the Indian subcontinent, visceral leishmaniasis (VL) has a strongly clustered distribution. The “index case approach” is promoted both for active case finding and indoor residual spraying (IRS). Uncertainty exists about the optimal radius. Buffer zones of 50–75 m around incident cases have been suggested for active case finding, for IRS the recommendation is to cover a radius of 500 m. Our aim was to establish optimal target areas both for IRS and for (re)active case finding. We plotted incident VL cases on a map per 6-month period (January–June or July–December) and drew buffers of 0 (same household), 50, 75, 100, 200, 300, 400, and 500 m around these cases. We then recorded total population and numbers of VL cases diagnosed over the next 6-month period in each of these buffers and beyond. We calculated incidence rate ratios (IRRs) using the population at more than 500 m from any case as reference category. There was a very strong degree of spatial clustering of VL with IRRs ranging from 45.2 (23.8–85.6) for those living in the same households to 14.6 (10.1–21.2) for those living within 75 m of a case diagnosed, during the previous period. Up to 500 m the IRR was still five times higher than that of the reference category. Our findings corroborate the rationale of screening not just household contacts but also those living within a perimeter of 50–75 m from an index case. For IRS, covering a perimeter of 500 m, appears to be a rational choice.

[open-access] This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Loading

Article metrics loading...

The graphs shown below represent data from March 2017
/content/journals/10.4269/ajtmh.18-0448
2018-12-05
2018-12-15
Loading full text...

Full text loading...

/deliver/fulltext/14761645/99/6/tpmd180448.html?itemId=/content/journals/10.4269/ajtmh.18-0448&mimeType=html&fmt=ahah

References

  1. Bhunia GS, Chatterjee N, Kumar V, Siddiqui NA, Mandal R, Das P, Kesari S, , 2012. Delimitation of kala-azar risk areas in the district of Vaishali in Bihar (India) using a geo-environmental approach. Mem Inst Oswaldo Cruz 107: 609620. [Google Scholar]
  2. Chappuis F, Sundar S, Hailu A, Ghalib H, Rijal S, Peeling RW, Alvar J, Boelaert M, , 2007. Visceral leishmaniasis: what are the needs for diagnosis, treatment and control? Nat Rev Microbiol 5: 873882. [Google Scholar]
  3. Bern C, Courtenay O, Alvar J, , 2010. Of cattle, sand flies and men: a systematic review of risk factor analyses for south Asian visceral leishmaniasis and implications for elimination. PLoS Negl Trop Dis 4: e599. [Google Scholar]
  4. Hasker E, Singh SP, Malaviya P, Picado A, Gidwani K, Singh RP, Menten J, Boelaert M, Sundar S, , 2012. Visceral leishmaniasis in rural Bihar, India. Emerg Infect Dis 18: 16621664. [Google Scholar]
  5. Ostyn B, Gidwani K, Khanal B, Picado A, Chappuis F, Singh SP, Rijal S, Sundar S, Boelaert M, , 2011. Incidence of symptomatic and asymptomatic Leishmania donovani infections in high-endemic foci in India and Nepal: a prospective study. PLoS Negl Trop Dis 5: e1284. [Google Scholar]
  6. Singh SP, 2010. The epidemiology of Leishmania donovani infection in high transmission foci in India. Trop Med Int Health 15 (Suppl 2): 1220. [Google Scholar]
  7. Bern C, 2007. The epidemiology of visceral leishmaniasis and asymptomatic leishmanial infection in a highly endemic Bangladeshi village. Am J Trop Med Hyg 76: 909914. [Google Scholar]
  8. Alvar J, Yactayo S, Bern C, , 2006. Leishmaniasis and poverty. Trends Parasitol 22: 552557. [Google Scholar]
  9. Boelaert M, Meheus F, Sanchez A, Singh SP, Vanlerberghe V, Picado A, Meessen B, Sundar S, , 2009. The poorest of the poor: a poverty appraisal of households affected by visceral leishmaniasis in Bihar, India. Trop Med Int Health 14: 639644. [Google Scholar]
  10. Huda MM, 2012. Active case detection in national visceral leishmaniasis elimination programs in Bangladesh, India, and Nepal: feasibility, performance and costs. BMC Public Health 12: 1001. [Google Scholar]
  11. Hirve S, 2010. Effectiveness and feasibility of active and passive case detection in the visceral leishmaniasis elimination initiative in India, Bangladesh, and Nepal. Am J Trop Med Hyg 83: 507511. [Google Scholar]
  12. Singh SP, 2011. Options for active case detection of visceral leishmaniasis in endemic districts of India, Nepal and Bangladesh, comparing yield, feasibility and costs. PLoS Negl Trop Dis 5: e960. [Google Scholar]
  13. WHO, 2010. Control of the Leishmaniases. Available at: http://apps.who.int/iris/bitstream/10665/44412/1/WHO_TRS_949_eng.pdf. Accessed April 24, 2018.
  14. NVBDCP, 2017. Accelerated Plan for Kala Azar Elimination 2017. Available at: http://nvbdcp.gov.in/Doc/Accelerated-Plan-Kala-azar1-Feb2017.pdf. Accessed April 24, 2018.
  15. Malaviya P, Picado A, Hasker E, Ostyn B, Kansal S, Singh RP, Shankar R, Boelaert M, Sundar S, , 2014. Health & demographic surveillance system profile: the Muzaffarpur-TMRC health and demographic surveillance system. Int J Epidemiol 43: 14501457. [Google Scholar]
  16. Cunningham J, 2012. A global comparative evaluation of commercial immunochromatographic rapid diagnostic tests for visceral leishmaniasis. Clin Infect Dis 55: 13121319. [Google Scholar]
  17. Coleman M, 2015. DDT-based indoor residual spraying suboptimal for visceral leishmaniasis elimination in India. Proc Natl Acad Sci USA 112: 85738578. [Google Scholar]
  18. Poche D, Garlapati R, Ingenloff K, Remmers J, Poche R, , 2011. Bionomics of Phlebotomine sand flies from three villages in Bihar, India. J Vector Ecol 36 (Suppl 1): S106S117. [Google Scholar]
  19. Perry D, Dixon K, Garlapati R, Gendernalik A, Poche D, Poche R, , 2013. Visceral leishmaniasis prevalence and associated risk factors in the saran district of Bihar, India, from 2009 to July of 2011. Am J Trop Med Hyg 88: 778784. [Google Scholar]
http://instance.metastore.ingenta.com/content/journals/10.4269/ajtmh.18-0448
Loading
/content/journals/10.4269/ajtmh.18-0448
Loading

Data & Media loading...

Supplemental Tables

  • Received : 27 May 2018
  • Accepted : 28 Aug 2018

Most Cited This Month

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error