Examination for intestinal parasites and enteric bacteria in the wastewater and treated wastewater from the city of Chiang Mai, Thailand.

An attempt to use treated wastewater for agriculture in the Chiang Mai area was made, but the re-use process had to be performed under a condition that limited the risks liable to leave pathogens present in the water. The objective of our study was to examine the intestinal parasites and enteric bacteria in the wastewater and treated wastewater from the Chiang Mai University campus as well as the treated wastewater from the Chiang Mai municipality. The raw wastewater (RW), primary treatment effluent water (PE), treated wastewater using the activated sludge system (AS) from the Chiang Mai University campus and treated wastewater using the aerated lagoon (AL) system from the Chiang Mai municipality were examined for intestinal parasites and enteric bacteria by using the centrifugal sedimentation and conventional methods respectively. The ground water (GW) and the irrigation water (IW) were used for comparison. All kinds of water were collected and examined twice a month for 6 months (February to July 2000). None of human intestinal parasites were found from any wastewater, whereas the RW and PE water contained hookworm larva, Ascaris egg and Taenia egg on some occasions. A small amounts of pathogenic bacteria that can cause severe diarrhea were detected. Salmonella enteritidis gr E was isolated from the AL water in April, while Vibrio cholerae type O139 was detected from the PE water in June. Some pathogenic bacteria that might cause gastroenteritis, such as Aerobacter spp, Citrobacter spp, Pseudomonas spp and Escherichia coli were also found in all kinds of water. Between the two types of treated wastewater, the bacteria found in AS water was less than that in AL water in terms of both amount and type of bacteria. The treated wastewater from the city of Chiang Mai, compared to natural water such as irrigation water, appears to be safe to use for agriculture.

Parasitic and bacterial contamination in collards using effluent from treated domestic wastewater in Chiang Mai, Thailand.

Thailand often has inadequate water supply for agriculture during the dry season. The reuse of treated wastewater treatment plants could solve this problem. Treatment of domestic wastewater of Chiang Mai municipality by the aerated lagoon system (AL) releases more than 25,000 m3 of treated water everyday. The reuse of wastewater in agriculture is an efficient use of water, especially in tropical countries or in drought zones. The objective of this study is to demonstrate the possibility of using treated wastewater in growing edible vegetables, ie collards (kale), without pathogenic parasite and bacterial contamination. Collards (Brassica oleracea var acephala) were grown using either the treated wastewater from the aerated lagoon system (AL) or ground water (GW). Three cropping times were scheduled in February, May and July, 2000. Samples of water from AL system and GW were taken two times per month (the consecutive weeks) from February to July and examined for bacteria and parasites. Irrigation water (IW) that was normally used in agriculture was also collected, at the same time of the AL and GW collection, for bacteria and parasite investigation. A soil sample was taken before and after each crop for parasite examination. Collards were also collected at the end of the crop for parasite investigation. The results showed that GW seems to be a clean water since no pathogenic bacteria were found although small amount of Escherichia coli was noted in May. For AL and IW, similar number and types of bacteria were found. They were Aeromonas sobria, A. hydrophila, E. coli, Citrobacter freundii, Pseudomonas aeruginosa, non-pathogenic type of Vibrio cholerae. The small number of Salmonella enteritidis gr E was found in AL in April. After investigating 12 samples in 6 months of each kind of water, ie GW, Al, and IW, no parasite was found. Only unidentified free living nematodes were found in IW but those parasites are non pathogenic. A small number of unidentified free living nematodes (UFLN), a natural parasite, were found in soil after cropping. After each cropping time, similar number of hookworm was found in the plots which used either GW or AL. Collards grown by using either GW or AL showed no harmful parasite contamination. We conclude that the effluent from wastewater treatment, using aerated lagoon system, of Chiang Mai municipality could be safely used for growing collards.

Application of hazard analysis critical control point (HACCP) as a possible control measure for Opisthorchis viverrini infection in cultured carp (Puntius gonionotus).

Opisthorchiasis due to Opisthorchis viverrini and transmitted through infected freshwater cyprinoid fish (carps) affects more than 8 million people in Thailand, People's Democratic Republic of Lao, and Vietnam. The Hazard Analysis Critical Control Point (HACCP)-concept has been recommended by FAO and WHO to be included in programs to control foodborne trematode infections (FBT). HACCP is a multifactorial approach to control food hazards through surveillance of diseases, foods, and operations and education. This study describes the first attempt to apply HACCP to the prevention and control of Opisthorchis viverrini in pond culture carp (Puntius gonionotus). The experiment was designed and carried out by a multidisciplinary "HACCP team" including experts in the field of public health, parasitology, epidemiology, aquaculture, fisheries extension and fish inspection. The investigation was performed in two fish ponds in the District of Sun Pa Tong, Chiang Mai, Thailand. In the experimental pond, fish was cultured according to HACCP principles and compared with the control pond, which followed conventional aquaculture practices. Water supply to the pond, fish fry, fish feed and pond conditions during the growing period were identified as critical control points (CCPs). Hazards were identified and analyzed, as well as control measures, critical limits, monitoring procedures, corrective actions, and record keeping developed for each one of the above CCPs. Complete pond preparation, particularly aiming to eliminate contamination of pond water with O. viverrini eggs, fish infected with parasite meacercariae and the first intermediate host (Bithynia spp), was conducted. After the pond was filled with water, O. viverrini metacercaria-free fry were released into the pond. The preliminary results obtained indicate that HACCP-based principles applied to carp pond culture could be used as a strategy to prevent and control O. viverrini. Further studies should be undertaken aiming to confirm these preliminary results.

Human immunodeficiency virus infection and self-treatment for sexually transmitted diseases among northern Thai men.

BACKGROUND AND OBJECTIVES: Self-treatment for sexually transmitted diseases (STD) is common, but little studied, in Thailand, and its influence on human immunodeficiency virus (HIV) infection is unknown. GOALS: To assess STD self-treatment and self-prophylaxis behaviors as well as HIV risks and serostatus among northern Thai men. STUDY DESIGN: Cross-sectional report from a cohort of military conscripts (N = 869). HIV and STD seroprevalence and reported risk behaviors, including STD history and antibiotic self-treatment, were obtained. Associations between STDs and self-treatment or prophylaxis and HIV infection were analyzed using t-tests, odds ratios, and logistic regression. RESULTS: The prevalence rate for HIV was 12.3%, and for syphilis it was 2.2%. Men who were seropositive for HIV were more likely to report having sex with commercial sex workers (OR 9.1), to have had an STD (OR 5.96) and to report inconsistent condom use with commercial sex workers (OR 3.13). Of 282 men reporting any STD, 65.2% treated themselves with antibiotics, and 8.5% used them before commercial sex. Among those who frequented commercial sex workers, 98.7% took preventive steps after sex by increasing urine output (69.2%), washing the genital area (28.9%), and using antibiotics (0.9%). Men reporting STD self-treatment were less likely to be HIV infected (OR 0.53; 95% CI 0.31, 0.93). CONCLUSIONS: These men are attempting to prevent HIV and STDs. Self-treatment with antibiotics may lower HIV risks associated with bacterial STD in a high-prevalence population.

PIP: In May 1993, at 11 military camps in the upper northern region of Thailand, civilians interviewed 869 men aged 21-29 years (most of whom were 21 years old) so researchers could determine the frequency and variety of self-treatment and self-prophylaxis behaviors for sexually transmitted disease (STD) and the relationship of these behaviors with the prevalence of HIV infection. 12.3% of the men at conscription into the military tested positive for HIV infection. 32.5% had ever had an STD. The leading STDs and syndromes were gonorrhea (16.1%), penile discharge with pus (15.5%), and pain while urinating (11.4%). HIV-positive men were more likely to have had sex with commercial sex workers (CSWs) (odds ratio [OR] = 9.14), to have had an STD (OR = 5.96), and not to use condoms consistently when having sexual intercourse with CSWs (OR = 3.13). 65.2% of men who had ever had an STD self-treated with antibiotics. 8.5% of men who had ever had an STD used antibiotics, particularly chloramphenicol, before having intercourse with a CSW. Among all the men who had sexual intercourse with CSWs, almost all (98.7%) had adopted steps to prevent STDs: increasing urine output (69.2%), washing the genitals with soap and water (28.9%), and using antibiotics (0.9%). Men who self-treated with antibiotics after having intercourse with CSWs were less likely to have HIV infection (OR = 0.53). Antibiotic use before intercourse with CSWs did not have as strong a protective effect as it did after intercourse (OR = 0.74). The protective effect of self-treatment was significant, even when controlling for syphilis, gonorrhea, lymphadenopathy, penile discharge with pus, and condom use with a CSW. These findings show that some sexually active men in northern Thailand are trying to prevent HIV and other STDs and that self-treatment with antibiotics may reduce the HIV risk associated with bacterial STDs in a high prevalence population.

Effect of storage on the creamatocrit and total energy content of human milk.

Human milk samples were collected from mothers on the third post-partum day with a manual breast-pump and pooled. They were divided into aliquots and stored at room temperature (24-25 degrees C), and at 4 degrees, 37 degrees and -20 degrees C. The creamatocrit (CR) values decreased significantly after storage at room temperature (P less than 0.03), or at 37 degrees C (P less than 0.001) for 45 min and 30 min, respectively. Creamatocrit remained stable for 14 d at 4 degrees C, and for up to 28 d at -20 degrees C. However, freezing and thawing samples twice significantly decreased creamatocrit values (P less than 0.001). The total energy concentration of the samples stored at -20 degrees C was stable for 28 d. These results indicate that strict precautions must be taken when handling and storing human milk samples for analysis of lipid content.

Iron status and the effect of iron supplementation in Thai male blood donors in northern Thailand.

The iron status of voluntary and professional male donor groups was investigated. The study indicated that serum ferritin level was lower significantly in those who donated three times per year compared to the first time donors (p less than 0.05) in voluntary donor group. Similar results were observed among the professional donors. Whereas haemoglobin, haematocrit and transferrin saturation were not altered by donating blood in both groups. It also showed that, in general, the body iron stores of professional donors were lower to those of voluntary donors. Supplementation with iron over a period of three months produced a rise in serum ferritin levels and the percentage prevalence of iron depleted subjects decreased from 23.6% to 6.4%. Haemoglobin, haematocrit and transferrin saturation levels also improved.