Changes in fatty acids during storage of artisanal-processed freshwater sardines (Rastrineobola argentea).

For ages, indigenous small fish species have been important in food and nutritional security of poor communities in low income countries. Freshwater fish, in particular fatty fish species are attracting a great attention because they are good sources of health promoting long chain omega-3 fatty acids. Docosahexaenoic acid (DHA, C22:6n-3), Docosapentaenoic acid (DPA, C22:5n-3) and eicosapentaenoic acid (EPA, C20:5n-3) are the main omega-3 PUFAs known to confer health benefits in humans if consumed in required amounts. While nutritionally valued, omega-3 PUFAs in fish are susceptible to oxidative damage during processing, transportation and subsequent storage. Lake Victoria sardines (Rastrineobola argentea), are rich source of chemically unstable omega-3 fatty acids DHA, DPA and EPA. Traditionally, sardines are preserved by sun drying, deep frying and smoking. Sardine products are transported, stored and marketed at ambient temperatures. Generally, uncontrolled and higher temperatures are known to increase vulnerability of polyunsaturated fatty acids to oxidation which in turn results into loss of nutritional and sensory qualities. This study investigated changes of fat acids in sun dried, deep fried and smoked sardines during storage. Lipolysis and the progressive hydroperoxides formation were monitored by free fatty acids (FFAs) and peroxide value (PV) respectively. None volatile secondary products of lipid oxidation were measured by thiobabituric acid reactive substances (TBARS). Fatty acids were analyzed by gas chromatography with a flameionization detector (GC-FID). Deep fried sardines maintained the lowest and apparently stable PV, TBARS and FFAs. Proportions of saturated fatty acids and polyunsaturated fatty acids decreased with time while that of monounsaturated fatty acids increased. Omega-3 fatty acids EPA, DPA and DHA decreased with increase in storage time. In 21 days of storage, DHA was oxidized beyond detectable levels in all sardine products. Gradual increase in FFAs in sun dried sardines was suggestive of lipid hydrolysis induced by enzymes.

Salmonella Heidelberg and Salmonella Minnesota in Brazilian broilers: Genomic characterization of third-generation cephalosporin and fluoroquinolone-resistant strains

Salmonella serovars Heidelberg and Minnesota encoding antimicrobial resistance to third-generation cephalosporins and fluoroquinolones are often detected in poultry/poultry meat. We analysed the genomes of 10 Salmonella Heidelberg (SH) and 4 Salmonella Minnesota (SM) from faecal isolates of Brazilian poultry. These featured virulent and multidrug-resistant characteristics, with AmpC beta-lactamase (blaCMY-2 ) predominance (9/14), for all SM (4/4) and some SH (3/10) located on IncC plasmid replicons. IncC carrying blaCTX-M-2 was only detected among SH (3/10). Mutation in the gyrA/parC genes was present in all SH, whereas SM harboured parC mutation plus qnrB19 on ColRNAI plasmids (3/4). In silico resistance overall corroborated with phenotypic results. Core genome phylogenies showed close clustering and high similarities between the Brazilian and poultry meat/food isolates from Europe, and to human isolates from European countries with documented import of Brazilian poultry meat. Conjugation assays with SM successfully transferred blaCMY-2 , and qnrB19 to an Escherichia coli recipient. The findings reinforce the ongoing antimicrobial resistance acquisition of SH and Minnesota and the risks for disseminating resistant strains and/or mobile elements which may increasingly affect importing countries and the need for controlling AMR in major poultry-exporting countries like Brazil.

Total Dietary Intake and Health Risks Associated with Exposure to Aflatoxin B1, Ochratoxin A and Fuminisins of Children in Lao Cai Province, Vietnam.

The health burden of foodborne mycotoxins is considerable, but particularly for children due to their lower detoxification capacity, rapid growth and high intake of food in proportion to their weight. Through a Total Dietary Study approach, the objective was to estimate the dietary exposure and health risk caused by mycotoxins for children under 5 years living in the Lao Cai province in northern Vietnam. A total of 40 composite food samples representing 1008 individual food samples were processed and analyzed by ELISA for aflatoxin B1, ochratoxin A and fumonisins. Results showed that dietary exposure to aflatoxin B1, ochratoxin A and total fumonisins were 118.7 ng/kgbw/day, 52.6 ng/kg bw/day and 1250.0 ng/kg bw/day, respectively. Using a prevalence of hepatitis of 1%, the risk of liver cancer related to exposure of aflatoxin B1 was 12.1 cases/100,000 individual/year. Age-adjusted margin of exposure (MOE) of renal cancer associated with ochratoxin A was 127, while MOE of liver cancer associated with fumonisins was 542. Antropometric data show that 50.4% (60/119) of children were stunted, i.e. height/length for age z-scores (HAZ) below -2, and 3.4% (4/119) of children were classified as wasted, i.e. weight for height z-scores (WHZ) below -2. A significant negative relationship between dietary exposure to individual or mixture of mycotoxins and growth of children was observed indicating that the high mycotoxin intake contributed to stunning in the children studied.

Dietary exposure to aflatoxin B1, ochratoxin A and fuminisins of adults in Lao Cai province, Viet Nam: A total dietary study approach.

Aflatoxins, fumonisins and ochratoxin A that contaminate various agricultural commodities are considered of significant toxicity and potent human carcinogens. This study took a total dietary study approach and estimated the dietary exposure of these mycotoxins for adults living in Lao Cai province, Vietnam. A total of 42 composite food samples representing 1134 individual food samples were prepared according to normal household practices and analysed for the three mycotoxins. Results showed that the dietary exposure to aflatoxin B1 (39.4 ng/kg bw/day) and ochratoxin A (18.7 ng/kg bw/day) were much higher than recommended provisional tolerable daily intake (PTDI) values mainly due to contaminated cereals and meat. The exposure to total fumonisins (1400 ng/kg bw/day) was typically lower than the PTDI value (2000 ng/kg bw/day). The estimated risk of liver cancer associated with exposure to aflatoxin B1 was 2.7 cases/100,000 person/year. Margin of exposure (MOE) of renal cancer linked to ochratoxin A and liver cancer associated with fumonisins were 1124 and 1954, respectively indicating risk levels of public health concern. Further studies are needed to evaluate the efficiency of technical solutions which could reduce mycotoxin contamination as well as to determine the health effects of the co-exposure to different types of mycotoxins.

Cryptosporidium and Giardia in Danish organic pig farms: Seasonal and age-related variation in prevalence, infection intensity and species/genotypes.

Although pigs are commonly infected with Cryptosporidium spp. and Giardia duodenalis, including potentially zoonotic species or genotypes, little is known about age-related infection levels, seasonal differences and genetic variation in naturally infected pigs raised in organic management systems. Therefore, the current study was conducted to assess seasonal and age-related variations in prevalence and infection intensity of Cryptosporidium and Giardia, evaluate zoonotic potential and uncover correlations between species/genotypes, infection intensity and faecal consistency. Shedding of oocysts and cysts ((oo-)cysts) was monitored at quarterly intervals (September 2011-June 2012) in piglets (n = 152), starter pigs (n = 234), fatteners (n = 230) and sows (n = 240) from three organic farms in Denmark. (oo-)Cysts were quantified by immunofluorescence microscopy; and 56/75 subsamples from Cryptosporidium infected pigs were successfully analysed by PCR amplification and partial sequencing of the small subunit (SSU) 18S rRNA and hsp70genes, while 13/67 Giardia subsamples were successfully analysed by amplification and partial sequencing of the 18S rRNA and the gdh genes. Altogether, Cryptosporidium or Giardia infections were observed in 40.9% (350/856) and 14.0% (120/856) of the pigs, respectively, including 8.2% (70/856) infected with both parasites. Prevalence, intensity of infections and presence of Cryptosporidium species varied significantly between age-groups; 53.3% piglets, 72.2% starter pigs, 40.4% fatteners and 2.9% sows were infected with Cryptosporidium, whereas 2.0% piglets, 27.4% starter pigs, 17.8% fatteners and 5.0% sows were infected with Giardia. The overall prevalence was stable throughout the year, except for dual-infections that were more prevalent in September and December (p < 0.05). The infection intensity was age-related for both parasites, and dual-infected pigs tended to excrete lower levels of oocysts compared to pigs harbouring only Cryptosporidium. Likewise, pigs infected with Cryptosporidium scrofarum excreted fewer oocysts (mean CPG: 54,848 ± 194,508CI: 9085-118,781) compared to pigs infected with Cryptosporidium suis (mean OPG: 351,035 ± 351,035CI: 67,953-634,117). No correlation between faecal consistency and (oo-)cyst excretion levels was observed. Of the successfully genotyped isolates, 38/56 (67.9%) were C. scrofarum and 18/56 (32.1%) were C. suis, while the livestock specific G. duodenalis Assemblage E was detected in 11/13 (84.6%) isolates and the potentially zoonotic Assemblage A was identified in 2/13 (15.4%) isolates. Piglets exclusively hosted C. suis, with one exception, while starter pigs and fatteners predominantly hosted C. scrofarum. As organic pigs are partly reared outdoors, environmental contamination with Cryptosporidium and Giardia is inevitable. Nevertheless, the present data indicate that the potential public health risk associated with both of these parasites in Danish organic pig production seems to be negligible.

Water used to moisten vegetables is a source of Escherichia coli and protozoan parasite contamination at markets in Hanoi, Vietnam.

The study was done to assess the level of fecal (Escherichia coli) and protozoan parasite (Cryptosporidium spp. and Giardia spp.) contamination in water used by traders to moisten vegetables at markets in Hanoi, Vietnam. A total of 200 splashing water samples from markets located within eight districts were analyzed for E. coli and Cryptosporidium spp. and Giardia spp. (oo)cysts. Giardia cysts were found in 17 splashing water samples and Cryptosporidium oocysts in nine samples, with median values of 20 cysts ml(-1) and 10 oocysts ml(-1), respectively. E. coli was found with a median concentration of 636 cfu ml(-1) and its occurrence was negatively correlated with the numbers of protozoan parasites. The splashing water was kept in buckets that were rarely cleaned and often used for handwashing. The finding of these pathogens in splashing water is likely to represent real food safety hazards.

High reinfection rate after preventive chemotherapy for fishborne zoonotic trematodes in Vietnam.

BACKGROUND: The World Health Organization aims for complete morbidity control of fishborne zoonotic trematodes (FZT) in endemic areas by 2020. The main intervention tool for achieving this goal is regular use of preventive chemotherapy by offering praziquantel to those at risk in endemic areas. The purpose of this study was to investigate the effectiveness of preventive chemotherapy to control FZT in an endemic area in Northern Vietnam. METHODOLOGY AND PRINCIPLE FINDINGS: We followed a cohort of 396 people who fulfilled the criteria for receiving preventive chemotherapy. Stool samples were examined by Kato-Katz technique for the presence of trematode eggs before, and two, 16, 29 and 60 weeks after preventive chemotherapy. The prevalence of trematode eggs in stool was 40.2% before, 2.3% two weeks after and increased to a cumulative prevalence of 29.8% sixty weeks after preventive chemotherapy. CONCLUSIONS: The effectiveness of preventive chemotherapy as a main component in control of FZT is not well documented in most endemic areas. We found a high reinfection rate within the first year after preventive chemotherapy. Since these trematodes are zoonoses, preventive chemotherapy may not have sufficient impact alone on the transmission to have a lasting effect on the prevalence. Animal reservoirs and farm management practices must be targeted to achieve sustainable control of fishborne zoonotic trematode infections, hence control programs should consider a One Health approach.

Reinfection of dogs with fish-borne zoonotic trematodes in northern Vietnam following a single treatment with praziquantel.

BACKGROUND: Fish-borne zoonotic trematodes (FZT) infections including liver- and minute intestinal flukes are common in Southeast Asia in both humans and domestic animals eating raw fish and since 2010, the liver flukes are recognised as neglected tropical diseases by WHO. Mass drug treatment with praziquantel is advised for humans, but no recommendations for control of the FZT in the reservoir hosts exist. METHODOLOGY/PRINCIPAL FINDINGS: A study was conducted to assess the ability of praziquantel treatment for control of FZT in farm dogs in an endemic area in Northern Vietnam. Initially, 101 dogs from 73 households were examined for small trematode eggs in their faeces. Forty seven copro-positive dogs were included in the study. Thirty eight dogs received treatment with a single dose of 40 mg/kg of praziquantel. A group of nine dogs were left untreated. Coprological examination for small trematode eggs was performed on day 0, 3, 10, 30, 60, 90 and 120 post treatment. Farmers were questioned about dog keeping practises. All dogs were copro-negative for small trematode eggs on both day 3 and 10 post treatment. From day 30 onwards previously negative dogs became positive again. The reinfection rates were 26.3% (day 30), 45.5% (day 60), 53.1% (day 90), 61.3% (day 120).The nine untreated dogs remained positive throughout the study period. There was no difference in the intensity of infection at day 0 and 120 neither in the treated or untreated group. CONCLUSION: Dogs had easy access to raw fish and did not receive treatment against flukes by their owner. More than 50% of the dogs were reinfected 3 months post treatment. We do not recommend controlling FZT infections in dogs by anthelmintic treatment alone since reinfection occurs fast under the existing farm management systems.

Field trial of praziquantel for control of fishborne zoonotic trematodes in reservoir hosts in Vietnam.

This field trial was conducted to determine whether 40 or 75 mg/kg of praziquantel is suitable for treatment of fishborne zoonotic trematodes (FZT) in naturally infected dogs (n=10) and cats (n=11). Three days after treatment all animals at either dose were negative for small trematode eggs. In two cats and one dog treated with 75 mg/kg, however, a few damaged eggs were found 3 days post-treatment; no small trematode eggs were seen in these animals at day 14 post-treatment. In addition, at the 75 mg dose, two cats and two dogs experienced vomiting or diminished appetite. Therefore a praziquantel dose of 40 mg/kg is suggested for treatment of FZT in dogs and cats.

Faecal and protozoan parasite contamination of water spinach (Ipomoea aquatica) cultivated in urban wastewater in Phnom Penh, Cambodia.

OBJECTIVE: To identify the level of contamination with thermotolerant coliforms (ThC), intestinal helminth eggs and protozoan parasites in water spinach (Ipomoea aquatica) cultivated in a wastewater-fed lake in Phnom Penh, Cambodia. METHODS: The investigation was carried out from July 2004 to May 2005 in Boeng Cheung Ek lake, a main recipient of wastewater from the city of Phnom Penh. Water spinach samples were collected near two wastewater entry points in the northern part of the lake and near a wastewater exit point in the southern part of the lake, where water is discharged from the lake into a stream. Water spinach samples were harvested at each of the three locations with and without wastewater contact according to the normal practices of farmers, and analysed for ThC, protozoan parasites (Giardia, Cryptosporidium and Cyclospora), and helminth eggs (Ascaris lumbricoides, Trichuris trichura and hookworm) using standard methods. Wastewater samples were also collected at each of the three locations and analysed for ThC and helminth eggs. RESULTS: High concentrations of ThC (approximately 10(5)-10(7)/g) were found in water spinach samples. ThC mean counts did not differ significantly, neither between sample types at each location, nor between locations. ThC mean concentration of water spinach samples collected in the rainy season of 2005 was higher than that in the dry season of 2004. Protozoan parasites were detected in the samples from all three locations and in water spinach harvested with and without wastewater contact. Giardia spp. were present in 56% (20) of samples with an average cyst concentration of 6.6/g. Mean counts of Giardia were not significantly associated with wastewater contact status of water spinach. Cryptosporidium oocysts were found in 17% (six) of samples with an average concentration of 0.5 oocyst per gram of water spinach. Cyclospora oocysts were detected in 8% (three) of samples. Four (11%) water spinach samples contained helminth eggs (average concentration: 0.1 egg per gram). Water samples contained approximately 10(4)-10(7) ThC per 100 ml and a mean of 27.4 helminth eggs per litre. There was a 2-3 log reduction of ThC between the water samples collected at the wastewater entry and exit point(s) of the lake. CONCLUSIONS: Water spinach cultivated in the lake was highly contaminated with feces, as indicated by high ThC concentrations and the presence of protozoan parasites. A reduction in ThC numbers almost to WHO guideline levels for irrigation water occurred through natural biological and physical processes in the lake, as shown by differences in ThC counts at wastewater entry and exit points.

Current status of cysticercosis in Vietnam.

This English review concerning the current status of cysticercosis in Vietnam has been compiled from various reports of studies conducted over the past 15 years, which have appeared in national publications in Vietnamese, in order to make the information available to the international community. Hospital surveys indicate that cysticercosis is emerging as a serious health problem in the country though most of the information comes from the Hanoi area. Many more men than women are being treated for cysticercosis with most patients being young to middle-aged adults though several juvenile cases have been seen in the south. Clinical manifestations of the disease in humans include subcutaneous nodules, epileptic seizures, severe headache, impaired vision and memory loss. Albendazole has been found to be the best drug for treating cysticercosis though it does not appear to be totally effective for curing cerebral cysts. Information concerning porcine and bovine cysticercosis is very limited and based mostly on passive surveillance at Hanoi slaughterhouses. Surveys for human taeniasis in central and northern provinces indicate a prevalence of 0.2-7.2%. However, techniques of low sensitivity were used and the results are inconclusive since it is unknown with which species of tapeworm the people were infected. In addition to Taenia solium which causes human cysticercosis, T. saginata and T. asiatica are also known to be present in Vietnam. Risk factors investigated thus far with regard to transmission of T. solium suggest that consumption of raw pork, inadequate or absent meat inspection and control, poor sanitation in some areas, and the use of untreated human waste as fertilizer for crops may play important roles in Vietnam but this remains to be validated. The evidence thus far collected suggests that a national surveillance program for cysticercosis is a great need for Vietnam. The authors recommend further research on the epidemiology and impact of cysticercosis in both human and pig hosts in order to determine whether a prevention and control program in Vietnam would be merited and cost effective.