Impact of environmental temperatures on resistance to organophosphate insecticides in Aedes aegypti from Trinidad.

Objective: To examine the effects of increasing larval rearing temperatures on the resistance status of Trinidadian populations of Aedes aegypti to organophosphate (OP) insecticides.

Methods: In 2007-2008, bioassays and biochemical assays were conducted on A. aegypti larvae collected in 2006 from eight geographically distinct areas in Trinidad (Trinidad and Tobago).

The control of hookworm disease in Commonwealth Caribbean countries.

Like other countries around the globe where conditions existed for the parasites causing hookworm disease to thrive, this disease was a serious problem to settlers in countries of the Commonwealth Caribbean, i.e. those countries that were formerly part of the British Empire.

Organophosphate resistance in Trinidad and Tobago strains of Aedes aegypti.

Aedes aegypti larvae from 8 sites in Trinidad and 1 in Tobago were assayed against temephos, malathion, and fenthion using the Centers for Disease Control and Prevention time-mortality-based bioassay method. Resistance ratios (RRs) and resistance thresholds (RTs) for each insecticide were calculated in relation to the Caribbean Epidemiology Center reference susceptible strain. Results showed that the Haleland Park and Tobago strains were susceptible to fenthion and malathion, respectively (RRs < 1), while the San Fernando strain had a high RR (33.

Characterization of insecticide resistance in Trinidadian strains of Aedes aegypti mosquitoes.

Bioassays and biochemical assays were conducted on eight Trinidadian strains of Aedes aegypti larvae to determine the involvement of biochemical mechanisms in resistance to insecticides. Larval strains were assayed to dichlorodiphenyltrichloroethane (DDT), bendiocarb, temephos and permethrin, using the Centers for Disease Control and Prevention (CDC) time-mortality bioassay method. A Resistance Threshold (RT) was calculated for each insecticide in relation to the CAREC reference susceptible Ae.

Relative importance of the various environmental sources of Cryptosporidium oocysts in three watersheds.

This study was conducted to guide the prioritisation of efforts to manage Cryptosporidum contamination of drinking water supplies in Trinidad, W.I. The main objective was to investigate the relative importance of three main types of sources of Cryptosporidium oocysts: urban, agriculture and wildlife.

Evidence for the interruption of transmission of lymphatic filariasis among schoolchildren in Trinidad and Tobago.

This study was carried out to provide some evidence for the interruption of transmission of lymphatic filariasis (LF) among schoolchildren in Trinidad and Tobago. A cross-sectional survey for LF antigenaemia was performed among 63 (13.2%) of the 479 primary schools located in eight administrative (and geographical) regions of Trinidad and Tobago.

Short communication: concomitant malaria and filariasis infections in Georgetown, Guyana.

Lymphatic filariasis and malaria are endemic in Guyana, South America. To determine the prevalence of concomitant infections, we conducted a 1-year survey of febrile patients attending the malaria (day) and filariasis (night) clinics in Georgetown. In all, 1278 thick blood smears were collected: 769 for filariasis, of which 103 were positive for Wuchereria bancrofti, and three for both W.

Seroprevalence of toxocariasis in schoolchildren in Trinidad.

The seroprevalence of toxocariasis was investigated in 1997/98 in 1009 schoolchildren (aged 5-12 years) throughout Trinidad. Infection, as measured by titre, was found to be high compared to values obtained from children in other countries. Using an excretory-secretory antigen and performing an ELISA test, it was found that 62.