Mayra E Solano

Seasonal profiles of Aedes aegypti (Diptera: Culicidae) larval habitats in an urban area of Costa Rica with a history of mosquito control

ABSTRACT Dengue is the most important arboviral disease worldwide and the principal vector-borne disease in Costa Rica. Control of Aedes aegypti populations through source reduction is still considered the most effective way of prevention and control, although it has proven ineffective or unsustainable in many areas with a history of mosquito control. In this study, seasonal profiles and productivity of Aedes aegypti were analyzed in the city of Puntarenas, Costa Rica, where vector control has been practiced for more than ten years. Households contained more than 80% of larval habitats identified, although presence of habitats was more likely in other locations like lots and streets. In the wet season, habitats in the “other” category, like appliances, small manholes, and miscellaneous containers, were the most frequent habitats observed as well as the most common and productive habitats for Ae. aegypti. In the dry season, domestic animal drinking containers were very common, although concrete washtubs contained 79% of Ae. aegypti pupae collected. Individually, non-disposable habitats were as likely or more likely to contain mosquito larvae, and large containers were more likely to harbor mosquito larvae than the small ones only in the dry season. Considering various variables in the logistic regressions, predictors for Ae. aegypti in a habitat were habitat type (p<0.001), setting (p=0.043), and disposability (p=0.022) in the wet season and habitat capacity in the dry season (p=0.025). Overall, traditional Ae. aegypti larval indices and pupal indices in Puntarenas were high enough to allow viral transmission during the wet season. In spite of continued vector control, it has not been possible to reduce vector densities below threshold levels in Puntarenas, and the habitat profiles show that non-household locations, as well as non-disposable containers, should be targeted in addition to the standard control activities.

Diversidad larval de mosquitos (Diptera: Culicidae) en contenedores artificiales procedentes de una comunidad urbana de San José, Costa Rica

A larval survey of mosquitoes was performed in artificial containers from indoor and outdoor enviroments in the neighborhood “La Carpio”, San José, Costa Rica. “La Carpio” is a community that suffered a dengue outbreak during the last months of the rainy season in 2002. During 2003, 582 and 369 houses were visited in the dry and rainy season, respectively, and the potencial mosquito breeding sites were searched for larvae. Of 1160 water containers identified, 152 (13.0%) were positive for at least one species of mosquito larvae and two mosquito species were found in 9 (0.78%) of the containers. In order to estimate the mosquito diversity, an infestation index by species (Ii) was calculated for each kind of container. Aedes aegypti, Culex quinquefasciatus, Cx. restuans, Cx. coronator, and Limatus durhamii were identified. Ae. aegypti was the most common species, and it showed the highest infestation index for all the containers (p < 0.05). In addition to Ae. aegypti, the presence of other species of Culicidae could mask the success of campaigns for prevention of dengue. This is also an important factor to consider in order to prevent the ocurrence of emerging vector borne diseases such as West Nile Virus Encephalitis.A larval survey of mosquitoes was performed in artificial containers from indoor and outdoor enviroments in the neighborhood “La Carpio”, San Jose, Costa Rica. “La Carpio” is a community that suffered a dengue outbreak during the last months of the rainy season in 2002. During 2003, 582 and 369 houses were visited in the dry and rainy season, respectively, and the potencial mosquito breeding sites were searched for larvae. Of 1160 water containers identified, 152 (13.0%) were positive for at least one species of mosquito larvae and two mosquito species were found in 9 (0.78%) of the containers. In order to estimate the mosquito diversity, an infestation index by species (Ii) was calculated for each kind of container. Aedes aegypti, Culex quinquefasciatus, Cx. restuans, Cx. coronator, and Limatus durhamii were identified. Ae. aegypti was the most common species, and it showed the highest infestation index for all the containers (p < 0.05). In addition to Ae. aegypti, the presence of other species of Culicidae could mask the success of campaigns for prevention of dengue. This is also an important factor to consider in order to prevent the ocurrence of emerging vector borne diseases such as West Nile Virus Encephalitis.

Cuantificación de formas larvales de Synthesiomyia nudiseta (Diptera: Muscidae) como un criterio en el análisis del intervalo post mortem

The number of larvae of Synthesiomyia nudiseta (Diptera: Muscidae) found in corpses was evaluated as a criterion for the estimation of the post-mortem interval (PMI) in a model with rabbit carcasses. New Zaeland rabbits (3,8 kg) were euthanasied during April, July and October of 2002, and January of 2003, three animals per cycle of observation. The corpses were exposed in a forested environment and samples of muscoid larvae were collected three times a week from each corpse during 80 days. Larvae of S. nudiseta were identified and counted during the observation period. The presence of S. nudiseta maggots was evident in all the observation cycles. Although the number of collected larvae was greater during the first days of their appearance on the body, there was great variability between each carcass. Although observation of the carcasses began on the second day post-exposition (DPE), in most of cycles, the collection of S. nudiseta larvae began between the 7 th and 11 th DPE and ended at aproximately the 30 th DPE. Cycle I (April-June) was an exception, where the recollection of S. nudiseta started later (18 th DPE) and lasted until the end of the period. These observations suggest that S. nudiseta is an important species in the colonization of corpses in the Neotropical Region. Although the great variability in number of larvae collected makes the quantitative interpretation unpractical, the finding of this species at a certain time in forensic investigations may support the estimation of the IPM determined by other criteria.

Miasis entérica por Hermetia illucens (Diptera: Stratiomyidae) en una paciente geriátrica de Costa Rica

(Diptera: Stratiomyidae) in a 71 year oldwoman. The patient showed history of ischemic hearth disease and hypertension. She also sufferedcolelitiasis and diverticulitis with high eosinophilia and recently there was diagnosed an abdominalcarcinomatosis process. The eosinophil levels were between 9 to 31% in different analysis. Consideringthe presence of

El problema de la pediculosis capitis en escolares del área metropolitana de San José, Costa Rica

The problem of pediculosis capitis was studied in 28 schools of the metropolitan area of San Jose, Costa Rica. 7.312 children were evaluated by naked eye observation (NEO) and a sample of hair or presuntive parasite forms was collected in all the suspected cases of pediculosis capitis. This material was cleared and mounted in Hoyer’s medium for microscopic observation. 730 (10.0%) of the tested children were positive at least for one of the following parasite forms: hatched or non-hatched eggs, nymphs and adults. 590 (80.8%) of the positive children were girls and 140 (19.2%) were boys.The prevalence rates observed in the studied schools showed values between 3.2 and 27.2%. These data suggest that pediculosis capitis is one of the most common public health problems in our children, that can interfere with their learning processes and general welfare.

Fur mite, Listrocarpus alouattae Fain (Acari: Atopomelidae), from Alouatta palliata Gray (Primates: Cebidae) in Costa Rica

Abstract Preliminary results of a study on ectoparasites of Costa Rican monkeys are presented. Thirty six mantled howler monkeys (Alouatta palliata Gray, 1849) and 3 capuchin monkeys (Cebus capucinus Linnaeus, 1758) from different zones of the country were examined for ectoparasites. Fur mites of the family Atopomelidae were found on 2 of the individuals of A. palliata, which were identified as Listrocarpus alouattae Fain, 1972 (Acari: Astigmata). A statistical analysis showed differences between most measurements of these specimens and those described by Fain (1979) suggesting that there are intraspecific variations in L. alouattae.

LARVAL DIVERSITY OF MOSQUITOES (DIPTERA: CULICIDAE) IN ARTIFICIAL CONTAINERS FROM AN URBAN COMMUNITY OF SAN JOSÉ, COSTA RICA

A larval survey of mosquitoes was performed in artificial containers from indoor and outdoor enviroments in the neighborhood “La Carpio”, San José, Costa Rica. “La Carpio” is a community that suffered a dengue outbreak during the last months of the rainy season in 2002. During 2003, 582 and 369 houses were visited in the dry and rainy season, respectively, and the potencial mosquito breeding sites were searched for larvae. Of 1160 water containers identified, 152 (13.0%) were positive for at least one species of mosquito larvae and two mosquito species were found in 9 (0.78%) of the containers. In order to estimate the mosquito diversity, an infestation index by species (Ii) was calculated for each kind of container. Aedes aegypti, Culex quinquefasciatus, Cx. restuans, Cx. coronator, and Limatus durhamii were identified. Ae. aegypti was the most common species, and it showed the highest infestation index for all the containers (p < 0.05). In addition to Ae. aegypti, the presence of other species of Culicidae could mask the success of campaigns for prevention of dengue. This is also an important factor to consider in order to prevent the ocurrence of emerging vector borne diseases such as West Nile Virus Encephalitis.A larval survey of mosquitoes was performed in artificial containers from indoor and outdoor enviroments in the neighborhood “La Carpio”, San Jose, Costa Rica. “La Carpio” is a community that suffered a dengue outbreak during the last months of the rainy season in 2002. During 2003, 582 and 369 houses were visited in the dry and rainy season, respectively, and the potencial mosquito breeding sites were searched for larvae. Of 1160 water containers identified, 152 (13.0%) were positive for at least one species of mosquito larvae and two mosquito species were found in 9 (0.78%) of the containers. In order to estimate the mosquito diversity, an infestation index by species (Ii) was calculated for each kind of container. Aedes aegypti, Culex quinquefasciatus, Cx. restuans, Cx. coronator, and Limatus durhamii were identified. Ae. aegypti was the most common species, and it showed the highest infestation index for all the containers (p < 0.05). In addition to Ae. aegypti, the presence of other species of Culicidae could mask the success of campaigns for prevention of dengue. This is also an important factor to consider in order to prevent the ocurrence of emerging vector borne diseases such as West Nile Virus Encephalitis.