The current prevalence and potential elimination of the soil transmitted helminth’s from Grenada

OBJECTIVE: This study formed part of a soil transmitted helminth elimination program in Grenada. The study assessed the prevalence of soil transmitted helminths (STH’s) in Grenadian primary school children. DESIGN AND METHODS: A longitudinal study was carried out on students attending 39 out of all 54 (72.2%) primary schools in Grenada, Carriacou and Petite Martinique between March 2013 and December 2014. The schools were randomly selected for inclusion in the study. Zinc Sulphate Floatation with centrifugation and Microscopy was used to assess the prevalence of STH’s in stool samples from Grenadian primary school children. RESULTS: The overall prevalence of STH was 1.3% (95% CI= 0.54-2.72). In 4 of the 8 parishes the prevalence was 0%. The highest prevalence was 3.9% (0.48-13.46) in St. Patrick. The STH identified were Ancylostoma duodenale, Ascaris lumbricoides and Trichuris trichuria. CONCLUSION: The prevalence of STH’s in the initial survey was 1.3%. This low prevalence indicates that the elimination program which utilizes a multi pronged approach including targeted chemotherapy and education may be feasible.

Short and long term knowledge of the transmission and prevention of soil transmitted helminths in primary schoolchildren assessed using Turning Point Technologies

OBJECTIVE: This study formed part of a soil transmitted helminth (STH) elimination program in Grenada. This study assessed the short and long term knowledge of primary school children on the transmission and prevention of STH using Turning Point Technologies. DESIGN AND METHODS: A longitudinal study was carried out on schoolchildren attending 39 out of all 54 (72.2%) primary schools from Grenada, Carriacou and Petite Martinique between March and November 2014. The schools were randomly selected for inclusion in the study. Turning Point Technology was used to assess the knowledge and administer the subsequent intervention to all students. The Pre, immediate-Post and long-term Post intervention (seven months later) data was analyzed using Chi Square. RESULTS: A total of 962 students participated in March 2014 and 805 students participated in October 2014. There was no significant (p< 0.05) inter school difference in the answering of questions. This displayed a ubiquitous knowledge transfer across the primary schools. There was a significant improvement in knowledge post turning point intervention, which was maintained at 7-months post-intervention. CONCLUSION: The advantages of using turning point technologies to impart this knowledge where class responses appear instantly, anonymously and can be used for immediate discussion were numerous. These include inter alia, active engaged participation.

Attitude, behavior and practice of primary school students with regard to soil transmitted helminths in Grenada

OBJECTIVE: To identify the attitude, behaviour and practice of parents, guardians and adolescents associated with Soil Transmitted Helminth’s (STH’s). DESIGN AND METHODS: A questionnaire was completed by 811 parents /guardians. The questionnaire posed questions on the socio economic, attitudes, behavior and practices of primary school students with regard to factors that could contribute to the transmission of STH’s in Grenada. RESULTS: 534 (66%) parents/guardian reported that their children regularly washed their hands before eating, 690 (85%) had an inside water supply, 465 (57%) had indoor toilets. Also, 579 (71%) said that their children never played around outdoor latrines and 326 (40%) said their children always wore shoes outdoors. 732 (90%) of the parents/guardians reported that vegetables and fruits were always washed before cooking and 662 (82%) said that their children had previously received de-worming medication. CONCLUSION: Practical recommendations such as in-house sanitation facilities and hand washing programs can be made. This will enable limited resources to be used more efficiently to combat the problem of transmission of STH’s.

An epidemiological overview of geohelminths and schistosomiasis in the Caribbean

The purpose of this publication is to provide a historical review of articles published on schistosomiasis and geohelminth infections in the Caribbean region. This is not an extensive overview of the entire region but rather one, which focuses on those nations and territories that have recent publications available. Efforts will be made in future revisions to examine countries and territories omitted from this review paper. The disease burden created by geohelminths as well as global prevalences will be discussed in this publication. In addition, various control and treatment methods will be explored. A summary of the data will be provided at the end of the publication (AU)

Intestinal parasites among young children in the interior of Guyana

Intestinal parasites contribute greately to morbidity in developing countries. While there have been several studies of the problem in the Caribbean, including the implementation of control programmes, this has not been done for Guyana. The aim of this study was to determine the prevalence of intestinal parasites among young children in a town located in the interior of Guyana. Eighty-five children under the age of 12 years were studied prospectively for intestinal parasites in Mahdia, Guyana. Stool samples were transported in formalin to the Department of microbiology, the University of the West Indies, Jamaica, for analysis using the formalin-ether concentration and Ziehl-Neelsen techniques. Data on age and gender of the children were recorded on field sheets. At least one intestinal parasite was detacted in 43.5 percent (37/85) of the children studied and multiple parasitic infections were recorded in 21.2 percent (18/85). The most common intestinal helminth parasite was hookworm (28.2 percent; 24/85), followed by Ascaris lumbricoides (18.8 percent; 16/85) and then Trichuris trichuria (14.1 percent; 12/85). Among the protozoan infections Giardia lamblia was detected in 10.5 percent (9/85) of the study population while Entamoeba histolytica appeared rarely. All stool samples were negative for Cryptosporidium and other intestinal Coccidia. There was no predilection for gender with any of the parasites. The pattern of distribution of worms in this area of Guyana was unlike that seen in other studies. Hookworm infection was the most common among the children and a large proportion had multiple infections. The study established the occurrence and prevalence of a number of intestinal parasites in the population of Guyana. This sets the stage for the design and implementation of more detailed epidemiological studies. (AU)

The changing picture of intestinal parasitoses in the Caribbean

The economic and public health importance of gastro-intestinal parasitoses varies enormously from country to country due to a complex interplay of organisms, the environment, the hosts involved, socio-economic conditions, and human behaviour. The major parasitoses include three roundworm species (nematodes) and three microscopic, unicellular (protozan) species. Infection with two or more species (polyparasitism) is not uncommon, and this aggregation of parasites leads to an increased morbidity and mortality. Aggregation may result from human behaviour, socio-economic conditions (level of education, water and sanitary conditions, ability to diagnose and treat infections etc.) and numerous still relatively arcane reasons, such as immunological and nutritional status and genetics (AU)

The prevalence of intestinal nematodes at the Adelphi All-age school in Saint James

A cross-sectional study of these rural school children was done to determine the level of infection in the school, and the types of geohelminths present. Data was collected through the use of one hundred and sixty-six (166) close-ended questionnaires, and the analysis of one hundred and nineteen (119) stool samples, and eighty (80) blood samples. A high prevalence of 22.3 percent was demonstrated in the school's population, with prevalence in the 10-12 age group reaching a high of 44 percent. Trichuris (13.4 percent), Ascaris (8.9 percent), and eosinophilia (6.4 percent), all showed significant prevalence. However, the prevalence of Hookworm (3.6 percent), and anaemia (2.6 percent), were not significant among the group. Infection strongly correlated with the eating of chalk and marl (a type of soil, composed chiefly of clay and limestone). The source of infection was identified as two marl pits located near the school, which are obviously used for indiscriminate defaecation. The construction of more latrines at the school, school health education, and public health education were recommended, to help eradicate worms from the school.(Au)

Pruritus ani: common infection and treatment

Pruritus ani is a manifestation of a wide spectrum of disease conditions. Infections form a minor aetiological fraction but include organisms from the various microbiological subdisciplines. Fungal causes of pruritus ani usually come from the normal flora, and can be diagnosed in the office, by microscopy using a mixture of potassium hydroxide and dimethyl sulfoxide. Parasites causing pruritus ani may be transmitted by direct contact, the faeco-oral or sexually. Treatment of scabies and enterobiasis should involve simultaneous treatment of family members. Articles of clothing and bed sheets must be exposed to heat. Lindane (gamma benzene hexachloride) should not be used in pregnant women and children under the age of two years to avoid potential neurotoxicity. Irrespective of the aetiology, severe pruritus ani predisposes to secondary bacterial infection (AU)

Immediate hypersensitivity in colon of children with chronic Trichuris trichiura dysentery

There are few data on mucosal immune responses to intestinal helminths in human beings, especially those involving the IgE system, which is thought to be important in parasite expulsion. We sought evidence of an immediate hypersensitivity reaction in the colon of children with chronic dysentery due to Trichuris trichiura. 28 children with Trichuris dysentery syndrome (TDS) were compared with 16 control children (with no TDS or worms visible on colonoscopy). All children were aged 1-11 years. Rectal biopsy samples were taken before and after expulsion of the worms by means of mebendazole treatment. Children wtih TDS had significantly greater numbers than controls of mast cells (mean [SD] 10.9 [1.3] vs 3.9 [0.6] percent of all cells; p<0.0003) and of cells with surface IgE (median [range] 11.1 [7.5-11.6] vs 1.0 [0-1.5] percent; p<0.001) in the subepithelial region of the mucosa. On electronmicroscopy, degranulating mast cells were prominent in parasitised children. In culture, rectal biopsy samples from parasitised children showed high rates of spontaneous histamine release, but only low rates of antigen-specific release. After treatment, spontaneous histamine release was significantly reduced and antigen-specific histamine release could be provoked. Thus, an IgE-mediated immune mucosal response to a helminth infection does occur in human beings but is not sufficient to cause appreciable parasite expulsion. (Summary)

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)

Parasitism and nutritional status of poor suburban Jamaican toddlers

A survey was conducted on 145 toddlers, 6-36 months of age, in a suburb in Kingston, Jamaica. The aim of the study was to measure the prevalence of and association between parasitism and nutritional status. Forty-two per cent were malnourished (<80 percent of standard weight for age), most commonly (76 percent) in the 12-17 month age group. Thirty-four per cent had one or more parasites, particularly Trichuris trichuria (21 percent) or Ascaris lumbricoides (19 percent). The peak prevalence of parasitism was among the 30-36 month old children (63 percent). Nutritional status did not differ between children with and without parasites. Most of them had light intensities of infection. Therefore, in this sample, there was no association between parasitism and nutritional status (AU)

Helminths and nutritional status in Jamaica toddlers - abstract

Malnutrition, ascariasis and trichuriasis are prevalent and co-exist among the poor. However, the nature of the relationship between nutritional status and helminthiasis remains unclear. We therefore compared the prevalence and intensity of infection with Trichuris trichuria and Ascaris lumbricoides in 11 to 25-month-old children in two groups from the same slum communities in Kingston, Jamaica. One group comprised 66 malnourished children (<90 percent weight-for-age) and the other 55 well-nourished children (<90 percent weight-for-age). Both groups of children had similar mean ages, comprised similar proportions of boys and girls and had similar socio-economic status. Duplicate faecal specimens were examined twice, using the Kato thick Smear technique. Infected children were treated with mebendazole (Janssen, Pharmaceuticals). Helminths occurred with similar prevalence among the well-nourished (38 percent) and the malnourished (44 percent) children. However, the prevalence was highest in the mildly wasted children (57 percent, n=30) and least in the moderately/severely wasted children (15 percent, p<0.05). Similar patterns were observed for both Ascaris and Trichuris. In both groups, the presence of helminths was positively associated with age (Xý = 10.7, p<0.05), acess to water (Xý = 9.1, p<0.05)and geophagia(Xý = 4.2, p<0.05). These results show that nutritional status alters the host-parasite relationship. Perhaps mild malnutrition increases whereas more severe malnutrition decreases susceptibility to helminths, as Bundy and Golden (Parasitolgy, 1987) have suggested (AU)

Experiments in schistosomiasis control in St. Lucia

The comparative parasitological effectiveness and cost of three methods of reducing transmission of S. mansoni were investigated in isolated valleys in the Caribbean island of St. Lucia. Changes in incidence were assessed during four years of snail control, community based chemotherapy and when households were provided with piped water and communities with laundry and shower units. Incidence was reduced by all methods, but most rapidly by chemotherapy. It increased, however, after a few years unless either focal snail control or water supplies with laundry and shower facilities were provided. Over a nine year period, chemotherapy was shown to be the least costly method of control (US $ 0.50/person/year), but this would be reduced with the use of recently introduced technology and drugs (AU)

The neurophysiological control and photosensory modulation of swimming in a cercaria, Cercaria caribbea LXXI

Scanning and transmission electron microscopy revealed that Cercaria caribbea LXXI has a small body (70 æm) with a pair of well-developed, rhabdomeric photoreceptors; and a large tail (4 mm) with six longitudinal, striated muscle bands. Muscle cells had an outer myofibrillar region adjecent to the tergument and an inner sarcoplasmic region, prolongations of which, may form sarconeural junctions. Sarcomere lengths were consistent with invertebrate fast muscle fibres. Diffuse Z-bands and the presence of numerous mitochondria are consistent with slow muscle fibres, adapted for prolonged work output. Interneuronal junctions with abundant electron-lucent and electron-dense vesicles, and neuromuscular junctions with mainly electron-lucent presynaptic vesicles were demonstrated. The neuromuscular connection between the body and tail appeared to be restricted to a single axon, implying that modulation of tail activity by the body may involve simple triggering or level setting actions, rather than complex modulation. The Falck-Hillarp Formaldehyde-Induced Fluorescence and the Gomori techniques indicated that the neuromuscular system utilizes primary catecholamines, serotonic (5-HT) and an acetylcholine-like transmitter. There were indications that 5-HT promotes activity and is held as a non-replenishable store, depleted through time within the cercarial tail. Exogenous application of a range of neuropharmacological agents, profoundly affected survivorship of the organism. Of the catecholaminergis group, propranolol (1.1-4 æM) and haloperidol (0.066-0.133 mM) most effectively reduced population half-line (T50). This was followed by the cholinergic agent, physostigmine (0.08-2.5 mM). The gamma-aminobutyric acid antagonist, picrotoxin (0.08-2.5mM), only weakly affected T50. Several drugs, especially reserpine (0.08-2.5mM), produced osmotic disturbances, leading to shortened life span. Survivorship was also dependent on pH, with a sharply defined tolerance range between pH 6 and 8. Suction electrodes recordings of electrical activity in the tail revealed spontaneous spike potentials (0.2-0.6 mV, 15-20/sec) superimposed on an underlying slow wave component. The effects of drugs on this activity were observed. 5-HT increased the amplitude and frequency of spike discharge from 0.2 mV to 0.8 mV and 15/sec to 25/sec, respectively. Physostigmine was the most effective reducer of both parameters. Indications were that cholinergic receptors in the nerve network may be excitatory nicotinic and inhibitory muscarinic. Excitatory beta adrenergic and inhibitory dopaminergic influences were observed. C. caribbea LXXI exhibited strong positive phototaxis. In response to light stimuli, the pigmented cercariae gave a maintained receptor potential with a small transient component. In the non-pigmented strain of C. caribbea LXXI, the photosensory receptor potential showed a large transient and a small maintained component. Drugs did not alter the photosensory response. A drug-induced decrease in linear translation towards a photic stimulus was therefore due to a disturbance in the neuromuscular system (AU)

The relative public morbidity caused by whipworm and roundworm - abstract

The whipworm's eggs are encountered more commonly than those of any other geohelminth in the stools of West Indian children. Eighty per cent (260) of the children aged 6 months to 6 years in the village of Anse-la-Rays, St. Lucia, were examined. A detailed history was taken by questionnaire, anthropometry, physical examination performed and stools collected. The physical examination and stool collection were repeated after two to three months. Of 9 children (3.4 percent) with reported rectal prolapse, seven had faecal egg counts indicative of heavy trichuris burdens, one other stool was positive at 1,440 eggs per gram (epg). 84 percent of all children (260) had trichuris; 62 percent, ascaris; 14 percent were ó 80 percent weight for age (WA); 7 percent 90 percent height for age (HA); 52 percent ó 15cm mid upper arm circumference (MUAC). 27 children with "Heavy Trichuris" i.e. egp > 25,000 and/or rectal prolapse, were significantly different from the rest of the population being between 2 and 4 years of age, 28 percent were ó 80 percent WA and ó 90 percent HA although MUAC was not different. Stool frequently and pica were positively associated with blood mucous and sand in the stool. Thirty-six children with "Heavy Ascaris" i.e. epg > 25000, were not significantly different to the total population. Our conclusion is that whipworm may cause more objective morbidity than roundworm to children, especially those over two years old. In a hyperendemic village massive trichuriasis is one of the most common factors associated with chronic diarrhoea (AU)

A community study of parasites, nutritional status and housing in young Jamaican children - abstract

Parasitic infections may contribute to gastoenteritis and protein-energy malnutrition (PEM) both important problems among young Caribbean children. We conducted an epidemiological study of the prevalence of parasitic infestation and its association with the environment and nutritional status of preschool age children in a poor Kingston neighbourhood. The sample comprised all the 145 children (6 -36 months old) in a defined area. There were equal numbers of boys and girls and in each of 5 age groups (6 - 11, 12 - 17, 18 -23, 24 -29, 30 -36 months). Single stool specimens were examined for helminth ova and protozoan cysts using the formolether method, with iodine staining for light microscopy. The children's weights and heights were measured and their guardians were interviewed about their housing, sanitation and social background. Thirty-four per cent of the children were infested with 1 - 5 organisms: Trichuris, 21 percent, Ascaris, 18 percent, with generally low - moderate loads (< 5,000 ova/500 mg stool). Giardia occurred in 12.6 percent with very few other protozoans (E. coli, 4.2 percent, C.mesnili, 2.1 percent and E. nana, 0.7 percent). The peak prevalence (70 percent) was among 30-36 month-olds, age being significantly positively associated with the presence of parasites (p 0.001). The infested children had significantly poorer sanitation and water facilities (p<0.05) and their parents had a lower educational level (p<0.05) than the non-infested. Sixty-one (42.9 percent) children had some degree of undernutrition with 13(9.1 percent)moderately - severly malnourished. Single stool specimens probably underestimated the true point prevalence and load of parasitic infestations. There was a significant positive association between nutritional status and the presence of parasites in this study, However, undernutrition occurred most often among young toddlers (12 - 17 months) and parasitic infestation among 30 - 36 month-olds. This suggests that parasitic infestation did not play an important role in the aetiology of PEM in this community (AU)