Status of intestinal parasites infection among primary school children in Kampongcham,Cambodia

A survey was made to find the extent of intestinal parasite infection in Kampongcham, Cambodia in February 2002. A total of 251 fecal specimens were collected from Tonlebat primary school children and examined by formalin-ether sedimentation technique. The overall infection rate of intestinal parasite was 54.2% (males, 57.3%; females, 50.8%). The infection rate of intestinal helminths by the species were as follows: Ascaris lumbricoides 26.3%, Echinostoma sp. 15.6%, hookworm 6.4%, Opisthorchis sp. 4.0%, Rhabditis sp. 2.4%, and Trichuris trichiura 0.4%. The infection rate of intestinal protozoa were as follows: E. coli 7.6%, G. lamblia 3.2%, I. butschlii 3.2%, and E. histolytica 0.8%. More than two different kinds of parasites were found in 16.7% of the stool samples. All the children infected were treated with albendazole, praziquantel and metronidazole according to parasite species. The results showed that intestinal parasites are highly endemic in this area.     

Plasmodium/intestinal helminth co-infections among pregnant Nigerian women.

Hospital based studies were conducted to investigate the occurrence of Plasmodium/intestinal helminth co-infections among pregnant Nigerian women, and their effects on birthweights, anaemia and spleen size. From 2,104 near-term pregnant women examined, 816 (38.8%) were found to be infected with malaria parasites. Among the 816 parasitaemic subjects, 394 (48.3%) were also infected with intestinal helminths, 102 (12.5%) having mixed helminth infections. The prevalence of the helminth species found in stool samples of parasitaemic subjects examined was, Ascaris lumbricoides (19.1%), hookworm (14.2%), Trichuris trichiura (7%) Schistosoma mansoni (3.4%), Enterobius vermicularis (2%), Hymenolepis sp. (1.6%) and Taenia sp. (1%). Mothers with Plasmodium infection but without intestinal helminth infection had neonates of higher mean birthweights than those presenting both Plasmodium and intestinal helminth infections and this effect was more pronounced in primigravids. The mean haemoglobin values of malarial mothers with intestinal helminth infections were lower than those with Plasmodium infection but without intestinal helminth infections but these were not statistically significant. Severe splenomegaly was predominant among parasitaemic gravidae who also harboured S. mansoni infection in two of the hospitals studied.     

Status of intestinal parasite infections among children in Bat Dambang, Cambodia

A survey was conducted to determine the extent of intestinal parasite infection in Bat Dambang, Cambodia in March 2004. A total of 623 fecal specimens was collected from kindergarten and schoolchildren and examined using the formalin-ether sedimentation technique. The overall infection rate of intestinal parasites was 25.7% (boys, 26.2%; girls, 25.1%), and the infection rates of intestinal helminthes by species were as follows: Echinostoma sp. 4.8%, hookworm 3.4%, Hymenolepis nana 1.3%, and Rhabditis sp. 1.3%. The infection rates of intestinal protozoa were; Entamoeba coli 4.8%, Giardia lamblia 2.9%, Iodamoeba butschlii 1.4%, Entamoeba polecki 1.1%, and Entamoeba histolytica 0.8%. There were no egg positive cases of Ascaris lumbricoides or Trichuris trichiura. All children infected were treated with albendazole, praziquantel, or metronidazole according to parasite species. The results showed that intestinal parasites are highly endemic in Bat Dambang, Cambodia.     

Descriptive epidemiology of intestinal helminth parasites from stray cat populations in Qatar

A total of 488 stray cats, 212 adult and 29 juvenile females plus 235 adult and 12 juvenile males, were examined post-mortem during the winter and summer months of 2006 from five sites in the vicinity of Doha and its outskirts. Five helminths, comprising three nematode and two cestode species were identified and the majority of cats harboured two of these species. The most prevalent was the cestode Taenia taeniaeformis (75.8%), followed by the cestode Diplopylidium sp. (42.8%), and the nematodes Ancylostoma tubaeforme (17.0%), Physaloptera sp. (6.6%) and Toxocara cati (0.8%). All five species were found to be typically overdispersed in their distribution. Using univariate and multivariate analyses, the prevalence and abundance of infections were primarily influenced by host gender and season, with females tending to harbour higher levels of infection during the summer. No significant differences were found relative to site except in the case of Physaloptera sp. Using bivariate Pearson product moment correlations, significant positive co-occurrences were identified between Diplopylidium sp. and T. taeniaeformis and also between A. tubaeforme and T. taeniaeformis. The results are discussed in relation to the effect of environmental conditions on the intestinal helminth infracommunities and their possible interactions in stray cat populations from such a harsh and arid region as Qatar.     

Intestinal Parasites in Children from a Day Care Centre in Matanzas City,Cuba

Background

Intestinal parasitic infections are widely distributed throughout the world and children are the most affected population. Day care centres are environments where children have proven to be more susceptible to acquiring IP.

Methods and Principal Findings

A cross-sectional study was carried to determine the prevalence of intestinal parasites in stool samples among children who attend to a day care centre in an urban area of Matanzas city, Cuba, from March to June 2012. 104 children under five years old were included on the study after informed consent form was signed by parents or legal guardians. Three fresh faecal samples were collected from each child in different days and were examined by direct wet mount, formalin-ether, and Kato- Katz techniques. Data relating to demography, socioeconomic status, source of drinking water, and personal hygiene habits were also collected using a standardized questionnaire. In total, 71.1% of children harbored at least one type of intestinal parasite and 47 (45.2%) were infected by more than one species. Giardia duodenalis and Blastocystis sp. were the most common parasites found, with prevalence rates of 54.8% and 38.5% respectively.

Conclusions

Despite public health campaigns, improvement in the level of education, and the availability of and access to medical services in Cuba infections by intestinal protozoan is high in this centre. Almost nothing is published regarding intestinal parasites in Matanzas province during the last 40 years so this work could also be the initial point to carry out other studies to clarify the IP status in this region.     

Dogs and intestinal parasites: a public health problem.

The stools of 239 stray dogs were examined for intestinal parasites. Of the helminths found, Toxocara canis (43.5%), tapeworms (25.5%), Ascaris species (21.3%) and hookworms (12.5%) were the commonest. Of the protozoans found, Isospora species and Entamoeba coli were the most prevalent. An unusual feature of the present study was the finding of Ascaris species. The importance of the high prevalence of intestinal parasites in dogs, the close contact of humans with dogs'' excreta and the possible role of this environmental pollution in the spread of human disease are discussed.     

Intestinal parasites in Kampuchea, Takeo Province

Fresh stool samples obtained from 1407 adult patients who sought treatment in Takeo province hospital and 332 Takeo preschool and school-age children from 3 to 18 years of age were examined for the presence of intestinal parasites using the technique of native preparation and the flotation method of Faust with subsequent staining with Lugol solution to demonstrate cysts. In hospital patients, a total of 13 protozoan and 9 helminth species were diagnosed. The prevalence of Entamoeba histolytica (cysts and trophozoites) was highest in the age group 15-18 years (18.3%), the peak prevalence of Gairdia lamblia (27.6%) occurred in children of the age group 6-9 years. The highest frequency distribution of Pentatrichomonas hominis (20.1%) was recorded in 3 to 5 years old, that of Enteromonas hominis (12.8%) in 6 to 9 years old. The predominant helminth was Ancylostoma duodenale, with the peak prevalence (65.2%) in patients older than 18 years, followed by Ascaris lumbricoides and Strongyloides stercoralis. Almost half of children patients under 6 was infected with at least two species of parasites, patients over 6 were infected simultaneously with two or more intestinal parasites in an absolute majority of cases. In Takeo preschool and school children the spectrum of diagnosed protozoan and helminth species was somewhat narrower than seen in hospital patients, but their prevalence rates were higher, except for the flagellate Pentatrichomonas hominis. The highest prevalence rates recorded were for E. histolytica 29.5% (age category 10-14 years), for G. lamblia 34.8% (age category 6-9 years), for P. hominis 19.3% (age category 3-5 years), for E. hominis 10.5% (age category 3-5 years), for A. duodenale 85.9% (age category 15-18 years), for A. lumbricoides 26.1% (age category 6-9 years), and for S. stercoralis 18.8% (age category 6-9 years). As many as 70% of children at the age between 6 and 15 years were simultaneously infected with two or three species of intestinal parasites.     

The parasite faunas of meso- and bathypelagic fishes of Norfolk Submarine Canyon, western North Atlantic

A total of 668 specimens representing 18 species of meso- and bathypelagic fishes collected from the western North Atlantic were examined for parasites. Seventeen species and 39.1% of the specimens harboured at least one type of parasite. The highest number of parasite taxa recovered from a single fish species was seven. Host species had overall infection prevalences ranging from 10.0 to 88.9% of the specimens examined. Cestodes were most common (22.8% of all specimens examined), followed by fungi (6.6%), nematodes (6.1%) and digenetic trematodes (4.9%). Mesopelagic fishes showed a greater prevalence of infection (49.1%) than bathypelagic fishes (28.9%). Most parasites recovered were immature; however, based on the presence of adult and postlarval stage parasites, definitive and second intermediate host status is suggested for at least three fish species (Nemichthys scolopaceus, Nessorhamphus ingolfianus and Eurypharynx pelecanoides ). The presence of the cestode Nybelinia and Anisakis-lype nematodes among a number of host species may have been due to predation on the euphausiid Nematoscelis , which was found in the stomachs of all host species infected by these two parasite taxa. Higher overall infection prevalences among host species were found than have been previously reported for mid-water fishes and it is possible that this may be a function of near-bottom presence of the fishes over the continental slope. It is suggested that the low prevalence of parasites within meso- and bathypelagic fishes when compared to benthic and shallow-water species reflects the lower overall energy of, and reduced probability of host-to-host transfer in, the deep-sea pelagic ecosystem.     

Patterns of parasitic infections in faecal samples from stray cat populations in Qatar

The parasite fauna of stray cat populations, comprising mainly helminth parasites, is described for the first time from the arid environment of the Qatar peninsula. During the winter and summer months of 2005, 824 faecal samples were examined from six sites in Qatar. Up to seven species of parasites were identified, six of which were nematodes - Strongyloides stercoralis as the most prevalent (18.4%), followed by Aelurostrongylus abstrusus (7.5%), Toxocara cati (6.1%), Ancylostoma tubaeforme (5.9%) and Physaloptera sp. (4.8%) and Toxascaris leonina (0.7%) - and one sporozoan species, Isospora felis (0.5%). Unidentified cestode eggs were also recovered from 10.7% of samples examined. The parasite species were found to be highly overdispersed in faecal samples from all sites, whereas the prevalence and intensity of infections were influenced by site and season. Infection levels tended to be higher during the winter season, especially in the case of A. abstrusus and A. tubaeforme, when conditions of temperature and humidity were more favourable for the development of egg and/or larval stages of parasites compared with the extremely hot and dry summer months. The results are discussed in relation to the distribution of the cat population in the vicinity of Doha and its outskirts and the potential threat of parasite transmission to human communities in Qatar.     

Intestinal helminths in a population of children from the Kashmir valley, India

In any geographical area, surveys of the prevalence of intestinal helminths are necessary to suggest appropriate control measures. The aim of this study was to determine the prevalence of intestinal helminth infections in children of the Kashmir valley and to identify the risk factors. Stool samples were collected from 2256 children from rural as well as urban areas of the Kashmir valley. The samples were examined by simple smear and zinc sulphate concentration methods. Intensity of the infection was quantified by Stoll's egg-counting technique. Infection by at least one intestinal helminth was found in 71.18% of the sampled population. The prevalence of Ascaris lumbricoides was highest (68.30%), followed by Trichuris trichiura (27.92%), Enterobius vermicularis (12.67%) and Taenia saginata (4.60%). Light (57.1%) to moderate (42.8%) intensity of infection was observed for A. lumbricoides, while the majority of the infected children (92.3%) harboured a light intensity of infection for T. trichiura. The age group, rural or urban residence, type of water source, boiled or unboiled water, type of defecation site, level of personal hygiene and maternal education were associated with helminth infection. Adequate control measures are urgently needed to combat the high prevalence of intestinal helminths and risk factors in the children of Kashmir valley.     

Intestinal parasites infestation and anemia in primary school children in Gaza Governorates--Palestine

A comparative study was carried out to identify the prevalence of anemia, nutritional indices and intestinal parasitic infestation in primary school children. The target population included 209 pupils aged 6-11 years, attending schools in two areas, Rimal area (urban) and Jabalia village (rural), in Gaza Governorates. Prevalence of intestinal parasites was high in Jabalia village (more than 53%) in comparison to Rimal area (33%). The main intestinal parasites were Entamoeba histolytica, Giardia intestinalis and Ascaris lumbricoides. Polyparasitism frequency is higher especially in rural area. In both areas anemia showed a high prevalence in children due to malnutrition and intestinal parasitic diseases. There was no association between intestinal parasitic infestation and children growth, but there was association between anemia and intestinal parasitic infestation in children, particularly in rural area. The correlation between anemia and mixed infestation reaches a highly significant level.     

Prevalence of Intestinal Parasitic Infections among Children under Five Years of Age with Emphasis on Schistosoma mansoni in Wonji Shoa Sugar Estate,Ethiopia

Intestinal parasite infections are major public health problems of children in developing countries causing undernutrition, anemia, intestinal obstruction and mental and physical growth retardation. This study was conducted to assess the prevalence of intestinal helminthic infections among children under five years of age with emphasis on Schistosoma mansoni in Wonji Shoa Sugar Estate, Ethiopia. A cross-sectional parasitological survey was conducted in under-five children living in Wonji Shoa Sugar Estate Ethiopia, April, 2013. Stool samples were collected and examined for intestinal parasites using single Kato-Katz and single Sodium acetate-acetic acid-formalin (SAF) solution concentration methods. Out of 374 children examined using single Kato-Katz and single SAF-concentration methods, 24.3% were infected with at least one intestinal parasite species. About 10.4%, 8.8%, 4.6%, 2.9%, 1.6% and 0.8% of the children were infected with Hymenolepis nana, Schistosoma mansoni, Ascaris lumbricoides, Trichuris trichiura, Enterobius vermicularis and hookworm, respectively. Prevalence of double, triple and quadruple intestinal helminthic infection was 6.4%, 0.54% and 1.1%, respectively. A significant increase in prevalence of S. mansoni (8.3% versus 3.2%) and T. trichiura (2.7% versus 0.5%) infection was observed when determined via the single Kato-Katz method compared to the prevalence of the parasites determined via the single SAF-concentration method. On the other hand, the single SAF-concentration method (9.1%) revealed a significantly higher prevalence of H. nana infection than the single Kato-Katz (1.6%) does. In conclusion, intestinal helminths infections particularly S. mansoni and H. nana were prevalent in under-five children of Wonji Shoa Sugar Estate. Including praziquantel treatment in the deworming program as per the World Health Organization guidelines would be vital to reduce the burden of these diseases in areas where S. mansoni and H. nana infections are prevalent among under-fives. Kato-Katz can be used in estimating the prevalence of S. mansoni and other helminth infections.     

Risk factors associated with intestinal pathogenic parasites in schoolchildren

Diseases caused by intestinal parasites impose a substantial burden on population of middle income countries including Pakistan. This research was aimed to assess the risk factors for intestinal parasites in school children of Malakand, Pakistan. Two hundred and eighty eight students were enrolled between February and June 2016. Out of the total enrolled 184 were agreed to collect stool specimens. A questionnaire was also used to collect the data on socio-demographic and socio-economic characteristics of the participants. All the students were guided to collect at least 10gof their own stool specimens. Each of the stool specimens was diagnosed for the presence of any stage of helminth or protozoal parasites. Formal ether concentration method and wet mount techniques were applied. One way ANOVA was used for calculation of P value when it was less than 0.05 which was considered significant. Eighty two percent of the participants were found infected with one species of parasite while 69.9% of the participants were infected with more than one species of intestinal parasites. The most prevalent parasite was hook worm 33.4% (n = 99/296) followed by Taenia saginata 28.7% (n = 85/296), Ascaris lumbricoides 27.7% (n = 82/296), Hymenolepis nana 6.08% (n = 18/296), Entamoeba histolytica 3.37% (n = 10/296) and least for each Enterobius vermicularis and Fasciola hepatica 0.37% (n = 1/296). Previously used drugs, level in school, ages, weight and upper arm circumference were the most significantly (P < 0.05) related factors for the occurrence of intestinal parasite infection. Present research endorsed that risk factors play a key role in the transmission of parasitic diseases. Lack of safe water supply, using raw vegetables, animal keeping, which should be considered for sustainable strategies in the control of these infections preferably in remote parts of the world.     

Enteric parasites and HIV infection: occurrence in AIDS patients in Rio de Janeiro, Brazil

The occurrence of intestinal parasites, its relation with the transmission mechanism of HIV, and the clinical state of the AIDS patients, were analyzed in 99 Group IV patients (CDC, 1986), treated at "Hospital Universitário Pedro Ernesto" (HUPE), between 1986 and 1988. The group consisted of 79 (79.8%) patients whose HIV transmission mechanism took place through sexual contact and of 16 (20.2%) who were infected through blood. Feces samples from each patient were examined by four distincts methods (Faust et al., Kato-Katz, Baermann-Moraes and Baxby et al.). The most occurring parasites were: Cryptosporidium sp., Entamoeba coli and Endolimax nana (18.2%), Strongyloides stercoralis and Giardia lamblia (15.2%), E. histolytica and/or E. hartmanni (13.1%), Ascaris lumbricoides (11.1%) and Isospora belli (10.1%). Furthermore, 74.7% of the patients carried at least one species. Intestinal parasites were found in 78.5% of the patients who acquired the HIV through sexual intercourse and in 56.3% of those infected by blood contamination. The difference, was not statistically significant (p greater than 0.05). In the group under study, the increase of the occurrence of parasitic infections does not seem to depend on the acquisition of HIV through sexual contact. It appears that in developing countries, the dependency is more related to the classic mechanisms of parasites transmission and its endemicity.     

Infection status of intestinal parasites in children living in residential institutions in Metro Manila, the Philippines

A small scale survey was performed to know the infection status of intestinal parasite in children of the residential institutions and street communities in Metro Manila, Philippines. A total of 284 stool samples from 11 institutions and 3 street communities was examined by the formalin-ether concentration method. The scotch tape anal swab was adapted to 121 children to investigate the infection status of Enterovius vermicularis. It was found out that 62.0% of the children examined were positive for one or more intestinal parasites. Multiple infections were observed in 34.2% of the children. Among 172 children who gave detail information, the prevalence for Ascaris lumbricoides, Trichuris trichiura, and hookworm was 36.0%, 44.8%, and 7.0% respectively. Of the children examined, 47.7% were found to be harboring parasitic protozoans such as Entamoeba histolytica, Giardia lamblia, and Blastocystis hominis. The most prevalent of these protozoans was B. hominis with an infection rate of 40.7%. The prevalence of these infections among children living in institutions was relatively high. More efforts should be made to implement anthelminthic programs including bi-annual follow-up treatments.     

Parasitological analyses of the male chimpanzees (Pan troglodytes schweinfurthii) at Ngogo, Kibale National Park, Uganda

Numerous intestinal parasites identified in populations of wild nonhuman primates can be pathogenic to humans. Furthermore, nonhuman primates are susceptible to a variety of human pathogens. Because of increasing human encroachment into previously nonimpacted forests, and the potential for disease transmission between human and nonhuman primate populations, further detailed investigations of primate ecological parasitology are warranted. For meaningful comparisons to be made, it is important for methods to be standardized across study sites. One aspect of methodological standardization is providing reliable estimates of parasite prevalence and knowing how many samples are needed to adequately estimate an individual's parasite prevalence. In this study the parasitic fauna of 37 adult, adolescent, and juvenile male chimpanzees from the Ngogo group, Kibale National Park, Uganda, were assessed from 121 fecal samples collected over a 3-month period. Twelve taxa of intestinal species (five helminth and seven protozoan) were recovered from the samples. The four most prevalent species were Troglodytella abrassarti (97.3%), Oesophagostomum sp. (81.1%), Strongyloides sp. (83.8%), and Entamoeba chattoni (70.3%). No one species was found in all samples from any one animal, and Troglodytella abrassarti, the most common intestinal organism, was found in all of the serial samples of only 69.4% of the chimpanzees. The cumulative species richness for individuals significantly increased for every sequential sample (up to three to four samples) taken per animal during this study. The results indicate that to accurately diagnose total intestinal infection and evaluate group prevalence, three to four sequential samples from each individual must be collected on nonconsecutive days. This conclusion applies only to short study periods in which possible seasonal effects are not taken into consideration. Validation of these results at different study sites in different regions with different climatic patterns is needed.     

The intestinal parasite infection status of inhabitants in the Roxas city,The Philippines

We carried out a small-scale survey to investigate the status of intestinal protozoa and helminthes infection of inhabitants in Roxas city, Mindoro, the Philippines. Total 301 stool samples were subjected to the formalin-ether concentration method for the detection of helminth ova and protozoan cysts. The overall positive rate was 64.5%, and that of male and female were 56.6% and 72.5%, respectively. The highest infected helminth was Ascaris lumbricoudes (51.2%), followed by Trichuris trichiura (27.6%), hookworm (8.0%) and Enterobius vermicularis (0.3%). The protozoa infection status revealed that Entamoeba coli was the most frequent (15.0%). Iodoamoeba buetschlii and E. histolytica were found but few. The multiple infection more than two parasites was 29.6%, and double infection with A. lumbricoides and T. trichiura was most common. The intestinal helminth infections were highly prevalent in this area, according to this result, and we concluded that anthelminthic drugs should be given to inhabitants, especially to children of 1 to 15 years-old.     

Prevalence of Microsporidium and Other Intestinal Parasites in Children from Malatya,Turkey

Parasite infections are common during the critical developmental period in children. The occurrences of intestinal parasites are also common in orphanage, nurseries and schools in Turkey. The study was carried out to determine the percentage of microsporidium and intestinal parasites in children from Malatya, Turkey. This study was carried out at the Department of Parasitology of Inonu University, Turgut Ozal Medical Center, during January–December 2006. Totally, 1,181 stool samples were examined using the native-Lugol, sedimentation-techniques, modified trichrome (MTS), acid-fast-trichrome stain and calcofluor staining methods. In addition, perianal region material was taken from the children to examine with cellophane tape method. Power analyses were performed for statistical analyses used. Microsporidia were found in 92 (7.8%) of the samples, and also intestinal parasites were detected in 329 (27.8%). The numbers of infections according to the species were as follows: 69 (5.8%) Entamoeba coli, 7 (0.6%) Blastocystis hominis, 114 (9.7%) Giardia intestinalis, 15 (1.3%) Iodomoeba butchlii, 8 (0.7%) Dientamoeba fragilis, 7 (0.6%) Taenia spp. 70 (5.9%) Enterobius vermicularis, 11 (0.9%) Hymenolepis nana, 25 (2.1%) Trichomonas intestinalis, 1 (0.1%) Ascaris lumbricoides and 2 (0.2%) Chilomastix mesnilii. Also, greater than 90% power values were achieved for statistical analyses. Whereas the detection rates of microsporidium and intestinal parasites were found to be low, it was concluded that in addition to intestinal parasites, microsporidium should be also searched for in children with complaints of intestinal system.     

Malaria, schistosomiasis, and intestinal helminths in relation to microdams in Tigray, northern Ethiopia.

A survey was undertaken in Tigray, Northern Ethiopia, to assess the prevalence of malaria, schistosomiasis, and intestinal helminths in relation to microdams. The survey took place from March to June 1995, during the dry season, at 41 microdams. At each site the village nearest the dam (within thirty minutes walk) was selected, ten households were randomly chosen, and all family members were examined for malaria and intestinal parasites. The overall study sample was 2271 people, of all age groups. Plasmodium falciparum infection was documented in four villages (at 10% of microdams); prevalence was 1.2% (range 0-20% by village). Larvae of Anopheles gambiae s.l. were found at one microdam. Infection with intestinal schistosomiasis was documented in 20 villages (at 49% of microdams), and one third of those infected had moderate to heavy infections. Biomphalaria species, the intermediate host snails of Schistosoma mansoni, were found at 16 microdams (39%), and snails infected by mammalian cercariae were found in one locality. Infections with soil-transmitted nematodes were prevalent: hookworm was detected in more than two thirds of the villages, and Ascaris lumbricoides and Trichuris trichiura were present in almost half of the villages. Out of 2078 stool examinations, the prevalence of S. mansoni infection was 7.2% (range 0-48% by village), of A. lumbricoides 2.3% (range 0-31%), of T. trichiura 2.4% (range 0-21%), and of hookworm 8.9% (range 0-78%). The prevalence of malaria, S. mansoni and hookworm was higher at altitudes below 2000 metres above sea level. S. mansoni was more prevalent in microdams built more than 5 years before the survey, while T. trichiura was more prevalent at recently constructed microdams. The widespread distribution of schistosomiasis and intestinal helminths, and the presence of malaria infection during the dry season confirm that microdams create favourable conditions for the transmission of these parasitic diseases. Health safeguards must be incorporated into the planning, construction, and operation of microdams and irrigation systems in order to prevent or reduce these diseases. In areas with high prevalence, control activities should be intensified.     

Helminths infecting the parthenogenetic whiptail lizard Cnemidophorus nativo in a restinga habitat of Bahia State, Brazil

A sample of 101 specimens of the unisexual whiptail lizard Cnemidophorus nativo (Squamata; Teiidae) from a coastal site in Bahia State, Brazil were examined for the presence of endoparasites. Of these, 35 (34.7%) harboured helminths. Six helminth species were recovered from C. nativo, including five nematodes (Physaloptera retusa, Physalopteroides venancioi, Subulura lacertilia, Skrjabinelazia intermedia and Parapharyngodon sp., and one cestode (Oochoristica ameivae), all representing new host records. Most lizards were infected by a single species of helminth and none by more than three. Infection rates were neither significantly influenced by host body size nor by environmental factors. The results are compared with data from studies on other whiptail species in both South and North America.