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1.
Am J Trop Med Hyg ; 62(1): 11-8, Jan. 2000.
Artigo em Inglês | MedCarib | ID: med-766

RESUMO

The expense and ineffectiveness of drift-based insecticide aerosols to control dengue epidemics has led to suppression strategies based on eliminating larval breeding sites. The present work attempts to estimate transmission thresholds for dengue based on an easily-derived statistic, the standing crop of Aedes aegypti pupae per person in the environment. We have developed these thresholds for use in the assessment of risk of transmission and to provide targets for the actual degree of suppression required to prevent or eliminate transmission in source reduction programs. The notion of thresholds is based on 2 concepts: the mass action principal- the course of an epidemic is dependent on the rate of contact between susceptible hosts and infectious vectors, and threshold theory - the introduction of a few infectious individuals into a community of susceptible individuals will not give rise to an outbreak unless the density of the vectors exceeds a certain critical level. We use validated transmission models to estimate thresholds as a function of levels of pre-existing antibody levels in human populations, ambient air temperatures, and the size and frequency of viral introduction. Threshold levels were estimated to range between about 0.5 and 1.5 Ae. aegypti pupae per person for ambient air temperatures of 28 degrees C and initial seroprevalences ranging between 0 percent to 67 percent. Suprisingly, the size of the viral introduction used in these studies, ranging between 1 and 12 infectious individuals per year was not seen to significantly influence the magnitude of the threshold. From a control perspective, these results are not particularly encouraging. The ratio of Ae. aegypti pupae to human density has been observed in limited field studies to range between 0.3 and >60 in 25 sites in dengue-epidemic of dengue-susceptible areas in the Caribbean, Central America, and South East Asia. If, for purposes of illustration, we assume an initial seroprevalence of 33 percent, the degree of suppression required to essentially eliminate the possibility of summertime transmission in Puerto Rico, Honduras, and Bangkok, Thailand was estimated to range between 10 percent and 83 percent; however in Mexico and Trinidad, reductions of >90 percent would be required.(AU)


Assuntos
21003 , Feminino , Humanos , Aedes/crescimento & desenvolvimento , Simulação por Computador , Dengue/transmissão , Insetos Vetores/crescimento & desenvolvimento , Modelos Biológicos , Anticorpos Antivirais/sangue , Dengue/epidemiologia , Dengue/prevenção & controle , Vírus da Dengue/crescimento & desenvolvimento , Honduras/epidemiologia , Mordeduras e Picadas de Insetos/epidemiologia , Mordeduras e Picadas de Insetos/virologia , México/epidemiologia , Porto Rico , Pupa/crescimento & desenvolvimento , Medição de Risco , Processos Estocásticos , Temperatura , Tailândia/epidemiologia , Trinidad e Tobago/epidemiologia
2.
The American journal of tropical medicine and hygiene ; 62(1): 11-18, Jan. 2000. tab, graf
Artigo em Inglês | MedCarib | ID: med-17779

RESUMO

The expense and ineffectiveness of drift-based insecticide aerosols to control dengue epidemics has led to suppression strategies based on eliminating larval breeding sites. With the notable but short-lived exceptions of Cuba and Singapore, these source reduction efforts have met with little documented success; failure has chiefly been attributed to inadequate participation of the communities involved. The present work attempts to estimate transmission thresholds for dengue based on an easily-derived statistic, the standing crop of Aedes aegypti pupae per person in the environment. We have developed these thresholds for use in the assessment of risk of transmission and to provide targets for the actual degree of suppression required to prevent or eliminate transmission in source reduction programs. The notion of thresholds is based on 2 concepts: the mass action principal-the course of an epidemic is dependent on the rate of contact between susceptible hosts and infectious vectors, and threshold theory-the introduction of a few infectious individuals into a community of susceptible individuals will not give rise to an outbreak unless the density of vectors exceeds a certain critical level. We use validated transmission models to estimate thresholds as a function of levels of pre-existing antibody levels in human populations, ambient air temperatures, and size and frequency of viral introduction. Threshold levels were estimated to range between about 0.5 and 1.5 Ae. aegypti pupae per person for ambient air temperatures of 28 degrees C and initial seroprevalences ranging between 0% to 67%. Surprisingly, the size of the viral introduction used in these studies, ranging between 1 and 12 infectious individuals per year, was not seen to significantly influence the magnitude of the threshold. From a control perspective, these results are not particularly encouraging. The ratio of Ae. aegypti pupae to human density has been observed in limited field studies to range between 0.3 and >60 in 25 sites in dengue-endemic or dengue-susceptible areas in the Caribbean, Central America, and Southeast Asia. If, for purposes of illustration, we assume an initial seroprevalence of 33%, the degree of suppression required to essentially eliminate the possibility of summertime transmission in Puerto Rico, Honduras, and Bangkok, Thailand was estimated to range between 10% and 83%; however in Mexico and Trinidad, reductions of >90% would be required. A clearer picture of the actual magnitude of the reductions required to eliminate the threat of transmission is provided by the ratio of the observed standing crop of Ae. aegypti pupae per person and the threshold. For example, in a site in Mayaguez, Puerto Rico, the ratio of observed and threshold was 1.7, meaning roughly that about 7 of every 17 breeding containers would have to be eliminated. For Reynosa, Mexico, with a ratio of approximately 10, 9 of every 10 containers would have to be eliminated. For sites in Trinidad with ratios averaging approximately 25, the elimination of 24 of every 25 would be required. With the exceptions of Cuba and Singapore, no published reports of sustained source reduction efforts have achieved anything near these levels of reductions in breeding containers. Practical advice on the use of thresholds is provided for operational control projects.


Assuntos
Animais , Humanos , Feminino , Aedes/crescimento & desenvolvimento , Anticorpos Antivirais/sangue , Simulação por Computador , Dengue/epidemiologia , Dengue/prevenção & controle , Dengue/transmissão , Vírus da Dengue/crescimento & desenvolvimento , Mordeduras e Picadas de Insetos/epidemiologia , Mordeduras e Picadas de Insetos/virologia , Insetos Vetores/crescimento & desenvolvimento , Pupa/crescimento & desenvolvimento , Modelos Biológicos , Medição de Risco , Processos Estocásticos , Temperatura , Trinidad e Tobago/epidemiologia , Tailândia/epidemiologia , México/epidemiologia , Porto Rico/epidemiologia , Honduras/epidemiologia
4.
Rev. panam. salud publica ; 5(1): 66-67, Jan. 1999.
Artigo em Espanhol | MedCarib | ID: med-16912

RESUMO

Work-related accidents and illnesses cause significant economic and social losses in Latin America and the Caribbean. However, the lack of reliable and systematized data on that situation makes it harder for health authorities and business operators to make decisions and for workers and the general public to take steps to improve working conditions, reduce risks, and prevent those accidents and illnesses. To address that concern, the Program on Workers' Health of the Pan American Health Organization (PAHO) coordinated the Project on Systematizing Basic Data on Workers' Health in the Countries of the Americas. A report on the project issued in August 1998 contains results, conclusions, and recommendations based on data collected from 10 countries of the Region: Barbados, Brazil, Chile, Colombia, Costa Rica, Jamaica, Mexico, Panama, Peru, and Venezuela. As a follow-up to this research, PAHO is working to compile more specific information on occupational health in the countries of the Region, through an approach that would improve the quality of the information and make it easier to compare the data that is collected (AU)


Assuntos
Humanos , Saúde Ocupacional , América Latina , Região do Caribe , Acidentes de Trabalho , Medição de Risco , América
5.
Sex Transm Infect ; 74(Suppl. 1): S123-7, Jun. 1998.
Artigo em Inglês | MedCarib | ID: med-1415

RESUMO

OBJECTIVES: To assess sexually transmitted diseases (STD) among women attending Jamaican family planning clinics and to evaluate decision models as alternatives to STD laboratory diagnosis. METHODS: Women attending two family planning clinics in Kingston were interviewed and tested for syphilis seroreactivity using toluidine red unheated serum test and Treponema pallidum haemagglutination, for gonorrhoea using culture, for chalamydial infection using enzyme linked immunoassay, and for trichomoniasis using culture. Urine was tested with leucocyte esterase dipstick (LED). The women were treated based upon a clinical algorithm. Computer simulations explored the use of risk inclusive decision models for detection of cervical infection and/or trichomoniasis. RESULTS: Among 767 women, 206 (26.9 percent) had at least one STD. The prevalence of gonorrhoea was 2.7 percent: chlamydial infection 12.2 percent, gonococcal and/or chlamydial cervical infection 14.1 percent; trichomoniasis 11.5 percent; syphilis seroreactivity 5.9 percent. The clinical algorithm was 3.7 percent sensitive and 96.7 percent specific in detecting cervical infection. Detection of cervical infection and/or trichomoniasis was 63.5 percent sensitive and 60.6 percent specific using LE and 57.7 percent sensitive and 46.2 percent specific using the risk inclusive algorithm employed in Jamaica STD clinics. Either cervical friability or LED (+) or family planning clinic attender less than 25 years old with more than one sexual partner in the past year was 72.5 percent sensitive and 53.3 percent specific. The positive predictive values of the STD clinic algorithm, LED, and two developed decision models ranged from 25.0 percent to 33.4 percent to detect cervical infection and/or trichomoniasis in these women. CONCLUSION: STDs were quite prevalent in these mainly asymptomatic family planning clinic attenders. None of the evaluated decision models can be considered a good alternative to case detection using laboratory diagnosis. Appropriate detection tools are needed. In the meantime, available STD control strategies should be maximised, such as promotion of condom use; adequate treatment of symptomatic STD patients and partners; and education of women and men (AU)


Assuntos
Adulto , Feminino , Humanos , Serviços de Planejamento Familiar/estatística & dados numéricos , Infecções Sexualmente Transmissíveis/epidemiologia , Algoritmos , Tomada de Decisões , Ensaios Enzimáticos Clínicos , Jamaica/epidemiologia , Prevalência , Medição de Risco , Parceiros Sexuais , Sorodiagnóstico da Sífilis , Infecções Sexualmente Transmissíveis/diagnóstico
6.
Clincal Science ; 87(5): 587-91, 1994.
Artigo em Inglês | MedCarib | ID: med-4780

RESUMO

We analysed the lumbar spine (L2-L4) and femoral neck bone mineral density results of Caucasian (n=2232), Asian (Indian sub-continent) (n=153) and Afro-Caribbean (n=102) women referred for bone densitomery over a 30 month period. To assess the risk of osteoporisis, the result of Caucasian and Asian Women were compared with those of a reference Caucasian population supplied by Lunar. Subject characteristics were similar in all three groups, other than expected ethnic differences in stature and weight. We found that lumbar spine and femoral neck bone mineral density in Caucasians was lower than in Afro-Caribbeans, but higher than in Asians. Consistent with this, bone mineral density was also lower in Asians as compared with the reference Caucasian population, a higher proportion of Asian women were classified as being at increased risk of osteoporosis than Caucasian women. Since ethnic differences in skeletal size might influence bone mineral density, we also obtained values for bone mineral content in Caucasian and Asian women that were corrected for projected skeletal area, and weight and years since menopause, using regression equations derived from the Caucasian study population. After this analysis, the difference in bone mineral content between Caucasian and Asians at the lumbar spine disappeared, while that at the femoral neck persisted. We conclude that the assessment of risk of osteoporosis in Asian women by comparing bone mineral density with a reference Caucasian population may have limited validity because of the influence of skeletal size on such measurements (AU)


Assuntos
Adulto , Pessoa de Meia-Idade , Feminino , Humanos , Estudo Comparativo , Densidade Óssea , Etnicidade , Osteoporose Pós-Menopausa/fisiopatologia , Adolescente , Idoso de 80 Anos ou mais , Idoso , Absorciometria de Fóton , Londres , Osteoporose Pós-Menopausa/prevenção & controle , Estudos Retrospectivos , Valores de Referência , Medição de Risco
7.
CAREC surveillance report ; 17(5): 1-7, May 1991.
Artigo em Inglês | MedCarib | ID: med-17244

RESUMO

Given the growing epidemic of cholera in South America since January, 1991, PAHO Managers, meeting in Belize April 29th - May 1st, asked Carec/Paho to host an emergency meeting on Cholera Preparedness in the Caribbean. The objectives of the meeting, held May 16th-17th, were to review cholera occurrence in the Americas to date; to assess the risk to CAREC member countries and measures taken and to develop recommendations, strategies and plans for prevention of occurence, early detection and control of cholera (AU)


Assuntos
Humanos , Epidemiologia de Desastres , Medição de Risco , Planejamento em Desastres , Guiana/epidemiologia , Jamaica/epidemiologia , Dominica/epidemiologia , Monitoramento Epidemiológico , Saneamento em Desastres , Cólera , Diarreia , Região do Caribe
8.
West Indian med. j ; 37(Suppl): 17, 1988.
Artigo em Inglês | MedCarib | ID: med-6631

RESUMO

A feasibility study was carried out on the use of a perinatal information system at the Mt. Hope Women's Hospital (MHWH). This system consists of the Simplified Perinatal Clinical Record (SPCR), a personal computer and a specially designed software package. The information system identifies high-risk pregnancies and provides statistical analysis on perinatal mortality and morbidity. Data from 1,000 consecutive deliveries at the MHWH from the 1st January to 28th February, 1986, were collected on the SPCR forms and analysed on a personal computer. The syste was easy to use. The results obtained indicated an apparent increase in the stillbirth rate in 1986 as compared to 1981 - 1984. It identified chronic anaemia (13.4 percent) and pre-eclampsia (8.0 percent as the two main causes of maternal pathology. It is recommended that this perinatal information system, with slight modification, should be introduced generally in Trinidad and Tobago and the rest of the Caribbean. (AU)


Assuntos
Humanos , Feminino , Gravidez , Recém-Nascido , Assistência Perinatal/estatística & dados numéricos , Medição de Risco , Interpretação Estatística de Dados , Trinidad e Tobago , Sistemas Computadorizados de Registros Médicos
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