[Environmental conditions and prevalence of parasitic infection in Xukuru-Kariri indigenous people, Caldas, Brazil]

OBJECTIVE

To describe the environmental conditions and the parasitic infection status of Xukuru-Kariri individuals living in the municipality of Caldas, state of Minas Gerais, Brazil.

METHODS

A cross-sectional study was carried out in March 2009. Sociodemographic and environmental data were collected through interviews. Water and fecal samples were collected for determination of environmental contamination and parasitic infection status.

RESULTS

The Xukuru-Kariri population living in Caldas included 86 people divided into 22 families. Of 22 heads of household, 81.8% had low schooling (not higher than elementary education). Of 26 water samples collected for microbiological analysis, 77.0% were positive for total coliforms and 4.0% for Escherichia coli. Residents of 27.3% of households defecated in the open. Trash was scattered in the yard of 54.5% of households. Fecal samples were collected from 60 individuals, with parasitic infection in 66.6%. The following prevalence rates were recorded: Entamoeba histolytica/dispar, 6.7%; Entamoeba coli, 60.0%; Endolimax nana, 1.8%; and Giardia duodenalis, 6.6%.

CONCLUSIONS

The people included in this study faced environmental characteristics that contributed to their health vulnerability. Health actions as well as the implementation of public policies to provide sanitation, with quality water and adequate collection and treatment of human and household waste, are essential to prevent environmental degradation and improve the quality of life of these individuals.

A descriptive epidemiology of giardiasis in New Zealand and gaps in surveillance data

INTRODUCTION

Giardia is the most commonly notified waterborne disease in New Zealand, which has high incidence rates compared with other developed countries. Four years of giardiasis notification data were analysed to describe the epidemiological patterns of infection in New Zealand and compared with local and international data.

METHODS

Anonymised information was collected nationally for 7818 notified cases of giardiasis between July 1996 and June 2000. International data were collected from the data sources of respective countries. Infection rates adjusted for confounding factors were calculated and presented by age, gender, ethnicity, and area using statistical and spatial methods.

RESULTS

Most cases occurred in the 1-4 year age group followed by the 25-44 year age group, and were of Pakeha/European ethnicity. Ethnicity was unknown for 18% of cases, thus affecting demographic calculations. Rates were elevated for several Health Districts in New Zealand (West Coast, Wellington, Waikato, Auckland, Hawke's Bay, Hutt, Rotorua, and Tauranga).

CONCLUSIONS

The higher rates of giardiasis observed in New Zealand, in comparison with other developed countries, may be related to environmental or social factors. Time-trend analysis suggests a seasonal pattern. This study identified vulnerable groups and major data-gaps. Recommendations for improvements in disease surveillance and data quality are discussed. Geographical information system (GIS) applications are useful for disease monitoring.

Towards the eradication of hookworm in an isolated Australian community

Hookworm (Ancylostoma duodenale) and other enteric parasites such as Giardia and Hymenolepis are common in Aboriginal communities in northem Australia, and their presence is associated with iron deficiency, anaemia, and failure to thrive. We report the outcome of a sustained, community-based control programme that used regular albendazole in one isolated community. Whereas hookworm has been effectively controlled by the programme, no sustained effect on the prevalence of Giardia and Hymenolepis was seen; the control of these parasites will depend on improvements in health education. This programme might serve as a model for community-based or population-based drug treatment programmes elsewhere.

Giardia lamblia carriage in Israeli Bedouin infants: risk factors and consequences

Giardiasis is a common protozoan infection, with varying clinical manifestations. We investigated the associations between Giardia lamblia carriage and environmental, family, illness, and growth characteristics. Bedouin infants (n=234) were followed from birth to age 18-23 months. At monthly home visits, stool samples were obtained, history of illness was determined, and an environmental assessment was done. The comparisons presented are between 4 groups defined by length of carriage of G. lamblia. Study children had a mean+/-SD of 4.1+/-2.9 diarrhea episodes. No illness, environmental, or family characteristics were associated with length of carriage. Significant differences were found in weight-for-age and weight-for-height z scores between the never-positive-for-G. lamblia group and all other carriage groups combined. Faltering growth was shown to be subsequent to G. lamblia infection rather than preceding it. Our findings confirm that G. lamblia carriage is not associated with diarrhea. However, the effect on growth deserves further investigation.

Clustering of giardiosis among AIDS patients in Los Angeles County

The purpose of this study was to determine the mode of the spread of the enteric parasitic infections among HIV+/AIDS patients attending the AIDS clinic of the King/Drew Medical Center in Los Angeles. Two hundred forty three patients diagnosed with HIV+/AIDS agreed to participate. The study was conducted by several interviews, questionnaires and stool sample collections over a one year period. Stool samples were processed for protozoan cysts and Helminth Ova using standard stool concentration and staining techniques. An indirect immunofluorescence monoclonal antibody technique was also used as an alternate to detect the parasites in samples. Forty three cases were positive for Giardia Lamblia (17.7%) and 10 cases were positive for Cryptosporidium (4%). No Helminth Ova were detected. The majority of the participants were African-American (72.6%) and 27.6% were Hispanic. Clustering studies were performed to determine the mechanism of spread of the parasites among the population study. The Nearest Neighbor Clustering Technique (NNT) was used to determine if there was spatial clustering of positive cases. Geocoding with the MapInfo Program was performed to determine the precise coordinates of the residence of the subjects. Application of the NNT showed a high degree of clustering for Giardia. The NNT statistic for Giardia was significant with the p value for 0.020 using the Simes multiple comparisons correction. Examination of the map plots indicated that there were two areas with high Giardia prevalence, one in Hollywood region, the other in South-Central Los Angeles. The odds ratio for sexual orientation was 14.2 (for homosexuals vs heterosexuals) with a p value of less than 0.001. These findings strongly suggest that male homosexual contact was the main mode of transmission of observed Giardia cases.

Incidence of protozoal diarrheal disease in an expatriate community in Addis Ababa

The incidence of diarrheal disease due to Entamoeba histolytica and Giardia lamblia in the United States Embassy American population was recorded over a 25 month period. Overall case rates of 4.2/100 person-months for amoebiasis and 3.3/100 person-months for giardiasis were distinguished by wide variations based on age group and rainfall. In some circumstances, gender and prior living in Africa also correlated with disease incidence. Practitioners should look for these entities in American expatriates in Addis Ababa, especially during the dry season.

Detection of Cryptosporidium and Giardia intestinalis in Bedouin children from southern Israel

During an 18 month period, a total of 4796 stool specimens collected from 151 Bedouin children enrolled in a cohort study and followed from birth, were screened for Giardia intestinalis, Cryptosporidium spp. and other intestinal parasites. Specimens were collected in phenol-alcohol-formalin (PAF) preservative and examined prior to, and after, formalin-ether concentration (FEC). During 6 months of the second year Giardia intestinalis was observed in 17.6% of the specimens and Cryptosporidium in 0.9% as compared with 1.8% (Giardia intestinalis) and 1.6% (Cryptosporidium) observed during the first year. Giardia intestinalis was detected in 8.4% (407/4796) of all the samples examined and Cryptosporidium in 1.3% (63/4796). Other intestinal protozoan parasites and helminthic ova demonstrated in the stool specimens included: Entamoeba coli (0.1%); Entamoeba histolytica (< 0.1%); Hymenolepis nana (0.1%); and Trichuris trichiura (< 0.1%). Mixed infection with 2 parasites was observed in 0.3% of the specimens. PAF fixation was found to be highly effective in preserving the integrity and antigenicity of both Cryptosporidium-oocysts and Giardia intestinalis-cysts. The detection rate of Giardia intestinalis and Cryptosporidium before FEC was not significantly different from that obtained after FEC, showing differences of only 1% and 3% for Giardia intestinalis and Cryptosporidium, respectively.

[The characteristics of HLA antigen distribution among patients with persistent lambliasis]

Fifty patients suffering from persistent giardiasis and 257 healthy persons from Uzbekistan were examined. HLA-typing was carried out by the Terasaki microlymphocytotoxicity technique. The patients with persistent giardiasis were characterized as a significant prevalence of HLA-B5, HLA-B14, HLA-DR3, DR4, DR7 and haplotypes HLA-A9-B5 and A1-B5. These haplotypes and HLA antigens can be considered as markers of predisposition to persistent giardiasis.