Environmental management and personal protection for the protection of Zika

This document prepared by Kim Bautista vector control Chief of Operations is a close physical comparison of the two Aedes vectors capable of transmitting Zika, Dengue and Chikungunya (the Aedes aegypti and the Aedes albopictus mosquito). It compares the habitat, flight range, biting habits, and environmental conditions under which these vectors thrive. The document also deals with several aspects of environmental control and personal protection at various levels, such as mosquito nets, clothing, insect repellent and condoms to protect against sexual transmission of the virus and also to prevent pregnancy during an outbreak of Zika, which can lead to birth defects when the virus is passed on to unborn babies.

The role of aedes aegypti survelliance and control in relation to the epidemiology. Prevention and control of dengue fever in Jamaica

The control of dengue fever depends on the level of Aedes aegypti infestation and thus relies heavily on the measures of controlling the vector. ... The vector apparently has adapted to or resisted most of the control methods. The failure of Aedes aegypti control programmes has been blamed on the vector's biological features fostering the development of species resistance to chemical control or environment factors favouring the increase of the Aedes aegypti population at a faster rate than the control methods can reduce them. Nevertheless, many Aedes aegypti control programmes are improperly planned and implemented or the control measures are often used as reactive methods of controlling dengue fever outbreaks, rather than as continuous proactive strategies for preventing the disease. Aedes aegypti breeding is basically a problem of domestic sanitation and therefore communities have an essential role to play in source reduction activities. The activities of some governmental departments, non govermental organizations and the private sector may encourage the increase of Aedes aegypti mosquitoes or play a positive role in vector control. Consequently, intra sectoral and intersectoral in vector control are very important. This study examined the control measures applied by the Jamaican Ministry of Health, Vector Control Department and the community for Aedes aegypti surveillance and control, and determined the effectiveness of and obstacles to the mosquito control activities presently being applied. The aim of the study was achieved through the execution of an entomology survey, an environmental survey, an insecticide susceptibility test, key informant interviews with vector control staff from the Ministry of Health and the administration of a Knowledge-Attitude-practice survey. The research results showed that the environmental conditions in the study area were conducive to Aedes aegypti breeding and proliferation, especially during the months July to October. Aedes aegypti mosquitoes were present throughout the study area, with a higher density ... Most of the community members in the study area had a poor attitude towards Aedes aegypti control and relied heavily on government to control... The attitude and practices of the community members relating to Aedes aegypti control were greatly influenced by whether the community was severly affected by mosquitoes or by the level of vector control attention given to the community by the government (AU)

Serum cholinesterase levels of vector control workers in Trinidad, West Indies (1979-1987)

During 1979-1987 studies were carried out in vitro on the serum cholinesterase levels of 46 vector control workers exposed to insecticides on a daily basis but without clinical manifestations of insecticide poisoning. The results were compared with those of a control group of workers who had not been exposed to insecticides at home or at work. Cholinesterase levels of both groups were determined by a standard colorimetric method. Suppressed serum cholinesterase levels were detected in all 46 workers exposed to insecticides, 25 of whom were aged 30-39 years. Four persons from the control group showed suppressed levels of enzyme; one of these had a genetically low level, and the other three were on medication when the low levels were recorded. (AU)

Suppression of Aedes aegypti by Toxorhynchites moctezuma in an island habitat - abstract

Dengue is endemic in the Caribbean where the mosquito vector is Aedes aegypti. This mosquito however, is becoming resistant to some of the insecticides used for its control, and householders themselves are objecting to the use of temephos (abate) placed in their drinking water. Consequently, alternative methods are being sought to control Aedes aegypti. Thus we have used the predatory mosquito Toxorhynchites moctezuma on an experimental basis to suppress Aed.aegypti in an island habitat. Toxorhynchites mosquitoes are predators in all larval stages. Tx. moctezuma, the species used in this project, was easily colonized from field-collected material in Trinidad. The trials were conducted in 2 villages in Union Island in the state of St. Vincent and the Grenadines in the Eastern Caribbean. One village, Ashton, served as the control while Clifton was the treated village. At Clifton, each permanent or semi permanent water-holding container received between 2 and 100 immature Tx. moctezuma, depending on its size. Baseline data were collected by obtaining ovitrap, house, Breteau, cistern and drum indices from the 2 villages for 4 months in 1988 prior to treatment. Impact of release of predators was evaluated by comparing the various indices and the percentage changes before and after the introduction of predators in the 2 villages. All indices were lower, and the percentage decline greater in the treatment village than in the control village. The use of Tx. moctezuma as a possible biological control agent for Aed.aegypti needs to be further evaluated (AU)

Current trends in screwworm myiasis in the Caribbean region

In a random sample of animal producers and animal health personnel, 33 percent of the respondents in Trinidad, 15 percent in Guyana, 11 percent in Suriname and 9 percent in Jamaica recalled at least one case of human myiasis due to Cochliomyia homivorax (Conquerel). During 1981, respondents in Suriname (88 percent), Jamaica (90 percent), Guyana (85 percent) and Trinidad and Tobago (82 percent found at least one case of myiasis in their livestock, occurring mainly in cattle, pigs and dogs. Feral animals, e.g. jaguars, were also found to be infested. The initial wounds were mainly the umbilicus of neonates, and arbitrary wounds, and vampire bites were also affected. Fifty-three to 78 percent of all respondents examined their livestock daily for wounds and infestation by the screwworm. Annual estimates of losses (in U. S. dollars) due to surveillance and medication ranged from $4.82 to $10.71 per animal. Nationally these losses amount to $0.30 million (Surinam), $1.02 million (Trinidad and Tobago), $$.33 million (Guyana) and $6.78 million (Jamaica). Figures for other losses, arising from failure to thrive, reduction in milk production and hide injury due to screwworm activity were not available. Most producers found that the greatest screwworm infestation occurred in the wet season, and most described it as second in importance to Bophilus spp. ticks as a pest of livestock, but of greater significance than biting flies, such as tabanids and stable flies. Eradication of the screwworms from the islands of Jamaica and Trinidad and Tobago can be recommended, but in Surinam and Guyana eradicationseems feasible only on the 100-km wide coastal strips where most human and livestock populations exist. (AU)

Abate for the control of blackfly larvae in the river Burru, Lethem area, Rupununi, Guyana

Abate (emulsifiable concentrate) for the control of Blackfly larvae was used in the river Burru, Lethem, Rupununi, Guyana. The results showed that it was not effective at 0.5 p.p.m. against larvae of S. incrustatum (AU)

Preliminary trials using abate to control Kabowra flies in the Rupununi, Guyana - abstract

Control of Simulium (called Kabowras in Guyana) black flies is usually directed to the larvae which breed in fast flowing waters. The purpose of the project was to determine the effectiveness of Abate Insecticide 200E in controlling Simulium sp., in a selected river in the Rupununi Savannah, Guyana. Two bioassays were carried out on the San Jose River near Lethem, Rupununi to determine the effective distance of Abate 200E at a concentration of 0.3 ppm during August, 1979 along a 2.4 km and 3.5 km stretch of the river. River discharge rates were calculated at a point of injection of the Abate. The volume of Abate required to give a concentration of 0.3 ppm when dispensed over approximatelty thirty minutes at the measured discharge was dripped into the stream. Counts of larvae on marked vegetation were made at several points before injection of Abate and four and nineteen hours after injection. The results of the first bioassay over 2.4 km showed at 57.8 percent drop in larvae four hours after injection of larvicide and a 99.3 percent drop within nineteen hours. Larval mortality was 97 percent at 2.4 km. Larval counts after the second Abate application two weeks later at 3.5 km showed a 52.8 percent drop after four hours and 96.1 percent after nineteen hours. Larval mortality was 100 percent at 2.7 km and 9.3 percent at 3.5 km. Larval counts were very low during the subsequent four weeks. Abate 200E at a concentration of 0.3 ppn was found to be effective in killing Simulium larvae over a distance of 3.5 km with a mortality of 93 percent nineteen hours after injection of larvicide. These trials should continue using lower concentrations of the larvicide (AU)

The organization of the health services in the parish of St. James, Jamaica

There is given (Chap. 1) a brief description of the parish of St. James, its capital city, Montego Bay, and its population. The reason for the choice of the parish is explained. Some historical aspects of the development of the Health Services in Jamaica are reviewed so that a few of the administrative problems facing health planners today may be better understood. In the following chapters the hospital and other facilities, as well as the health status of the population, are examined. A special effort is made to identify preventable causes of morbidity and mortality. In the final chapter, some areas of research are suggested, and recommendations made towards the solution of the problems found (AU)

Control of some houseflies on some West Indian islands with metepa, alpholate, and trichlorfon baits

Two chemosterilants, metepa and alpholate and an insecticide, trichlorfon were applied in sweetened baits in the pits of all privies on 3 islands in the West Indies for control of houseflies, Musca domestica L. Semiweekly treatments were made, first with granular baits and then with sugar syrup. On Grand Turk, 1 percent metepa liquid bait usually induced sterility in excess of 80 percent and reduced fly abundance more than 90 percent over 18 months. On Mayaguana, 1 percent liquid apholate bait produced about 60-80 percent sterility over three months under less favourable conditions and reduced fly abundance 50-80 percent. On San Salvador, 1 percent liquid trichlorfon bait reduced fly abundance 50-90 percent. The flies did not develop resistance to the chemosterilants during two years of exposure; instead the fertility of the treated strain apparently declined slightly (AU)

Observations on anopheles (Kertezia) bellator D. & K. in British Guiana

The geographic distribution of the subgenus Kertezia Kertezia of Anopheles in general, and of Anopheles bellator in particular is reviewed. A new record for A. bellator is reported in British Guiana where it was found in the upper reaches of all the rivers in the North West District adjoining a known focus in Eastern Venezuela. A. bellator was found also in the Potaro River, on the Kaieteur escarpment, and on the east bank of the Essequibo River. High rainfall was a common feature in all these areas. Larval findings indicative of the presence in the North West District of one or more other species of Kertezia are recorded. The principal bromelaid host plants for A. bellator were the arboreals Guzmania capituligera, G. Altonii, Vriesia platynema, V. albiflora, wittmackia adora; and the large terrestrial plant Brochhinia micrantha. High densities of adult A. bellator were recorded only at Kaieteur Falls, but in a small Amerindian community in the North West District epidemiological evidence of active malaria transmission is presented. The potentialities of extended A. bellator malaria are briefly reviewed in relation to future development in the hinterlands

Sandfly research unit in Montego Bay, Jamaica

Prior to 1960 the main biting nuisance in the Montego Bay area was caused by the swamp sandflies culicoides furens and culicoides barboai. Filling the swamps with sand, whilst eliminating these two species, encouraged the development of a hitherto little-known species (leptoconops bequaerti) whose nuisance value soon exceed that of the original species. The discovery of the breeding sites of this sandfly in 1962 enabled its distribution to be studied and treatment with insecticide started. The limited nature of the breeding grounds shows good prospects for environmental control in the future (AU)