Influence of the agrochemicals used for rice and vegetable cultivation on insecticide resistance in malaria vectors in southern Côte d'Ivoire.

BACKGROUND: Vector control can contribute to the development of resistance to insecticides in malaria vectors. As the swamps and wetlands used for some agricultural activities constitute productive breeding sites for many mosquito species, agricultural pest control may increase the selection pressure for insecticide resistance in mosquitoes. Understanding the use of agrochemicals by farmers is important to plan and initiate effective integrated pest and vector management interventions. METHODS: A knowledge-attitude-practice study, using questionnaires, was undertaken with 102 rice farmers in Tiassalé and 106 vegetable farmers in Dabou (South Côte d'Ivoire) in order to generate information on pesticide usage. In addition, insecticide susceptibility bioassays were conducted using adult mosquitoes obtained from larvae collected within farms, and the persistence of agricultural pesticides in the farming environment, including sediment and mosquito breeding site water, was investigated by HPLC. RESULTS: Herbicides and insecticides appeared to be the most frequently used pesticides for both crops. Amino phosphonates (mostly glyphosate) represented the most used herbicides (45 % for rice up to 89 % for vegetables). Pyrethroids appeared to be the most used insecticides (accounting for 90 % of all the insecticide use reported). Approximately 75 % of respondents had not been to school and do not understand product labels. Only about 45 % of farmers respect the recommended pesticide dosage and about 10-15 % of pesticides used for rice and vegetable, respectively, are not recommended for these crops. As per WHO criteria, the mosquito local populations from the two localities were resistant to three of the four insecticides tested, as mortalities were less than 35 % for deltamethrin, DDT and bendiocarb. Higher susceptibility was observed for malathion, although the population was considered resistant in Dabou (80 % mortality) and susceptible in Tiassalé (98 % mortality). With the exception of glyphosate, residues from each of six chemicals tested for were detected in each of the sites visited in the two localities. CONCLUSION: The study describes the use of insecticides and herbicides on crops and highlights the importance of considering agriculture practices when attempting to manage resistance in malaria vectors. Inter-sectoral collaboration between agriculture and public health is required to develop efficient integrated pest and vector management interventions.

[Malaria transmission in an area of high coverage with long lasting insecticidal nets in central Côte d'Ivoire]. / Transmission du paludisme en zone de haute couverture en moustiquaires imprégnées d'insecticide de longue durée, au centre de la Côte d'Ivoire.

The purpose of this study was to assess malaria transmission in an area of high coverage with long-lasting insecticidal nets (LLINs) in central Côte d'Ivoire. Two four-day larva collections were carried out in April and July 2008. Adult mosquito samples were collected by conducting human bait catches during a total of 80 man-nights. Vector infection rates were determined using an ELISA circumsporozoite antibody test. A total of 1582 mosquitoes were captured. Mansonia was the dominant genus in the culcidian fauna followed by Anopheles that was dominant in the anopheline fauna. The only Plasmodium vector was An. gambiae s.l. The high household bednet coverage rate probably accounted for the relatively low biting rate: 0.75 to 4.15 bites per person per night (b/p/n). Households not using bednets appear to have benefited from a passive protection effect associated with high LLIN coverage. Biting and entomological inoculation rates were 2.25 to 4.1 b/p/n (range) and 0.184 ib/p/n respectively in households that did not use LLINs and 0.75 to 4.15 b/p/n (range) and 0.341 ib/p/n respectively in households using LLINs.

The difficulty of questioning clinical practice: experience of facility-based case reviews in Ouagadougou, Burkina Faso.

OBJECTIVE: To describe the implementation of facility-based case reviews (medical audits) in a maternity unit and their effect on the staff involved. DESIGN: Cross-sectional descriptive study. SETTING: A 26-bed obstetric unit in a district hospital in Ouagadougou, Burkina Faso. SAMPLE: Sixteen audit sessions conducted between February 2004 and June 2005. Thirty-five staff members were interviewed. METHODS: An analysis of all the tools used in the management of the audit was performed: attendance lists, case summary cards and register of recommendations. The perceptions of the staff about the audits were collected through a questionnaire administrated by an external investigator from 10 June 2005 to 16 June 2005. MAIN OUTCOME MEASURES: Session participation, types of problems identified, recommendations proposed and implemented and staff reaction to the audits. RESULTS: Only 7 midwives from a total of 15 regularly attended the sessions. Eighty-two percent of the recommendations made during the audits have been implemented, but sometimes after a delay of several months. Interviewed personnel had a good understanding of the audit goals and viewed audit as a factor in changing their practice. However, midwives highlighted problems of bad interpersonal communication and lack of anonymity during the audit sessions, and pointed out the difficulty of practising self-criticism. CONCLUSIONS: A lack of staff commitment and the resistance of maternity personnel to being evaluated by their peers or service users are reducing acceptance of routine audits. The World Health Organization must take all these factors into account when promoting the institutionalisation of medical audits in obstetrics.

Nutrient adequacy and dietary diversity in rural Mali: association and determinants.

OBJECTIVE: To examine the association between nutrient adequacy and dietary diversity, and to assess and compare the determinants for the two constructs in an adult population in rural Mali. DESIGN: Cross-sectional study assessing food intake by a validated 7-day quantitative food frequency questionnaire. Two different dietary diversity indexes were created: food variety score (FVS), a simple count of food items, and diet diversity score (DDS) a count of food groups. Mean adequacy ratio, the mean ratio of intake to recommended intake (each truncated at one) of energy and nine nutrients, was calculated as an indicator of nutrient adequacy. Information on household and individual characteristics, including demography, socioeconomic conditions and food production strategies was obtained using precoded questionnaires. SETTING: Bafoulabé district, Kayes region, Western Mali. SUBJECTS: In total, 502 subjects (55% women) aged 15-45 y from 319 different households. RESULTS: Both FVS and DDS had a positive correlation with mean adequacy ratio (MAR). Multivariate analysis (linear regression) showed that the most important factors explaining MAR was the number of milk products, vegetables and green leaves consumed, as well as sex and the number of crops produced in the household. Dietary diversity was associated with socioeconomic status, residence and age. CONCLUSION: Dietary diversity is useful as an indicator of nutrient adequacy. It is important to examine how various food groups contribute to the nutrient adequacy of the diet in an area.

Validation of food variety as an indicator of diet quality assessed with a food frequency questionnaire for Western Mali.

OBJECTIVE: To assess the validity of two diet quality indexes-food variety score (FVS) and diet diversity score (DDS) in Western Mali. DESIGN: In two separate studies (A and B), FVS and DDS were derived from a food frequency questionnaire (FFQ) and were compared with the same scores and with measures of nutrient adequacy derived from 2-day weighed records (WR). SETTING: Two rural, adjacent villages in Mali, West Africa. SUBJECTS: In study A (1996), 48 women and 27 men (15-59 y) participated. Study B (1999) included 34 women and 36 men (15-45 y). RESULTS: Spearman's correlation coefficients between FVS from the FFQ and WR for men were 0.5 in study A and 0.4 in study B. The corresponding correlations for DDS were 0.2 and 0.4, respectively. Correlations for women were lower, especially in study B. Classification into quartiles was also best for men. Correlations for the two diet variety scores from the FFQ with nutrient adequacy from the WR in study A were about 0.3 for men, but lower for women. In study B, these correlations were around 0.5 for men, whereas for women there was no association. CONCLUSION: FVS and DDS can be assessed by our FFQ. The two diet variety scores reflect diet quality and are simple tools that can be used for monitoring. The validation study gave better results for men than for women, which has implications for further use of these instruments.