dengue cases may have been much higher than reportedResearchers estimate that each 12 dengue cases, only 1 He entered the official bulletins.
A study published in the journal of the Center in February for Disease Control and Prevention, linked to the US government, a team of Brazilian researchers suggests that official data on dengue cases in Brazil are underreported.
Researchers estimate that each 12 dengue cases, only 1 He entered the official bulletins of Disease Registry of the federal government in the period analyzed.
According to the study, the discrepancy is even greater in the months in which the transmission of the virus is low: decade 17 diagnoses made by scientists, only 1 It was reported to the government in this period.
The group came to this conclusion after analyzing 3,8 thousand cases of patients who were admitted in a public health unit in Salvador (BA), between January 2009 and December 2011, with high fever report, one of the symptoms of dengue.
After making two blood tests with fifteen days apart on each participant, the researchers detected the virus of dengue in 997 cases. However, that amount, only 57 They were recorded in the Information System for Notifiable Diseases (SINAN), Ministry of Health. That is, less than 6% of dengue cases entered the federal radar.
Worse, of more than 70% cases which test for dengue was negative, 26 They were reported to the Ministry of Health as carriers of the disease.
The clue to such discrepancy may be the way diagnoses are closed in Brazil, according to reports study coordinator, Guilherme de Sousa Ribeiro, professor at the Federal University of Bahia and researcher at Fiocruz, the newspaper El País.
Laboratory tests are not required to determine whether a person has dengue or not - so much so that in four survey respondents who reported fever, only one was subjected to laboratory tests in addition to those offered by the survey.
"The underreporting of dengue cases has been attributed to passive case detection, failing to identify people who do not seek medical care. We have shown that supervision also failed to detect dengue cases in symptomatic patients seeking medical help ", says study.
Among the measures proposed by the group to reduce underreporting is applying rapid testing of dengue in all patients with the symptoms - method not yet available in all public.
"Given the recent emergence of the virus Chikungunya and Zika, improvements in surveillance and laboratory diagnostics are needed to prevent misclassification and management of cases ", or text says.
Last year, Brazil broke record of diagnoses of people infected with the dengue virus. They were over 1,6 million confirmed cases.