The resting behavior of Aedes aegypti (L.) adults was investigated in 14 districts of Panama City, Panama, in relation to ground ultra-low volume (ULV) applications of malathion. Adults primarily rested inside the premises (75.1%) at a distance Ͼ6 m from the street (86.4%). Both sexes rested mainly in bedrooms, living rooms, and bathrooms. The small ULV aerosol droplets (2Ð 4 m) penetrated all indoor resting sites of Ae. aegypti, but in low amounts. Because of the low amount of insecticide reaching the primary resting sites within the premises, limited control of the Ae. aegypti was obtained. This limited the potential effectiveness of ground vehicle ULV applied insecticide as a dengue epidemic control method.KEY WORDS Aedes aegypti, culicidae, resting behavior, ultra-low volume insecticides DURING THE 1950S and 1960s, Ͼ20 countries in the Americas were able to eradicate Aedes aegypti (L.), but in the last 20 yr, almost every one of these countries including Panama has become reinfested and has had sizable epidemics of dengue fever (Gubler and Kuno 1997). Although future outbreaks of dengue fever may be avoided by eliminating larval habitats through community participation, there are still areas with Ae. aegypti infestation that may allow outbreaks of the disease. For this reason, emergency measures must be available for use in future dengue outbreaks.The intervention used during epidemics is the ground application of small quantities of aerosol insecticide (ultra-low volume or ULV). Elsewhere, ULV applications have been shown repeatedly to give Ͻ100% control of adult Ae. aegypti populations (Hudson 1986, Focks et al. 1987, Perich et al. 1990. One reason for this reduced effectiveness is Ae. aegypti resting behavior. A portion of the population is found in wardrobes, under beds, behind furniture and in closed rooms where it is difÞcult for aerosol droplets to reach. Focks et al. (1987) hypothesized that gravid females remain sequestered during treatment periods in places that are well-protected from aerosols.Schoof (1967) indicated that the resting habits of this mosquito are relatively unknown, but suggested that adults gather at breeding places, resting there and on adjoining surfaces. In Thailand, Pant and Yasuno (1970) demonstrated that 95% of the mosquitoes rest indoors, and of these, Ͼ90% did so on surfaces that could not be sprayed with residual compounds, such as clothing, pictures, decorative objects, coverlets, and mosquito nets. This Þnding indicated that it was of little value to use residual insecticides on indoor walls. Nelson (1986) reported that mosquitoes rested indoors most frequently in bedrooms, bathrooms, and kitchens where they preferred vertical surfaces such as walls, furniture, and hanging articles such as clothing, towels, curtains, and mosquito nets, although they also were found on the ceiling and under furniture such as beds.Detailed investigation of the resting behavior of Ae. aegypti is needed if chemical control is to be adopted for the control of adult mosquitoes. In th...

Hantavirus pulmonary syndrome (HPS), a severe respiratory disease with high mortality caused by rodent-borne hantaviruses, has previously been identified in the United States and Canada as well as central and southern South America. In late 1999 and early 2000, an outbreak of acute illness compatible with HPS was reported in Los Santos, Panama, with the death of 3 of the 12 (25%) suspected cases. Hantavirus-specific antibodies were detected in patient sera, and virus RNA was detected by reverse transcriptase-polymerase chain reaction. Sequence analysis of virus genome N-, G1-, and G2-encoding fragments showed this to be a novel hantavirus, Choclo virus. Serologic and virus genetic analyses of rodents trapped in the area showed Oligoryzomys fulvescens to be the likely reservoir for the HPS-associated Choclo virus. In addition, Zygodontomys brevicauda rodents were shown to harbor another genetically unique hantavirus, Calabazo virus.

The first identified outbreak of hantavirus pulmonary syndrome in Central America is described.

Contribución de los autores:Todos los autores contribuyeron en la redacción y corrección del manuscrito, análisis e interpretación de los datos, verificación de referencias bibliográficas, observaciones y revisión crítica del mismo. ARTÍCULO ORIGINAL Biomédica 2012;32:557-69 doi: http://dx.doi.org/10.7705/biomedica.v32i4.773 Caracterización de la transmisión de la malaria por Plasmodium vivax en la región fronteriza de Panamá con Costa Rica en el municipio de Barú, Panamá Characterization of Plasmodium vivax malaria transmission at the border of Panamá and Costa RicaIntroduction. Few studies have described the factors associated with Plasmodium vivax transmission dynamics in endemic regions from Panamá. Objective. Malaria transmission dynamics produced by P. vivax were characterized at the border between Panamá and Costa Rica. Materials and methods. In the municipality of Barú, an observational, descriptive and cross-sectional study was undertaken to measure the annual parasite index (API), slide positivity index (SPR), and the annual blood examination rate (ABER). The most frequent symptoms and signs in malaria patients were recorded. The anopheline species were identified in the area and the preferred larval habitats, the density of larval populations in the larval habitats and the bites/human/night were characterized. Results. Of a total of 10,401 thick smear blood samples, 83 were positive for P. vivax. Of these, 84% came from rural areas and 79% were from economically active individuals. The median and average ages were 36 and 30 years, respectively, and 58.5% of the malaria cases were male. API was 4.1/1,000 inhabitants; SPR was 0.8% and ABER was 51.9%. Of the diagnosed cases, 54% showed blood parasitemias ranging between 100-2,000 parasites/µl. The majority of the cases were observed in May and June. Two mosquito vector species were identified--Anopheles albimanus and An. punctimacula. Conclusion. These observations indicate the advisibility of continued entomological studies, strengthening of epidemiological surveillance, consideration of additional risk factors and evaluation

No abstract