TY - JOUR
T1 - Households as foci for dengue transmission in highly urban Vietnam
AU - Anders, Katherine
AU - Le, Hong Nga
AU - Nguyen, Thi Van Thuy
AU - Tran, Van Ngoc
AU - Cao, Thi Tam
AU - Luong, Thi Hue Tai
AU - Nguyen, Thanh Truong
AU - Huynh, Thi Le Duyen
AU - Trung, Vu Tuan
AU - Kien, Duong Thi Hue
AU - Wolbers, Marcel
AU - Wills, Bridget
AU - Chau, Nguyen Van Vinh
AU - Nguyen, Dac Tho
AU - Simmons, Cameron P
PY - 2015
Y1 - 2015
N2 - Background Dengue control programs commonly employ reactive insecticide spraying around houses of reported cases, with the assumption that most dengue virus (DENV) transmission occurs in the home. Focal household transmission has been demonstrated in rural settings, but it is unclear whether this holds true in dense and mobile urban populations. We conducted a prospective study of dengue clustering around households in highly urban Ho Chi Minh City, Vietnam. Methods We enrolled 71 index cases with suspected dengue (subsequently classified as 52 dengue cases and 19 non-dengue controls); each initiated the enrollment of a cluster of 25?35 household members and neighbors who were followed up over 14 days. Incident DENV infections in cluster participants were identified by RT-PCR, NS1-ELISA, and/or DENV-IgM/-IgG seroconversion, and recent infections by DENV-IgM positivity at baseline. Principal Findings/Conclusions There was no excess risk of DENV infection within dengue case clusters during the two-week follow-up, compared to control clusters, but the prevalence of recent DENV infection at baseline was two-fold higher in case clusters than controls (OR 2.3, 95 CI 1.0?5.1, p = 0.05). Prevalence of DENV infection in Aedes aegypti was similar in case and control houses, and low overall (1 ). Our findings are broadly consistent with household clustering of dengue risk, but indicate that any clustering is at a short temporal scale rather than sustained chains of localized transmission. This suggests that reactive perifocal insecticide spraying may have a limited impact in this setting.
AB - Background Dengue control programs commonly employ reactive insecticide spraying around houses of reported cases, with the assumption that most dengue virus (DENV) transmission occurs in the home. Focal household transmission has been demonstrated in rural settings, but it is unclear whether this holds true in dense and mobile urban populations. We conducted a prospective study of dengue clustering around households in highly urban Ho Chi Minh City, Vietnam. Methods We enrolled 71 index cases with suspected dengue (subsequently classified as 52 dengue cases and 19 non-dengue controls); each initiated the enrollment of a cluster of 25?35 household members and neighbors who were followed up over 14 days. Incident DENV infections in cluster participants were identified by RT-PCR, NS1-ELISA, and/or DENV-IgM/-IgG seroconversion, and recent infections by DENV-IgM positivity at baseline. Principal Findings/Conclusions There was no excess risk of DENV infection within dengue case clusters during the two-week follow-up, compared to control clusters, but the prevalence of recent DENV infection at baseline was two-fold higher in case clusters than controls (OR 2.3, 95 CI 1.0?5.1, p = 0.05). Prevalence of DENV infection in Aedes aegypti was similar in case and control houses, and low overall (1 ). Our findings are broadly consistent with household clustering of dengue risk, but indicate that any clustering is at a short temporal scale rather than sustained chains of localized transmission. This suggests that reactive perifocal insecticide spraying may have a limited impact in this setting.
UR - http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4332484/pdf/pntd.0003528.pdf
U2 - 10.1371/journal.pntd.0003528
DO - 10.1371/journal.pntd.0003528
M3 - Article
SN - 1935-2727
VL - 9
JO - PLoS Neglected Tropical Diseases
JF - PLoS Neglected Tropical Diseases
IS - 2
M1 - e0003528
ER -
