Heavy Infection Research Articles

Soil- transmitted nematode infections in school children in a peri-urban area, North Central Nigeria

Parasitic infections caused by Soil Transmitted Nematodes (STN) are a common occurrence in developing countries with unfavourable environmental conditions that favour the development of eggs and larvae of STN. This was a cross sectional study carried out from January to April, 2018 to determine the prevalence and intensity of STN infections in six randomly selected primary schools in the Ilorin South Local Government Area, Kwara State, Nigeria. Stool specimens were collected from 508 pupils (259 males; 249 females), which were prepared and examined using the Kato-Katz technique. Of 508 stool specimens examined, 206 (40.6%) were infected with at least one of the STN. Eggs of Ascaris lumbricoides, Trichuris trichiura, Enterobius vermicularis and hookworms were identified with prevalences of 37.9%, 4.9%, 2.4% and 30.1% respectively. In all six schools examined, 115 males (44.4%) and 91 females(36.5%) were found to be infected (P<0.01). Pupils in the age group 5-7 years were found to be the most infected (52.2%), while the least occurred in the age group 14-16 years (28.2%). Of the 206 (40.6%) infected pupils; light, moderate and heavy infections were noted in 12.2%,20.7% and 7.5% respectively. The egg-count of Ascaris lumbricoides, Trichuris trichiura, hookworms and Enterobius vermicularis were 277.8±168.4, 160±118.1, 199.7±131.4 and 33.6±13.1 eggs per gram of faeces respectively. The intensity of STN infections was higher among males (231.3±159.8) than among females (230.8±154.8). Pupils in the age group 11-13 had the highest intensity of infection (267.0±158.1). Prevalence of single and double infections was 75.3% and 24.7% respectively. STN infections are prevalent in the study area which calls for regular deworming, health education and provision of basic sanitary and social amenities to reduce the disease burden.

Deworming children for soil-transmitted helminths in low and middle-income countries: systematic review and individual participant data network meta-analysis

ABSTRACTIntestinal parasites affect millions of children globally. We aimed to assess effects of deworming children on nutritional and cognitive outcomes across potential effect modifiers using individual participant data (IPD). We searched multiple databases to 27 March 2018, grey literature, and other sources. We included randomised and quasi randomised trials of deworming compared to placebo or other nutritional interventions with data on baseline infection. We used a random-effects network meta-analysis with IPD and assessed overall quality, following a pre-specified protocol. We received IPD from 19 trials of STH deworming. Overall risk of bias was low. There were no statistically significant subgroup effects across age, sex, nutritional status or infection intensity for each type of STH. These analyses showed that children with moderate or heavy intensity infections, deworming for STH may increase weight gain (very low certainty). The added value of this review is an exploration of effects on growth and cognition in children with moderate to heavy infections as well as replicating prior systematic review results of small effects at the population level. Policy implications are that complementary public health strategies need to be assessed and considered to achieve growth and cognition benefits for children in helminth endemic areas.

Soil-transmitted helminth infection in school age children in Sierra Leone after a decade of preventive chemotherapy interventions

BackgroundBaseline mapping of soil-transmitted helminth (STH) infections among school age children (SAC) in 2008–2009 found high or moderate prevalence in 13 of the 14 districts in Sierra Leone. Following these surveys, mass drug administration (MDA) of mebendazole/albendazole was conducted biannually at national level targeting pre-school children (PSC) aged 12–59 months and intermittently at sub-national level targeting SAC. In addition, MDA with ivermectin and albendazole for eliminating lymphatic filariasis (LF) has been conducted nationwide since 2010 targeting individuals over 5 years of age. Each MDA achieved high coverage, except in 2014 when all but one round of MDA for PSC was cancelled due to the Ebola emergency. The objective of the current study was to determine the prevalence and intensity of STH infections among SAC after a decade of these deworming campaigns.MethodsSeventy-three schools in 14 districts were purposefully selected, including 39 schools from the baseline surveys, with approximately two sites from each of low, moderate and high prevalence categories at baseline per district. Fresh stool samples were collected from 3632 children aged 9–14 years (male 51%, female 49%) and examined using the Kato Katz technique.ResultsThe prevalence of STH infections in Sierra Leone decreased in 2016 compared to 2008: Ascaris lumbricoides 4.4% (95% confidence interval [CI]: 3.7–5.1%) versus 6.6% (95% CI: 0–25%), Trichuris trichiura 0.7% (95% CI: 0.5–1.1%) versus 1.8% (95% CI: 0–30.2%), hookworm 14.9% (95% CI: 13.8–16.1) versus 38.5% (95% CI: 5.4–95.1%), and any STH 18.3% (95% CI:17.0–19.5%) versus 48.3% (CI: 5.4–96.3%), respectively. In 2016, no district had high hookworm prevalence and four districts had moderate prevalence, compared with eight and four districts respectively in 2008. In 2016, the arithmetic mean hookworm egg count in all children examined was light: 45.5 eggs per gram (EPG) of faeces, (95% CI:\\ 35.96–55.07 EPG); three (0.08%) children had heavy infections and nine (0.25%) children had moderate infections.ConclusionsSierra Leone has made considerable progress toward controlling STH as a public health problem among SAC. As LF MDA phases out (between 2017 and 2021), transition of deworming to other platforms and water and sanitation strategies need to be strengthened to maintain STH control and ultimately interrupt transmission.

Evaluation of integrated interventions layered on mass drug administration for urogenital schistosomiasis elimination: a cluster-randomised trial

SummaryBackgroundElimination of schistosomiasis as a public health problem and interruption of transmission in selected areas are targets set by WHO for 2025. Our aim was to assess biannual mass drug administration (MDA) applied alone or with complementary snail control or behaviour change interventions for the reduction of Schistosoma haematobium prevalence and infection intensity in children from Zanzibar and to compare the effect between the clusters.MethodsIn a 5-year repeated cross-sectional cluster-randomised trial, 90 shehias (small administrative regions; clusters) in Zanzibar eligible owing to available natural open freshwater bodies and public primary schools were randomly allocated (ratio 1:1:1) to receive one of three interventions: biannual MDA with praziquantel alone (arm 1) or in combination with snail control (arm 2), or behaviour change activities (arm 3). Neither participants nor field or laboratory personnel were blinded to the intervention arms. From 2012 to 2017, annually, a single urine sample was collected from approximately 100 children aged 9–12 years in the main public primary school of each shehia. The primary outcome was S haematobium infection prevalence and intensity in 9–12-year-old children after 5 years of follow-up. This study is completed and was registered with the ISRCTN, number 48837681.FindingsThe trial was done from Nov 1, 2011, through to Dec 31, 2017 and recruitment took place from Nov 2, 2011, until May 17, 2017. At baseline we enrolled 8278 participants, of whom 2899 (35%) were randomly allocated to arm 1, 2741 (33%) to arm 2, and 2638 (32%) to arm 3. 120 (4·2%) of 2853 in arm 1, 209 (7·8%) of 2688 in arm 2, and 167 (6·4%) of 2613 in arm 3 had S haematobium infections at baseline. Heavy infections (≥50 eggs per 10 mL of urine) were found in 126 (1·6%) of 8073 children at baseline. At the 5-year endline survey, 46 (1·4%) of 3184 in arm 1, 56 (1·7%) of 3217 (odds ratio [OR] 1·2 [95% CI 0·6–2·7] vs arm 1) in arm 2, and 58 (1·9%) of 3080 (1·3 [0·6–2·9]) in arm 3 had S haematobium infections. Heavy infections were detected in 33 (0·3%) of 9462 children.InterpretationBiannual MDA substantially reduced the S haematobium prevalence and infection intensity but was insufficient to interrupt transmission. Although snail control or behaviour change activities did not significantly boost the effect of MDA in our study, they might enhance interruption of transmission when tailored to focal endemicity and applied for a longer period. It is now necessary to focus on reducing prevalence in remaining hotspot areas and to introduce new methods of surveillance and public health response so that the important gains can be maintained and advanced.FundingUniversity of Georgia Research Foundation Inc and Bill & Melinda Gates Foundation.

First molecular identification of Strongyloides vituli in cattle in Japan and insights into the evolutionary history of Strongyloides parasites of ruminants

Traditionally, Strongyloides nematode infecting cattle had been thought to be a single species, S. papillosus. Surprisingly, Eberhardt et al. in 2008 reported two, rather than one Strongyloides species infected cattle, with one being S. papillosus and the other S. vituli. However, there was no subsequent report to support their findings.In July 2018, a case of a sudden death of a calf believed to be due to heavy infection with S. papillosus at a dairy farm in Miyazaki Prefecture, Japan, was reported. One month after the initiation of a deworming program to prevent further sudden deaths, fecal specimens from 24 cattle housed in the same barn were examined. Eight samples were positive for Strongyloides eggs. For species determination, the nucleotide sequences of 18S rDNA (small subunit ribosomal DNA gene), rpl-10 (ribosomal protein L10 gene), and mitochondrial (mt) cox1 (cytochrome c oxidase subunit 1 gene) were obtained. Typing data for all three marker genes indicated the presence of both species, S. papillosus and S. vituli, in the fecal samples. To our knowledge, this study is the first to support the original report by Eberhardt et al. regarding the sympatric existence of S. papillosus and S. vituli in cattle, and to report the presence of S. vituli in Japan.Interestingly, phylogenetic analyses of both rpl-10 and mt cox1 sequences indicated a closer genetic relationship of S. vituli with S. venezuelensis (Strongyloides of rats) than with S. papillosus, shedding light on the speciation history of Strongyloides nematodes.

Molecular characterization of highly pathogenic Eimeria species among beef cattle on Java Island, Indonesia

Gastrointestinal parasites including Eimeria spp. are known to affect domestic animal productivity causing watery or lethal bloody diarrhea. However, there are few reports on the detailed distribution of bovine Eimeria spp. in cattle, particularly in developing tropical and sub-tropical areas. Using a total of 289 fecal samples collected from beef cattle on Java Island, one of the five main islands of Indonesia, fecal examinations by the Whitlock and sugar flotation methods and molecular surveys were conducted to reveal the prevalence of 6 Eimeria spp. As a result of morphological screening using Whitlock methods and sugar flotation, Eimeria spp. prevalences of 9.4% and 52.3% were confirmed, respectively. The prevalence was higher in younger cattle [under 1 year (63.9%), 1–2 years (75.0%) and more than in 2 year old cattle (42.3%)]. The prevalences of identified species were as follows: 10.4% for E. bovis, 2.8% for E. ellipsoidalis, 2.1% for E. alabamensis, 1.4% for E. zuernii, 1.1% for E. auburnensis, and 0.4% for E. cylindrica. Moreover, prevalences of 12.8% for Strongyloides papillosus, 7.3% for Trichuris globulosa, and 0.3% for Capillaria bovis were detected. Although the average number of oocysts per gram of feces was <100 among the positive samples, and cases of heavy infection were limited, the endemicity of these pathogenic Eimeria species among farms in Indonesia should be noted.

Heavy infection of Ichthyophthirius multifiliis in striped catfish (Pangasianodon hypophthalmus, Sauvage 1878) and its treatment trial by different therapeutic agents in a control environment

ABSTRACTStriped catfish (Pangasianodon hypophthalmus) fingerlings were stocked (60 fishes/m3) in cemented square tanks for ornamental fishery purposes at the College Fish Farm in Mangalore. A total of 400 fishes with a mean weight (g) ranging from 3.24 ± 1.21 to 6.70 ± 1.13 and a mean length (cm) of 7.50 ± 0.94 to 9.50 ± 1.10 were examined. A severe outbreak of salt-like granule white spots was found on the body surface. Ichthyophthirius multifiliis, a ciliate pathogen, was identified as the causative agent by clinical signs, wet mount, and histopathological observations. Infected fishes were transferred and equally distributed to the 0.45 m3 glass aquaria and treated with three treatments: (T1) methylene blue + salt; (T2) raising temperature with salt; and (T3) formalin + malachite green. The best fingerling survival (55 ± 9.36%) was obtained by elevated water temperature with salt in T2.

A 5-Year intervention study on elimination of urogenital schistosomiasis in Zanzibar: Parasitological results of annual cross-sectional surveys.

BackgroundThe Zanzibar Elimination of Schistosomiasis Transmission (ZEST) project aimed to eliminate urogenital schistosomiasis as a public health problem from Pemba and to interrupt Schistosoma haematobium transmission from Unguja in 5 years.MethodologyA repeated cross-sectional cluster-randomized trial was implemented from 2011/12 till 2017. On each island, 45 shehias were randomly assigned to receive one of three interventions: biannual mass drug administration (MDA) with praziquantel alone, or in combination with snail control or behavior change measures. In cross-sectional surveys, a single urine sample was collected from ~9,000 students aged 9- to 12-years and from ~4,500 adults aged 20- to 55-years annually, and from ~9,000 1st year students at baseline and the final survey. Each sample was examined for S. haematobium eggs by a single urine filtration. Prevalence and infection intensity were determined. Odds of infection were compared between the intervention arms.Principal findingsPrevalence was reduced from 6.1% (95% confidence interval (CI): 4.5%-7.6%) to 1.7% (95% CI: 1.2%-2.2%) in 9- to 12-year old students, from 3.9% (95% CI: 2.8%-5.0%) to 1.5% (95% CI: 1.0%-2.0%) in adults, and from 8.8% (95% CI: 6.5%-11.2%) to 2.6% (95% CI: 1.7%-3.5%) in 1st year students from 2011/12 to 2017. In 2017, heavy infection intensities occurred in 0.4% of 9- to 12-year old students, 0.1% of adults, and 0.8% of 1st year students. Considering 1st year students in 2017, 13/45 schools in Pemba and 4/45 schools in Unguja had heavy infection intensities >1%. There was no significant difference in prevalence between the intervention arms in any study group and year.Conclusions/SignificanceUrogenital schistosomiasis was eliminated as public health problem from most sites in Pemba and Unguja. Prevalence was significantly reduced, but transmission was not interrupted. Continued interventions that are adaptive and tailored to the micro-epidemiology of S. haematobium in Zanzibar are needed to sustain and advance the gains made by ZEST.

Management of Ceratocystis manginecans in plantations of Acacia through optimal pruning and site selection

Wilt disease has become a threat to Acacia plantations in SE Asia. There are about 1.3 million ha of Acacia auriculiformis, A. mangium and Acacia hybrid plantations in Vietnam that require management of wilt disease caused by Ceratocystis manginecans. To identify options for management, we examined affect of pruning (tree age, pruning time and pruning technique) and site traits (altitude, slope and position) on disease expression from natural infections. Ceratocystis wilt disease and disease indices were more serious in younger than older pruned trees. Pruning in the rainy season resulted in heavier infection by Ceratocystis than pruning in the dry season. Decreasing bark tearing during pruning reduced the levels of infection and disease. Tip pruning of branches reduced disease compared to pruning close to the trunk. The interaction effects of terrain factors showed that A. auriculiformis and Acacia hybrid plantations were most severely affected when trees were planted in foot-hills, at altitudes below 300 m and on slopes below 15o. Results for the pruning time and pruning technique trials have application for reducing the impact of Ceratocystis wilt disease in Acacia plantations in Vietnam.

Challenges and opportunities for control and elimination of soil-transmitted helminth infection beyond 2020.

More than half of the world’s population lives in places endemic for soil-transmitted helminths (STHs), and an estimated 1.45 billion people are infected [1,2]. In 2017, the global burden of STH infection (Ascaris lumbricoides, hookworm, and Trichuris trichiura) was estimated at 1.9 million disability-adjusted life years (DALYs) [3]. Moderate and heavy infection intensity and chronic STH infection are associated with anemia, malnutrition, educational loss, and cognitive deficits, but recent systematic reviews and meta-analyses produced conflicting results on the impact of preventive chemotherapy (PC) [4–6]. The Soil-Transmitted Helminthiasis Advisory Committee (hereafter called “the Committee”) is a group of independent experts with a broad range of expertise. It is convened annually by Children Without Worms (CWW), an organization whose purpose is to utilize available evidence to identify best practices and opportunities for the prevention and control of STH infection [7]. On November 1 and 2, 2017, the Committee met in Baltimore, Maryland, United States of America, in order to discuss the critical need to develop a data-driven guide to the STH endgame on late-stage program functioning, processes, and surveillance. The focus was on research and field experiences from countries approaching the “elimination of STH infection as a public health problem” after consecutive years of PC and countries that are now considering scaling down their PC frequency but may be concerned about infection rebound. Emphasis was placed on interim recommendations for monitoring and decision-making for national program managers desiring to achieve the World Health Organization (WHO) goal of eliminating STH infection as a public health problem by 2020, particularly related to STH infections in risk groups other than school-age children (SAC), namely preschool-age children (PSAC) and women of reproductive age (WRA) [8]. The following is the Committee’s recommendations stemming from the Baltimore meeting in November 2017. It complements and updates the publication derived by the Committee’s meeting a year earlier in Basel, Switzerland [7], and was instrumental in shaping the agenda for the October 2018 meeting, convened jointly by CWW and WHO, with recommendations to be reported elsewhere.

Prevalence of intestinal helminth parasites of pigeons (Columba livia domestica Gmelin 1789) in Kano State, North-Western Nigeria.

In Nigeria, helminths have over the last decades been established as important parasite of poultry including pigeons. However, the prevalence of these parasites of pigeons in Kano State is yet to be established. The prevalence of helminth parasites of domestic pigeon (Columba livia domestica) in Kano State, Nigeria was investigated in this study. The differences in the prevalence of infection between the pigeons examined on the basis of sex of the pigeon and season of the year were analyzed statistically using the students' "t" -test. The intestinal contents of 144 pigeons were examined for gastrointestinal helminths between February and April representing the dry season and between June and August for the wet season. Pigeons were grouped according to Squabs (chicks) (0-4 weeks), Squeakers (Juveniles) (5-8 weeks) and Youngsters (Adults) (9 weeks onwards). Intestinal parasites found include Cestodes: Raillietina tetragona, 20 (13.80%), R. echinobothrida, 11 (7.64%), Amoebotaenia cuneata, 5 (3.47%), Hymenolopis contaniana, 10 (6.95%), Davainea proglottina, 1(0.69%) and Ornithostrongylus quadriatus 1(0.69%). Nematodes: Capillaria obsignata, 10(6.95%) and Ascaridia columbae, 9(6.25%). Forty-two (29.16%) of the birds had mild infection, 17 (11.81%) had moderate infection, 9 (6.25%) and 2(1.39%) had heavy and severe infection, respectively. The prevalence was higher during the wet season (36.65%) than during the dry season (27.97%). Of all the age groups, only Youngsters, 34 (23.61%) were infected with intestinal helminths. However, there were statistically significant differences between the age, sex and seasons in this study (P < 0.005). Pigeons raised on semi-intensive had the highest rate of infection (37.50%) and those raised on intensive management had the lowest rate of infection (9.03%). A number of measures are recommended for the control of these helminthic parasites.

Prevalence, Intensity of Soil-Transmitted Helminths, and Factors Associated with Infection: Importance in Control Program with Ivermectin and Albendazole in Eastern Côte d'Ivoire.

Evaluation of soil-transmitted helminths (STHs) and implementation of additional interventions are required in the region of a filariasis control program, given that antifilariasis drugs also have a beneficial effect on STHs. Thus, this study determines the extensive epidemiology of STHs to improve their successful control. Stool samples were analyzed using the Kato-Katz method. Chi-squared and Kruskal-Wallis tests were used to measure differences in infection rates and intensities, respectively, and logistic regression identified the risks of infection. The main intestinal helminths (A. lumbricoides, hookworm [N. americanus], S. mansoni, and T. trichiura) were found in the population. The overall prevalence of STHs was 19.5%. The prevalence of hookworm, the predominant species, ranged from 2% (n=6) to 28% (n=97). The overall prevalence of the other intestinal helminths was less than 6% (n=18). Intensity of hookworm was mostly light with a range from 1.6% (n=5) to 25.9% (n=90). However, the intensity of the species was significantly greater in Soribadougou compared to the other localities. Heavy infection was found in old children and adults but not in young children. Open defecation (OR=3.23, p≤0.05), dog/cat raising (OR=1.94, p≤0.05), farming (OR=14.10, p≤0.05), and irrigated culture (OR=3.23, p≤0.05) were positively associated with hookworm. It was observed that the participants missed the follow-up examinations due to trip (32.7%) or misunderstanding (15%) and lack of information (11.8%) of the purpose of the survey. Thus, to sustain the control of STHs, the MDA program should target the entire community and add education about the use of toilets, best practices of farming, and dog/cat raising.

Prevalence of Schistosomiasis in a neglected community, South western Nigeria at two points in time, spaced three years apart.

In recent years, the prevalence of schistosomiasis, a neglected tropical infection, has increased in underprivileged rural communities characterized by poverty. This cross-sectional community-based study was carried out to determine the prevalence of urinary schistosomiasis in a neglected community of Apojola community, South-Western Nigeria at two points in time, spaced three years apart. A total of 145 participants were screened and 44.1% were diagnosed to have urinary Schistosoma haematobium infection after sedimentation and microscopy. The prevalence of schistosomiasis among females was higher (45.3%) than that among males (42.4%) but not significantly different (0.723). The prevalence of participants with light infection (26%) was significantly higher than those with heavy infection (11.0%). The predisposing factors with statistically significant association with Schistosoma haematobium infection were age (0.000), level of education (0.002), eating/selling of snails (0.037), occupation (0.000), drinking water (0.001), swimming (0.008), and washing in a river (0.019). These findings indicate that the study area is still endemic to urinary schistosomiasis after three years of research and school-age children and teenagers are the populations at risk of urinary schistosomiasis. Community health education on the cause, mode of transmission, prevention, and prompt treatment of schistosomiasis is recommended.

To what extent are hake fat and its oil quality affected by the parasite &lt;em&gt;Lernaeocera lusci&lt;/em&gt;?

The copepod Lernaeosera lusci is a common ectoparasite of the hake Merluccius merluccius, which constitutes its definitive host. The present study is the first to investigate the impact of L. lusci and its infection intensity on the fatty acid (FA) composition and oil quality of its host. The results revealed a substantial decrease in the total FA content, which dropped by 50, 70 and 83% when fish was infected by one (L1), two (L2) and three (L3) parasites, respectively. The lipid profile showed a tendency for a significant decrease in the saturated fatty acid (SFA), monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA) levels in all parasitized groups and in a parasite load dependant manner (p &lt; 0.05). The same tendency was observed for the most commonly analysed FA and in particular for essential FA, such as e arachidonic (ARA), eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids, which showed smaller amounts associated with L. lusci co-infection. From a nutritional standpoint, our findings revealed that L. lusci is able to cause severe deterioration in the nutritional quality of its host oil. In addition to the increase in the thrombogenicity index (IT) and the high atherogenicity index (IA) values, the low hypocholesterolemic / hypercholesterolemic fatty acid ratio (H/H) and the modest amount of DHA+EPA (20 and 10 mg/100g) recorded at heavy infection levels make the parasitized fish inadequate sources of these PUFA and unsuitable for consumers with special dietary needs.

Human schistosomiasis in Benin: Countrywide evidence of Schistosoma haematobium predominance

BackgroundA national mapping of human schistosomiasis was conducted in Benin to provide the baseline epidemiological data required to implement the national strategy for schistosomiasis control and elimination to achieve the WHO’s goal of reaching at least 75% of school-age children in endemic areas by 2020. MethodsParasitological surveys were conducted from 2013 to 2015, among 19,250 children aged 8–14 years randomly sampled in 385 units (schools/villages) across all districts. Urine and stool samples were examined using parasite-egg filtration for urine samples and the Kato-Katz technique for stool specimens. ResultsHuman schistosome eggs from two major species (S. haematobium and S. mansoni) were detected in the surveyed population with variable prevalence and parasite intensity. Urinary schistosomiasis due to S. haematobium was widely distributed and detected in 76/77 districts with a national average prevalence of 17.56% (95 °CI:16.80%– 18.32%), compared to S. mansoni detected in 28/77 districts with a national prevalence of 2.45% (95 °CI:2.14%–2.76%). The combined national prevalence of schistosomiasis, defined by infections with either or both schistosome species was 19.78% (95% CI:18.90% –20.49%), and was detected in 76/77 districts. Based on our findings, 31 districts were classified as low-risk (>0% and <10%); 37 as moderate-risk (≥10% and <50%); and 8 as high-risk (≥50%) of schistosome infection. No infection was detected in Kpomassè district in this study. In several districts where the two species were endemic with prevalence ≥10%, S. haematobium was the most prevalent schistosome species. Boys were relatively more infected than girls (18.29% v 16.82%, p = 0.007). Of note, heavy infections with S. haematobium (>50 eggs/10 mL) were detected in several districts of Atacora, Donga, Borgou, Collines, Ouémé and Atlantique departments. ConclusionsThe schistosomiasis mapping reported here clearly present a nationwide view of the epidemiological pattern of Schistosoma infections and the baseline data for implementing an effective control strategy by preventive chemotherapy (PCT). Although PCT might not be required in 32/77 districts, a yearly and bi-annual deworming is needed in 2 and 43 districts, respectively. If no environmental change occurs, and no mass treatment is delivered, prevalence is likely to remain stable for many years owing to poor hygiene and sanitation.

Evaluation of various culture techniques for identification of hookworm species from stool samples of children.

Background & objectives:Different coproculture techniques have been developed for culturing the hookworm (HW) larvae for morphological identification in the resource-limited settings. The objective of this study was to compare the performances of Harada-Mori culture (HMC), agar plate culture (APC) and modified APC (MAPC) of HW positive stool specimens for identification of HW species in East Sikkim.Methods:This prospective study was done in East Sikkim from May 2015 to May 2016. Stool and blood samples were collected from paediatric patients with gastrointestinal symptoms. The HW positive stool specimens by microscopy were subjected to HMC, APC and MAPC techniques to harvest HW larvae. Stoll's dilution egg count for determining egg intensity and blood parameters were performed in all the 12 HW-positive patients.Results:Twelve of the 180 samples were found positive for HW by microscopy and predominance of Necator americanus (75%) over Ancylostoma duodenale (25%) was observed. Blood parameters results showed high pack cell volume (PCV) values in 78.6 per cent, anaemia in 75 per cent and high eosinophil count in most patients. Stoll's dilution egg count showed moderate infection in 66.6 per cent, light and heavy infections in 16.7 per cent each.Interpretation & conclusions:Our results showed that APC yielded 100 per cent results and was easier to perform in the laboratory compared to MAPC and HMC techniques.

Vanilla bahiana Hoehne (Orchidaceae): studies on fruit development and new perspectives into crop improvement for the Vanilla planifolia group

Abstract: Vanilla is the most well-known and economically important genus of Orchidaceae in the world. Vanilla bahiana is restricted to Brazil and its conservation status was recently assessed as ‘Endangered’. The species is phylogenetically closely related to V. planifolia, whose pods are the main natural source of vanillin. The primary desirable traits for vanilla production are high fruit set and great resistance to abiotic stress. High temperatures (&gt; 32ºC) and heavy rain favor fungal infection, and thus are indirectly responsible for fruit drop by V. planifolia in cultivation. The aim of the present study was to follow the process of pod ripening of V. bahiana in a restinga fragment in an Environmental Protection Area of Bahia State, and to highlight implications for vanilla crop improvement. Fieldwork was carried out from April 2016 to January 2017. A total of nine manual self-pollinations and nine manual cross-pollinations were successfully carried out. Fruit length, diameter and girth were recorded every two weeks. Fruit permanence in the infrutescence was measured as consecutive days from pollination. Descriptive statistics were calculated and Pearson correlation analysis performed among all attributes per pollination method. The influence of temperature and rainfall was also analyzed. Pod measurements and fruit permanence in the infrutescence were higher for cross-pollination than self-pollination. Higher rainfall results in fruit drop. The use of V. bahiana in breeding efforts for the genus is here strongly suggested and supported by previously published studies that allowed us to highlight several desirable traits: vanillin production, its wide geographical distribution and occurrence in a variety of habitats; substantial populations; resistance to conditions of drought and high luminosity and temperature; extensive blooming period; high number of flowers per raceme; possible synchronised flowering with V. planifolia, and fruiting throughout the year. These prospects are promising and should be further evaluated, not only for V. bahiana but for other vanilla crop wild relatives. Studies of pollination ecology can be used to set guidelines for the conservation of the V. planifolia group and to encourage the development of strategies to increase the production of fruit and, consequently, vanillin for its culinary uses and medical applications.

Resistance of ewes to gastrointestinal nematode infections during the peripartum and dry periods and the performance of their lambs

ABSTRACT This study aimed to evaluate the resistance of Texel (Tx) and Ile de France (IF) sheep to gastrointestinal nematode infections in the periparturient period and after weaning, and the performance of their lambs. Fecal samples were collected from 19 IF and 17 Texel ewes to determine fecal egg counts (FEC) and larval cultures were prepared to determine the prevalence of nematodes. The ewes were weighed to determine body weight (BW) and blood samples were taken to determine the packed cell volume (PCV) and plasm protein values (PPV). The ewes were classified into two groups by FEC (heavy and moderate infection). The IF presented higher FECs than Tx 28 and 14 days before parturition; 14, 28, and 56 days after parturition; and 28 days after weaning (P&lt;0.05). In the weaning and dry periods, the IF presented higher PCVs than Tx (P&lt;0.05). The PPV did not differ between the groups (P&gt;0.05). The IF presented a higher BW than Tx 14, 28, and 42 days after parturition, and in the weaning and dry periods (P&lt;0.05). The ewes of both breeds classified as moderately infected had the highest BW at weaning (P&lt;0.05). IF ewes with a moderate infection produced weaning lambs that were heavier than those of Tx with the same level of infection (P&lt;0.05). Overall, Tx ewes presented a better ability to withstand infections during the periparturient period and after weaning. Although the IF ewes presented the highest FEC and more intense periparturient rise, they managed to maintain their level of production.

Importance, Biology, Epidemiology, and Management of Loose Smut (Ustilago nuda) of Barley (Hordeum vulgare): A Review

Barley (Hordeum vulgare) is an economically, nutritionally and industrially important cereal crop worldwide. Ethiopia is believed to be the center of origin and diversity of the cultivated barley crop. The crop has been cultivated in the country since time immemorial. The midlands and highlands of Ethiopia are suitable for barley cultivation. However, there are many biotic and abiotic factors that reduce production and productivity of the crop in Ethiopia and elsewhere. Of the various fungal plant diseases limiting barley productivity, loose smut (Ustilago nuda) is one of the major cosmopolitan and destructive seedborne pathogen in many barley-producing countries in the world. This piece of work was undertaken to: 1) review the economic importance and ecological requirements of barley and extent of grain loss due to barley loose smut; 2) review the biology and ecological requirements of the pathogen leading to epidemics; and 3) compile the management options for sustainable barley production and productivity. To achieve these objectives, data and information were gleaned from scientific journal publications, PhD dissertations, Master’s theses, research reports, books and book chapters, proceedings and symposia papers, relevant compendia, internet resources, personal communications, and similar other resources. From the reviews made, it could be deduced that barley loose smut on average causes estimated grain yield losses that range from 25 to 30% in the world. The systemic pathogen is embedded in the scutellum part of the embryo and easily transmitted to the next cropping season. The pathogen sori commonly replace the spike during anthesis and healthy ears are infected at flowering through the teliospores blown by wind. Warm soil when seedlings emerge is more conducive to loose smut than cold soil; however, moderate temperature (15 to 22 oC) and damp cloudy weather or heavy rainfall at flowering time are the preconditions required by the pathogen for heavy infection because of elongated or extended period of open flowers. Barley loose smut can be better managed through the use of proper cultural practices in integration with hot water and solar heat seed treatment, use of resistant varieties, and effective systemic fungicides, like Azoxystrobin, Carboxin, Difenoconazole, Mancozeb, Propiconazole, Tebuconazole, Triadimenol, and Triticonazole. It could, thus, be concluded that barley loose smut is a very important disease that seriously affects barley production and productivity worldwide, but can be reasonably managed through the use of smut-free seed, certified seed, host resistance, and hot water/solar heat or systemic fungicidal seed treatment or their integration.

Yield Performance and Blast Susceptibility of SomeWheat (Triticum aestivum) Varieties in Jashore

A trial was conducted during 2015-16 to 2017-18 at the Regional Agricultural Research Station (RARS) of Bangladesh Agricultural Research Institute (BARI), Jashore to select some tolerant varieties against wheat blast. Fourteen varieties including eight old varieties (Sonalika, Kanchan, Sourav, Gourab, Shatabdi, Sufi, Bijoy, Prodip) and six newly released varieties (BARI Gom 25, BARI Gom 26, BARI Gom 27, BARI Gom 28, BARI Gom 29 and BARI Gom 30) were evaluated. The experiments were non-replicated and were planted in two sowing dates, at optimum (mid November) and late (mid December) conditions. Three irrigations were applied, at crown root initiation (CRI), heading and grain filling stages. Plants of border rows were inoculated by Magnaporthe oryzae triticum (MoT) spores (104 conidia ml-1) for infection once per week from three weeks after sowing until primary infection was observed. The significantly higher grain yield was observed in 2016-17 (3505 kg ha-1) which was similar to 2017-18 (3448 kg ha-1) and the lowest was in 2015-16 (1680 kg ha-1). The higher grain yield was obtained due to the higher grains spike-1 (45 no.) and 1000 grain weight (36.6 g) and lower blast disease incidence (% blast index 18.1%). In all three years, there was heavy infection of wheat blast in late sowing condition (% blast index 40.7) compared to the optimum sowing condition (% blast index 1.4), resulting in very poor crop yield (1696 kg ha-1). Among the varieties, the variety Gourab produced the highest yield (3395 kg ha-1) which was similar to the newly released variety BARI Gom 28 (3196 kg ha-1) and BARI Gom 30 (3134 kg ha-1). In case of blast disease severity, old varieties were less infested with some exception in Sonalika and Kanchan. On the other hand, BARI Gom 25 and BARI Gom 26 were more susceptible (% blast index 35.3-36.5) to wheat blast compared to BARI Gom 28 and BARI Gom 30 (% blast index 20.2-22.5).&#x0D; The Agriculturists 2018; 16(2) 65-74