Mechanisms of pyrethroid resistance in Aedes (Stegomyia) aegypti from Colombia.

In Colombia Aedes (Stegomyia) aegypti is the main vector of urban arboviruses such as dengue, chikungunya and Zika. This urban mosquito has a well-established capacity to develop insecticide resistance to different types of insecticides (pyrethroids, organochlorides, organophosphates), using multiple resistance mechanisms. An understanding of ongoing resistance mechanisms is critical to determining the activities of vector control programs.

Socioeconomic factors, attitudes and practices associated with malaria prevention in the coastal plain of Chiapas, Mexico.

Background: Mexico is in the malaria pre-elimination phase; therefore, continuous assessment and understanding of the social and behavioural risk factors related to exposure to malaria are necessary to achieve the overall goal. The aim of this research was to investigate socio-economic backgrounds, attitudes and practices related with malaria in rural locations from the coastal plain of Chiapas.

Methods: In January 2012, 542 interviews were conducted to householders from 20 villages across the coastal plain of Chiapas.

Towards a genetic map for Anopheles albimanus: identification of microsatellite markers and a preliminary linkage map for chromosome 2.

Fifty microsatellite loci were identified in the malaria vector Anopheles albimanus. Markers segregating in F2 progeny of crosses between laboratory strains of An. albimanus were used to construct a preliminary genetic map.

Acceptability and perceived side effects of insecticide indoor residual spraying under different resistance management strategies.

Objective: To assess household acceptability and perceived side effects of residual indoor pyrethroid (PYR), carbamate and organophosphate insecticides sprayed by annual rotation (ROT), spatial mosaic (MOS), and a single insecticide (DDT or PYR) in communities of the coastal plain of Chiapas, Mexico.

Material And Methods: A questionnaire to assess the acceptability and perceived side effects of indoor insecticides was administered to one member of 30% of the families in eight villages of Chiapas. The association of different insecticide treatments with their responses was evaluated (Chi-square).

Knowledge and beliefs about malaria transmission and practices for vector control in southern Mexico.

Objective: To investigate the knowledge and beliefs about malaria transmission and practices for vector control in eight villages on the coastal plain of Chiapas, Mexico.

Material And Methods: A cross-sectional survey was conducted during May and June 1995 in Chiapas, Mexico. A questionnaire to investigate family structure, knowledge on malaria transmission, preventive measures and attitudes towards seeking treatment was applied to both family heads of a sample of households.

Pteridine concentrations differ between insectary-reared and field-collected Anopheles albimanus mosquitoes of the same physiological age.

Biopterin, isoxanthopterin and 6-pterincarboxylic acid were identified in the head of the malaria vector mosquito Anopheles albimanus Weidemann (Diptera: Culicidae) by HPLC. Total pteridine concentrations (TPC) were estimated in heads, body parts (BP: abdomen, legs and wings) and whole bodies of insectary-reared and field-collected females, by spectrofluorometry, to investigate whether they could be used for age determination. Pteridine concentrations diminished with age in both mosquito groups.

Resistance management strategies in malaria vector mosquito control. Baseline data for a large-scale field trial against Anopheles albimanus in Mexico.

A high level of DDT resistance and low levels of resistance to organophosphorus, carbamate and pyrethroid insecticides were detected by discriminating dose assays in field populations of Anopheles albimanus in Chiapas, southern Mexico, prior to a large-scale resistance management project described by Hemingway et al. (1997). Biochemical assays showed that the DDT resistance was caused by elevated levels of glutathione S-transferase (GST) activity leading to increased rates of metabolism of DDT to DDE.