Seroprevalence of Chikungunya Virus in a Rural Community in Brazil

Abstract

BackgroundThe emergence of the Chikungunya virus (CHIKV) is currently expanding. In 2015, 38,332 cases of Chikungunya were reported to the Brazilian epidemiological surveillance system. Eighteen months after notification of the first case in the city of Feira de Santana, we conducted the first serosurvey to define the magnitude of transmission in a rural community in Brazil.Methodology/Main findingsThe serosurvey was conducted in a random sample of 450 residences in the Chapada district, located 100 kilometers from Feira de Santana. We administered questionnaires and tested 120 sera from Chapada district residents for CHIKV IgM- and IgG-specific antibodies. An individual with CHIKV infection was defined as any person with CHIKV IgM or IgG antibodies detected in the serum. One Hundred cases of Chikungunya were reported after prolonged rainfall, which reinforced the relationship between the rainfall index and CHIKV transmission. Eighteen months after the start of the outbreak, we identified a seroprevalence of 20% (95% CI, 15.4–35%). CHIKV IgG- and IgM-specific antibodies were detected in 22/120 (18.3%) and 6/120 (5.0%) individuals, respectively. Among seropositive patients, 13/24 (54.2%) reported fever and joint pain over the previous two years (p<0.01). The rate of symptomatic CHIKV infection was 40.7%.Conclusions/SignificanceWe identified a moderate seroprevalence of Chikungunya in the Chapada district, and in half of the confirmed CHIKV infections, patients reported arthralgia and fever over the previous two years.

Chikungunya virus outbreak in the Amazon region: replacement of the Asian genotype by an ECSA lineage

“…We estimate that 39% (95% CI: 36 – 45)% of Roraima’s population was infected with CHIKV-ECSA-Br during the outbreak in 2017. Our estimates are higher than the 20% seropositive observed in a rural community in Bahia [10], and slightly lower than the 45.7 – 57.1% observed in two serosurveys conducted in the same state [12], where the ECSA lineage also seems to predominate. The observed differences in terms of the proportion of the population exposed to CHIKV in Roraima compared to previous estimates from the northeast region could result from partial protection resulting from low-level transmission of the CHIKV-Asian genotype during 2014 – 2016 in the north region.…”

“…If we assume 32.7 – 41.2% of the estimated infections are symptomatic, as previously reported in Bahia and Sergipe [53], then we estimate that the local observation success of symptomatic cases was between 12.8 – 16.1%. However, if we assume that 75 – 97% of people infected with CHIKV will develop symptomatic infections, as reported for the Indian Ocean lineage [10, 54, 55], then the chances of reported a symptomatic CHIKV case decrease to 5 – 7% [9]. Case reports suggest that the beginning of the exponential phase of the outbreak was in December 2016 ( Figure S4 ), while genetic data suggests that the outbreak clade emerged around July 2016.…”

“…Serological data from La Reunion, Philippines and the Indian Ocean island of Mayotte suggest that 75-97% of persons infected with CHIKV develop symptomatic infections [9]. Seroprevalence data from Brazil suggests that 45.7 to 57.1% Riachão do Jacuípe and of Feira de Santana, both located in Bahia state, were exposed to CHIKV in 2015, with a total of 32.7% to 41.2% of the population reporting symptoms [10].…”

Seroprevalence of Chikungunya among Febrile Patients in a Tertiary Care Hospital

“…The virus was first isolated in blood samples obtained during an epidemic of a "denguelike" disease that occurred between 1952 and 1953 in Tanzania (Cunha et al, 2017). CHIKV is an emerging arbovirus that is widespread in tropical regions and is spreading rapidly to temperate climates with recent epidemics in Africa and Asia and also documented outbreaks in Europe and America (Akinola et al, 2017).…”

Chikungunya fever: General and oral healthcare implications

“…As the clinical–epidemiological criteria used for the diagnosis of chikungunya fever (WHO, ) in epidemic situations show high agreement with the result of the specific serology for CHIKV (Marques et al., ; Marques et al., ,b), it is not recommended to perform this test for the diagnosis of uncomplicated cases. Because of the high attack rate of CHIKV (20% to 50% of the exposed population) (Cunha et al., ), performing specific serology for all cases is practically unfeasible from an economic point of view. For acute cases, the serology for CHIKV (IgM and IgG) should only be performed in atypical forms or in view of the need for differential diagnosis and should be requested from the 10th day of onset of symptoms.…”