Spatial distribution of Zika virus infection in Northeastern Colombia.

In this study, we investigated the weekly reported spatio-temporal distribution and topographic risk factors for Zika virus (ZIKV) infection in northeastern Colombia. Weekly reported surveillance data, including clinical, suspected and confirmed cases from the ongoing ZIKV epidemic in the Santander and Norte de Santander departments (Santanderes) in Colombia were used to estimate cumulative incidence rates. Spatial analysis was performed to develop hot spot maps and to identify spatial topographic risk factors for infection. From January 1, 2016 to March 19, 2016, 11,515 cases of ZIKV were reported in Santanderes, with cumulative rates of 316.07 cases/100,000 population for the region (representing 18.5% of the cases of the country). Five municipalities (four in Norte de Santander) reported high incidence of ZIKV infection (>1,000 cases/100,000 pop); these municipalities are close to the border with Venezuela. Most of the cases reported occurred mainly in low altitude areas, and persistent hot spots were observed. Higher infection rates were reported in the Northeastern part of the study area. Use of risk maps can help guide decisions for the prevention and control of ZIKV. Hotspots on the Colombia-Venezuela border can have implications for international spread.

Mapping the ecoepidemiology of Zika virus infection in urban and rural areas of Pereira, Risaralda, Colombia, 2015-2016: Implications for public health and travel medicine.

OBJECTIVE: Geographical information systems (GIS) have been demonstrated earlier to be of great use to inform public health action against vector-borne infectious diseases. METHODS: Using surveillance data on the ongoing ZIKV outbreak from Pereira, Colombia (2015-2016), we estimated incidence rates (cases/100,000 population), and developed maps correlating with the ecoepidemiology of the area. RESULTS: Up to October 8, 2016, 439 cases of ZIKV were reported in Pereira (93 cases/100,000 pop.), with highest rates in the South-West area. At the corregiments (sub-municipalities) of Pereira, Caimalito presented the highest rate. An urban area, Cuba, has 169 cases/100,000 pop., with a low economical level and the highest Aedic index (9.1%). Entomological indexes were associated with ZIKV incidence at simple and multiple non-linear regressions (r2 > 0.25; p < 0.05). CONCLUSIONS: Combining entomological, environmental, human population density, travel patterns and case data of vector-borne infections, such as ZIKV, leads to a valuable tool that can be used to pinpoint hotspots also for infections such as dengue, chikungunya and malaria. Such a tool is key to planning mosquito control and the prevention of mosquito-borne diseases in local populations. Such data also enable microepidemiology and the prediction of risk for travelers who visit specific areas in a destination country.

Estimating and mapping the incidence of dengue and chikungunya in Honduras during 2015 using Geographic Information Systems (GIS).

Geographical information systems (GIS) use for development of epidemiological maps in dengue has been extensively used, however not in other emerging arboviral diseases, nor in Central America. Surveillance cases data (2015) were used to estimate annual incidence rates of dengue and chikungunya (cases/100,000 pop) to develop the first maps in the departments and municipalities of Honduras. The GIS software used was Kosmo Desktop 3.0RC1®. Four thematic maps were developed according departments, municipalities, diseases incidence rates. A total of 19,289 cases of dengue and 85,386 of chikungunya were reported (median, 726 cases/week for dengue and 1460 for chikungunya). Highest peaks were observed at weeks 25th and 27th, respectively. There was association between progression by weeks (p<0.0001). The cumulated crude national rate was estimated in 224.9 cases/100,000 pop for dengue and 995.6 for chikungunya. The incidence rates ratio between chikungunya and dengue is 4.42 (ranging in municipalities from 0.0 up to 893.0 [San Vicente Centenario]). Burden of both arboviral diseases is concentrated in capital Central District (>37%, both). Use of GIS-based epidemiological maps allow to guide decisions-taking for prevention and control of diseases that still represents significant issues in the region and the country, but also in emerging conditions.

Mapping Zika virus disease incidence in Valle del Cauca.

OBJECTIVE: Geographical information systems (GIS) use for development of epidemiological maps in tropical diseases is increasingly frequently utilized. Here, we apply this technique to map the current Zika virus (ZIKV) outbreak in Colombia. METHODS: Surveillance cases data of the ongoing epidemic of ZIKV in Valle del Cauca department and its capital, Cali (2015-2016), were used to estimate cumulated incidence rates (cases/100,000 population) to develop the first maps in the department and it municipalities. The GIS software used was Kosmo Desktop 3.0RC1®. Three thematic incidence rate maps were developed. RESULTS: Up to April 2, 2016, 9,825 cases of ZIKV were reported (15.15 % of the country cases). The burden of ZIKV infection has been concentrated in the North of the department. Valle del Cauca borders with other departments with incidence of ZIKV infection, such as Quindío (173 cases) and Risaralda (687 cases). Eleven municipalities of Valle del Cauca had cases in the range between 250 and 499 cases/100,000, all in the North and East of the department. Cali, the capital concentrates more than a third of the reported cases of ZIKV in Valle del Cauca. CONCLUSIONS: Use of GIS-based epidemiological maps allows to guide decision-making for prevention and control of diseases that constitute significant public health problems in the region and the country, such as exemplified by the emergence of ZIKV infection, particularly in departments such as Valle del Cauca with a high disease incidence.

Estimating and mapping the incidence of giardiasis in Colombia, 2009-2013.

BACKGROUND: Giardiasis is one of the most common intestinal infections in the world. There have been no national studies on the morbidity of giardiasis in Colombia. In this study, incidence rates of giardiasis were estimated for the years 2009-2013. METHODS: An observational, retrospective study of the giardiasis incidence in Colombia, 2009-2013, was performed using data extracted from the personal health records system (Registro Individual de Prestación de Servicios, RIPS). Official population estimates from the National Department of Statistics (DANE) were used for the estimation of crude and adjusted incidence rates (cases/100 000 population). RESULTS: During the period studied, 15 851 cases were reported (median 3233/year; 5-year cumulated crude national rate of 33.97 cases/100 000 population). Of these, 50.3% were female; 58.4% were <10 years old and 14.8% were 10-19 years old. By region, 17.7% were from Bogotá (10.07 cases/100 000 population, 2009), 10.9% from Antioquia (9.42, 2009), 8.6% from Atlántico (15.67, 2009), and 6.5% from Risaralda (33.38, 2009). Cases were reported in all departments (even insular areas). CONCLUSIONS: As giardiasis is neglected in many countries, surveillance is not regularly undertaken. Despite its limitations, this study is the first attempt to provide estimates of national giardiasis incidence with consistent findings regarding affected age groups and geographical distribution.

Mapping Zika virus infection using geographical information systems in Tolima, Colombia, 2015-2016.

OBJECTIVE: Geographical information systems (GIS) have been extensively used for the development of epidemiological maps of tropical diseases, however not yet specifically for Zika virus (ZIKV) infection. METHODS: Surveillance case data of the ongoing epidemics of ZIKV in the Tolima department, Colombia (2015-2016) were used to estimate cumulative incidence rates (cases/100,000 pop.) to develop the first maps in the department and its municipalities, including detail for the capital, Ibagué. The GIS software used was Kosmo Desktop 3.0RC1®. Two thematic maps were developed according to municipality and communes incidence rates. RESULTS: Up to March 5, 2016, 4,094 cases of ZIKV were reported in Tolima, for cumulated rates of 289.9 cases/100,000 pop. (7.95% of the country). Burden of ZIKV infection has been concentrated in its east area, where municipalities have reported >500 cases/100,000 pop. These municipalities are bordered by two other departments, Cundinamarca (3,778 cases) and Huila (5,338 cases), which also have high incidences of ZIKV infection. Seven municipalities of Tolima ranged from 250-499.99 cases/100,000 pop., of this group five border with high incidence municipalities (>250), including the capital, where almost half of the reported cases of ZIKV in Tolima are concentrated. CONCLUSIONS: Use of GIS-based epidemiological maps helps to  guide decisions for the prevention and control of diseases that represent significant issues in the region and the country, but also in emerging conditions such as ZIKV.

Mapping malaria in municipalities of the Coffee Triangle region of Colombia using Geographic Information Systems (GIS).

Geographical Information Systems (GIS) have been used extensively for the development of epidemiological maps of malaria but not in the Coffee Triangle region of Colombia, endemic for P. vivax, P. falciparum and P. malariae. Surveillance case data (2007-2011) were used to estimate annual incidence rates per Plasmodium spp. (cases/100,000 pop) to develop the first malaria maps in the 53 municipalities of this region (departments Caldas, Quindío, Risaralda). The GIS software used was Kosmo Desktop 3.0RC1(®). Thirty thematic maps were developed according to the municipalities, years, parasite etiology, and uncomplicated and complicated cases. A total of 6582 cases were reported (6478 uncomplicated and 104 complicated, 77.8% Risaralda), for a cumulated rate of 269.46 cases/100,000 pop. Among uncomplicated cases, 5722 corresponded to P. vivax (234.25 cases/100,000 pop), 475 to P. falciparum (19.45 cases/100,000 pop), 8 to P. malariae (0.33 cases/100,000 pop) and 273 mixed (P. falciparum/P. vivax) (11.18 cases/100,000 pop). The highest rate reported was in the more undeveloped and rural municipality of Risaralda (Pueblo Rico, 57.7 cases/1000 pop, 2009). The burden of disease was concentrated in one department (>75% of the region). The use of GIS-based epidemiological maps helps to guide decision-making for the prevention and control of this public health problem that still represents a significant issue in the region and the country, particularly in children.

Geographical and occupational aspects of leptospirosis in the coffee-triangle region of Colombia, 2007-2011.

BACKGROUND: There are few studies occupationally profiling as well as using Geographic information system (GIS) to map human leptospirosis. There are no detailed, municipality-level, epidemiological maps in Colombia neither in South America. We developed such maps for the Coffee-triangle region, Colombia and assess some occupational issues. METHODS: surveillance cases data (2007-2011) were used to estimate the annual incidence rates (cases/100,000 population) of leptospirosis to develop the first maps of disease in the 53 municipalities of the Coffee-triangle region of Colombia. GIS used was Kosmo(®) 3.1. Five thematic maps were developed according to municipalities and years. Using labor official information, analyses between agriculture (harvested areas) with disease occurrence was done (linear regression). RESULTS: Between 2007 and 2011, 786 cases were reported (77.8% from one department, Risaralda), for a cumulated rate of 32.18 cases/100,000 population. The highest rate was reported in the less developed municipality of one department (Pueblo Rico, Risaralda) with 1535.05 cases/100,000 population (187 cases, 2009). Armenia (Quindio department capital city), reported 23.41 cases/100,000pop (2011). In those patients with identified occupations, 33.3% were agriculture workers, finding a significant relationship between the number of cases in 2008 and the harvested area by municipality (r(2)=0.48; p=0.0083). CONCLUSION: one of the 53 municipalities contributed with almost a quarter of the cases. Agriculture was significantly associated with the incidence. Use of GIS-based epidemiological maps allow to focus actions in prevention and control for risk zones for leptospirosis which still represents a significant issue in the region and Colombia, particularly in agriculture workers.