Personal protective measures of pregnant women against Zika virus infection / Medidas de proteção individual de gestantes contra a infecção pelo zika vírus

ABSTRACT OBJECTIVE To evaluate the adherence of pregnant women to personal protective measures against mosquito bites, recommended by the Ministry of Health, and to investigate the factors associated with the non-adoption of these measures. METHODS We interviewed 177 pregnant women between November 2016 and February 2017 in the 10 basic health units of the municipality of Propriá, state of Sergipe, two located in the rural area and eight in the urban area, during prenatal appointments, to raise information about the use of preventive measures against the vector transmission of Zika virus. Data were analyzed using descriptive statistical methods, chi-square test or Fisher's exact test, and the odds ratio was calculated. The independent variables were grouped by the analysis of principal components, and the dependents (the use of repellent, mosquito nets, garments, screens and insecticides) were analyzed using the logistic regression method. RESULTS Among the measures recommended by the Ministry of Health, mosquito nets were the most used by pregnant women living in rural areas and with low education level, while the repellents were more used by women in the urban area and with higher education level. Women in a vulnerable socio-economic situation presented a risk 2.4 times higher for not using screens in their homes, 1.9 times higher for not changing clothes and 2.5 times higher for not using repellent than pregnant women in better economic conditions. CONCLUSIONS The socioeconomic status of pregnant women, especially among the less privileged, influenced the use of protective measures against Zika virus, from the purchase of repellent, clothing, insecticides to other resources in the municipality of Propriá, SE.

RESUMO OBJETIVO Avaliar a adesão de gestantes às medidas de proteção individual contra picadas de mosquitos, recomendadas pelo Ministério da Saúde e investigar os fatores associados à não adoção dessas medidas. MÉTODOS Foram entrevistadas 177 gestantes entre novembro de 2016 e fevereiro de 2017 nas 10 unidades básicas de saúde da cidade de Propriá, SE, duas localizadas na zona rural e oito na zona urbana, durante as consultas de pré-natal, para levantar informações sobre o uso de medidas preventivas contra a transmissão vetorial do zika vírus. Os dados foram analisados utilizando métodos de estatística descritiva, teste do qui-quadrado ou teste exato de Fisher, e foi calculado o odds ratio . As variáveis independentes foram agrupadas por meio da análise de componentes principais, e as dependentes (uso de repelentes, mosquiteiros, vestimentas, telas e inseticidas) foram analisadas pelo método de regressão logística. RESULTADOS Entre as medidas recomendadas pelo Ministério da Saúde, o uso de mosquiteiros foi a mais utilizada por gestantes residentes na zona rural e de baixa escolaridade, enquanto os repelentes foram mais utilizados por mulheres da zona urbana e com maior tempo de estudo. Mulheres com situação socioeconômica vulnerável apresentaram risco 2,4 vezes maior de não utilizar telas em suas residências, 1,9 vezes maior de não mudar o modo de se vestir e 2,5 vezes maior de não usar repelentes do que gestantes em melhores condições econômicas. CONCLUSÕES A condição socioeconômica das gestantes, especialmente entre as mulheres menos favorecidas, influenciou o uso das medidas de proteção contra o zika vírus, desde a compra de repelentes, vestimentas, inseticidas até outros recursos na cidade de Propriá, SE.

Persistence and efficacy of a new formulation based on dog allomonal repellents against Rhipicephalus sanguineus sensu lato tick / Persistência e eficácia de uma nova formulação baseada em repelentes alomônios de cães contra o carrapato Rhipicephalus sanguineus sensu lato

Abstract Beagles are less susceptible to Rhipicephalus sanguineus sensu lato tick due to the production of the allomones benzaldehyde and 2-hexanone. Our previous published work showed that these compounds can reduce tick burden on susceptible dogs. Here we tested the hypothesis that an increase in repellent dose and release rate could increase repellent efficacy and persistence. Slow-release formulations of these compounds, with higher doses and release rates, were tested on artificially-infested dogs. Ten dogs were randomly assigned to two groups with five dogs each. The treated group received collars with slow-release formulations of the compounds attached, while the control group received collars with clean formulations attached. Five environmental infestations were performed, with the number of ticks (at all stages) on the dogs being counted once a day for 40 days. No significant increase in repellent efficacy was observed with the higher doses and release rates, whereas a greater persistence in repellent activity was observed. Treatment with the formulations resulted in a two-to-three-fold reduction in the number of immature stage ticks for up to three weeks. However, the number of adults was similar in both groups. Loss of repellent activity after the third week of testing coincided with a marked change in the relative release rates for the two compounds. It is hypothesized that relative amounts, rather than absolute amounts, of repellent release from slow-release formulations are important for repellent activity. We also hypothesize that the avoidance of less-preferred hosts by ticks relies on olfactory-mediated perception of specific blends of volatile cues from less preferred hosts.

Resumo Beagles são menos suscetíveis ao carrapato Rhipicephalus sanguineus sensu lato devido à produção de benzaldeído e 2-hexanona. Nosso trabalho anterior já publicado mostrou que esses compostos podem reduzir a carga de carrapatos em cães suscetíveis. Aqui testamos a hipótese de que um aumento na dose destes repelentes e na taxa de liberação poderia aumentar a eficácia e a persistência do efeito repelente. As formulações de liberação lenta destes compostos, com doses e taxas de liberação mais elevadas foram testadas em cães infestados artificialmente. Dez cães foram distribuídos aleatoriamente em dois grupos com cinco cães cada. O grupo tratado recebeu colares contendo formulações de liberação lenta dos compostos, enquanto o grupo controle recebeu colares com formulações limpas. Cinco infestações ambientais foram realizadas, com o número de carrapatos (em todas as fases) nos cães sendo contados, uma vez ao dia, por 40 dias. Não se observou aumento significativo na eficácia do repelente com doses e taxas de liberação mais elevadas e, enquanto observou-se maior persistência na atividade repelente. O tratamento com as formulações resultou em uma redução de duas a três vezes no número de carrapatos dos estágios imaturos, por até três semanas. No entanto, o número de adultos foi semelhante em ambos os grupos. A perda de atividade repelente após a terceira semana de teste coincidiu com uma mudança nas taxas de liberação relativa para os dois compostos. A hipótese é que as quantidades relativas, ao invés das quantidades absolutas de liberação lenta, são importantes para a atividade repelente. Então, a hipótese é de que a repelência apresentada por hospedeiros menos susceptíveis aos carrapatos depende da percepção pelos carrapatos de misturas específicas de voláteis liberados por estes hospedeiros.

Efectividad de repelentes comerciales disponibles contra el mosquito Aedes aegypti (L ) en Yucatán, México / Effectiveness of commercial repellents against Aedes aegypti (L ) in Yucatan, México

Resumen: Objetivo: Determinar la eficacia de repelentes comerciales disponibles en Yucatán contra el mosquito Aedes aegypti, vector del dengue, Chikungunya y Zika. Material y métodos: Se determinó el tiempo de protección con base en el protocolo WHO/CTD/WHOPES/IC y la NOM-032-SSA2-2014. Resultados: Sólo el repelente con DEET (N, N-dietil-3-metilbenzamida) al 25% cumplió con la protección recomendada. La eficacia fue directamente proporcional a la concentración del DEET; aquéllos con componentes botánicos fueron poco o nada protectores. Conclusiones: Los resultados muestran que los repelentes con DEET proveen protección contra Ae. Aegypti; los repelentes botánicos, incluyendo las pulseras impregnadas, ofrecen nula protección.

Abstract: Objective: We assessed the efficacy of commercial repellents available in Yucatan against Aedes aegypti, vector of dengue, Chikungunya and Zika. Materials and methods: Protection time was determined based on WHO/CTD/ WHOPES/IC y la NOM-032-SSA2-20I4. Results: Products with DEET (N, N-diethyl-3-methylbenzamide) at 25% met the recommended protection. Efficacy was directly proportional to the concentration of DEET; botanicals repellents resulted no protective. Conclusions: Repellents with DEET provided more protection against Ae. aegypti and botanical repellents, including impregnated wristbands, provided no protection.

Efficacy of Advanced Odomos repellent cream (N, N-diethyl-benzamide) against mosquito vectors.

Background & objectives: Repellents are commonly used personal protection measures to avoid mosquito bites. In the present study, Advanced Odomos cream (12% N, N-diethyl-benzamide) was tested for its efficacy against mosquitoes in comparison to DEET (N,N-diethyl-3-methyl benzamide). Methods: Bioassays were conducted to assess the repellency of Advanced Odomos and DEET creams against Anopheles stephensi and Aedes aegypti. Their efficacy was tested on human volunteers applied with different concentrations of test creams ranging from 1 to 12 mg/cm2 and by exposing them to mosquitoes at hourly intervals. Field evaluation was also carried out to test the duration of protection of the test creams against Anopheles and Aedes mosquitoes during whole night and day time collections, respectively on human volunteers. Mosquito collections were done using torch light and aspirator. Results: Complete (100%) protection was achieved at 10 mg/cm2 cream formulation of Advanced Odomos (1.2 mg a.i/cm2) dose against An. stephensi and 12 mg/cm2 (1.44 mg a.i./cm2) against Ae. aegypti on human baits. There was no statistically significant differences in per cent protection against mosquito bites between Advanced o0 domos and DEET cream (P>0.05) in respective doses. Complete protection up to 11 h was observed against Anopheles mosquitoes during whole night collections and up to 6 h against Ae. aegypti in day time collections. No adverse reactions such as itching, irritation, vomiting, nausea, etc. were reported by the volunteers. Interpretation & conclusions: Advanced odomos cream applied at 10 mg/cm2 concentration provided 100% protection from Anopheles mosquitoes up to 11 h whereas about 6 h protection was recorded against Ae. aegypti. The laboratory and field trials indicate that for longer protection against Anopheles mosquitoes 10 mg/cm2 will be appropriate and in case of Ae. aegypti more than 10 mg/cm2 application is required for complete protection. In conclusion, the Advanced Odomos cream was comparable to the known repellent cream DEET for prolonged protection against malaria and dengue vectors.

Actualización: repelentes naturales y sintéticos / Update: natural and synthetic repellents

Las picaduras de mosquitos constituyen un riesgo frecuente al que se adiciona la posible transmisión de enfermedades. Para evitarlas contamos con barreras físicas, ropas, mosquiteros y repelentes. La elección del repelente a usar debe desprenderse de una meticulosa evaluación entre los beneficios y los riesgos generados por cada producto. El DEET (n,n-dietil,m,toluamida o su nueva denominación n,n-dietil-3-metilbenzamida) es, hasta el momento, el repelente más usado, mejor estudiado y efectivo, pero existen otros productos más nuevos. En este artículo se describen los repelentes naturales y sintéticos más utilizados que se encuentran disponibles en el mercado y se intenta orientar para una adecuada elección de los mismos en situaciones especiales como el embarazo, la lactancia y la niñez.

Mosquitoe bites are a common risk in which we have to take into account the transmission of many diseases. To prevent both risks we count with physical barriers, clothes, nets and repellents. The election of the repellent should be the result of a very meticulous evaluation of the risks and benefits of each product. The DEET (n,n-dietil,m,toluamida or the new name for the same product: n,n-dietil-3-metilbenzamida) is up to date the most used, best studied and effective repellent, but there are many other new options. In this article we describe the different natural and synthetic repellents on the market and try to help on the adequate election in special situations such as pregnancy, nursing and childhood.

Biochemical changes in serum, lung, heart and spleen tissues of mice exposed to sub-acute toxic inhalation of mosquito repellent mat vapour.

The toxicity of sub-acute inhalation of mosquito repellent mat vapour exposure 3 hr daily, either for a duration of 15 days (Group II) or for 30 days (Group III) on biochemical parameters in serum and vital organs was evaluated in mice. The control animals were exposed to ambient air 3 hr daily, either for 15 days [Group I (a)] or 30 days [Group I (b)]. In both the Group II and Group III exposure studies, elevation in the activity of aspartate transaminase (AST) and alanine transaminase (ALT) was observed in the serum and heart tissue and a decrease in their activity in lung and spleen tissue. This biochemical lesion indicates that exposure to mat vapour is capable of interfering with the metabolism of non-essential amino acids and induce cellular damage in the tissues. The elevation in the activity of AST along with that of lactate dehydrogenase (LDH) observed in serum and heart tissue in Group II and III studies indicate that exposure to mat vapour is capable of inducing changes in the myocardial function. The elevation in the activity of alkaline phosphatase (ALP) in serum and a decrease in its activity in lung and heart tissue of mice exposed to mat vapour for 30 days (Group III) observed in this study denotes that mat vapour could interfere with various metabolic functions to induce derangements at cellular level. Inhalation of hitherto unidentified volatile chemicals emanated from mosquito repellent mat, may contribute as stress factors may contribute as in an indoor environment to produce above mentioned biochemical lesions in vital organs.

Laboratory and field trial of developing medicinal local Thai plant products against four species of mosquito vectors.

Oils of Syzygium aromaticum (clove) and Zanthoxylum limonella (makaen), widely used essential oils for dental caries or flavoring of food in Thailand, were prepared as 10 experimental repellent products in gel or cream form against Aedes aegypti, Culex quinquefasciatus, and Anopheles dirus under laboratory conditions, using the human-arm-in-cage method. Two products that gave the longest-lasting complete protection were selected to examine their repellency against a variety of mosquito species under field conditions. In laboratory tests, 0.1 g of each product was applied to 3x10 cm of exposed area on a volunteer's forearm, while in field trials, 1.0 g was applied to each volunteer's leg (from knee to ankle). In the laboratory, the gel dosage form contained 20% clove oil (Gel B) or 10% clove plus 10% makaen oil mixture (Gel E) were promising plant-based repellents against three mosquito species and gave significantly longer complete protection times of 4-5 hours than all other developing products. Therefore, their efficacy in the field was evaluated. Under field conditions, Gel E showed complete protection for 4 hours and gave 95.7% repellency after 5 hours application, whereas Gel B and 20% deet (di-methyl benzamide) provided only 86.8 and 82.7% repellency after treatment, respectively against Ae. aegypti, daytime-biting mosquitos. For nighttime-biting, the 3 repellents under development yielded equally excellent (average 97.1%) repellency for 5 hours against the predominant Cx. quinquefasciatus and Mansonia uniformis, but they gave 89.0% repellency against Cx. tritaeniorhynchus and Cx. gelidus. This finding demonstrated the effectiveness of Gel B and Gel E products for possible use by low-income rural communities against various mosquito species.

Acute oral toxicity of insect repellent N,N-diethylphenylacetamide in mice, rats and rabbits and protective effect of sodium pentobarbital.

Median lethal dose (LD50) of undiluted liquid insect repellent N,N-diethylphenylacetamide (DEPA) in male mice, rats and rabbits was 900, 825 and 635 mg/kg respectively when administered by gavage. Signs of DEPA intoxication point to stimulation of central nervous system (CNS). Acetazolamide (10 mg/kg), sodium bicarbonate (40 mg/kg), and atropine (5 mg/kg) when injected (ip) 5 min after a lethal oral dose of DEPA (1700 mg/kg) did not prevent mortality, while sodium pentobarbital (SPB; 20 mg/kg) when injected 5 min after or 15 min before DEPA provided greater protection to the animals. SPB pretreatment elevated the LD50 of DEPA to 1780 and 1535 mg/kg in mice and rats respectively and 85% rats survived when SPB was injected 5 min after acute oral exposure to DEPA (1000 mg/kg). Carboxylesterase (CaE) inhibition is not a factor in the protection mechanism of SPB. DEPA (1000 mg/kg) when given orally elevated blood PCO2 and reduced pH, O2 content and per cent O2 saturation, while administration of SPB after the same dose of DEPA reduced the degree of acidosis and raised PCO2, and increased the O2 content and per cent O2 saturation to near normal status. The CNS depressant action of SPB may be a crucial factor in protection of rats from DEPA poisoning.

Protección personal con un repelente natural contra Lutzomyia youngi, vector de leishmaniasis cútanea urbana en Venezuela / Personal protection with the natural repellent by lutzomyia youngi cutaneus leishmaniasis vector in venezuela

Ante la actividad hematogáfica intradomociiar de Lutzmyiayoungi, principal transmisor de leishmaniasis cutáneo urbana de trujillo, Venezuela, se ensaya el uso de repelentes como protectores personales. Se compra la actividad del aceite de limón obtenido por los autores con la del citronellal y eldett, tanto en experincias de laboratorios como de campo. L actividad protectoraen el laboratorio fue de 70, 63y33 para el aceite esencial, el deet y el citronellal respectivamente. La dosis efectiva media (DE50) para el aceite esencial fue de 7,46ug/cm² de piel con efecto similar al deet. Los coeficientes de protección en condiciones de campo, usando tres voluntarios, fueron de 84,8 para el aceite esencial y 3,7 para el deet

Development & evaluation of controlled release formulations of DEPA, an insect repellent.

Three controlled release formulations of the insect repellent DEPA (N, N-Diethyl phenylacetamide), Depa-A, Depa-B and Depa-C have been developed and tested on human subjects against Aedes aegypti adult mosquitoes for repellency and the results were compared to those of a solution of DEPA (Depa-0). The increase in the protection time of the formulations, as compared to Depa-0 was compared. Depa-B was found to be effective with a protection time of 7.13 and 6.15 h and percentage increase in protection time of 44.5 and 38.2 at the two application rates of 0.5 and 0.25 mg/cm2 of the repellent. This observation agreed with the studies carried out on the evaporation of the repellent formulations on two models, on adsorbing and nonadsorbing surfaces for the relative adsorption and evaporation by analysing the repellent concentrations, using an infrared spectrophotometer.