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Malaria case in Madagascar, probable implication of a new vector, Anopheles coustani.

Nepomichene TN, Tata E, Boyer S - Malar. J. (2015)

Bottom Line: For An. funestus, in April 2013, the EIR was 0.13 ipm.The highest HBR value was observed for An. coustani, 86.13 ipm outdoors.The highest sporozoite rate was also for An. coustani, 9.5 % of An. coustani caught in stable was sporozoite positive.

View Article: PubMed Central - PubMed

Affiliation: Unité d'Entomologie Médicale, Institut Pasteur de Madagascar, BP 1274, Ambatofotsikely, 101, Antananarivo, Madagascar. Jthiery@pasteur.mg.

ABSTRACT

Background: Indoor spraying of insecticides and the use of insecticide-treated bed nets are key strategies for national malaria vector control in the central highlands of Madagascar. During the year 2013, malaria outbreaks were reported by the National Malaria Control Programme in the highlands, including the district of Ankazobe.

Methods: Entomological trapping was carried out in April and May 2013 and in March 2014, using human landing catches, collection of mosquitoes resting in stables and in houses by oral aspirators, and Centers for Disease Control and Prevention light traps. Detection of Plasmodium in mosquitoes was carried out on head and thorax of anopheline females by ELISA, CSP and PCR (Plasmodium falciparum, Plasmodium malariae, Plasmodium vivax, or Plasmodium ovale). Human biting rate (HBR), sporozoite index and entomological infection rate (EIR) were calculated for Anopheles funestus, Anopheles arabiensis, Anopheles mascarensis, and Anopheles coustani.

Results: In Ankazobe district, the presence of malaria vectors such as An. funestus, An. arabiensis and An. mascarensis was confirmed, and a new and abundant potential vector, An. coustani was detected. Indeed, one individual of An. funestus and two An. coustani were detected positive with P. falciparum while one An. mascarensis and four An. coustani were positive with P. vivax. For An. coustani, in March 2014, the EIR varied from 0.01 infectious bites/person/month (ipm) outdoors to 0.11 ipm indoors. For An. funestus, in April 2013, the EIR was 0.13 ipm. The highest HBR value was observed for An. coustani, 86.13 ipm outdoors. The highest sporozoite rate was also for An. coustani, 9.5 % of An. coustani caught in stable was sporozoite positive.

Conclusion: The implication of An. coustani in malaria transmission was not previously mentioned in Madagascar. Its very high abundance and the detection of Plasmodium coupled with an opportunistic feeding behaviour in villages with malaria cases supports its role in malaria transmission in Madagascar.

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Study sites
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Fig1: Study sites

Mentions: Entomological surveys were conducted in two communes: Kiangara and Marondry within the Ankazobe district (Fig. 1). The site of Andranovelona II (Site I, S 18°23′25.2′′/EO 47°01′00.0′′) was sampled in April and May 2013 whereas the sites of Bemasoandro (Site A, 17°S 57′26; 47°EO 02′60), Kianjasoa (Site B, 17°S 58′25; 47°EO 01′80), Ambohimiadana (Site C, 17°S 58′59; 47° EO 03′26), Ambohimanjaka (Site D, 17°S 59′27; 47°EO 02′07), Morafeno (Site E, 18°S 24′13; 47°EO 03′03), Miarinarivo Sud (Site F, 18°S 26′05; 47°EO 00′02), Voninahitrinitany (Site G, 18°S 31′50; 47°EO 01′42), and Tsarahonenana (Site H, 18°S 33′30; 47°EO 01′49) were sampled in March 2014 (Fig. 1). In April 2013, human landing catches (HLC), Centers for Disease Control and Prevention simple light traps (CDC LT), collection of mosquitoes resting indoors (MRI) and collection of mosquito resting in stables by oral aspirator were carried out. In May 2013 and March 2014, collection of mosquitoes resting in stables and HLC were carried out, respectively.Fig. 1


Malaria case in Madagascar, probable implication of a new vector, Anopheles coustani.

Nepomichene TN, Tata E, Boyer S - Malar. J. (2015)

Study sites
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4666205&req=5

Fig1: Study sites
Mentions: Entomological surveys were conducted in two communes: Kiangara and Marondry within the Ankazobe district (Fig. 1). The site of Andranovelona II (Site I, S 18°23′25.2′′/EO 47°01′00.0′′) was sampled in April and May 2013 whereas the sites of Bemasoandro (Site A, 17°S 57′26; 47°EO 02′60), Kianjasoa (Site B, 17°S 58′25; 47°EO 01′80), Ambohimiadana (Site C, 17°S 58′59; 47° EO 03′26), Ambohimanjaka (Site D, 17°S 59′27; 47°EO 02′07), Morafeno (Site E, 18°S 24′13; 47°EO 03′03), Miarinarivo Sud (Site F, 18°S 26′05; 47°EO 00′02), Voninahitrinitany (Site G, 18°S 31′50; 47°EO 01′42), and Tsarahonenana (Site H, 18°S 33′30; 47°EO 01′49) were sampled in March 2014 (Fig. 1). In April 2013, human landing catches (HLC), Centers for Disease Control and Prevention simple light traps (CDC LT), collection of mosquitoes resting indoors (MRI) and collection of mosquito resting in stables by oral aspirator were carried out. In May 2013 and March 2014, collection of mosquitoes resting in stables and HLC were carried out, respectively.Fig. 1

Bottom Line: For An. funestus, in April 2013, the EIR was 0.13 ipm.The highest HBR value was observed for An. coustani, 86.13 ipm outdoors.The highest sporozoite rate was also for An. coustani, 9.5 % of An. coustani caught in stable was sporozoite positive.

View Article: PubMed Central - PubMed

Affiliation: Unité d'Entomologie Médicale, Institut Pasteur de Madagascar, BP 1274, Ambatofotsikely, 101, Antananarivo, Madagascar. Jthiery@pasteur.mg.

ABSTRACT

Background: Indoor spraying of insecticides and the use of insecticide-treated bed nets are key strategies for national malaria vector control in the central highlands of Madagascar. During the year 2013, malaria outbreaks were reported by the National Malaria Control Programme in the highlands, including the district of Ankazobe.

Methods: Entomological trapping was carried out in April and May 2013 and in March 2014, using human landing catches, collection of mosquitoes resting in stables and in houses by oral aspirators, and Centers for Disease Control and Prevention light traps. Detection of Plasmodium in mosquitoes was carried out on head and thorax of anopheline females by ELISA, CSP and PCR (Plasmodium falciparum, Plasmodium malariae, Plasmodium vivax, or Plasmodium ovale). Human biting rate (HBR), sporozoite index and entomological infection rate (EIR) were calculated for Anopheles funestus, Anopheles arabiensis, Anopheles mascarensis, and Anopheles coustani.

Results: In Ankazobe district, the presence of malaria vectors such as An. funestus, An. arabiensis and An. mascarensis was confirmed, and a new and abundant potential vector, An. coustani was detected. Indeed, one individual of An. funestus and two An. coustani were detected positive with P. falciparum while one An. mascarensis and four An. coustani were positive with P. vivax. For An. coustani, in March 2014, the EIR varied from 0.01 infectious bites/person/month (ipm) outdoors to 0.11 ipm indoors. For An. funestus, in April 2013, the EIR was 0.13 ipm. The highest HBR value was observed for An. coustani, 86.13 ipm outdoors. The highest sporozoite rate was also for An. coustani, 9.5 % of An. coustani caught in stable was sporozoite positive.

Conclusion: The implication of An. coustani in malaria transmission was not previously mentioned in Madagascar. Its very high abundance and the detection of Plasmodium coupled with an opportunistic feeding behaviour in villages with malaria cases supports its role in malaria transmission in Madagascar.

Show MeSH
Related in: MedlinePlus