Anna Stewart
PLACA Summer Grant Report 2010
Overview
Dengue fever is a re-emerging public health threat across Latin America. The disease is caused by a virus
transmitted to humans by the Aedes aegypti mosquito. Since June 2010, I have been conducting field
research on the role of climatic and social risk factors in dengue fever transmission in Ecuador. In June
and July of 2010, with support from the PLACA summer grant, I began studying how dengue fever is
currently managed by the Ministry of Health in Ecuador. Guayaquil, the largest city in Ecuador, is
considered the epicenter of the dengue fever crisis, since the disease is transmitted year-round and all
four strains of the virus are co-circulating. Through informal interviews and field observations, I studied
(1) the structure of the different institutions within the Ministry of Health that play a role in dengue
fever management, (2) current vector (mosquito) control practices, and (3) current public health policy
regarding dengue fever management. I also began collaborating with the National Institute of
Meteorology and Hydrology to develop a climate-driven model of historical reported cases of dengue
fever. This collaboration led us to submit a grant proposal to the Ecuadorian government to support a 4
year research program on climate and health.
Preliminary results:
To my knowledge, there is no comprehensive national plan to manage dengue fever in Ecuador. The
country has adopted general guidelines put forth by the WHO, but has not developed a plan of action
that reflects the local reality. Many of officials were not aware of any national policy documents on
dengue fever.
Top officials at the National Service for the Control of Vector Borne Diseases (SNEM) in Guayaquil set the
national standards for vector control practices; however, there is significant variation in the
implementation of vector control practices across the country. Some felt that the top leadership at
SNEM was lacking in technical skill, since the positions are political appointments, and the people
selected to fill the positions often have limited prior experience in managing vector borne diseases.
Dengue fever management in Ecuador has focused on chemical methods (fumigation, larvicide) to
reduce Aedes aegypti populations. SNEM in Guayaquil not actively supported or implemented
alternative methods of vector control, such as biological control or community based management;
however, other provinces have experimented in alternative vector control methods on an ad hoc basis.
Dengue fever management is compartmentalized into three general areas overseen by three different
institutes of the Ministry of Health: (1) epidemiology (public health data) overseen by the SubSecretary
of the Ministry of Health, (2) virology (dengue fever diagnostics) overseen by the National Institute of
Hygiene, and (3) entomology (vector control) overseen by SNEM in Guayaquil. This
compartmentalization has led to tensions among the institutions and inefficient disease management
due to a weak information system. When a case of dengue fever is diagnosed by the National Institute
of Hygiene, they alert the SubSecretary, which in turn alerts SNEM. It can take over one week for SNEM
to be alerted of a positive case of dengue fever, at which time they can begin fumigation in the infected
zone. Ideally, all institutions would have access to a real time national database of reported cases of
disease. This would allow SNEM to be alerted immediately when a case of dengue fever was reported,
so that they could intervene in the infected zone and stop the chain of disease transmission by
eliminating the mosquito carrying the virus.
Ongoing Research
In September I began collaborating with SNEM in Machala, Ecuador, to continue my research on the
climatic and social factors influencing vulnerability to dengue fever. I am identifying social risk factors in
low and middle income neighborhoods in Machala through household surveys, interviews with
community members, and container surveys around the home to identify the presence of Aedes
aegypti. I am also exploring the role of climate on Aedes aegypti population dynamics by monitoring the
presence of Aedes aegpyti in 80 households every week from November to June. I am continuing my
research of the institutional factors influencing dengue fever management through semi-structured
interviews with public health officials at regional, national, and international institutions.
Expenditures:
I used my funding from PLACA to support my living expenses in Guayaquil, Ecuador, during June and July
2010. My primary expenses were taxi fares to and from meetings in Guayaquil, airfare to Quito to meet
with collaborators, groceries and other food, and phone cards for my local cell phone.