12,866 research outputs found
Anopheles gambiae larval habitats in an arid savanna village of Burkina Faso: characterization of bionomical parameters and potential markers of ecological niche partitioning among three sympatric taxa of the complex.
No full textMarino Artico, Paolo Amati, Laura Frontal
Evaluation of the impact of long lasting insecticidal nets (llins) on malaria transmission in Burkina Faso
No full textBackground. Malaria is the first parasitic disease in the world for mortality and
morbidity, recording the highest prevalence in sub-Saharan Africa with about 445.000
deaths and 2 million of new cases every year. LLINs are among the most effective
strategies in malaria control. LLIN three-year distribution campaigns, recommended by the
WHO, prevented 68% of the malaria cases in Africa, thanks to the combination of physical
barrier and insecticidal activity against vectors. Despite this success, the effectiveness of
LLINs in sub-Saharan Africa seems to be heterogeneous, since in some hyperendemic
countries like Burkina Faso (where the LLIN reached 70%) the malaria incidence and the
entomological infection rates are still very high. According to this scenario, from an
entomological survey conducted in the rural village of Goden (Burkina Faso) in 2011 - i.e
one year after the first LLINs distribution campaign - we detected unexpected high
Plasmodium Sporozoite Rates (SR) of 7.1% in malaria vectors. This suggests a partial
protective effect of LLINs in reducing transmission at population level in this area.
Objectives: we aim to evaluate the impact of LLINs on malaria transmission in Burkina
Faso, taking the opportunity of a new distribution of nets in 2019 considering two areas
differing for climate and vector species composition: Goden and Banfora. To this purpose,
through the period 2019-2021, several endpoints will be monitored in the villages:
entomological parameters (SR, human biting rates, insecticide resistance), local malaria
clinical information and bednet physic conditions. Moreover, a systematic review will be
conducted in order to investigate, at larger scale, possible correlation between malaria
annual incidence and the performance of different LLIN brands according to their local
usage in the country.
Preliminary and expected results. Data on mosquitoes collected in 2015 in Goden
shows a rate of 1.5 infective bites/person/night both inside and outside houses, confirming
partial protective effect of LLINs. Thus, the three-year entomological survey planned in
two representative settings, as well as the information gathered from meta-analysis on
different LLIN brands distributed in the country, will allow to measure the LLIN protective
effect at individual and community level and to point out possible limits in durability
(physical integrity, wash resistance, insecticide content) of LLINs used in Burkina Faso.
Future perspectives. This study could help to enlighten the reasons of LLINs reduced
efficacy in Burkina Faso and possibly in other countries of sub-Saharan Africa where this
tool seems to be ineffective, ultimately adding information of major importance in the
planning of appropriate country-based malaria control strategies
Mosquitoes (Culicidae)
No full textMosquitoes (Diptera, Culicidae) are the insect group that historically most influenced human activities, not only for their constant nuisance, but also for their primary role as vectors of pathogens for human and animal diseases. Increased global trade and human mobility, together with concomitant climate and environmental changes, allowed invasive mosquito species to successfully exploit passive means of dispersal and quickly adapt to a wide range of new environments, from natural to highly anthropized habitats. In this chapter, key aspects of mosquito biology and ecology are summarized, highlighting also their vector role as well as the state of the art of surveillance and control strategies
Aedes albopictus (Diptera: Culicidae) a Roma: analisi sperimentale di parametri rilevanti in strategie di controllo.
No full textNew entomological sampling method for the surveillance of vector-borne pathogens
No full textBackground. Vector-borne diseases account for more than 17% of all infectious diseases,
causing more than 1 million deaths annually. Global travel, trade and environmental
challenges can affect their transmission, causing the introduction or re-introduction of
pathogens in countries where they were unknown or eradicated. Early detection of pathogens
in arthropod vectors is highly important in prevention of vector-borne diseases and has the
potential of providing the timely indicator of pathogens circulation before reaching humans.
Objectives. The aim of this study is to develop a new entomological surveillance
approach that can be used in different contexts both of endemic and emerging vector borne
diseases areas. For this purpose, we propose a trapping system able to i) detect directly the
pathogen circulating in a specific area and preserve pathogen RNA/DNA in samples collected
without the need of cooling chain ii) work in autonomy without frequent servicing thus
reduce the economic and working effort, an essential feature in remote areas useful also in
other contexts.
Preliminary results. We have modified a trapping device for mosquito monitoring (BG
Sentinel) in which pathogen nucleic acids carried by infected specimens can be preserved for
several days at environmental temperature and subsequently molecularly detected. The trap
is provided with an artificial feeding system, based on the assumption that it is possible detect
pathogens in mosquito saliva released during a sugar meal directly on FTA card soaked with
a honey-based solution. We have tested the feeding system in laboratory and successively in
the field in an Italian endemic area for West Nile Virus (WNV) in order to evaluate i) the
best sugar solution and the feeding rate in mosquitoes ii) the modified BG trap’s efficiency
compared with CDC-CO2 trap, commonly used as gold standard in WNV surveillance iii) the
mosquito ability to release WNV on the feeder’s card in field conditions iv) the possibility to
molecularly detect the virus from the FTA card. Preliminary results confirm the ability of
mosquitoes to take a meal on FTA cards, baited with a mixture of honey, hydroxyl-ethylcellulose hydrogel and methylene blue, both in laboratory and field conditions. Also, WNV
is detectable in the cards from traps with infected mosquitoes, confirming a sufficient
sensitivity of the system for surveillance purposes.
Future perspectives. The next step is to validate the system in tropical areas with
circulation of different vectors and pathogens, such as Burkina Faso, a sub-Saharan country
endemic for malaria
Malaria in Italy - Migrants Are Not the Cause
No full textRecently, five cases of malaria werereported in Italy. These people hadnot travelled abroad, promptingsome media and political organiza-tions to fuel a climate of fear byconnecting the cases with migrantscoming into the country. Here, wediscuss scientific data highlightingthe limited risk of malaria reintro-duction in Italy
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