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Implication of vector characteristics of Phlebotomus argentipes in the kala-azar elimination programme in the Indian sub-continent.

Chowdhury R, Kumar V, Mondal D, Das ML, Das P, Dash AP, Kroeger A - Pathog Glob Health (2016)

Bottom Line: However, information about breeding places, seasonal variation of vector densities, and 47 out of the selected 51 papers are available from the ISC and can be used for intelligent design of control operations.Vector control services should undertake routine insecticide resistance monitoring and adapt indoor residual spraying rounds to the seasonality of vector densities.Further research is needed on potential animal reservoirs for L. donovani, on the breeding habitat, and life cycle of sand flies in the ISC.

View Article: PubMed Central - PubMed

Affiliation: a KalaCORE Programme (Consortium for the Control and Elimination of Visceral Leishmaniasis) , Dhaka , Bangladesh.

ABSTRACT

Background: Visceral leishmaniasis (VL), also known as kala-azar in the Indian sub-continent (ISC), is a major public health concern in Bangladesh, India, and Nepal, where it is caused by Leishmania donovani transmitted by the sand fly Phlebotomus argentipes. Various ecological parameters including air temperature, rainfall, wind speed, relative humidity, soil moisture, pH, and organic carbon are known to influence the oviposition of female sand flies, as well as the survival and development of larvae. However, more detailed knowledge on vector behavior, such as biting times, breeding places, and preferred hosts are needed to design optimal evidence-based vector control interventions.

Methods: In order to facilitate rational decisions regarding VL vector control, a systematic review was conducted to identify the prevailing practice and knowledge gaps in relation to vector bionomics and behavior. Search terms included 'sand fly bionomics', 'habitat', and 'visceral leishmaniasis/kala-azar vector control' using the Boolean operator AND to identify the country of interest, namely: Bangladesh, India, and Nepal. Both PubMed and Google search engines were used. Additional unpublished documents in the three countries were also analyzed.

Results: Information on the life cycle of VL vectors, their breeding behavior, infection rate with L. donovani, feeding behavior, and seasonal variation are useful for designing vector control operations. Unfortunately, none of the studies on the life cycle of P. argentipes was conducted in field settings of the ISC, so the publications from other locations had to be used for determining the duration of life cycle and development from egg to adult. However, information about breeding places, seasonal variation of vector densities, and 47 out of the selected 51 papers are available from the ISC and can be used for intelligent design of control operations.

Conclusion: Vector control services should undertake routine insecticide resistance monitoring and adapt indoor residual spraying rounds to the seasonality of vector densities. Further research is needed on potential animal reservoirs for L. donovani, on the breeding habitat, and life cycle of sand flies in the ISC.

No MeSH data available.


Related in: MedlinePlus

Seasonality and monthly variation of Phlebotomus sand fly density (Bangladesh) and P. argentipes (India and Nepal) observed per household trap during night by month: from September 2002 to August 2003 (Bangladesh) and 2006 to 2007 (India and Nepal).
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Figure 0002: Seasonality and monthly variation of Phlebotomus sand fly density (Bangladesh) and P. argentipes (India and Nepal) observed per household trap during night by month: from September 2002 to August 2003 (Bangladesh) and 2006 to 2007 (India and Nepal).

Mentions: In Bihar, the maximum number of immature stage of sand flies in soil samples was found in January, and the minimum in September.32 The emergence of adult P. argentipes from soil samples was observed from April to October.35 A study in West Bengal highlighted that sand flies were present throughout the year with minimum abundance in winter and maximum during monsoon and post-monsoon months.51 In Bihar, seasonal fluctuations in sand fly density showed peaks in November and from May to August. The highest proportions of gravid female sand flies were captured during May. Of the sand flies trapped, the majority was P. argentipes (72.1% of 52,653 sand flies).52 In Bangladesh, the peak sand fly densities were found in March. From December to February, the density was low due to cool temperatures (Fig. 2).53 In Nepal, the density of P. argentipes showed two peaks, one during April and May and another in September and October.47 The seasonality of P. argentipes is similar in India and Nepal, with two annual density peaks around May and October (Fig. 2).54 Density of P. argentipes was significantly higher in summer (March to June) in comparison to monsoon months (July–October) and winter (November–February).37 Thus, the most intense transmission of L. donovani in the ISC occurs during two periods: a pre-winter peak in September–November and a post-winter peak in March–May.55


Implication of vector characteristics of Phlebotomus argentipes in the kala-azar elimination programme in the Indian sub-continent.

Chowdhury R, Kumar V, Mondal D, Das ML, Das P, Dash AP, Kroeger A - Pathog Glob Health (2016)

Seasonality and monthly variation of Phlebotomus sand fly density (Bangladesh) and P. argentipes (India and Nepal) observed per household trap during night by month: from September 2002 to August 2003 (Bangladesh) and 2006 to 2007 (India and Nepal).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4940889&req=5

Figure 0002: Seasonality and monthly variation of Phlebotomus sand fly density (Bangladesh) and P. argentipes (India and Nepal) observed per household trap during night by month: from September 2002 to August 2003 (Bangladesh) and 2006 to 2007 (India and Nepal).
Mentions: In Bihar, the maximum number of immature stage of sand flies in soil samples was found in January, and the minimum in September.32 The emergence of adult P. argentipes from soil samples was observed from April to October.35 A study in West Bengal highlighted that sand flies were present throughout the year with minimum abundance in winter and maximum during monsoon and post-monsoon months.51 In Bihar, seasonal fluctuations in sand fly density showed peaks in November and from May to August. The highest proportions of gravid female sand flies were captured during May. Of the sand flies trapped, the majority was P. argentipes (72.1% of 52,653 sand flies).52 In Bangladesh, the peak sand fly densities were found in March. From December to February, the density was low due to cool temperatures (Fig. 2).53 In Nepal, the density of P. argentipes showed two peaks, one during April and May and another in September and October.47 The seasonality of P. argentipes is similar in India and Nepal, with two annual density peaks around May and October (Fig. 2).54 Density of P. argentipes was significantly higher in summer (March to June) in comparison to monsoon months (July–October) and winter (November–February).37 Thus, the most intense transmission of L. donovani in the ISC occurs during two periods: a pre-winter peak in September–November and a post-winter peak in March–May.55

Bottom Line: However, information about breeding places, seasonal variation of vector densities, and 47 out of the selected 51 papers are available from the ISC and can be used for intelligent design of control operations.Vector control services should undertake routine insecticide resistance monitoring and adapt indoor residual spraying rounds to the seasonality of vector densities.Further research is needed on potential animal reservoirs for L. donovani, on the breeding habitat, and life cycle of sand flies in the ISC.

View Article: PubMed Central - PubMed

Affiliation: a KalaCORE Programme (Consortium for the Control and Elimination of Visceral Leishmaniasis) , Dhaka , Bangladesh.

ABSTRACT

Background: Visceral leishmaniasis (VL), also known as kala-azar in the Indian sub-continent (ISC), is a major public health concern in Bangladesh, India, and Nepal, where it is caused by Leishmania donovani transmitted by the sand fly Phlebotomus argentipes. Various ecological parameters including air temperature, rainfall, wind speed, relative humidity, soil moisture, pH, and organic carbon are known to influence the oviposition of female sand flies, as well as the survival and development of larvae. However, more detailed knowledge on vector behavior, such as biting times, breeding places, and preferred hosts are needed to design optimal evidence-based vector control interventions.

Methods: In order to facilitate rational decisions regarding VL vector control, a systematic review was conducted to identify the prevailing practice and knowledge gaps in relation to vector bionomics and behavior. Search terms included 'sand fly bionomics', 'habitat', and 'visceral leishmaniasis/kala-azar vector control' using the Boolean operator AND to identify the country of interest, namely: Bangladesh, India, and Nepal. Both PubMed and Google search engines were used. Additional unpublished documents in the three countries were also analyzed.

Results: Information on the life cycle of VL vectors, their breeding behavior, infection rate with L. donovani, feeding behavior, and seasonal variation are useful for designing vector control operations. Unfortunately, none of the studies on the life cycle of P. argentipes was conducted in field settings of the ISC, so the publications from other locations had to be used for determining the duration of life cycle and development from egg to adult. However, information about breeding places, seasonal variation of vector densities, and 47 out of the selected 51 papers are available from the ISC and can be used for intelligent design of control operations.

Conclusion: Vector control services should undertake routine insecticide resistance monitoring and adapt indoor residual spraying rounds to the seasonality of vector densities. Further research is needed on potential animal reservoirs for L. donovani, on the breeding habitat, and life cycle of sand flies in the ISC.

No MeSH data available.


Related in: MedlinePlus