EID Updates:
Emerging and Reemerging Infectious Diseases,
Region of the Americas
Vol. 2, No. 24—12 August 2004
Main Updates index
- Cholera Confirmed in Colombia
- Cases of Hantavirus in Central Brazil in the Federal District and Goiás State
On 21 July 2004, the National Institute of Health of the Ministry of Social Protection in Colombia confirmed the isolation of Vibrio cholerae O1 El Tor, Ogawa serotype in stools of a man from the Candelillas district, in the municipality of Tumaco (Nariño). Symptoms started on 11 July 2004.
The epidemiologic field investigation identified one additional case from which Vibrio cholerae was isolated in the same district. Examination of the water from Quespi creek, which flows into the Mira River and supplies the water to this district and to San Andrés de Tumaco, yielded a positive result for Vibrio cholerae.
On 17 July, the Departmental Institute of Health in Nariño mobilized a commission to the Municipality of Tumaco to jointly evaluate and prepare a Contingency Plan for intervention in public health surveillance (epidemiology, patient care, and laboratory), basic sanitation (food protection, water and excreta disposal) and for the strengthening of information, education and communication actions.
In light of the importance of this event, and due to this bacterium’s high potential for causing outbreaks, prevention and control measures have been targeted toward the municipalities of the Pacific coast in general and all the municipalities in the department of Nariño.
As of 12 August, no more clinical cases of cholera have been confirmed nor have been isolated in other samples, and no deaths have been registered.
Source: Ministry of Social Protection, Colombia, 11 August 2004.
Cases of Hantavirus in Central Brazil in the Federal District and Goiás State
Between May and the second week of August 2004, 17 cases of Hantavirus Cardio-Pulmonary Syndrome were reported in people living in the Federal District (Brasília, Distrito Federal / DF). Nine deaths have taken place, with a case-fatality rate of 53% (see Table 1 below).
Four additional cases of the disease were confirmed in residents in the State of Goiás, with two deaths (50%) (see Table 2 below). This is the first report of hantavirus in this region of the country.
Table 1: Distribution of Cases by Place of Residence and Outcome, DF
| Place of Residence in the DF | Deaths | Total Cases |
| São Sebastião | 4 | 10 |
| Paranoá | 1 | 2 |
| Guará | 1 | 1 |
| Ceilândia | 1 | 1 |
| Sobradinho | 1 | 1 |
| Recanto das Emas | -- | 1 |
| Brasília | 1 | 1 |
| Total | 9 | 17 |
Source: Ministry of Health, Brazil, 10 August 2004. | ||
Table 2: Distribution of Cases by Place of Residence and Outcome, Goiás State
| Place of Residence in Goiás | Deaths | Total Cases |
| Cristalina | 1 | 2 |
| São Antônio do Descoberto | 1 | 1 |
| Valparaíso | -- | 1 |
| Total | 2 | 4 |
Source: Ministry of Health, Brazil, 10 August 2004. | ||
In the municipality of São Sebastião, there is evidence that transmission occurred in its rural area, where wild infected rodents were found. For the residents of the other municipalities, including Brasilia, the place of transmission is still being established. The difficulty of this determination lies in the disease’s long incubation periods of up to 60 days, forcing a search of all places where the individuals could have been exposed to wild rodents during this period.
The first detected cases occurred in the second half of May (on the 23rd); however, retrospective investigations indicated the occurrence of cases since the month of April in the two federal units (states).
All the municipalities with confirmed cases belong to a typically closed biome (with low vegetation and shrubs), that has abundant presence of Brachiaria grasses. The presence of the species Bolomys lasiurus was identified, and samples obtained from these rodents yielded positive serology for hantavirus. This evidence, together with hantavirus isolation from these animals in outbreaks in other Brazilian states with similar biome characteristics, suggests that this is the reservoir involved with the outbreak.
During the week of 9 August, control measures have been intensified, with recommendations regarding preventive measures for the population, training of health professionals to improve patient care, mobilization of fire departments to carry out educational campaigns in rural areas, and the preparation of an Emergency Plan for the control of hantavirus.
One of the main hypotheses for the occurrence of this outbreak was the intensity and the length of the rainy season (from November to March), leading to abundance of food for the wild rodents that its reproduction. This, together with the intense urban expansion and occupation of the periurban area of the Federal District by weekend houses, provide a greater probability of contact of the wild rodents with human beings.
Source: Ministry of Health, Brazil, 10 August 2004.