Haemagogus

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Haemagogus
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Diptera
Family: Culicidae
Genus: Haemagogus
(Linnaeus, 1758)

Haemagogus, is a genus of mosquitoes belonging to the family Culicidae. They mainly occur in Central America and northern South America (including Trinidad), although some species inhabit forested areas of Brazil, and range as far as northern Argentina. In the Rio Grande Do Sul area of Brazil, one species, H. leucocelaenus, has been found carrying Yellow fever virus. Several species have a distinct metallic sheen.

Several species of this genus are vectors in the transmission of "sylvan" or "jungle yellow fever" which is often carried by monkeys in the forest canopies. Haemagogus spp. have also been found to carry the Mayaro virus and Ilheus virus.[1][2] As these mosquitoes, in general, have relatively long lives, they can transmit viruses for long periods.

They tend to live in the canopy of forests where the female lays eggs in between layers of tree bark or in cut bamboos. The eggs adhere to the surface and when submerged by rain water quickly develop into larva.

Species[edit]

[3]

Yellow fever epidemics involving Haemagogus spp.[edit]

The discovery of a sick Red Howler monkey by two scientists from the Trinidad Regional Virus Laboratory, (who was found to be suffering from yellow fever) in 1953 provided the first indication that yellow fever was still endemic in Trinidad although there had not been a case reliably reported from Trinidad since an outbreak in 1914.

It was discovered that a form of the disease "jungle yellow fever" was carried by Red Howler monkeys (Alouatta seniculus insulanus Elliot) who provided a continuous reservoir for the disease and spread by the Haemagogus s. spegazzini mosquito which normally inhabits rainforest regions, both at ground level and in the treetops.

After Government felling of large stands of native forest, yellow fever was isolated from a patient from Cumaca in the northern range in 1954. It soon began to spread to humans and be transmitted by the common Aedes aegypti mosquitoes.

Blood specimens were taken from over 4,500 humans in late 1953 and early 1954, and checked to detect the presence of a wide variety of known viruses. Over 15% showed antibodies to yellow fever and more human cases quickly followed.

Warnings were made that an epidemic was imminent and Wilbur Downs and Dr. A. E. (Ted) Hill, a specialist in Tropical medicine, began a program of inoculating health workers and stockpiling vaccine. Trinidad health authorities followed up with large-scale vaccination and intensive anti-aegypti measures including public education, regular inspection for breeding sites, and spraying of domestic residences with DDT. In spite of these measures, and the fact that an estimated 80% of the population of Port of Spain were immune to yellow fever and dengue, several more cases were soon reported. Most probably due to the health measures taken it did not develop into a widespread epidemic in Trinidad itself.

An attempt was made to totally quarantine the island just before Christmas, 1954, but the disease quickly spread to the nearby mainland of Venezuela and, from there, all the way to southern Mexico, probably killing several thousand people in the process.[4]

In 1998 an epidemic of Yellow Fever killed many Howler monkeys near the city of Altamira in eastern Amazonia, in Brazil. The virus was isolated in specimens of Haemagogus janthinomys.[5]

Footnotes[edit]

  1. ^ The Arthropod-borne Viruses of Vertebrates: An Account of The Rockefeller Foundation Virus program 1951-1970. 1973, pp. 133, 153. Max Theiler and W. G. Downs. Yale University. ISBN 0-300-01508-9.
  2. ^ [1]
  3. ^ [2]
  4. ^ The Arthropod-borne Viruses of Vertebrates: An Account of The Rockefeller Foundation Virus program 1951-1970. 1973, pp. 155-157. Max Theiler and W. G. Downs. Yale University. ISBN 0-300-01508-9.
  5. ^ "Isolation of Yellow Fever Virus from Nulliparous Haemagogus (Haemagogus) janthinomys in Eastern Amazonia" by B. Mondet, et al. in Vector-Borne and Zoonotic Diseases. March 1, 2002, 2(1): 47-50. Downloaded from: [3]

References[edit]

  • The Arthropod-borne Viruses of Vertebrates: An Account of The Rockefeller Foundation Virus program 1951-1970. 1973. Max Theiler and W. G. Downs. Yale University. ISBN 0-300-01508-9.
  • Global Mapping of Infectious Diseases: Methods, Examples and Emerging Applications. (1963). Edited by S. I. Hay, Alastair Graham, David J. Rogers. Updated edition with DVD 2007. Academic Press; Pbk/Dvdr R edition. ISBN 978-0-12-031764-6.

External links[edit]