Schistosoma mansoni Vector Snails in Antigua and Montserrat, with Snail-Related Considerations Pertinent to a Declaration of Elimination of Human Schistosomiasis.

Investigations leading to a WHO-validated declaration of elimination of schistosomiasis transmission are contemplated for several countries, including Caribbean island nations. With assistance from the Pan American Health Organization, we undertook freshwater snail surveys in two such nations, Antigua and Barbuda, and Montserrat in September and October 2017. Historically, the transmission of Schistosoma mansoni supported by the Neotropical vector snail Biomphalaria glabrata occurred in both countries. Transmission on the islands is thought to have been interrupted by the treatment of infected people, improved sanitation, introduction of competitor snails, and on Montserrat with the eruption of the Soufrière volcano which decimated known B. glabrata habitats. Guided by the available literature and local expertise, we found Biomphalaria snails in seven of 15 and one of 14 localities on Antigua and Montserrat, respectively, most of which were identified anatomically and molecularly as Biomphalaria kuhniana. Two localities on Antigua harbored B. glabrata, but no schistosome infections in snails were found. For snail-related aspects of validation of elimination, there are needs to undertake basic local training in medical malacology, be guided by historical literature and recent human schistosomiasis surveys, improve and validate sampling protocols for aquatic habitats, enlist local expertise to efficiently find potential transmission sites, use both anatomical and molecular identifications of schistosomes or putative vector snail species found, if possible determine the susceptibility of recovered Biomphalaria spp. to S. mansoni, publish survey results, and provide museum vouchers of collected snails and parasites as part of the historical record.

Modifying continuous ambulatory peritoneal dialysis for the Caribbean

Continuous ambulatory peritoneal dialysis (CAPD) is currently estimated to cost over BDS$20,000 [US$1=BDS$2] per year, twice the estimated cost of hemodialysis in Barbados. In addition CAPD has a higher rate of more serious complications. However, this method is preferred for the treatment of children and is the only service available to patients with chronic renal failure who live on islands with no hemodialysis service or those patients who are denied access to hemodialysis because of hepatitis, HIV infection or those with no vascular access. CAPD will only be a feasible option for Caribbean patients if the complication rates are reduced significantly and if the cost of providing the service is reduced. This paper presents the results of a pilot study which sought to identify ways in which CAPD can be adopted for use in the Caribbean. Ten patients were treated with CAPD over a period of 18 months; six of them continue to be dialysed satisfactorily. Two utilize a modified protocol which costs BDS$500 per month. Two patients have had severe problems with peritonitis and are expected to stop this method of dialysis as soon as alternatives are available. Two other patients have died, one from complications of diabetes mellitus, and the other after voluntary withdrawal of dialysis. Further modifications to make CAPD in Barbados economically feasible will require training of staff, identification of a designated CAPD Unit and team and a cheaper supply of dialysis fluids and other CAPD supplies (AU)

Clustering of human T lymphotropic virus type 1 seropositive in Montserrat, West Indies: evidence for an environmental factor in transmission of the virus

A community survey of human T cell lymphotropic virus type I (HTLV-I) in Montserrat, West Indies, identified 22 instances in which 2 HTLV-I-seropositive adults lived within 60 m of each other (close pairs), compared with 7.8 expected (P<.001). Five of these close pairs were mother offspring or husband-wife. The remaining 17 pairs were of unrelated members in separate households. The percentages of male-female (41 percent), female-female (41 percent), and male-male (18 percent) types in these 17 pairs were similar to those among the 1377 similarly defined pairs in which neither or only 1 member was seropositive, affording no support for extramarital heterosexual activity as an explanation for the clustering observed. Thus, the demography of HTLV-I was not accounted for completely by sexual and mother-to-offspring tranmission. The predominace of clustering of unrelated HTLV-I-seropositive individuals in locations with high mosquito infestation raised the possibility of sporadic transmission of HTLV-I by hematophagous insects (AU)

HTLV-1 and dengue seropositivity in Montserrat - abstract

Over 80 percent of the adult population of three villages in Montserrat donated blood samples for screening for HTLV-I and dengue antibodies. Twenty-five (7.2 percent) of the 349 samples tested were positive for HTLV-I antibodies and 17 of them live in 4 clusters of neighbouring households which was statistically significant. This clustering was not primarily due to viral or mother-to-child transmission but was the result of related and unrelated seropositive individuals living near to each other far more frequently than by chance alone. Two hundred and two (61 percent) of 331 samples tested were seropositive for dengue. Dengue seropositivity prevalence rates increased markedly with age and showed a strong difference in prevalence by altitude. This high prevalence of dengue seropositivity was surprising since no epidemics of dengue fever were reported in Montserrat. There is no evidence to support the hypothesis that the same insect vectors have a role in both dengue and HTLV-I transmission. However, the clustering observed, the inverse relation between HTLV-I sero prevalence and altitude and the failure of HTLV-I to establish itself in temperate climates, justify the need for further studies (AU)

Pelvic inflammatory disease in Montserrat - abstract

During the period, January 1989 to December 1990, 41 women or 25 percent of all female patients between the ages of 15 and 50 years who presented to a private family practice were diagnosed as having pelvic inflammatory disease (PID). Seventy-eight per cent were between the ages of 20 and 40 years, 83 percent presented with pain, 56 percent with vaginal discharge and 15 were infertile. Fifty-one percent were treated with a combination of tetracyline and metronidazole and 22 percent with cotrimoxazole. Seventy-four per cent obtained a symptomatic cure and 26 percent continued with persistent pain. Forty-five per cent of 11 patients presenting with rupture tubal pregnancy gave a history of previous PID. A review of the results of bacteriological investigation of women with PID over the period January 1989 to December 1990 showed that 49.7 percent had no pathogens, 26.4 percent had candida albicans, 8.2 percent trichomonas, 46 percent E. Coli, 4.6 percent haemophilus, 4.4 percent streptococcus, 15 percent N. Gonorrhea and 10.4 percent other organisms (AU)

Helminthiasis in Montserrat after the parasite control programme and hurricane Hugo - abstract

The Parasite Control Programme of Montserrat, West Indies, was a child-targeted chemotherapeutic control programme which ran from August 1986 to July 1989. The Programme involved the delivery of a broad spectrum antihelminthic to children (2-15 years old) once every school term. Two months after the end of the Programme, Hurricane Hugo devastated Montserrat on September 17, 1989. The Health Department (Montserrat) felt that the reductions in prevalence and intensity of Trichuris trichiura and Ascaris lumbricoides gained as a result of the Programme would be compromised by the disruption to sanitation and water supply caused by Hugo. In December 1989, a cycle of treatment was therefore administered to the child target group using the same infrastructure and procedure as that used in the Control Programme. The treatment compliance was 97.0 percent of the student population (n=2,125). Six months later, an age-stratified survey was done to assess the level of infection in the population and the age-standardised prevalence of T. trichiura for the overall population. Changes in the age-standardised intensity of both helminths before and after Hugo were recorded for the overall population: for T. trichiura the intensity went from 0.8 to 1.5 epg-faeces, while for A. lumbricoides the intensity rose from 1.2 to 1.7 epg.faeces. The observed rise in the infection levels of the overall population not statistically significant. The changes seen in the prevalence and intensity of both parasites taken from the surveys before and after Hugo were all found to be non-significant. There appeared to have been a non-significant increase in parasitic infection levels 9 months after Hugo to levels seen in the latter part of the Control Programme (AU)

Post-disaster epidemiological surveillance following Hurricane Hugo in Montserrat - abstract

Hurricane Hugo struck the island of Montserrat during the night of 17th September, 1989. Sustained winds of 130 mph were experienced for 8 hours with damage to 93 per cent of buildings; 50 per cent seriously and 20 per cent destroyed. The main hospital lost its roof and most health centres were severely affected. Two thousand five hundred persons were rendered homeless, of whom 1,000 were housed in shelters. Three days after, environmental health surveillance revealed unsatisfactory conditions in shelters with inadequate water supplies and faecal disposal. Water was trucked to shelters and a pit latrine programme commenced so that by the first week of October, all shelters had acceptable faecal disposal facilities. Island-wide, symptom-based daily reports of disease surveillance was introduced 9 days after the hurricane for respiratory infections and gastroenteritis. This allowed daily monitoring of disease occurrence by locality, targeting of health education and environmental health measures, and made it easier to dispel rumors which occurred after the hurricane. There was an increase in gastroenteritis 10 - 14 days after, but this subsided as potable water supplies were established. One month after, 30 cases of fever of unknown origin were detected. At first suspected to be dengue fever, it turned out to be influenza A (hl, N1) (AU)

The age-targeted chemotherapeutic control of helminthic infections in Montserrat - abstract

This study describes the age-targeted chemotherapeutic control of Trichuris trichiura and Ascaris lumbricoides in the total population (n = 11,479) of Montserrat, West Indies. The intervention programme involved the treatment with a single dose albendazole of all children aged 2-15 years (approximately 2,500) in seven sequential cycles at 4 monthly intervals. Infection status was monitored by an initial coprological survey of an age-stratified sample (11.5 per cent) of the population, and by surveys of smaller samples (4-5 per cent) after two (7 months), 4 (15 months), 6 (23 months), and 7 (29 months) cycles of treatment. The programme delivered treatment to > 90 per cent of the target population at each cycle. The overall prevalence of T.trichiura fell from 12.1 per cent at the initial survey to 1.4 per cent 29 months later. Similarly, the prevalence and intensity of infection was observed to fall in both the target group and the adults (>15 years) even though the treatment of the latter was not actively sought. The study demonstrates that child targeted chemotherapy is effective and can be practically implemented within an existing health and educational infrastructure (AU)

Control of geohelminths by delivery of targeted chemotherapy through schools

This study describes the age-targeted chemotherapeutic control of geohelminthiasis in the total population (n=11 500) of the island of Montserrat, West Indies. The intervention programme involved the treatment with single dose albendazole of all children aged 2-15 years (approximately 2500) in 4 sequential cycles at intervals of 4 months. Infection status was monitored by an inital coprological survey of an age-stratified sample (11.5 percent) of the population, and by the surveys of smaller samples (4-5 percent) after 2 and 4 cycles of treatment (7 and 15 months respectively). The programme delivered treatment to >90 percent of the target population in each cycle, and reduced the prevalence and intensity of Ascaris lumbricoides and Trichuris trichiuria infection in the target age-class. A decline in infection was observed in the 16-25 year age class, even though 4 percent of adults received treatment. The study demonstrates that chemotherapy targeted only at children can be implemented within an existing health infrastructure, and can achieve an overall reduction in the prevalence and intensity of geohelminth infection. (AU)

Childhood handicap in Montserrat - abstract

Handicap in childhood is a worldwide phenomenon that is gaining an increasingly high priority as a health problem in developing countries. In Montserrat, prior to 1988, no attempt to define the prevalence, range or severity of handicap had been made. During February to April 1988, a programme of developmental screening in under-five-year-old children, with assessment of any identified problems, was introduced in Montserrat. As part of this programme, a register of handicapped children of all ages was compiled. Sixty children (2 per cent of approx. 3,000 children under 16 years old) with significant disability were identified. This was considerably more than local health workers expected. The main categories diagnosed were 12 with severe global disability, 21 with mental retardation, one with visual, hearing and speech problems only, 7 with physical disability and 3 with learning difficulties. Although all major handicapped children have probably been identified, these figures may still present an under-estimate; particularly of under-five-year-olds, who are not yet all screened, and school learning difficulties (surveys not yet completed). For realistic manpower and resource planning, it is essential that comprehensive handicap registers be compiled (AU)

The effect of targeted chemotherapy on the prevalence and intensity of helminthic infections in Montserrat - abstract

The Parasite Control Programme targeted treatment to all registered school children in Montserrat. The effect of this targeted chemotherapy was later assessed by two parasitological surveys and compared with a baseline survey conducted before the star of the treatment rogime. Once in a school term, between March 1987 and June 1988, students (2 to 15 years old) were given a dose of 400 mg albendazole. Adults were treated upon request or if they were diagnosed for an helminth infection. Parasitological surveys were done before and twice during the study period. Faecal specimens were collected through selected schools and district clinics, using an age-stratified protocol, and were processed by the Kato thick smear method. Six school visits were conducted with almost 96 percent of the students receiving treatment. The baseline survey sampled 12 percent (1,320 samples) of the island's population, while the September 197 survey sampled 4.6 percent (531 samples), and the May 1988 survey sampled 4.1 percent (472 samples). The overall prevalence oa Ascaris lumbricoides decreased from 2.0 percent to 0.6 percent to 0.2 percent at successive surveys. For Trichuris trichiura, the prevalence declined from 12.1 percent to 4.5 percent to 3.0 percent. From the baseline to each subsequent survey, the prevalence and intensity of both helminths showed a noticeable decrease in the child age groups. This implies that targeted chemotherapy to the school age population reduces the risk of morbidity due to i nfection and the potential for infection transmission from this group. A final island-wide parasitological survey will be carried out at the end of the programme to assess the longitudinal effects of targeted chemotherapy. This Programme is supported by the Ministry of Health, (Montserrat), Imperial Colloge (London) and Smith, Kline and French Labs. Ltd (AU)

An island-wide survey for helminth parasites in Montserrat, West Indies - abstract

In August 1986, a three-year Parasite Control Programme, based on the targeting of treatment to children, was started in Montserrat. The first phase of this programme was an island-wide population survey to assess the current prevalence and intensity of helminth infection. From August to December 1986, faecal specimens were collected through all four district clinics of each of the three health regions, using an age-stratified protocol. Samples were processed by the KATO Thick Smear method. Twelve per cent (1,320 samples) of the island's population was sampled by the survey; of this, 12.1 percent were positive for Trichuris trichiura, 2.0 percent for Ascaris lumbricoides, and less than 1.0 percent for hookworm, Schistosoma mansoni and Enterobius vermicularis. Children are therefore most at risk of morbidity and are the major source of infection. The treatment of children on a national scale should give maximum results for the minimum of doses dispensed, i.e. chemotherapy should be cost-effective. This programme is supported by the Ministry of Health, Montserrat and Smith, Kline and French Ltd. (AU)