1779-1800: The first reports concerning dengue originate from the year 1779, during which it was observed at Java (Batavia), and about the same time at Cairo and Alexandria. During the years following, the reports of epidemic outbreaks accumulated. The disease prevailed in 1780 upon the coasts of Coromandel, of Arabia, and Persia.

Even at that time the disease made an isolated excursion over the subtropical zone, and during the hot summer of 1780 broke out suddenly in Philadelphia (40° N. Lat.).

During the year 1784 it appeared for the first time in Europe with epidemic outbreaks in Cadiz (36.5° N. Lat.) and Seville (37.5° N. Lat.). Most probably the disease was carried thither by troopships which came from the West Indies. A second epidemic broke out in Cadiz in 1788. At the end of the previous century dengue was reported from Grenada (Lesser Antilles). 1818: Epidemic in Lima (Peru).

1824-1828: With the years 1824-1825 a geographically extensive period of dengue begins, which gradually spread over a great portion of the tropical and subtropical zone.

Great epidemics on the western coast of Farther India (Rangoon) and on the eastern coast of India (Calcutta, Madras) ushered in this period in 1824. Soon the disease showed itself in Suez, on the sea route from India.

In the years 1826-1828 dengue spread itself in extensive epidemics over the greater portion of West India, the Virginian Isles, and the Greater and Lesser Antilles (Havana, 1826; St. Thomas, 1827).

From here numerous coast towns of Central America and of the most southern portion of North America and the most northern portion of South America were attacked (Havana, Charleston, New Orleans, Vera Cruz, the coast of Florida, and Venezuela). Isolated cases are alleged to have been observed at that time in New York and Boston, and notably again in Philadelphia, among the crew of a ship coming from Cuba. 1830-1870: During these four decads dengue is met with in large and small epidemics at numerous places in its tropical and subtropical area of distribution. The principal sites of the disease were:

Numerous coast towns of India (1830, 1835-1836, 1844-1847, 1853-1854).

Tahiti and other South Sea Islands (1852-1853). The coast of Arabia and northern Egypt (Alexandria, Cairo, Port Said).

The principal epidemic years here were 1835-1836, 1845, 1868. Furthermore:

Tripoli (1856), Cyprus, and Syria (1861).

Reunion (1851), Zanzibar and Madagascar (1864), Senegambia and Greece (1845-1848, 1856, 1865), the Canary Islands (1856).

Numerous West Indian Islands (1860-1863).

Central America, especially New Orleans, Savannah, Charleston, Iberville, New Iberia, Georgia and Louisiana, Mobile, the coast of Texas and Ohio (1839, 1844, 1848, 1850).

South America, Peru (1852), and Rio de Janeiro (1846-1848).

In Europe: Cadiz (1863, 1867).

Two facts stand out during this period in the geographic distribution of dengue. To begin with, its first important appearance in South America, namely, in Rio de Janeiro, where from 1846-1848 the disease prevailed yearly "on water and on land" during the hot season (December and January), and each time with considerable severity. Secondly is to be noticed that, during this period, Europe was twice attacked, and, as on the previous occasions of 1784, so too in 1863 and 1867, the harbor city of Cadiz in southern Spain became the center of an epidemic, which in both instances was brought in by troops returning from West India, the home of dengue. From Cadiz the disease spread to Xeres, Seville, and a few other cities of Andalusia, but the north remained exempt; in fact, in Spain, as a whole, the disease remained insignificant.

1871-1873: A very extensive outbreak of dengue occurred in the years 1871-1873, when it appeared first on the East African coast (Zanzibar), then on the Arabian coast (Aden, Jiddah, Mecca, Medina, and Tanyef), and in Port Said. From here it was carried by an emigrant steamer to Java, from Aden by a troop ship direct to Bombay, Kananur, and Calcutta. Following on this it spread through the countries of the Indian Ocean, Hindustan, especially in Calcutta and Madras, Rangoon, China, Formosa, Java, Celebes, and Sumatra. The last appearances in this important epidemic period occurred on the Persian coast, in the islands of Mauritius and Reunion, situated on the coast of eastern Africa, and, furthermore, in Tripoli and Senegambia. In the same year, 1873, epidemics took place in the southernv portion of North America bordering on the Gulf of Mexico, Louisiana, Alabama, etc.

1876-1888: During the year 1876 there was an epidemic in Hong-Kong. During the year 1878 the disease was brought to Ismailia (Suez Canal) by a pilgrim ship, and from this place it traveled to Alexandria and up the Nile. In the same year Malta was also infected by a troop ship from India. We further add: 1880, the ports of the Red Sea, especially Jiddah; 1880-1881, Cairo; 1881: Khania, to Crete and Syria; 1885-1886: the Fiji Islands; 1887, Gibraltar; 1888: Cyprus, and in the same year "whole Virginia" (Charlottesville).

Within this period fall numerous epidemic outbreaks in Syria, especially in Beirut, where, according to de Drum and Suquet, no fewer than fourteen epidemic years could be counted from 1861 to 1889.

1889: Of particular interest is the considerable distribution of dengue immediately preceding the influenza pandemic of 1889; in Syria and Palestine, in Asia Minor, Cyprus, Rhodes, Chios, and the islands of the Archipelago; furthermore, in Cairo and Ismailia. The disease spread "with incredible rapidity," and attacked now for the first time Damascus and Jerusalem.

From Beirut, Smyrna and Maghnissa were infected, and from the latter place Constantinople, and soon afterward the port of Pirseus and Athens. From Constantinople the disease was carried to the Pontine southern coast (Trapezunt) and to Varna and further still to Salonica.

On this occasion dengue continued even into the cool season (November), and in some places was almost continuous with the succeeding influenza. To this fact much importance must be attached; for if influenza and dengue were identical diseases, as they have so often erroneously been maintained to be, they would not have succeeded each other in such a short time-in Constantinople, Athens, and Salonica. But since dengue is a specific infectious disease sui generis, it also did not render the inhabitants of these cities immune against the approaching influenza coming from the north. Also in the Fiji islands in 1885 there existed an influenza and a dengue epidemic closely following and even overlapping each other.

1890-1895: During these periods only a few epidemic outbreaks are known. They affected Senegambia (St. Louis) in 1890, in 1893 the East Indian fleet, and in 1895 Hongkong.