3.Seroepidemiological Study of Chagas Disease in the Southern Amazon Region of Ecuador
Angel G. Guevara ; Richard D. Atherton ; Michael A. Wauters ; Yosselin Vicuña ; Marcos Nelson ; Jose Prado ; Hirotomo Kato ; Manuel H. Calvopiña ; Yoshihisa Hashiguchi
Tropical Medicine and Health 2013;41(1):21-25
To determine the extent of Trypanosoma cruzi infection and/or transmission in the southern Amazon region of Ecuador, three indigenous communities in the provinces of Pastaza and Morona Santiago were serosurveyed. ChagatestTM, Immunocomb®II and immunofluorescent (IF) assays were used. Among the 385 inhabitants examined, nine (2.34%) were seropositive for T. cruzi infection. Of the nine positive sera, four (44.4%) fall in the 10–19, one each in the 20–29, 30–39 and 40–49, and two in the 50–59 age groups. These results suggested the possible existence of an autochthonous active T. cruzi transmission in the region and provide the first serological evidence for T. cruzi infection in the southern province of Morona Santiago bordering Peru. Further studies are needed in these Amazonian provinces to ascertain the spread of T. cruzi infection in the area.
4.Sand Fly Fauna (Diptera, Pcychodidae, Phlebotominae) in Different Leishmaniasis-Endemic Areas of Ecuador, Surveyed Using a Newly Named Mini-Shannon Trap
Kazue Hashiguchi ; Lenin Velez N. ; Hirotomo Kato ; Hipatia Criollo F. ; Daniel Romero A. ; Eduardo Gomez L. ; Luiggi Martini R. ; Flavio Zambrano C. ; Manuel Calvopina H. ; Abraham Caceres G. ; Yoshihisa Hashiguchi
Tropical Medicine and Health 2014;42(4):163-170
To study the sand fly fauna, surveys were performed at four different leishmaniasis-endemic sites in Ecuador from February 2013 to April 2014. A modified and simplified version of the conventional Shannon trap was named “mini-Shannon trap” and put to multiple uses at the different study sites in limited, forested and narrow spaces. The mini-Shannon, CDC light trap and protected human landing method were employed for sand fly collection. The species identification of sand flies was performed mainly based on the morphology of spermathecae and cibarium, after dissection of fresh samples. In this study, therefore, only female samples were used for analysis. A total of 1,480 female sand flies belonging to 25 Lutzomyia species were collected. The number of female sand flies collected was 417 (28.2%) using the mini-Shannon trap, 259 (17.5%) using the CDC light trap and 804 (54.3%) by human landing. The total number of sand flies per trap collected by the different methods was markedly affected by the study site, probably because of the various composition of species at each locality. Furthermore, as an additional study, the attraction of sand flies to mini-Shannon traps powered with LED white-light and LED black-light was investigated preliminarily, together with the CDC light trap and human landing. As a result, a total of 426 sand flies of nine Lutzomyia species, including seven man-biting and two non-biting species, were collected during three capture trials in May and June 2014 in an area endemic for leishmaniasis (La Ventura). The black-light proved relatively superior to the white-light with regard to capture numbers, but no significant statistical difference was observed between the two traps.
5.Findings and lessons from establishing Zika virus surveillance in southern Viet Nam, 2016
Lan Trong Phan ; Quang Chan Luong ; Thi Hong Hien Do ; Cindy H Chiu ; Thang Minh Cao ; Thao Thi Thanh Nguyen ; Hai Thanh Diep ; Thao Phuong Huynh ; Dung Tri Nguyen ; Nga Hong Le ; Satoko Otsu ; Phu Dac Tran ; Thuong Vu Nguyen ; Masaya Kato
Western Pacific Surveillance and Response 2019;10(2):22-30
Objective:
To document the evolution and optimization of the Zika virus (ZIKV) disease surveillance system in southern Viet Nam in 2016 and to describe the characteristics of the identified ZIKV-positive cases.
Methods:
We established a sentinel surveillance system to monitor ZIKV transmission in eight sites in eight provinces and expanded the system to 71 sites in 20 provinces in southern Viet Nam in 2016. Blood and urine samples from patients who met the case definition at the sentinel sites were tested for ZIKV using real-time reverse transcription polymerase chain reaction at the Pasteur Institute in Ho Chi Minh City (PI-HCMC). We conducted descriptive analysis and mapped the ZIKV-positive cases.
Results:
In 2016, 2190 specimens from 20 provinces in southern Viet Nam were tested for ZIKV at PI-HCMC; 626 (28.6%), 484 (22.1%), 35 (1.6%) and 1045 (47.7%) tests were conducted in the first, second, third and fourth quarters of the year, respectively. Of these tested specimens, 214 (9.8%) were ZIKV positive with 212 (99.1%) identified in the fourth quarter. In the fourth quarter, the highest positivity rate was those in age groups 30–39 years (30.0%) and 40–59 years (31.6%). Of the 214 ZIKV-positive patients, 210 (98.1%) presented with rash, 194 (90.7%) with fever, 149 (69.6%) with muscle pain, 123 (57.5%) with joint pain and 66 (30.8%) with conjunctivitis.
Discussion
The surveillance system for ZIKV disease underwent several phases of optimization in 2016, guided by the most up-to-date local data. Here we demonstrate an adaptable surveillance system that detected ZIKV-positive cases in southern Viet Nam.