Update: Aedes albopictus Infestation -- United States, Mexico
Aedes albopictus, a mosquito of Asian origin, was discovered in
Texas
in 1985 (1,2). This mosquito transmits dengue virus in Asia (3,4)
and
under laboratory conditions can transmit pathogenic viruses
indigenous
to the United States (5).
Surveillance for Ae. albopictus in the eastern United States was
initiated in 1986; by 1988, infestations had been found in 113
counties
in 17 states (Figure 1, page 445) (6-8). In 1988, the mosquito was
also
found in a tire in Matamoros, Mexico. This is the southernmost
identification of Ae. albopictus in North America; however,
subsequent
surveys in Matamoros have not detected further evidence of
infestation.
Separate infestations of Ae. albopictus, originating from tropical
Asia, have been established in four Brazilian states (6).
Ae. albopictus was probably introduced into the United States in
used-tire casings imported from Asia (9). On January 1, 1988, new
regulations were implemented to control the importation of
used-tire
casings originating in Asian countries. These regulations require
that
used-tire casings be clean and dry and be treated by one of three
approved fumigation procedures. During 1988, 34 (0.5%) of 6533
casings
examined in U.S. ports contained water--a 98% reduction from levels
found in earlier surveys (9). During 1988, no viruses were isolated
from 10,679 Ae. albopictus specimens from Indiana, Illinois,
Tennessee,
and Louisiana.
Reported by: State and local health and vector-control agencies in
Alabama, Arkansas, Delaware, Florida, Georgia, Illinois, Indiana,
Kentucky, Louisiana, Maryland, Mississippi, Missouri, North
Carolina,
Ohio, Oklahoma, South Carolina, Tennessee, Texas, and Virginia. KJ
Tennessen, Tennessee Valley Authority, Muscle Shoals, Alabama. TW
Walker, Aberdeen Proving Ground, Maryland. J Sepulveda-Amor, MD,
Direccion General de Epidemiologia, J Fernandez de Castro, MD,
Direccion General de Medicina Preventiva, Secretaria de Salubridad,
Mexico City, Mexico. Div of Quarantine, Center for Prevention Svcs;
Div
of Vector-Borne Viral Diseases, Center for Infectious Diseases,
CDC.
Editorial Note
Editorial Note: The public health importance of the introduction
and
infestation of Ae. albopictus in the United States remains
undetermined. The potential for Ae. albopictus to transmit certain
pathogenic arboviruses indigenous to the United States has been
proven
in laboratory experiments (5); however, disease transmission by
this
mosquito in natural settings has not been documented. La Crosse
virus,
a leading cause of childhood encephalitis in the upper and
midwestern
United States, is usually restricted to rural areas by the behavior
of
its principal vector mosquito, although the virus could extend to
urban
centers if carried by Ae. albopictus. La Crosse virus has not been
isolated from Ae. albopictus, and no case of encephalitis has been
epidemiologically attributed to this mosquito.
The potential for dengue virus transmission in the United States
by
Ae. albopictus is of particular concern. The principal vector of
dengue
virus, Ae. aegypti, is prevalent throughout the Southeast but
cannot
overwinter in northern states. However, because Ae. albopictus can
overwinter as far north as latitude 42 N and in summer can extend
even
farther north, the risk for epidemic dengue in the United States is
heightened.
In suburban areas of New Orleans with abundant vegetation, Ae.
albopictus has replaced Ae. aegypti and has become the principal
source
of mosquito complaints to the health department. Ae. aegypti
remains
dominant in urban areas where housing density is high and
vegetation is
sparse.
Although Ae. albopictus now is entrenched in the United States,
continued monitoring of imported used-tire casings is needed to
prevent
further introductions of this mosquito and to prevent the
introduction
of other exotic mosquito species and Asian arboviruses (9). Spot
surveys support the effectiveness of the new regulations regarding
the
importation of tires from Asia.
References
Sprenger D, Wuithiranyagool T. The discovery and distribution of
Aedes albopictus in Harris County, Texas. J Am Mosq Control Assoc
1986;2:217-9.
Jumali, Sunarto, Gubler DJ, Nalim S, Eram S, Sulianti Saroso J.
Epidemic dengue hemor rhagic fever in rural Indonesia:
III--Entomological studies. Am J Trop Med Hyg 1979; 28:717-24.
Metselaar D, Grainger CR, Oei KG, et al. An outbreak of type 2
dengue fever in the Seychelles, probably transmitted by Aedes
albopictus (Skuse). Bull WHO 1980;58:937-43.
Shroyer DA. Aedes albopictus and arboviruses: a concise review
of
the literature. J Am Mosq Control Assoc 1986;2:424-8.
CDC. Update: Aedes albopictus infestation--United States. MMWR
1986;35:649-51.
CDC. Update: Aedes albopictus infestation--United States. MMWR
1987;36:769-73.
Craven RB, Eliason DA, Francy DB, et al. Importation of Aedes
albopictus and other exotic mosquito species into the United States
in
used tires from Asia. J Am Mosq Control Assoc 1988;4:138-42.
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