1
|
de Oliveira GL, Daniel LA. Removal of Giardia spp. cysts and Cryptosporididum spp. oocysts from anaerobic effluent by dissolved air flotation. ENVIRONMENTAL TECHNOLOGY 2021; 42:141-147. [PMID: 31136251 DOI: 10.1080/09593330.2019.1625447] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 05/23/2019] [Indexed: 06/09/2023]
Abstract
Lab-scale studies were carried out to investigate the efficiency of dissolved air flotation (DAF) for the removal of Giardia spp. cysts and Cryptosporidium spp. oocysts from anaerobic effluent from the pilot UASB reactor. Raw wastewater, UASB and DAF effluent samples were collected weekly and protozoan (oo)cysts were concentrated using IMS followed by protozoa detection using immunofluorescense assay (IFA). The number of Cryptosporidium spp. oocysts in the raw wastewater was always lower than that of Giardia spp. cysts with 28-33 oocysts L-1 and 3177-4267 cysts L-1, respectively. Log10 removal of Giardia cysts utilising polyaluminium chloride (PACl) was higher than that with FeCl3, but no statistically significant difference between the two coagulants was observed. Cryptosporidium was absent in most of the treated effluent samples. The results indicate that DAF reached more than 2 log of cyst removal. In addition, the results demonstrated that these parasites are prevalent in the study area and E. coli and total coliforms were not good indicator microorganisms in terms of cyst and oocysts numbers.
Collapse
Affiliation(s)
- Gabriela Laila de Oliveira
- Hydraulic and Sanitation Department, São Carlos School of Engineering, University of São Paulo, São Paulo, Brazil
| | - Luiz Antonio Daniel
- Hydraulic and Sanitation Department, São Carlos School of Engineering, University of São Paulo, São Paulo, Brazil
| |
Collapse
|
2
|
Hassan EM, Örmeci B, DeRosa MC, Dixon BR, Sattar SA, Iqbal A. A review of Cryptosporidium spp. and their detection in water. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2021; 83:1-25. [PMID: 33460403 DOI: 10.2166/wst.2020.515] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Cryptosporidium spp. are one of the most important waterborne pathogens worldwide and a leading cause of mortality from waterborne gastrointestinal diseases. Detection of Cryptosporidium spp. in water can be very challenging due to their low numbers and the complexity of the water matrix. This review describes the biology of Cryptosporidium spp. and current methods used in their detection with a focus on C. parvum and C. hominis. Among the methods discussed and compared are microscopy, immunology-based methods using monoclonal antibodies, molecular methods including PCR (polymerase chain reaction)-based assays, and emerging aptamer-based methods. These methods have different capabilities and limitations, but one common challenge is the need for better sensitivity and specificity, particularly in the presence of contaminants. The application of DNA aptamers in the detection of Cryptosporidium spp. oocysts shows promise in overcoming these challenges, and there will likely be significant developments in aptamer-based sensors in the near future.
Collapse
Affiliation(s)
- Eman M Hassan
- Department of Civil and Environmental Engineering, Carleton University, 1125 Colonel By Drive, Ottawa, K1S 5B6, Canada E-mail:
| | - Banu Örmeci
- Department of Civil and Environmental Engineering, Carleton University, 1125 Colonel By Drive, Ottawa, K1S 5B6, Canada E-mail:
| | - Maria C DeRosa
- Department of Chemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Canada, K1S 5B6
| | - Brent R Dixon
- Bureau of Microbial Hazards, Food Directorate, Health Canada, Ottawa, Canada, K1A 0K9
| | - Syed A Sattar
- Department of Civil and Environmental Engineering, Carleton University, 1125 Colonel By Drive, Ottawa, K1S 5B6, Canada E-mail: ; C.R.E.M. Co Labs, Units 1-2, 3403 American Drive, Mississauga, ON, Canada, L4V 1T4
| | - Asma Iqbal
- C.R.E.M. Co Labs, Units 1-2, 3403 American Drive, Mississauga, ON, Canada, L4V 1T4
| |
Collapse
|
3
|
Noman EA, Al-Gheethi AAS, Radin Mohamed RMS, Talip BA, Nagao H, Mohd Kassim AH, Bakar SA. Consequences of the Improper Disposal of Greywater. MANAGEMENT OF GREYWATER IN DEVELOPING COUNTRIES 2019. [DOI: 10.1007/978-3-319-90269-2_2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
4
|
Kong FE, Deighton MA, Thurbon NA, Smith SR, Rouch DA. Cryptosporidium parvum decay during air drying and stockpiling of mesophilic anaerobically digested sewage sludge in a simulation experiment and oocyst counts in sludge collected from operational treatment lagoons in Victoria, Australia. JOURNAL OF WATER AND HEALTH 2018; 16:435-448. [PMID: 29952332 DOI: 10.2166/wh.2018.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The inactivation of Cryptosporidium species oocysts during sewage sludge treatment is important to protect human health when the residual biosolids are applied to agricultural land. Quantifying the decay of Cryptosporidium species during sludge treatment for microbiological assurance purposes is difficult if low numbers are present in wastewater. The rate of decay of Cryptosporidium parvum oocysts during solar/air drying treatment and in sludge stockpiles in temperate environment conditions was simulated in laboratory inoculation experiments using sludge sampled from a mesophilic anaerobic digester. Oocyst numbers were also determined in settled lagoon sludge samples collected from three operational rural wastewater treatment plants (WWTPs). C. parvum oocysts were enumerated by immunomagnetic separation followed by staining with vital dyes and examination by confocal laser scanning microscopy. An air-drying/storage period equivalent to 11 weeks was required for a 1 log10 reduction of viable oocysts inoculated into digested sludge. Oocyst viability in air-dried and stored digested sludge decreased with time, but was independent of sludge desiccation and dry solids (DS) content. No oocysts were detected in sludge samples collected from the anaerobic digester, and the average concentration of oocysts found in settled lagoon sludge from the rural WWTP was 4.6 × 102 oocysts/g DS.
Collapse
Affiliation(s)
- Frederic E Kong
- Biotechnology and Environmental Biology, School of Applied Sciences, RMIT University, Bundoora West Campus, Plenty Road, Bundoora, VIC 3083, Australia E-mail: ;
| | - Margaret A Deighton
- Biotechnology and Environmental Biology, School of Applied Sciences, RMIT University, Bundoora West Campus, Plenty Road, Bundoora, VIC 3083, Australia E-mail: ;
| | - Nerida A Thurbon
- Biotechnology and Environmental Biology, School of Applied Sciences, RMIT University, Bundoora West Campus, Plenty Road, Bundoora, VIC 3083, Australia E-mail: ;
| | - Stephen R Smith
- Department of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - Duncan A Rouch
- Biotechnology and Environmental Biology, School of Applied Sciences, RMIT University, Bundoora West Campus, Plenty Road, Bundoora, VIC 3083, Australia E-mail: ;
| |
Collapse
|
5
|
Amorós I, Moreno Y, Reyes M, Moreno-Mesonero L, Alonso JL. Prevalence of Cryptosporidium oocysts and Giardia cysts in raw and treated sewage sludges. ENVIRONMENTAL TECHNOLOGY 2016; 37:2898-904. [PMID: 27080207 DOI: 10.1080/09593330.2016.1168486] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Treated sludge from wastewater treatment plants (WWTPs) is commonly used in agriculture as fertilizers and to amend soils. The most significant health hazard for sewage sludge relates to the wide range of pathogenic microorganisms such as protozoa parasites.The objective of this study was to collect quantitative data on Cryptosporidium oocysts and Giardia cysts in the treated sludge in wastewater treatment facilities in Spain. Sludge from five WWTPs with different stabilization processes has been analysed for the presence of Cryptosporidium and Giardia in the raw sludge and after the sludge treatment. A composting plant (CP) has also been assessed. After a sedimentation step, sludge samples were processed and (oo)cysts were isolated by immunomagnetic separation (IMS) and detected by immunofluorescence assay (IFA). Results obtained in this study showed that Cryptosporidium oocysts and Giardia cysts were present in 26 of the 30 samples (86.6%) of raw sludge samples. In treated sludge samples, (oo)cysts have been observed in all WWTP's analysed (25 samples) with different stabilization treatment (83.3%). Only in samples from the CP no (oo)cysts were detected. This study provides evidence that (oo)cysts are present in sewage sludge-end products from wastewater treatment processes with the negative consequences for public health.
Collapse
Affiliation(s)
- Inmaculada Amorós
- a Instituto de Ingeniería del Agua y Medio Ambiente, Universitat Politècnica de València , Valencia , Spain
| | - Yolanda Moreno
- a Instituto de Ingeniería del Agua y Medio Ambiente, Universitat Politècnica de València , Valencia , Spain
| | - Mariela Reyes
- a Instituto de Ingeniería del Agua y Medio Ambiente, Universitat Politècnica de València , Valencia , Spain
| | - Laura Moreno-Mesonero
- a Instituto de Ingeniería del Agua y Medio Ambiente, Universitat Politècnica de València , Valencia , Spain
| | - Jose L Alonso
- a Instituto de Ingeniería del Agua y Medio Ambiente, Universitat Politècnica de València , Valencia , Spain
| |
Collapse
|
6
|
Kumar T, Abd Majid MA, Onichandran S, Jaturas N, Andiappan H, Salibay CC, Tabo HAL, Tabo N, Dungca JZ, Tangpong J, Phiriyasamith S, Yuttayong B, Polseela R, Do BN, Sawangjaroen N, Tan TC, Lim YAL, Nissapatorn V. Presence of Cryptosporidium parvum and Giardia lamblia in water samples from Southeast Asia: towards an integrated water detection system. Infect Dis Poverty 2016; 5:3. [PMID: 26763230 PMCID: PMC4712598 DOI: 10.1186/s40249-016-0095-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 01/04/2016] [Indexed: 11/10/2022] Open
Abstract
Background Access to clean and safe drinking water that is free from pathogenic protozoan parasites, especially Cryptosporidium parvum and Giardia lamblia that cause gastrointestinal illness in humans, is still an issue in Southeast Asia (SEA). This study is the first attempt to detect the aforementioned protozoan parasites in water samples from countries in SEA, using real-time polymerase chain reaction (qPCR) assays. Methods A total of 221 water samples of 10 l each were collected between April and October 2013 from Malaysia (53), Thailand (120), the Philippines (33), and Vietnam (15). A physicochemical analysis was conducted. The water samples were processed in accordance with the US Environmental Protection Agency’s methods 1622/1623.1, microscopically observed and subsequently screened using qPCR assays. Results Cryptosporidium oocysts were detected in treated water samples from the Philippines (1/10), with a concentration of 0.06 ± 0.19 oocyst/L, and untreated water samples from Thailand (25/93), Malaysia (17/44), and the Philippines (11/23), with concentrations ranging from 0.13 ± 0.18 to 0.57 ± 1.41 oocyst/L. Giardia cysts were found in treated water samples from the Philippines (1/10), with a concentration of 0.02 ± 0.06 cyst/L, and in untreated water samples from Thailand (20/93), Vietnam (5/10), Malaysia (22/44), and the Philippines (16/23), with concentrations ranging from 0.12 ± 0.3 to 8.90 ± 19.65 cyst/L. The pathogens C. parvum and G. lamblia were detected using using qPCR assays by targeting the 138-bp fragment and the small subunit gene, respectively. C. parvum was detected in untreated water samples from the Philippines (1/23) and Malaysia (2/44), whilst, G. lamblia detected was detected in treated water samples from the Philippines (1/10) and in untreated water samples from Thailand (21/93), Malaysia (12/44), and the Philippines (17/23). Nitrate concentration was found to have a high positive correlation with (oo)cyst (0.993). Conclusion The presence of (oo)cysts in the water samples means that there is potential risk for zoonotic disease transmission in the studied countries. Detection using qPCR is feasible for quantifying both pathogenic C. parvum and G. lamblia in large water samples.
Collapse
Affiliation(s)
- Thulasi Kumar
- Department of Parasitology (Southeast Asia Water Team), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Mohamad Azlan Abd Majid
- Department of Parasitology (Southeast Asia Water Team), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Subashini Onichandran
- Department of Parasitology (Southeast Asia Water Team), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Narong Jaturas
- Department of Parasitology (Southeast Asia Water Team), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,Department of Microbiology and Parasitology, Faculty of Medical Science, Naresuan University, Phitsanulok, Thailand
| | - Hemah Andiappan
- Department of Parasitology (Southeast Asia Water Team), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Cristina C Salibay
- Biological Science Department, College of Science and Computer Studies, De La Salle University-Dasmariñas, Dasmariñas, Philippines
| | - Hazel A L Tabo
- Biological Science Department, College of Science and Computer Studies, De La Salle University-Dasmariñas, Dasmariñas, Philippines
| | - Norbel Tabo
- Biological Science Department, College of Science and Computer Studies, De La Salle University-Dasmariñas, Dasmariñas, Philippines
| | - Julieta Z Dungca
- School of Science and Technology, Centro Escolar University, Manila, Philippines
| | - Jitbanjong Tangpong
- School of Allied Health Sciences and Public Health, Walailak University, Nakhon Si Thammarat, Thailand
| | | | - Boonyaorn Yuttayong
- Regional Medical Sciences Center, Department of Medical Sciences, Ministry of Public Health, Nakhon Ratchasima, Thailand
| | - Raxsina Polseela
- Department of Microbiology and Parasitology, Faculty of Medical Science, Naresuan University, Phitsanulok, Thailand
| | - Binh Nhu Do
- Department of Parasitology, Faculty of Medicine, Vietnam Military Medical University, 160 Phung Hung Road, Phuc La Ward, Ha Dong District, Hanoi, Vietnam
| | - Nongyao Sawangjaroen
- Department of Microbiology, Faculty of Science, Prince of Songkla University, Hat Yai, Thailand
| | - Tian-Chye Tan
- Department of Parasitology (Southeast Asia Water Team), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Yvonne A L Lim
- Department of Parasitology (Southeast Asia Water Team), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Veeranoot Nissapatorn
- Department of Parasitology (Southeast Asia Water Team), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
| |
Collapse
|
7
|
Nishi L, Vieira A, Vieira M, Silva G, Bergamasco R. Application of Hybrid Process of Coagulation/Flocculation and Membrane Filtration for the Removal of Protozoan Parasites from Water. ACTA ACUST UNITED AC 2012. [DOI: 10.1016/j.proeng.2012.07.405] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
8
|
Meireles MV. Cryptosporidium infection in Brazil: implications for veterinary medicine and public health. ACTA ACUST UNITED AC 2011; 19:197-204. [PMID: 21184694 DOI: 10.1590/s1984-29612010000400002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Accepted: 11/09/2010] [Indexed: 11/22/2022]
Abstract
The aim of this review paper is to report the results of cryptosporidiosis research in Brazil, mainly its occurrence in animals and implications for veterinary medicine and public health. An increasing number of papers related to Cryptosporidium spp. infection in Brazil are available at national and international literature. The main focus described in these papers is the occurrence of Cryptosporidium spp. in food, environmental samples, in humans and several animal species, particularly birds, cattle, dogs and cats. Using molecular biology techniques, most Cryptosporidium species and genotypes identified in other countries have been described in Brazil. In mammals, there are descriptions of infection by C. bovis, C. canis, C. felis, C. meleagridis, C. parvum, and the cervine genotype; in birds, the following species and genotypes have been described: C. baileyi, C. galli, C. meleagridis, C. parvum and the avian genotypes I, II and III. Several species have been described in humans, such as C. parvum, C. hominis, and some species adapted to animal hosts such as C. canis, C. felis and C. meleagridis.
Collapse
Affiliation(s)
- Marcelo Vasconcelos Meireles
- Curso de Medicina Veterinária, Universidade Estadual Paulista, Rua Clóvis Pestana 793, Bairro Dona Amélia, Araçatuba-SP, Brazil.
| |
Collapse
|
9
|
Koompapong K, Sutthikornchai C, Sukthana Y. Cryptosporidium oocyst detection in water samples: floatation technique enhanced with immunofluorescence is as effective as immunomagnetic separation method. THE KOREAN JOURNAL OF PARASITOLOGY 2009; 47:353-7. [PMID: 19967082 DOI: 10.3347/kjp.2009.47.4.353] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2009] [Revised: 08/02/2009] [Accepted: 08/21/2009] [Indexed: 11/23/2022]
Abstract
Cryptosporidium can cause gastrointestinal diseases worldwide, consequently posing public health problems and economic burden. Effective techniques for detecting contaminated oocysts in water are important to prevent and control the contamination. Immunomagnetic separation (IMS) method has been widely employed recently due to its efficiency, but, it is costly. Sucrose floatation technique is generally used for separating organisms by using their different specific gravity. It is effective and cheap but time consuming as well as requiring highly skilled personnel. Water turbidity and parasite load in water sample are additional factors affecting to the recovery rate of those 2 methods. We compared the efficiency of IMS and sucrose floatation methods to recover the spiked Cryptosporidium oocysts in various turbidity water samples. Cryptosporidium oocysts concentration at 1, 10(1), 10(2), and 10(3) per 10 microl were spiked into 3 sets of 10 ml-water turbidity (5, 50, and 500 NTU). The recovery rate of the 2 methods was not different. Oocyst load at the concentration < 10(2) per 10 ml yielded unreliable results. Water turbidity at 500 NTU decreased the recovery rate of both techniques. The combination of sucrose floatation and immunofluorescense assay techniques (SF-FA) showed higher recovery rate than IMS and immunofluorescense assay (IMS-FA). We used this SF-FA to detect Cryptosporidium and Giardia from the river water samples and found 9 and 19 out of 30 (30% and 63.3%) positive, respectively. Our results favored sucrose floatation technique enhanced with immunofluorescense assay for detecting contaminated protozoa in water samples in general laboratories and in the real practical setting.
Collapse
Affiliation(s)
- Khuanchai Koompapong
- Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | | | | |
Collapse
|
10
|
Nishi L, Baesso ML, Santana RG, Fregadolli P, Falavigna DLM, Falavigna-Guilherme AL. Investigation ofCryptosporidiumspp. andGiardiaspp. in a Public Water-Treatment System. Zoonoses Public Health 2009; 56:221-8. [DOI: 10.1111/j.1863-2378.2008.01189.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
11
|
Jex AR, Smith HV, Monis PT, Campbell BE, Gasser RB. Cryptosporidium--biotechnological advances in the detection, diagnosis and analysis of genetic variation. Biotechnol Adv 2008; 26:304-17. [PMID: 18430539 DOI: 10.1016/j.biotechadv.2008.02.003] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2007] [Revised: 01/29/2008] [Accepted: 02/14/2008] [Indexed: 11/19/2022]
Abstract
Cryptosporidiosis is predominantly a gastrointestinal disease of humans and other animals, caused by various species of protozoan parasites representing the genus Cryptosporidium. This disease, transmitted mainly via the faecal-oral route (in water or food), is of major socioeconomic importance worldwide. The diagnosis and genetic characterization of the different species and population variants (usually recognised as "genotypes" or "subgenotypes") of Cryptosporidium is central to the prevention, surveillance and control of cryptosporidiosis, particularly given that there is presently no broadly applicable treatment regimen for this disease. Although traditional phenotypic techniques have had major limitations in the specific diagnosis of cryptosporidiosis, there have been major advances in the development of molecular analytical and diagnostic tools. This article provides a concise account of Cryptosporidium and cryptosporidiosis, and focuses mainly on recent advances in nucleic acid-based approaches for the diagnosis of cryptosporidiosis and analysis of genetic variation within and among species of Cryptosporidium. These advances represent a significant step toward an improved understanding of the epidemiology as well as the prevention and control of cryptosporidiosis.
Collapse
Affiliation(s)
- A R Jex
- Department of Veterinary Science, The University of Melbourne, Werribee, Victoria, Australia.
| | | | | | | | | |
Collapse
|
12
|
Teixeira MCA, Barreto ML, Melo C, Silva LR, Moraes LRS, Alcântara-Neves NM. A serological study of Cryptosporidium transmission in a periurban area of a Brazilian Northeastern city. Trop Med Int Health 2007; 12:1096-104. [PMID: 17714433 DOI: 10.1111/j.1365-3156.2007.01892.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVES To study the prevalence of Cryptosporidium infection by measuring the levels of anti-Cryptosporidium IgG antibodies among people inhabiting three neighbourhoods of a periurban area of Salvador, Northeast of Brazil; and to investigate the effects of environmental sanitation measures, hygienic habits and household water supply, storage and handling on the frequency of these antibodies in sera of the studied population. METHODS Cryptosporidium inter-household transmission was studied by comparing the frequency of anti-Cryptosporidium IgG antibodies among people inhabiting areas with or without different environmental sanitation measures and intra-household transmission by comparing the presence of these antibodies in families with or without cases of diarrhoea, associated with the presence of Cryptosporidium oocysts in their stools. Children or family members with diarrhoeal episodes were evaluated parasitologically for Cryptosporidium infection by testing stool specimens with the Ritchie-modified formol-ether concentration and the acid-fast staining methods. All groups were serologically evaluated for parasite exposure by an indirect enzyme-linked immunosorbent assay. RESULTS A statistically significant difference was detected in the prevalence of Cryptosporidium infection between area 1 which had no environmental sanitation measures and area 3 which had improved environmental sanitation measures (P = 0.044). Most of the hygienic habits investigated did not correlate with the presence of anti-Cryptosporidium antibody in sera of the population studied. However, positive associations were found between both poor household water supply (OD = 0.17; 90% CI = 0.09-0.32; P = 0.0001) and drinking unboiled/unfiltered water (OD = 0.40; 90% CI = 0.24-0.67; P = 0.0002) with high levels of anti-Cryptosporidium antibodies in sera. CONCLUSIONS These data suggest that although uncorrected household water supply, storage and handling play an important role on Cryptosporidium transmission in periurban areas of developing country cities, like Salvador, Brazil, inadequate environmental conditions may also contribute to the spread of this parasite.
Collapse
Affiliation(s)
- M C A Teixeira
- Faculdade de Farmácia, Universidade Federal da Bahia, Bahia, Brazil.
| | | | | | | | | | | |
Collapse
|