Progress towards international adoption of the World Health Organization ultrasound classification of cystic echinococcosis.

Cystic echinococcosis (CE) is a global parasitic zoonosis for which ultrasound (US) is the gold standard modality for diagnosis. In 2003, the WHO published a standardized US classification of CE, on which WHO treatment guidelines are based. In 2014, global adoption of the classification was questioned by a publication which indicated that, between 2004 and 2014, only half of studies utilizing a classification used the WHO classification. More recent studies have demonstrated that the WHO classification best reflects the natural history of CE, and is used with high reliability by experts in the field; despite these attributes, the classification's impact is ultimately limited by the extent of its adoption. A PubMed search using the terms "Echinococcus granulosus ultrasound," "Echinococcus granulosus classification," "cystic echinococcosis ultrasound," and "cystic echinococcosus classification" revealed publications on human CE utilizing a US classification. Classification(s) used, year of publication, and the country of the first author's institution were recorded. From 2004 to 2010, the WHO classification was used in 50% or fewer of included publications for 6 of the 7 years. After 2011, it appeared in a low of 75% (2013) to a high of 96% (2017) of included publications. Of all included studies published from 2004 to 2017, the WHO classification was referenced in 18% (3 of 17) from Africa, 64% (32 of 50) from Asia, 79% (89 of 113) from Europe, 89% (8 of 9) from North America, and 100% (9 of 9) from South America. Findings suggest that the WHO classification has been progressively taking preference to other classifications, with rate of adoption depending on continent of origin of the research. Residual use of the classification developed by Dr. Hassen Gharbi of Tunisia in 1982, used widely prior to development of the WHO classification (which reversed two stages in Gharbi's classification in order to more closely reflect the natural history of CE) suggests that adoption of a new classification takes time and varies regionally.

Cystic echinococcosis in Turkana, Kenya: 30 years of imaging in an endemic region.

Cystic echinococcosis (CE), a widespread, complex zoonosis, causes chronic disease associated with high morbidity. The pastoral Turkana people of Kenya have one of the highest prevalence rates of CE in the world. Between 1983 and 2015, a CE control program in the Turkana region used ultrasound (US) screening surveys and surgical outreach visits to evaluate CE prevalence and treat those with the disease. As the gold standard modality for diagnosing CE, US reveals a great deal of information about the disease in affected populations. The aim of this study is to discuss the characteristics of untreated CE in the Turkana people as revealed by US data collected during the CE control program and evaluate disease presentation, factors influencing the risk of transmission, and the timeline of disease progression. Data were obtained from written patient notes from US screenings and images; cysts were classified using the World Health Organization (WHO) standardized US classification of CE. Findings include greater prevalence of cysts, later stages of cysts, and multiple cysts in older age groups, with no multiple cysts occurring in patients under six years of age, which are consistent with the assertion that rates of exposure, transmission, and infection increase with age in endemic regions. Findings also raise questions regarding the timeline of disease progression, and factors potentially influencing disease transmission within this and other endemic populations. A comprehensive survey focusing on cultural and community observations (e.g., changing behaviors, hygienic practices, etc.) may provide more detailed information regarding factors that facilitate transmission.

Production-level risk factors for syncytial hepatitis in farmed tilapia (Oreochromis niloticus L).

Syncytial hepatitis (SHT) is an emerging viral disease of tilapia characterized by significant morbidity and mortality. This study aimed to establish the production-level risk factors associated with presence and severity of SHT. Production factors were analysed during multiple outbreaks of SHT that occurred between 2011 and 2013 on a single tilapia farm in Ecuador and compared with the year 2010 before the SHT outbreaks. Relative risks, t tests, modified Poisson and forward stepwise linear regression analyses were performed using EPIINFO™. Compared to other strains, Chitralada had an elevated risk of SHT [RR = 2.1 (95%CI 1.8-2.4)]. Excessive mortality associated with the presence (and severity) of SHT increased by 611 (365), 6,814 (5,768) and 388 (340) deaths per 100,000 fry when stocking density, dissolved oxygen and pond production cycles were raised by 1 fish/m2 , 1 mg/L and 1 cycle, respectively. Excessive mortality associated with the presence (and severity) of SHT decreased by 337 (258) and 1,354 (1,025) deaths per 100,000 when stocking weight and water temperature increased by 1 g and 1°C, respectively. Time (season and stocking year) was not significantly associated with SHT. This study shows that some production factors increase the risk incidence and severity of SHTon a farm.

The natural history of cystic echinococcosis in untreated and albendazole-treated patients.

The World Health Organization (WHO) treatment protocols for cystic echinococcosis (CE) are based on the standardized ultrasound (US) classification. This study examined whether the classification reflected the natural history of CE in untreated and albendazole-treated patients. Data were collected during mass US screenings in CE endemic regions among transhumant populations, the Turkana and Berber peoples of Kenya and Morocco. Cysts were classified using the WHO classification. Patient records occurring prior to treatment, and after albendazole administration, were selected. 852 paired before/after observations of 360 cysts from 257 patients were analyzed. A McNemar-Bowker χ2 test for symmetry was significant (p<0.0001). 744 observations (87.3%) maintained the same class, and 101 (11.9%) progressed, consistent with the classification. Regression to CE3B occurred in seven of 116 CE4 cyst observations (6.0%). A McNemar-Bowker χ2 test of 1414 paired before/after observations of 288 cysts from 157 albendazole-treated patients was significant (p<0.0001). 1236 observations (87.4%) maintained the same class, and 149 (10.5%) progressed, consistent with the classification. Regression to CE3B occurred in 29 of 206 CE4 observations (14.1%). Significant asymmetry confirms the WHO classification's applicability to the natural history of CE and albendazole-induced changes. Regressions may reflect the stability of CE3B cysts.

Prevalence, serovars and antimicrobial susceptibility of Salmonella spp. from wild and domestic green iguanas (Iguana iguana) in Grenada, West Indies.

Cloacal swabs from 62 green iguanas (Iguana iguana), including 47 wild and 15 domestic ones from five parishes of Grenada, were sampled during a 4-month period of January to April 2013 and examined by enrichment and selective culture for the presence of Salmonella spp. Fifty-five per cent of the animals were positive, and eight serovars of Salmonella were isolated. The most common serovar was Rubislaw (58.8%), a serovar found recently in many cane toads in Grenada, followed by Oranienburg (14.7%), a serovar that has been causing serious human disease outbreaks in Japan. Serovar IV:48:g,z51 :- (formerly, S. Marina) highly invasive and known for serious infections in children in the United States, constituted 11.8% of the isolates, all of them being from domestic green iguanas. Salmonella Newport, a serovar recently found in a blue land crab in Grenada, comprised 11.8% of the isolates from the green iguanas. The remaining four less frequent serovars included S. Javiana and S. Glostrup. Antimicrobial susceptibility tests conducted by a disc diffusion method against amoxicillin-clavulanic acid, ampicillin, cefotaxime, ceftazidime, ciprofloxacin, enrofloxacin, gentamicin, nalidixic acid, streptomycin, tetracycline and trimethoprim-sulfamethoxazole showed that drug resistance is minimal, with intermediate susceptibility, mainly to streptomycin, tetracycline and cefotaxime. This is the first report of isolation and antimicrobial susceptibilities of various Salmonella serovars from wild and domestic green iguanas in Grenada, West Indies.

Seroprevalence of Toxoplasma gondii in pigs, sheep, goats, and cattle from Grenada and Carriacou, West Indies.

Prevalence of Toxoplasma gondii infection in pregnant women in Grenada is considered high. Little is known of the epidemiology of T. gondii infection in Caribbean Islands. Serum samples of 750 food animals in Grenada and Carriacou were tested for antibodies to T. gondii by the modified agglutination test (MAT). Antibodies to T. gondii (MAT, 1∶25 or higher) were found in 23.1% of 247 pigs, 44.1% of 204 sheep, 42.8% of 180 goats, and 8.4% of 119 cattle. Seroprevalence increased with age, indicating postnatal acquisition of T. gondii. Antibody titers of 1∶200 or higher were present in 65 of 90 seropositive sheep, 61 of 77 seropositive goats, and 23 of 57 seropositive pigs. However, none of the cattle had a MAT titer of 1∶200, suggesting that bovines are a poor host for T. gondii. Results indicate that pigs, sheep, and goats could be important sources of T. gondii infection if their meat is consumed undercooked.

Seroprevalence of Toxoplasma gondii and concurrent Bartonella spp., feline immunodeficiency virus, and feline leukemia virus infections in cats from Grenada, West Indies.

Toxoplasma gondii and Bartonella spp. are zoonotic pathogens of cats. Feline immunodeficiency virus (FIV) and feline leukemia virus (FeLv) are related to human immunodeficiency virus, and human leukemia virus, respectively; all of these viruses are immunosuppressive. In the present study, the prevalence of antibodies to T. gondi, Bartonella spp., FIV, as well as FeLv antigen were determined in sera from 75 domestic and 101 feral cats (Felis catus) from the Caribbean island of Grenada, West Indies. Using a modified agglutination test, antibodies to T. gondii were found in 23 (30.6%) of the 75 pet cats with titers of 1:25 in 1, 1:50 in 3, 1:400 in 4, 1:500 in 12, 1:800 in 2, and 1:1,600 in 1, and 28 (27.7%) of 101 feral cats with titers of 1:25 in 4, 1:50 in 7, 1:200 in 4, 1:400 in 1, 1:500 in 3, 1:800 in 2, 1:1,600 in 3, and 1:3,200 in 4. Overall, in both pet and feral cats, the seroprevalence increased with age. Antibodies to Bartonella spp. were found in 38 (50.6%) of the 75 pet cats and 52.4% of 101 feral cats. Antibodies to FIV were found in 6 domestic and 22 feral cats. None of the 176 cats was positive for FeLv antigen. There was no correlation among T. gondii, Bartonella spp., and FIV seropositivity.

Existence of Angiostrongylus cantonensis in rats (Rattus norvegicus) in Grenada, West Indies.

The zoonotic rat lung worm, Angiostrongylus cantonensis is endemic to Asia, North America, Africa and Australia. The parasite is expanding geographically and has recently been recorded in some of the Greater Antilles in the northern part of the Caribbean. In this study A. cantonensis is reported for the first time in the Lesser Antilles in one of the southernmost islands, Grenada. Between September 2005 and September 2006, 192 rats (Rattus norvegicus) were trapped throughout the island. The rats were anesthetized, exsanguinated, necropsied and the lungs were fixed whole in 10% buffered formalin, trimmed, processed, cut at 3microm, stained with hematoxylin and eosin and examined microscopically. A total of 45 (23.4%) of the 192 rats examined were found to be infected with A. cantonensis and adult worms were found in the cardiopulmonary system of one of the rats. Microscopically, pulmonic lesions, consisting of pulmonary thrombosis, hypertrophy of pulmonary arteries and granulomatous pneumonia were associated with intralesional adults, larvae and embryonated eggs of A. cantonensis. An incidental finding of variably sized (2-7mm) solitary to multiple cysts containing larvae of Taenia taeniaformis were seen in the livers of 57 rats. This report of A. cantonensis in Grenada provides evidence of the further global expansion of this important zoonotic parasite and the public health implications of this discovery is discussed.

Prevalence of gastrointestinal parasites in free-range poultry in Grenada, West Indies.

Rural poultry production systems in Grenada are based on the scavenging indigenous domestic fowl (Gallus domesticus), the predominant species in the poultry sector. This study was done to establish the species and frequency of gastrointestinal parasites in 106 free-ranges chickens ages between 1-2 years, and collected from 13 households. Three nematodes and one tapeworm were identified: Gongylonema ingluvicola (29.2%); Ascaridia galli (10.3%); Heterakis gallinarum (4.7%); Capillaria contorta (2.83%); Railietina tertagona (38.6%). Helminth infections in free-range chickens, even when they occur in low numbers, may result in subclinical disease. High numbers can produce clinical disease. Further studies may be required to devise appropriate prevention and control methods, with improved management systems. This is the first report of gastrointestinal parasites of free-ranging poultry in Grenada.

Prevalence of gastrointestinal parasites in free-range poultry in Grenada, West Indies.

Rural poultry production systems in Grenada are based on the scavenging indigenous domestic fowl (Gallus domesticus), the predominant species in the poultry sector. This study was done to establish the species and frequency of gastrointestinal parasites in 106 free-ranges chickens ages between 1-2 years, and collected from 13 households. Three nematodes and one tapeworm were identified: Gongylonema ingluvicola (29.2%); Ascaridia galli (10.3%); Heterakis gallinarum (4.7%); Capillaria contorta (2.83%); Railietina tertagona (38.6%). Helminth infections in free-range chickens, even when they occur in low numbers, may result in subclinical disease. High numbers can produce clinical disease. Further studies may be required to devise appropriate prevention and control methods, with improved management systems. This is the first report of gastrointestinal parasites of free-ranging poultry in Grenada.

Prevalence of Toxoplasma gondii in rats (Rattus norvegicus) in Grenada, West Indies.

Cats are important in the natural epidemiology of Toxoplasma gondii, because they are the only hosts that can excrete environmentally resistant oocysts. Cats are infected with T. gondii via predation on infected birds and rodents. During 2005, 238 rats (Rattus norvegicus) were trapped in Grenada, West Indies, and their sera along with tissue samples from their hearts and brains were examined for T. gondii infection. Antibodies to T. gondii were assayed by the modified agglutination test (MAT, titer 1:40 or higher); only 2 (0.8%) of 238 rats were found to be infected. Brains and hearts of all rats were bioassayed in mice. Toxoplasma gondii was isolated from the brain and the heart of only 1 rat, which had a MAT titer of 1:320. All of 5 mice inoculated with the heart tissue, and the 5 mice inoculated with the brain tissue of the infected rat remained asymptomatic, even though tissue cysts were found in their brains. Genetically, the isolates of T. gondii from the heart and the brain were identical and had genotype III by using the SAG1, SAG2, SAG3, BTUB, and GRA6 gene markers. These data indicate that rats are not important in the natural history of T. gondii in Grenada.

Isolation, tissue distribution, and molecular characterization of Toxoplasma gondii from chickens in Grenada, West Indies.

The prevalence of Toxoplasma gondii in free-range chickens is a good indicator of the prevalence of T. gondii oocysts in the soil because chickens feed from the ground. The prevalence of T. gondii in 102 free-range chickens (Gallus domesticus) from Grenada was determined. Antibodies to T. gondii were assayed by the modified agglutination test (MAT). Antibodies were found in 53 (52%) chickens with titers of 1:5 in 6, 1:10 in 4, 1:20 in 4, 1:40 in 4, 1:80 in 15, 1:160 in 9, 1: 320 in 5, 1:640 in 4, and 1:1,280 or greater in 2. Hearts, pectoral muscles, and brains of 43 seropositive chickens with MAT titers of 1:20 or greater were bioassayed individually in mice. Tissues of each of 10 chickens with titers of 1:5 and 1:10 were pooled and bioassayed in mice. Tissues from the remaining 49 seronegative chickens were pooled and fed to 4 T. gondii-free cats. Feces of cats were examined for oocysts; they did not shed oocysts. T. gondii was isolated from 35 of 43 chickens with MAT titers of 1:20 or greater; from the hearts, brains, and pectoral muscles of 2, hearts and brains of 20, from the hearts alone of 11, and brains alone of 2. T. gondii was isolated from 1 of 10 chickens with titers of 1:5 or 1:10. All 36 T. gondii isolates were avirulent for mice. Genotyping of these 36 isolates using polymorphisms at the SAG2 locus indicated that 29 were Type III, 5 were Type I, 1 was Type II, and 1 had both Type I and Type III. Genetically, the isolates from Grenada were different from those from the United States; Type II was the predominant type from the United States. Phenotypically, all isolates from Grenada were avirulent for mice, whereas those from Brazil were mouse-virulent. This is the first report of isolation of T. gondii from chickens from Grenada, West Indies.

Beta-haemolytic streptococci in school children 5-15 years of age with an emphasis on rheumatic fever, in the tri-island state of Grenada.

The objective of this study is to determine the prevalence of beta-haemolytic streptococci in the pharynx and antibodies to beta-haemolytic streptococci in school children 5-15 years of age in the tri-island state of Grenada Blood samples and throat swabs were obtained from 1388 school children, aged 5-15 years old attending randomly selected schools in each parish of the tri-island state of Grenada. Serum samples were subjected to antistreptolysin o testing (ASOT) while throat swabs were cultured on sheep blood agar plates. The prevalence of positive throat swab was 15.4% (95% CI = 13.4%, 17.2%). The rate was highest in St Patrick (21.8%) and lowest in Carriacou (5.7%). The prevalence of antibodies was 38.6% (95% CI = 37.6%, 42.8%). It was highest in St Patrick (54.4%) and lowest in Petit Martinique (26.8%). In St Patrick, males were significantly more likely than females to have a positive ASOT (p = 0.0084). In St George's, males were significantly more likely than females to have a positive throat culture (p = 0.0172). Thirty-four per cent of the positive cultures were type A, 10% were type C and 56% type G. The data illustrate that there is a high prevalence of beta-haemolytic streptococci in school children in certain parishes in Grenada. Public health measures should address prevention and control of beta3-haemolytic streptococcal infection in order to prevent the possible sequelae of this disease.

Beta-haemolytic streptococci in school children 5-15 years of age with an emphasis on rheumatic fever, in the tri-island state of Grenada / Estreptococos Beta-hemolíticos en Escolares de 5 a 15 años de edad con Énfasis en la Fiebre Reumática en el Estado Triinsular de Granada

The objective of this study is to determine the prevalence of beta-haemolytic streptococci in the pharynx and antibodies to beta-haemolytic streptococci in school children 5-15 years of age in the tri-island state of Grenada Blood samples and throat swabs were obtained from 1388 school children, aged 5-15 years old attending randomly selected schools in each parish of the tri-island state of Grenada. Serum samples were subjected to antistreptolysin o testing (ASOT) while throat swabs were cultured on sheep blood agar plates. The prevalence of positive throat swab was 15.4 (95 CI = 13.4, 17.2). The rate was highest in St Patrick (21.8) and lowest in Carriacou (5.7). The prevalence of antibodies was 38.6 (95 CI = 37.6, 42.8). It was highest in St Patrick (54.4) and lowest in Petit Martinique (26.8). In St Patrick, males were significantly more likely than females to have a positive ASOT (p = 0.0084). In St George's, males were significantly more likely than females to have a positive throat culture (p = 0.0172). Thirty-four per cent of the positive cultures were type A, 10 were type C and 56 type G. The data illustrate that there is a high prevalence of beta-haemolytic streptococci in school children in certain parishes in Grenada. Public health measures should address prevention and control of beta3-haemolytic streptococcal infection in order to prevent the possible sequelae of this disease

El objetivo de este estudio es determinar el predominio de estreptococos ß-haemolíticos en la región faríngea y los anticuerpos de los estreptococos ß-hemolíticos en escolares de 5 a 15 años de edad en el Estado tri-insular de Granada. Se obtuvieron muestras de sangres e hisopos de garganta de 1,388 escolares comprendidos en las edades de 5 a 15 años, que asistían a escuelas seleccionadas de manera aleatoria, en cada parroquia del Estado tri-insular de Granada. Muestras de suero fueron sometidas a la prueba de antistreptolisina O (ASTO), mientras que las muestras tomadas de los hisopos de garganta fueron cultivadas en placas de agar de sangre bovina. La prevalencia de muestras de garganta positivas fue 15.4% (95% CI = 13.4%, 17.2%). Los por cientos más elevados correspondieron a Saint Patrick (21.8%) y los más bajos a Carriacou (5.7%). El predominio de anticuerpos fue de 38.6% (95% CI = 37.6%, 42.8%). El más alto correspondió a Saint Patrick (54.4%) y el más bajo a Petit Martinique (26.8%). En Saint Patrick, la probabilidad de tener un ASTO positivo (p=0.0084) fue significativamente más alta en los hombres que en las mujeres. En Saint George's, la probabilidad de tener un cultivo de garganta positivo, fue significativamente más alta en los hombres (p = 0.0172) que en las mujeres. El treinta y cuatro por ciento de los cultivos positivos fueron del tipo A, el 10% fue del tipo C y el 56% del tipo G. Los datos indican que hay un alto predominio de estreptococos ß-hemolíticos en los niños escolares en ciertas parroquias de Granada. Las medidas de salud públicas deben dirigirse a la prevención y control de la infección estreptocócica ß-hemolítica, a fin de prevenir las posibles secuelas de esta enfermedad

Cancer incidence and mortality in Grenada 1990-2000

This paper summarizes and discusses the available cancer incidence (1996-2000) and mortality data (1990-2000) for the tri-island Caribbean nation of Grenada, Carriacou and Petit Martinique. Data for the analysis came from three sources: the Grenada Department of Statistics, the histopathology specimen books from St George's General Hospital and the Death Registry of the Ministry of Health, Grenada. The age-standardized rates (ASR) per 100 000 for all cancer sites combined were 170.2 in females and 158.2 in males. The four most frequent diagnoses (ASR) by cancer site in females were cervix (60.7), breast (49.1), uterus (28.4) and skin (13.3); and among males, prostate (61.4), bladder (16.3), skin (19.3) and stomach (10). Age-standardized mortality rates per 100 000 for all cancer sites combined were 105.4 in females and 165 in males. The four most frequent cancer associated mortalities (ASR) in females were breast (17.9), uterus (11.2), colon (10.3) and cervix (9.7); and among males, prostate (53.6), lung (18.7), stomach (14.5) and colon (10.9). This study found statistically significant spatial trends for overall cancer mortality and temporal trends in incidence and mortality rates for prostate and for incidence rates of stomach cancer. These rates are compared with those from other areas in the Caribbean and the United States of America and encourage efforts to establish a cancer registry in Grenada

Cystic echinococcosis in the Berber of the Mid Atlas mountains, Morocco: new insights into the natural history of the disease in humans.

Precise knowledge of the natural history of cystic echinococcosis (CE) in humans remains somewhat arcane. The aim of the present study was to determine whether aspects of the natural history of established human infection with Echinococcus granulosus could be investigated by using a cross-sectional approach, in a community where CE was endemic. A mass ultrasound-screening survey, coupled with a questionnaire to record all previous surgical histories related to CE, was carried out amongst the primarily transhumant Berber people of the Mid Atlas mountains in Morocco. During two periods of intensive screening, of 10 days in May 2000 and 11 days in May 2001, 11,612 people, representing > 98% of the local population, were checked. One hundred and twenty six (1.1%) of the subjects--75 (59.5%) of the 6864 females investigated and 51 (40.5%) of the 4748 males--were found ultrasound-positive for CE. Overall, 14.1% of the CE cases detected were children aged 1-15 years (who made up 44% of the study population). Most (77.4%) of the ultrasound-positive subjects investigated were also found seropositive for CE. The frequency of a past history of surgery for CE increased with subject age (P = 0.024), 125 (1.1%) of the subjects being recorded as having had such surgery. The frequency of surgery for pulmonary CE was relatively constant in all age-groups, indicating that infection can occur at any time. The frequency of abdominal CE increased with age (R2 = 0.8102). Assuming that the incidence of infection remains fairly constant over time and that the longer a person spends in this endemic area the more likely it is that he or she will develop CE, then a progression from active through transitional to inactive CE should occur. The cysts observed by ultrasound in the present study were categorized, as type 1, 2, 3, 4 or 5, according to the new, standardized, ultrasound classification of CE developed by the World Health Organization (WHO). There was a clear exponential decline in the frequency of the various cyst types, from type 1 (the most frequent) to type 5 (the rarest). This decline validates the assumptions made, about the natural history of established CE, by those who developed the WHO's classification. The classification should therefore be invaluable to surgeons and clinicians, when they have to consider treatment options for patients with the various types of CE, and to policy makers trying to establish the economic costs of treating CE in endemic settings.

Cancer incidence and mortality in Grenada 1990-2000.

This paper summarizes and discusses the available cancer incidence (1996-2000) and mortality data (1990-2000) for the tri-island Caribbean nation of Grenada, Carriacou and Petit Martinique. Data for the analysis came from three sources: the Grenada Department of Statistics, the histopathology specimen books from St George's General Hospital and the Death Registry of the Ministry of Health, Grenada. The age-standardized rates (ASR) per 100 000 for all cancer sites combined were 170.2 in females and 158.2 in males. The four most frequent diagnoses (ASR) by cancer site in females were cervix (60.7), breast (49.1), uterus (28.4) and skin (13.3); and among males, prostate (61.4), bladder (16.3), skin (19.3) and stomach (10). Age-standardized mortality rates per 100 000 for all cancer sites combined were 105.4 in females and 165 in males. The four most frequent cancer associated mortalities (ASR) in females were breast (17.9), uterus (11.2), colon (10.3) and cervix (9.7); and among males, prostate (53.6), lung (18.7), stomach (14.5) and colon (10.9). This study found statistically significant spatial trends for overall cancer mortality and temporal trends in incidence and mortality rates for prostate and for incidence rates of stomach cancer. These rates are compared with those from other areas in the Caribbean and the United States of America and encourage efforts to establish a cancer registry in Grenada.

Public health education/importance and experience from the field. Educational impact of community-based ultrasound screening surveys.

The public health educational impact of community-based ultrasound (US) surveys for cystic echinococcosis (CE) can form an important part of the development about the awareness of the importance of the disease in an endemic area. In addition to identifying asymptomatic carriers and thereby facilitating early diagnosis and treatment, such surveys can be used to impart important educational messages at the individual, household, community, regional and national levels. US surveys are usually appealing to rural communities where such services are not available but where the technique is generally appreciated by its application in a wide field of medical applications. The qualities of the test (painless, non-invasive and gives instant recordable results) are also attractive to participants during such surveys and the majority of the population in a selected study area choose to be screened. Two such surveys were carried out amongst the Berber people of the mid-Atlas mountains in central Morocco in May 2000 and 2001. Over 11,000 people were screened in the two 10-day surveys. Informed consent had been obtained through community meetings and with the chiefs of villages prior to the surveys being conducted. Individuals who volunteered to be screened entered the study and as far as is known there were no refusals. The concept of voluntary participation, the explanation of the life cycle and clinical manifestations of the disease and its prevention are all-important educational messages. The occurrence of CE is almost always known in an endemic community but is usually very poorly understood leading in many cases to a fear of the disease, especially amongst families with an infected individual who has previously undergone surgery. During the US survey considerable attention was paid to provide educational input before, during and after the survey. Information was provided at the start of the survey to local leaders, doctors, veterinarians and school teachers on the aims of the study and to obtain informed consent. At the start of the study everyone was individually schooled about the route of transmission of the parasite and how this may be best prevented. The knowledge level of those screened was assessed by showing hydatid cysts, either freshly obtained from the abattoir of from photographs. Animal cysts were recognised by almost everyone but its transmission and link to human disease was invariably unknown. Patients found to be infected with CE were always confidentially counselled and followed up for treatment, if required. Treatment options were explained to the individual or to parents in the case of a child. Local physicians participated in discussions on the WHO guidelines for the treatment of CE and all cases were fully discussed providing an educational element for the local doctors. The 1% US prevalence found sent an important message to the local politicians and the perceived importance of the disease had an impact at the leadership level. Local leaders made calls for a control programme. The long term educational impact remains to be evaluated as does the role such surveys play in the future collaboration of communities with the implementation of a control programme.

Application of ultrasound in diagnosis, treatment, epidemiology, public health and control of Echinococcus granulosus and E. multilocularis.

The last 30 years have seen an impressive use of ultrasonography (US) in many fields of veterinary and clinical medicine and the technique is being increasingly applied to a wide variety of parasitic infections including the cestode zoonoses Echinococcus granulosus and E. multilocularis. US provides real-time results which are permanently recordable with a high resolution and diagnostic accuracy. These properties, coupled with the clinical value of the images obtained and the non-invasive nature of the test which is safe, require no special patient preparation time; it is easy to operate and this has resulted in the establishment of US as the diagnostic technique of choice for cystic (CE) and alveolar (AE) echinococcosis. The lack of ionizing radiation and side-effects mean that examination times are not restricted. The hand-held probes facilitate what amounts to a rapid, bloodless non-invasive laparotomy, enabling a search from an infinite number of angles for lesions producing information on their number, size and type of cysts, their location and clinical implications. Such clinical information has facilitated the development of treatment protocols for different cyst types. Less invasive surgical techniques, such as US guidance for PAIR (Puncture, Aspiration, Injection, Re-aspiration), PAIRD (PAIR plus Drainage) or PPDC (Percutaneous Puncture with Drainage and Curettage) are also possible. Longitudinal US studies have facilitated monitoring the effects of the outcome of treatment and chemotherapy. Portable ultrasound scanners which today weigh as little as a few pounds, powered by battery or generators have facilitated the use of the technique in mass community-based screening studies. The majority of these studies have been conducted in remote, low socio-economic areas where there were few, if any, hospitals, veterinary facilities, schools or trained personnel. The surveys led to the discovery of unexpectedly high prevalences of CE and AE in asymptomatic individuals of endemic areas and especially amongst transhumant or nomadic pastoralists living in various parts of the world. Screening for CE and AE is justified as an early diagnosis leads to a better prognosis following treatment. The application of US in field and clinical settings has led to a better understanding of the natural history of CE and AE and to the development of a WHO standardized classification of cyst types for CE. This classification can be used in helping define the treatment options for the different cysts found during the surveys, which in turn can also be used to calculate the public health cost of treating the disease in an endemic community. The case mix revealed can also influence the specificity (particularly proportions of cyst types CE4 and CE5 and cystic lesions--CL) of US as a diagnostic test in a particular setting. Community based US surveys have provided new insights into the public health importance of CE and AE in different endemic settings. By screening whole populations they disclose the true extent of the disease and reveal particular age and sex risk factors. Through the treatment and follow-up of all infected cases found during the mass screening surveys a drastic reduction in the public health impact of the disease in endemic communities can be achieved. Educational impacts of such surveys at the national, community and individual levels for both professional and lay people are beginning to be appreciated. The translation of the information gained into active control programmes remains to be realized. In areas where intermediate hosts, such as sheep and goats, are not slaughtered in large numbers mass US screening surveys to determine the prevalence of CE in livestock has proved possible. Longitudinal studies in such intermediate hosts would reveal changes in prevalence over time, which has been used as a marker for control success in other programmes. Mass US screening surveys in an ongoing control programme in Argentina has demonstrated the early impact of control in the human population and identified breakthroughs in that control programme. Mass US screening surveys must adhere to the highest ethical standards and the outcome of surveys should result in the application of appropriate WHO recommended treatment options for different cyst types. Follow-up strategies have to be in place prior to the implementation of such surveys for all infected individuals who do not require treatment and for all suspected, but not confirmed, cases found during the surveys. The use of US in community screening surveys has revealed the complexity of ethical issues (informed consent, confidentiality, follow-up, detection of lesions that are not the focus of the study etc) and also provided real solutions to providing the most ethical guidelines for the early detection and treatment of CE and AE.