High prevalence of sub-microscopic infections in Colombia
| Autor: | Alvaro Alvarez, Pablo Chaparro, Andres F. Vallejo, Juan Pablo Quintero, Sócrates Herrera, Myriam Arévalo-Herrera, Yoldy Benavides, Julio Padilla |
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| Jazyk: | angličtina |
| Předmět: |
Male
Cross-sectional study Plasmodium vivax 0302 clinical medicine Epidemiology Prevalence Malaria Falciparum Child Asymptomatic Infections Aged 80 and over 0303 health sciences education.field_of_study biology 1. No poverty Middle Aged 3. Good health Infectious Diseases Child Preschool Female Adult medicine.medical_specialty Adolescent Plasmodium falciparum 030231 tropical medicine Population Colombia Real-Time Polymerase Chain Reaction Young Adult 03 medical and health sciences Environmental health parasitic diseases Malaria Vivax medicine Humans education Aged 030304 developmental biology business.industry Research Public health Infant Newborn Infant medicine.disease biology.organism_classification Cross-Sectional Studies Immunology Tropical medicine Parasitology business Malaria |
| Zdroj: | Malaria Journal |
| ISSN: | 1475-2875 |
| DOI: | 10.1186/s12936-015-0711-6 |
| Popis: | Background Malaria transmission in Latin America is typically characterized as hypo-endemic and unstable with ~170 million inhabitants at risk of malaria infection. Although Colombia has witnessed an important decrease in malaria transmission, the disease remains a public health problem with an estimated ~10 million people currently living in areas with malaria risk and ~61,000 cases reported in 2012. This study aimed to establish the malaria prevalence in three endemic regions of Colombia to aid in designing new interventions for malaria elimination. Methods A cross-sectional survey was conducted in three regions of Colombia with different malaria epidemiological profiles: Tierralta (Ta), Tumaco (Tu) and Buenaventura (Bv). The Annual Parasite Index (API) was 10.7, 6.9 and 3.1, respectively. Participants were asked to respond to a sociodemographic questionnaire and then were bled to determine the Duffy genotype and the prevalence of malaria infection by microscopy and quantitative real-time PCR (qPCR). Results The study was conducted between October 2011 and January 2012. Eight sentinel sites with 1,169 subjects from 267 households were included. The overall prevalence of sub-microscopic infections measured by thick blood smear (TBS) was 0.3% (n = 4) whereas by qPCR it was 9.7% (n = 113), with a greater proportion (13%) in 40-50 years old individuals. Furthermore, different regions displayed different prevalence of sub-microscopic infections: Bv 12%, Ta 15%, and Tu 4%. From these 113 samples (qPCR), 74% were positive for P. vivax and 22% for P. falciparum, and 4% were mixed infections, which correlates to the overall parasite prevalence in Colombia. This study showed that in the southern Pacific coast of Colombia (Bv and Tu), around 56% of the population have a Duffy-negative genotype, compared to the northern region (Ta) where the percentage of Duffy-negative genotype is around 3%. Conclusions Sub-microscopic infections are prevalent across different regions in Colombia, particularly in areas with relatively low transmission intensity. The poor microscopy results suggest the need for more sensitive diagnostic tools for detection of sub-microscopic infections. This study underscores the importance of conducting active case surveillance to more accurately determine malaria incidence, and highlights the need for updating the malaria guidelines to track and treat sub-microscopic malaria infections. |
| Databáze: | OpenAIRE |
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