Larvicidal activity of micronized aqueous suspension of calcium hydroxide against Aedes aegypti and Culex quinquefasciatus (Diptera: Culicidae).

In the search of alternatives for the control of mosquitoes of medical importance, we evaluated the larvicidal activity of micronized suspensions of calcium hydroxide [Ca(OH)2] against Aedes aegypti and Culex quinquefasciatus. Tests conducted under laboratory conditions determined a LC50 = 0.027% (LC90 = 0.096%) for A. aegypti and a LC50 = 0.092% (LC90 = 0.2%) for C. quinquefasciatus, at 24 h post-treatment. Considering that the LC50 for the less susceptible species killed 100% of larvae for both species at 48 h post-treatment, we decided to use the diagnostic concentration of 0.1% which eliminated 100% of larvae at 48 h under a simulated field trial. There was a residual effect for up to 84 and 70 days for A. aegypti and C. quinquefasciatus, respectively. Evaluation of Ca(OH)2 on breeding sites showed a larvicidal activity of 100% for up to 56 days. When the micronized Ca(OH)2 was incorporated at concentrations from 0.02% (w/v), a superficial film was formed which killed 100% of the larvae of both species after 24 h of contact, and the activity remains until the film broke apart due to stirring. The fact that Ca(OH)2 is cheap and the people in rural areas of Mexico and other countries know the handling procedures for this compound led us to consider that 0.1% suspensions of Ca(OH)2 could be used for mosquito control in deposits of water placed in human premises both in urban and rural areas.

Trichuris vulpis (Froelich, 1789) infection in a child: a case report.

We present a human infection with the canine whipworm, Trichuris vulpis, in a child suffering from rhinitis with a diagnosis of rhinitis. T. vulpis eggs resemble those of T. trichiura but they can be differentiated based on their morphological features and egg size, using micrometry with an ocular micrometer. T. vulpis eggs measured an average of 90 µm by 44 µm (range 86-99 µm by 38-47 µm). Prevalence of hookworms (28.1%), Toxocara canis (11.8%), and Trichuris vulpis (3.5%) was found in 292 fecal samples of dogs collected at the peri-domicile, which showed that the risk of infection was not only fortuitous. The treatment of canine whipworm infections is similar to that of T. trichiura infection. We recommend differentiation of the 2 species for their epidemiological and prevention implications.

Taenia saginata: failure treatment in a child with 5-year long-lasting infection.

The management of these infections requires protocols that allow the clinic and laboratory to reach a timely and accurate diagnosis through the differential identification of Taenia species and consequently determine appropriate treatment. On the other hand, the inadequate implementation of treatments and the lack of follow-up coupled with biological phenomena such as resistance to drugs contribute important risks of infection for the population. This case could be caused by a strain of T. saginata with a low sensitivity to albendazole. This case emphasizes the need of developing and implementing techniques that will help us differentiate the species of Taenia in laboratories as well as establish treatments with alternative drugs. It is important to report this kind of infection with the aim of giving laboratory personnel as well as healthcare providers a broader knowledge of these parasites in order to improve treatment with alternative drugs. In addition, improvements in the habits among individuals must be addressed to avoid the increased risk of infection.