CAREC Epinote
AN UPDATE OF DENGUE FEVER IN THE CARIBBEAN - 1998
October 5, 1998
See also Dengue Information (A Historical Background)
As at epidemiologic week number 38 of 1998 (week-ending September 26, 1998), 3,160
cases of dengue fever were reported to CAREC's Epidemiology Division from twelve member
countries for a sub-regional incidence rate of 49.5 cases per 100,000 population. This
figure includes a single cumulative report received from Suriname, which indicates the
occurrence of 1,015 suspected cases of dengue fever and 125 laboratory confirmed cases as
at August 14, 1998.
The epidemiologic pattern for 1998 is typical for the sub-region with a high incidence
of reported morbidity during the first quarter of the year, followed by a second quarter
(dry season) trough and a subsequent increasing third quarter (wet season) incidence [Figure 1]. Reported weekly morbidity during the first and
third quarters of 1998 are in excess of the threshold values, which are represented by 1.3
standard deviations above historic (1990-1997) means.
A review of CAREC's laboratory data indicates that over the same period, clinical
samples were referred for 1924 persons from fifteen member countries for diagnosis of
dengue fever. Of this number, 434 (22.5%) were laboratory confirmed as dengue fever.
Additionally, 30 persons with febrile rash illness, referred through the Measles
Elimination Surveillance system were also confirmed as having dengue fever. Based on
individual member country referrals, laboratory confirmation rates ranged from 12.5 % for
Grenada and St. Christopher/Nevis to 42.0% for St. Vincent and the Grenadines.
During the first quarter of 1998, dengue virus circulation was predominant in Barbados,
Trinidad and Tobago, Guyana and St. Vincent & the Grenadines [Figure 2 a-e]. During the second quarter viral activity was
observed in Suriname, while significant third quarter activity was recorded in Trinidad
and Tobago and the Bahamas.
During 1998, all four dengue virus types have been circulating in CAREC member
countries. While the type 3 virus has only been identified in Belize to date, the other
virus types have been recovered in other of our member countries [Table 1].
Together, the presence of multiple circulating virus types in populations where dengue
fever has been endemic and frequently epidemic within recent years; the high level of
Aedes aegypti infestation in many of our member countries; and the adequate opportunities
for spread of new virus types through travel of infected human hosts or introduction of
infected vectors, all facilitate the occurrence of new epidemics and the potential for
high morbidity and mortality due to dengue haemorrhagic fever and shock syndrome.
Against this background, our member countries are being reminded of the need for the
following:
