Viruses In Drinking Water Research Articles

Virus contamination, removal characteristics and quantitative risk assessment from drinking water source to secondary water supply system

The drinking water (DW) supply system is the last line of defense against virus infections for people's DW health. This study systematically evaluated the virus pollution characteristics and human health risks in the entire DW supply systems. The detection frequency range of the virus in DW was 5.30% to 71.21%, and the concentration range at not detected (n.d.) -1.45×105 copies/L. DNA virus like adenovirus was more persistent than RNA viruses like norovirus and enterovirus in the DW system. Drinking water treatment plants (DWTPs) play a crucial role in reducing the target virus with degradation rates ranging from 47.09% to 100% when compared with the removal rates in DW source and secondary water supply (SWS). It was found the persistence and accumulation of the virus in the treated water from DWTPs to the downstream water transmission network. Principal component analysis showed that the virus contamination was positive correlation with water quality indexes like total phosphorus (TP), total nitrogen (TN), dissolved oxygen (DO) but negative correlation with temperature and the dose of free chlorine. Quantitative microbial risk assessment (QMRA) of adenovirus in the SWS showed that the DALYs/person/year of gastroenteritis ranged from 8.11×10-6 to 2.68×10-4 DALYs/person/year. Uncertainty analysis of different distributions of model inputs like virus concentrations showed the risk caused by adenovirus was changed appreciably for different person by using 100,000 Monte Carlo simulations. It is necessary to efficiently remove the virus in the DW systems to ensure human health for the direct ingestion of secondary water supply water.

ANALISIS FAKTOR RISIKO KUALITAS BAKTERIOLOGIS AIR MINUM ISI ULANG DI KABUPATEN OGAN ILIR

Latar Belakang: Kontaminasi bakteri dan virus pada air minum menjadi permasalahan utamapencemaran air di negara sedang berkembang sampai dengan saat ini. Penelitian oleh InstitutePertanian Bogor dan Badan Pengawas Obat dan Makanan menyatakan bahwa sebagian besarproduk air minum dihasilkan oleh DAMIU dinilai belum memenuhi standar industri air minumdalam kemasan. Tujuan dari penelitian ini ialah untuk memperoleh faktor-faktor apa saja yangmempengaruhi adanya kandungan bakteri coliform pada air minum isi ulang yang berasal daridepot air minum isi ulang.Metode: Penelitian ini merupakan penelitian observasional analitik dengan menggunakan metodecross sectional. Sampel pada penelitian ini ialah 40 DAMIU yang ada di Kabupaten Ogan Ilir. Datadianalisis secara univariat dan bivariat, serta dilakukan uji laboratorium kandungan bakteri coliformpada sampel air.Hasil penelitian: Berdasarkan pemeriksaan laboratorium ditemukan 13DAMIU (32,5%) yangsampel airnya positif mengandung bakteri koliform. Hasil analisis bivariat diperoleh bahwavariabel izin operasi, alat sterilisasi, sumber air baku, ruang pengisian, kebersihan DAMIU, tempatsampah, pemeriksaan bakteriologis, pakaian kerja, pelatihan penajmah makanan, pengawasanberkala, higiene personal, kebersihan diri dan fasilitas cuci tangan tidak memiliki hubungan yangbermakna dengan kualitas bakteriologis air.Kesimpulan: Higiene dan sanitasi Depot Air Minum Isi Ulang (DAMIU) di Kabupaten Ogan Ilirmasih tergolong ke dalam kategori buruk. Sehingga peningkatan pengetahuan dan kesadarankaryawan DAMIU mengenai hygiene sanitasi serta pengawasan dari dinas kesehatan danmemfasilitas pemeriksaan bakteriologis air perlu dilakukan. Keyword: Depot air minum isi ulang, higiene, sanitasi

The establishment and application of the method with virus concentration and detection in drinking water

This study aimed to construct an effective method to concentrate and detect virus in drinking water, and human adenovirus pollution status in actual water samples was monitored by constructed method. The concentration efficient of NanoCeram filter for the first concentration with source water and drinking water and the concentration efficient of the different concentrations of PEG 8000 for the second concentration were assessed by spiking f₂ bacteriophage into water samples. The standard of human adenovirus for real-time PCR was constructed by T-A clone. The plasmid obtained was identified through sequence analyzing and consistency check comparing to target gene fragment was conducted by using blast algorithm. Then, real-time PCR was constructed to quantify the concentration of human adenovirus using the plasmid as standard. Water samples were concentrated by using NanoCeram filter on the spot and then concentrated for the second time by PEG/NaCl in 2011. The DNA of concentrated samples were extracted for the quantification of human adenovirus in real-time PCR subsequently to monitor the pollution of human adenovirus in water. For the first concentration by NanoCeram filter, the recovery rates were (51.63 ± 26.60)% in source water and (50.27 ± 14.35)% in treated water, respectively. For the second concentration, the highest recovery rate was reached to (90.09 ± 10.50)% at the concentration of 0.13 kg/L of PEG 8000. The sequence identity score of standard of adenovirus for real time PCR and adenovirus gene was 99%, implying that it can be successfully used to quantification with human adenovirus. The levels of human adenovirus in the water samples sampled in 2011 ranged from 4.13×10³ to 2.20×10⁶ copies/L in source water, while range from 5.57×10² to 7.52×10⁵ copies/L in treated water and the removal efficiency range was (75.49 ± 11.71)%. NanoCeram filers combined with PEG/NaCl was an effective method to concentrate virus in aquatic environment. There was a large number of human adenovirus in source water, and it is not sufficient to remove them thoroughly through conventional water treatment processes.

Public Health Significance of viral contamination of drinking water

Water-borne enteric viruses pose a threat to both human and animal life causing a wide range of illnesses. Groundwater is the commonest transmission route for these viruses. About 50% of groundwater related disease outbreaks are attributable to viruses. Recent studies in developed countries have focused on public water systems, unfortunately, without much attention to private household wells and storage facilities. This paper reviews disease outbreaks attributed to water-borne viruses, the public health significance of enteric viral diseases and problems encountered in the development of diagnostic assays. The objective of this review is to confer the rationale for more research to provide reliable baseline information on the significance of water-borne viruses in the developing world. Since the virological quality of drinking water can no longer be compromised, rapid and sensitive methods for detecting enteric viruses in drinking water, recreational water and their sources is a necessity. As a preventive measure, ground, surface and treated drinking water must be protected from viral contamination. Enforcement of legislative measures for regular viral monitoring of drinking water in the industry will ensure safety of consumers.