TABLE III. (Cont'd.) Cases of specified notifiable diseases, United States, weeks ending February 27, 1988 and February 28, 1987 (8th Week)

* measles only, imported cases includes both out-of-state and international importations. lot notifiable U: Unavailable *International Out-of-state

TABLE III. (Cont'd.) Cases of specified notifiable diseases, United States, weeks ending February 27, 1988 and February 28, 1987 (8th Week)

*Mortality data in this table are voluntarily reported from 121 cities in the United states, most of which have populations of 100,000 or more. A death is reported by the place of its occurrence and by the week that the death certificate was filed. Fetal deaths are not included.

**Pneumonia and influenza.

†Because of changes in reporting methods in these 3 Pennsylvania cities, these numbers are partial counts for the current week. Complete counts will be available in 4 to 6 weeks.

††Total includes unknown ages.

§ Data not available. Figures are estimates based on average of past available 4 weeks.

AHC has been associated, on rare occasions, with neurological complications (3). Such complications were not reported during this outbreak, nor have they been reported in conjunction with CA24v-induced AHC in the past. The clinical characteristics of AHC caused by Ad11 are nearly identical to those caused by EV70 and CA24v, but the incubation period and the illness are slightly longer (1 ).

The etiologic agent of an outbreak of AHC can be identified by serologic studies of all three viruses and by isolation studies of Ad11 and CA24v. In recent years, EV70 has been difficult to isolate, even when cases have been serologically confirmed (1).

CA24v has caused large outbreaks of AHC in areas with tropical climates, such as Southeast Asia and the Indian Subcontinent (1). In 1986, CA24v was isolated in Taiwan, American Samoa (CDC, unpublished data), and India (4). CA24v was first isolated in the Western Hemisphere during the period October-November 1986, in, Trinidad, Jamaica, and St. Croix (5). Subsequently, CA24v has been isolated from patients with AHC in Panama (6) and Mexico (CDC, unpublished data). References

1. Hierholzer JC, Hatch MH. Acute hemorrhagic conjunctivitis. In: Darrell RW, ed. Viral diseases of the eye. Philadelphia: Lea & Febiger, 1985:165-96.

2. Melnick JL. Enteroviruses. In: Evans AS, ed. Viral infections of humans: epidemiology and control. 2nd ed. New York: Plenum Publishing, 1984:187-251.

3. Kono R, Miyamura K, Tajiri E, et al. Virological and serological studies of neurological complications of acute hemorrhagic fever in Thailand. J Infect Dis 1977;135:706-13.

4. ICMR Centre of Virology. An outbreak at [sic] acute viral conjunctivitis in October-November 1986. North Arcot District [India] Health Information 1986;Dec:6-7.

5. Centers for Disease Control. Acute hemorrhagic conjunctivitis caused by Coxsackievirus A24-Caribbean. MMWR 1987;36:245-6, 251.

6. Baynard V, ed. Aumento de conjunctivitis en la Region Metropolitana. Boletin Epidemiologico 1987;2(5):1-4.

Dengue and Dengue Hemorrhagic Fever in the Americas, 1986

Dengue activity in the American region was higher in 1986 than in other recent years. A total of 88,750 cases was reported (Table 1), whereas 68,998 cases had been reported in 1985, and 43,435, in 1984 (1,2). Because of underreporting in many countries, however, the 1986 figure is probably underestimated. In Brazil and Puerto Rico, for example, seroepidemiologic studies indicated that the actual number of dengue infections was many times higher than that reported.

As in previous years, three virus serotypes (DEN-1, DEN-2, and DEN-4) circulated in the region. DEN-2 had the most widespread distribution but was responsible only for small outbreaks in Suriname, French Guiana, and the U.S. Virgin Islands. DEN-1 and DEN-4 were again responsible for the major epidemics in which the virus serotypes were known. Four countries (Mexico, the Dominican Republic, Puerto Rico, and Venezuela) had three virus serotypes circulating simultaneously in 1986.

The large epidemic in Brazil in 1986 was caused by DEN-1. Transmission began in the Rio de Janeiro area in February and was confirmed in Fortaleza and Maceió on the northeastern coast by late summer. Seroepidemiologic studies carried out in two cities in the Rio de Janeiro area indicated that 216,480 dengue infections occurred between March and the end of May. Brazilian health authorities estimated the total number of dengue infections in 1986 at between 300,000 and 500,000.

Mexico continued to have high levels of dengue transmission in 1986, with outbreaks occurring in Veracruz in the east; Nuevo León in the north; Oaxaca in the south; Colima, Jalisco, and Nayarit on the west coast; and Puebla and Morelos in the central part of the country. Three dengue serotypes (DEN-1, DEN-2, and DEN-4) continued to circulate in Mexico, although the outbreaks were all associated with DEN-1 and DEN-4. Some outbreaks occurred at high altitudes (1,500 meters), in Oaxaca and Puebla.

Puerto Rico had a larger number of cases of dengue hemorrhagic fever (DHF) during the 1986 epidemic than at any other time in the past. Multiple virus serotypes (DEN-1, DEN-2, and DEN-4) circulated, but DEN-4 was the predominant virus. Peak transmission occurred during the period September-October, and most of the cases occurred in the San Juan metropolitan area. Officials received reports of 10,659 cases of dengue, but seroepidemiologic studies indicated that between 377,000 and 555,000 dengue infections occurred in 1986. These findings indicate considerable underreporting by the medical community.

Complete details of the dengue outbreaks in Colombia are not available. However, a mixed outbreak of DEN-1 and DEN-2 occurred in the port city of Tumaco in late 1985 and early 1986. Also, a DEN-1 epidemic in Cali began in late 1986 and continued into 1987.

Surveillance data for other countries in the region are incomplete. No information was made available from Guatemala and Belize. Low-level transmission was reported

TABLE 1. Cases of dengue in the Americas, by country, 1986