Anopheles deaneorum: a new potential malaria vector in State of Santa Catarina, Brazil (Diptera: Culicidae)

Dear Editor,

Although the vast majority of malaria cases in Brazil occur at Amazonian region, imported and autochthonous cases also occur at the State of Santa Catarina¹. The healthcare professionals of this state are probably not prepared to diagnose and treat malarial cases², and this could even be life-threatening³.

Even after the malaria control program, several Anopheline species are being reported for the state4, and Anopheles cruzii, well adapted to primary and secondary forests, is the greatest potential vector. The previous report of Anopheles deaneorum at eight municipalities of Santa Catarina⁴ has a great significance, but was poorly detailed and probably has not received enough attention though. Mosquitoes belonging to this species, of Anopheles albitarsis complex, are highly anthropophilic⁵ and as susceptible to experimental infection with Plasmodium vivax ⁶ and Plasmodium falciparum ⁷ as <i>Anopheles darlingi</i>, being found naturally infected with both Plasmodium species at the State of Rondônia, Brazil⁸.

At October 8th, 2012, a gathering was performed in the twilight near the headquarters of the Parque Estadual da Serra do Tabuleiro (headquarters' coordinates: 27°50'35.70"S, 48°37'35.76"W), at the locality of Baixada do Maciambu (Palhoça Municipality). The gathering was accomplished using a lamp with the Shannon Trap and a device to suck mosquitoes and blow them into plastic boxes⁹ (coordinates: 27°50'42.60"S, 48°37'38.76"W). In just half an hour, among the hundreds of mosquitoes flying under the trap's flaps, we captured 55 specimens of A. deaneorum, which were either landing in the trap's cloth or trying to bite the gatherers. Several of them bit those gatherers at the laboratory, in the following days, for the obtainment of eggs.

The area of collection has arboreal and bushy vegetation typical of the Restinga (Southern Brazilian Coastal Sandy Vegetation) areas, having well cared trails for the visitors and also wetlands, being located 40km from the downtown of Florianópolis (Capital of State of Santa Catarina) and 8.5km from the Pinheira Beach, which is a heavily inhabited area, especially at the summer. Although the period of collection was short, the collected quantity indicates a great population of this mosquito in the area and a risk of bites and transmission of malaria parasites to be evaluated.

Anopheles deaneorum was previously reported in Brazil in the Amazonian region and Central-West regions, at the western area the States of Paraná and São Paulo, apart from reports at Paraguay, Bolivia and at the north of Argentina. Therefore this report and the one from Portes et al.4, in which six of the studied municipalities are at the east area of the state, extend considerably the known geographic distribution of the species.

Aside from Anopheles deaneorum, there were gathered specimens of Anopheles rondoni, Anopheles rachoui, Coquillettidia shannoni, Psorophora ciliata and Ochlerotatus 'Scapularis Group', amounting 136 mosquito specimens.

Since the Restinga (Southern Brazilian Coastal Sandy Vegetation) areas are widely distributed along the coastal area of the state, there is greater potential for the contact of human populations with the mosquitoes in those areas than at forest areas, and the plentiful presence of this potential vector represents a great risk of malaria transmission. This mosquito is associated with great collections of water and can be very common at households in Rondônia¹⁰. The development of studies on the biology and geographic distribution of this mosquito at the east of Santa Catarina is urgent, to better evaluate the potential risk, besides being of fundamental importance to improve and maintain the epidemiological vigilance in that part of the state. The susceptibility of the mosquitoes from the state to samples of human Plasmodium species shall be tested.

The finding of this mosquito at the Indaial municipality⁴, where Plasmodium-infected howler monkeys have been reported, should be emphasized. Since the vertical distribution of A. deaneorum is not known, Anopheles cruzii, which moves easily between soil and canopy¹¹, continues to be the prime suspect as the responsible for Plasmodium transmission between monkeys and to humans at Santa Catarina¹².

REFERENCES

• ¹
  Machado RLD, Couto AARA, Cavasini CE, Calvosa VSP. Malária em região extra-amazônica: situação no Estado de Santa Catarina. Rev Soc Bras Med Trop 2003; 36:581-586.
• ²
  Marcondes CB, Marchi MJ. Estão os médicos de fora da Amazônia preparados para diagnosticar e tratar malária? Rev Soc Bras Med Trop 2010; 43:477.
• ³
  Costa AP, Bressan CS, Pedro RS, Valls-de-Souza R, Silva PRSS, et al. Diagnóstico tardio de malária em área endêmica de dengue na extra-Amazônia Brasileira: experiência recente de uma unidade sentinela no estado do Rio de Janeiro. Rev Soc Bras Med Trop 2010; 43:571-574.
• ⁴
  Portes MG, Rossi JC, Nascimento JC, Zeccer S, Silva LA. Anofelinos de Santa Catarina (Diptera: Culicidae), Brasil. Rev Soc Bras Med Trop 2010; 43:156-160.
• ⁵
  Klein TA, Lima JB Tang AT. Biting behavior of Anopheles mosquitoes in Costa Marques, Rondonia, Brazil. Rev Soc Bras Med Trop 1991; 24:13-20.
• ⁶
  Klein TA, Lima JB, Tada MS, Miller R. Comparative susceptibility of anopheline mosquitoes in Rondonia, Brazil to infection by Plasmodium vivax. Am J Trop Med Hyg 1991; 45:463-470.
• ⁷
  Klein TA, Lima JB, Tada MS. Comparative susceptibility of anopheline mosquitoes to Plasmodium falciparum in Rondonia, Brazil. Am J Trop Med Hyg 1991; 44:598-603.
• ⁸
  Branquinho MS, Lagos CB, Rocha RM, Natal D, Barata JM, Cochrane AH, et al. Anophelines in the state of Acre, Brazil, infected with Plasmodium falciparum, P. vivax, the variant P. vivax VK247 and P. malariae. Trans R Soc Trop Med Hyg 1993; 87:391-394.
• ⁹
  Marcondes CB, Alencar J, Balbino VQ, Guimarães AE. Description of three practical and inexpensive devices for the collection of mosquitoes and other small insects. J Am Mosq Control Assoc 2007; 23:84-86.
• ¹⁰
  Santos JB, Santos F, Macêdo V. Variação da densidade anofélica com o uso de mosquiteiros impregnados com deltametrina em uma área endêmica de malária na Amazônia Brasileira. Cad Saude Publica 1999; 15:281-292.
• ¹¹
  Deane LM, Ferreira Neto JA, Lima MM. 1984 The vertical dispersion of Anopheles (Kerteszia) cruzii in a forest in southern Brazil suggests that human cases of malaria of simian origin might be expected. Mem Inst Oswaldo Cruz 1971; 79:61-63.
• ¹²
  Deane LM, Deane MP, Ferreira-Neto JA, Almeida FB. On the transmission of simian malaria in Brazil. Rev Inst Med Trop 1971; 13:311-319.

Publication Dates

• Publication in this collection
  Jan-Feb 2013

History

• Received
  22 Oct 2012
• Accepted
  29 Nov 2012