Intestinal Parasitic Infections among Inhabitants of Karaj City, Tehran Province, Iran in 2006-2008

Karaj is an area with large influx of refugee people in Iran. To increase knowledge about parasitic infections, we carried out this research during 2006-2008. We recorded the stool examination results and some of their personal characteristics. A total of 13,915 human stools were examined, and 649 (4.7%) were positive for intestinal parasites. Among them, 13 (0.09%) had worm and 636 (4.6%) had protozoan infections. Maximum infections belonged to Giardia intestinalis, and 534 (3.8%) samples had this infection. Other parasitic infections included Entamoeba coli (0.39%), Entamoeba histolytica (0.021%), Blastocystis hominis (0.08%), Trichomonas hominis (0.1%), Iodamoeba butschlii (0.06%), Chilomastix mesnili (0.007%), Endolimax nana (0.05%), Enterobius spp. eggs (0.028%), Taenia proglottids (0.028%), and Strongyloides stercoralis larvae (0.03%). The maximum numbers of referred people to laboratories were in July and the maximum percentage of infections was in August. There is a point that all 5 Strongyloides stercoralis infections were pertained to 2008. With attention to the rate of parasitic infections (4.7%), it seems that we should take additional educational information to wide spectrum of people living in this city.     

A Survey of Intestinal Protozoan Infections among Gastroenteritis Patients during a 3-Year Period (2004-2006) in Gyeonggi-do (Province), South Korea

The incidence and etiology of parasite-associated gastroenteritis during 2004-2006 in Gyeonggi-do (province), South Korea was determined by means of antigen detection ELISA on 6,071 stool specimens collected from 6 general hospitals. At least 1 parasitic agent was detected in 3.4% (208/6,071) of the stool samples. Among these, Giardia lamblia was the most numerous (152 cases; 2.5%), followed by Entamoeba histolytica (25 cases; 0.4%), Cryptosporidium parvum (23 cases; 0.4%), and mixed infections (8 cases; 0.1%). Patients aged 1-5 years had the largest proportion (69.2%; 144/208) of parasite-positive stool specimens. Parasite-mediated gastroenteritis was most common from June to September. The detection rate gradually increased from 2004 to 2006. This study shows that parasite-mediated gastroenteritis may be significant among children in Korea and that parasite infection surveillance should be constantly performed.     

Prevalence of Intestinal Protozoans among Schoolchildren in Suburban Areas near Yangon,Myanmar

Although intestinal protozoans are common etiologies of diarrhea, few studies have been conducted in Myanmar. This study planned to investigate the prevalence of Giardia lamblia, Entamoeba coli, Entamoeba histolytica, and Endolimax nana among schoolchildren and their guardians in suburban areas near Yangon, Myanmar. We performed a cross-sectional survey among schoolchildren and their guardians from 7 primary schools in South Dagon and Hlaing Thar Yar districts, Yangon, Myanmar. Stool samples were observed with a microscope after concentration technique and iodine staining. Total 821 stool samples, including 556 from schoolchildren and 265 from guardians, were examined. The median age was 6 years old for schoolchildren and 36 years old for guardians. A 53.1% of the school children and 14.6 % of the guardians were males. The overall prevalence of each intestinal protozoan species was as follows: 3.4% (28/821) for G. lamblia; 3.5% (29/821) for E. coli; 1.2% (10/821) for E. histoytica, and 3.0% for E. nana. This study showed that intestinal protozoans are common in primary schoolchildren and their guardians in suburban areas near Yangon, Myanmar. Health interventions, such as hand washing education, improvement of sanitation, and establishment of water purification systems are urgently needed in this area.     

Pentatrichomonas hominis in laboratory-bred common marmosets

Trichomonadid protozoa have been found in the intestinal tracts of common marmosets (Callithrix jacchus). However, there is little information available on species identification and the pathogenicity of these trichomonads. In this study, we conducted a fecal survey of a common marmoset colony maintained as laboratory animals in Japan and identified the trichomonad species. Screening using a fecal smear examination revealed that 66% (58/88) of the marmosets had trichomonadid trophozoites in their feces. The trichomonads were found in both normal feces (31/49, 63%) and diarrhea (27/39, 69%), with no significant difference in frequency. The protozoa were identified as Pentatrichomonas hominis using morphological characters and the 100% identity of the nucleotide sequence of the partial 18S rRNA gene (297 bp). The intraspecific genetic variability between P. hominis from the marmosets in this study and P. hominis from other reported mammal hosts was ≤1% in the nucleotide sequence, including the internal transcribed spacer (ITS)-1, 5.8S rRNA gene, and ITS-2 (293 bp). P. hominis inhabits the large intestine of various mammalian hosts, including primates, and is considered nonpathogenic. These results suggest that P. hominis is transmitted among marmosets and other mammals but is not a primary cause of bowel disease in marmosets.     

Effects of Hygiene and Defecation Behavior on Helminths and Intestinal Protozoa Infections in Taabo,C?te d’Ivoire

Background

More than 1 billion people are currently infected with soil-transmitted helminths and schistosomes. The global strategy to control helminthiases is the regular administration of anthelmintic drugs to at-risk populations. However, rapid re-infection occurs in areas where hygiene, access to clean water, and sanitation are inadequate.

Methodology

In July 2011, inhabitants from two villages and seven hamlets of the Taabo health demographic surveillance system in south-central Côte d’Ivoire provided stool and urine samples. Kato-Katz and ether-concentration methods were used for the diagnosis of Schistosoma mansoni, soil-transmitted helminths (Ascaris lumbricoides, Trichuris trichiura, and hookworm), and intestinal protozoa. Urine samples were subjected to a filtration method for the diagnosis of Schistosoma haematobium. A questionnaire was administered to households to obtain information on knowledge, attitude, practice, and beliefs in relation to hygiene, sanitation, and defecation behavior. Logistic regression models were employed to assess for associations between questionnaire data and parasitic infections.

Principal Findings

A total of 1,894 participants had complete data records. Parasitological examinations revealed prevalences of hookworm, S. haematobium, T. trichiura, S. mansoni, and A. lumbricoides of 33.5%, 7.0%, 1.6%, 1.3% and 0.8%, respectively. Giardia intestinalis and Entamoeba histolytica/E. dispar were detected in 15.0% and 14.4% of the participants, respectively. Only one out of five households reported the presence of a latrine, and hence, open defecation was common. Logistic regression analysis revealed that age, sex, socioeconomic status, hygiene, and defecation behavior are determinants for helminths and intestinal protozoa infections.

Conclusions/Significance

We found that inadequate sanitation and hygiene behavior are associated with soil-transmitted helminths and intestinal protozoa infections in the Taabo area of south-central Côte d’Ivoire. Our data will serve as a benchmark to monitor the effect of community-led total sanitation and hygiene education to reduce the transmission of helminthiases and intestinal protozoa infections.     

Subtype Distribution of Blastocystis in Thai-Myanmar Border,Thailand

Blastocystis sp. is a common zoonotic intestinal protozoa which has been classified into 17 subtypes (STs). A cross-sectional study was conducted to determine the prevalence and subtype distribution of Blastocystis in villagers living on the Thai-Myanmar border, where the risk of parasitic infection is high. A total of 207 stool samples were collected and DNA was extracted. PCR and sequencing using primers targeting small-subunit ribosomal RNA (SSU rRNA) gene were performed. The prevalence of Blastocystis infection was 37.2% (77/207). ST3 (19.8%; 41/207) was the predominant subtype, followed by ST1 (11.6%; 24/207), ST2 (5.3%; 11/207), and ST4 (0.5%; 1/207). A phylogenetic tree was reconstructed using the maximum likelihood (ML) method based on the Hasegawa-Kishino-Yano + G + I model. The percentage of bootstrapped trees in which the associated taxa clustered together was relatively high. Some sequences of Blastocystis positive samples (TK18, 39, 46, 71, and 90) were closely related to animals (pig and cattle) indicating zoonotic risks. Therefore, proper health education in parasitic prevention for the villagers should be promoted to improve their personal hygiene. Further longitudinal studies are required to monitor the prevalence of parasitic infections after providing health education and to investigate Blastocystis ST in animals living in these villages.     

Intestinal Parasite Prevalence in an Area of Ethiopia after Implementing the SAFE Strategy,Enhanced Outreach Services,and Health Extension Program

Background

The SAFE strategy aims to reduce transmission of Chlamydia trachomatis through antibiotics, improved hygiene, and sanitation. We integrated assessment of intestinal parasites into large-scale trachoma impact surveys to determine whether documented environmental improvements promoted by a trachoma program had collateral impact on intestinal parasites.

Methodology

We surveyed 99 communities for both trachoma and intestinal parasites (soil-transmitted helminths, Schistosoma mansoni, and intestinal protozoa) in South Gondar, Ethiopia. One child aged 2–15 years per household was randomly selected to provide a stool sample of which about 1 g was fixed in sodium acetate-acetic acid-formalin, concentrated with ether, and examined under a microscope by experienced laboratory technicians.

Principal Findings

A total of 2,338 stool specimens were provided, processed, and linked to survey data from 2,657 randomly selected children (88% response). The zonal-level prevalence of Ascaris lumbricoides, hookworm, and Trichuris trichiura was 9.9% (95% confidence interval (CI) 7.2–12.7%), 9.7% (5.9–13.4%), and 2.6% (1.6–3.7%), respectively. The prevalence of S. mansoni was 2.9% (95% CI 0.2–5.5%) but infection was highly focal (range by community from 0–52.4%). The prevalence of any of these helminth infections was 24.2% (95% CI 17.6–30.9%) compared to 48.5% as found in a previous study in 1995 using the Kato-Katz technique. The pathogenic intestinal protozoa Giardia intestinalis and Entamoeba histolytica/E. dispar were found in 23.0% (95% CI 20.3–25.6%) and 11.1% (95% CI 8.9–13.2%) of the surveyed children, respectively. We found statistically significant increases in household latrine ownership, use of an improved water source, access to water, and face washing behavior over the past 7 years.

Conclusions

Improvements in hygiene and sanitation promoted both by the SAFE strategy for trachoma and health extension program combined with preventive chemotherapy during enhanced outreach services are plausible explanations for the changing patterns of intestinal parasite prevalence. The extent of intestinal protozoa infections suggests poor water quality or unsanitary water collection and storage practices and warrants targeted intervention.     

Parasitic infections in HIV-infected patients who visited Seoul National University Hospital during the period 1995-2003

The prevalence of parasitic infections was investigated in human immunodeficiency virus (HIV)-infected patients (n = 105) who visited Seoul National University Hospital, Seoul, Korea, during the period from 1995 to 2003. Fecal samples were collected from 67 patients for intestinal parasite examinations, and sputum or bronchoalveolar lavage samples from 60 patients for examination of Pneumocystis carinii. Both samples were obtained from 22 patients. Thirty-three (31.4%) of the 105 were found to have parasitic infections; Cryptosporidium parvum (10.5%; 7/67), Isospora belli (7.5%; 5/67), Clonorchis sinensis (3.0%; 2/67), Giardia lamblia (1.5%; 1/67), Gymnophalloides seoi (1.5%; 1/67), and Pneumocystis carinii (28.3%; 17/60). The hospital records of the 11 intestinal parasite-infected patients showed that all suffered from diarrhea. This study shows that parasitic infections are important clinical complications in HIV-infected patients in the Republic of Korea.     

Breast-Feeding Protects Infantile Diarrhea Caused by Intestinal Protozoan Infections

This study investigated the effect of breast-feeding in protection against protozoan infection in infants with persistent diarrhea. Infants were classified into 2 groups; 161 breast-fed infants and the same number of non-breast-fed infants. Microscopic examinations of stool were done for detection of parasites and measuring the intensity of infection. Moreover, serum levels of IgE and TNF-α were measured by ELISA. Cryptosporidium spp., Entamoeba histolytica/Entamoeba dispar, Giardia lamblia, and Blastocystis sp. were demonstrated in infants with persistent diarrhea. The percentage of protozoan infections was significantly lower in breast-fed infants than that in the non-breast-fed infants. The levels of IgE and TNF-α were significantly lower in the breast-fed group than in the non-breast-fed group. There were significant positive associations between the serum levels of IgE and TNF-α and the intensity of parasite infection in the breast-fed group. It is suggested that breast-feeding has an attenuating effect on the rate and intensity of parasite infection.     

High Prevalence of Haplorchis taichui, Phaneropsolus molenkampi, and Other Helminth Infections among People in Khammouane Province, Lao PDR

The prevalence of liver and intestinal helminth infections, including Opisthorchis, Haplorchis, Phaneropsolus, hookworms, Enterobius, and Taenia, was surveyed in Khammouane province, Lao PDR. Fecal specimens were collected from 1,242 people (590 men and 652 women) in 3 Mekong riverside villages and were examined by the Kato-Katz thick smear technique. The overall helminth egg positive rate was 81.1%. The positive rate for small trematode eggs, including Opisthorchis viverrini, heterophyids, and lecithodendriids, was 81.1% and the positive rate for hookworms was 6.7%. To obtain adult worms, 35 people who were positive for small trematode eggs were treated with 20-30 mg/kg praziquantel and 10-15 mg/kg pyrantel pamoate, and then purged. Diarrheic stools were collected from 33 of these people and searched for helminth parasites using a stereomicroscope. Mixed infections with various helminths (Haplorchis taichui, Haplorchis yokogawai, Prosthodendrium molenkampi, Phaneropsolus bonnei, echinostomes, hookworms, Trichostrongylus spp., Trichuris trichiura, Enterobius vermicularis, and/or Taenia saginata) were found. The total number of helminth specimens collected was 20,907 (approximately 634 per person). The most common species was H. taichui, followed by P. molenkampi, O. viverrini, P. bonnei, E. vermicularis, hookworms, and Trichostrongylus spp. These results show that diverse species of intestinal nematodes, trematodes, and cestodes are infecting humans in Khammouane province, Lao PDR.     

Risk of Intestinal Parasitic Infections in People with Different Exposures to Wastewater and Fecal Sludge in Kampala,Uganda: A Cross-Sectional Study

BackgroundThere are health risks associated with wastewater and fecal sludge management and use, but little is known about the magnitude, particularly in rapidly growing urban settings of low- and middle-income countries. We assessed the point-prevalence and risk factors of intestinal parasite infections in people with different exposures to wastewater and fecal sludge in Kampala, Uganda.MethodologyA cross-sectional survey was carried out in September and October 2013, enrolling 915 adults from five distinct population groups: workers maintaining wastewater facilities; workers managing fecal sludge; urban farmers; slum dwellers at risk of flooding; and slum dwellers without risk of flooding. Stool samples were subjected to the Kato-Katz method and a formalin-ether concentration technique for the diagnosis of helminth and intestinal protozoa infections. A questionnaire was administered to determine self-reported signs and symptoms, and risk factors for intestinal parasite infections. Univariate and multivariate analyses, adjusted for sex, age, education, socioeconomic status, water, sanitation, and hygiene behaviors, were conducted to estimate the risk of infection with intestinal parasites and self-reported health outcomes, stratified by population group.Conclusions/SignificanceUrban farmers are particularly vulnerable to infections with soil-transmitted helminths, S. mansoni, and intestinal protozoa. Hence, our findings call for public health protection measures for urban farmers and marginalized communities, going hand-in-hand with integrated sanitation safety planning at city level.     

Intestinal protozoan infections and echinococcosis in the inhabitants of Dornod and Selenge, Mongolia (2003)

The status of intestinal parasitic infections and seroprevalence of cystic echinococcosis in the inhabitants in Dornod and Selenge, Mongolia, was observed with stool and serum samples from 165 and 683 residents from August 9 to August 15, 2003. A total of 10 inhabitants (6.1%) were found to be infected with protozoan cysts or oocysts by stool examinations; 7, 1 and 2 cases with Entamoeba coli, Giardia lamblia and Cryptosporidium parvum, respectively. A total of 62 people (9.1%) revealed significantly high levels of specific antibodies against Echinococcus granulosus by enzyme-linked immunosorbent assay (ELISA). The surveyed areas are rural areas and the sanitized tab water is not available. There is a possibility of endemic transmission of water-borne protozoan diseases in these areas. The clinical echinococcosis is needed to be searched from the seropositive inhabitants.     

Infection Status of Hospitalized Diarrheal Patients with Gastrointestinal Protozoa, Bacteria, and Viruses in the Republic of Korea

To understand protozoan, viral, and bacterial infections in diarrheal patients, we analyzed positivity and mixed-infection status with 3 protozoans, 4 viruses, and 10 bacteria in hospitalized diarrheal patients during 2004-2006 in the Republic of Korea. A total of 76,652 stool samples were collected from 96 hospitals across the nation. The positivity for protozoa, viruses, and bacteria was 129, 1,759, and 1,797 per 10,000 persons, respectively. Especially, Cryptosporidium parvum was highly mixed-infected with rotavirus among pediatric diarrheal patients (29.5 per 100 C. parvum positive cases), and Entamoeba histolytica was mixed-infected with Clostridium perfringens (10.3 per 100 E. histolytica positive cases) in protozoan-diarrheal patients. Those infected with rotavirus and C. perfringens constituted relatively high proportions among mixed infection cases from January to April. The positivity for rotavirus among viral infection for those aged ≤ 5 years was significantly higher, while C. perfringens among bacterial infection was higher for ≥ 50 years. The information for association of viral and bacterial infections with enteropathogenic protozoa in diarrheal patients may contribute to improvement of care for diarrhea as well as development of control strategies for diarrheal diseases in Korea.     

Intestinal Parasites among Wild Rodents in Northern Gangwon-do,Korea

To determine geographical patterns of natural parasite infections among wild rodents, a total of 46 wild rodents from 3 different localities in northern Gangwon-do (Province), Korea were examined for intestinal parasite infections. Along with nematodes such as hookworms and Syphacia spp., Plagiorchis muris (2 specimens) (Trematoda) were collected from striped field mice, Apodemus agrarius. In a Korean wood mouse, Apodemus peninsulae, the overall nematode infections were similar to A. agrarius, but an adult worm of Echinostoma hortense (Trematoda) was collected. In addition, 2 species of cestodes, i.e., Hymenolepis nana and Hymenolepis diminuta, were collected from A. agrarius. Through this survey, A. agrarius and A. peninsule were confirmed as the natural definite hosts for zoonotic intestinal helminths, i.e., P. muris, E. hortense, H. nana, and H. diminuta, in northern Gangwon-do, Korea. Considering increased leisure activities around these areas, seasonal and further comprehensive surveys on wild rodents seem to be needed to prevent zoonotic parasite infections.     

Human Infections with Liver and Minute Intestinal Flukes in Guangxi, China: Analysis by DNA Sequencing, Ultrasonography, and Immunoaffinity Chromatography

The prevalence of liver and intestinal fluke infections was determined by surveying inhabitants of Hengxuan, Fusui, and Shanglin villages which were known to be endemic for liver flukes in Guangxi, China in May 2010. A total of 718 people were examined for helminth eggs by the Kato-Katz thick smear technique, ultrasonography, immunoaffinity chromatography, and DNA sequencing. The overall egg positive rate was found to be 59.6% (28.0-70.6%) that included mixed infections with liver and intestinal flukes. Cases showing higher than 20,000 eggs per gram of feces (EPG) were detected between 1.3% and 16.2%. Ultrasonographic findings exhibited overall 28.2% (72 of 255 cases) dilatation rate of the intrahepatic bile duct. Clonorchis sinensis infection was detected serologically in 88.3% (38 of 43 cases) among C. sinensis egg positive subjects by the immunoaffinity chromatography using a specific antigen for C. sinensis. For differential diagnosis of the liver and intestinal flukes, more precise PCR and nucleotide sequencing for copro-DNA were performed for 46 egg positive cases. Mixed infections with C. sinensis and Metagonimus yokogawai were detected in 8 of 46 egg positive cases, whereas 29 specimens were positive for Haplorchis taichui. Ultrasonographic findings and immunoaffinity chromatography results showed usefulness, even in a limited way, in figuring out of the liver fluke endemicity.     

Intestinal Helminthic Infections Diagnosed by Colonoscopy in a Regional Hospital during 2001-2008

The present study investigated characteristics of 24 parasite infection cases detected during colonoscopy in a regional hospital from January 2001 to December 2008. Sixteen patients were confirmed with Trichuris trichiura infection, 6 patients were with Ascaris lumbricoides infection, 1 patient with Enterobius vermicularis infection, and 1 patient with Anisakis infection. Among them, 7 patients (43.8%) were asymptomatic. Colonoscopy findings were normal in 18 patients (75.0%). Among the patients with T. trichiura infection, colonoscopy showed several erosions in 2 patients (8.3%) and non-specific inflammation of the affected segment of the colon in 3 patients (12.5%). In 1 patient with anisakiasis, colonoscopy revealed a markedly swollen colonic wall. Stool examinations were performed before treatment in 7 patients (29.2%) and were all negative for parasite eggs or worms. These results suggest that colonoscopy is a useful diagnostic approach for parasitic infections even for asymptomatic patients and for patients with negative stool examinations.     

Cryptosporidium hominis Infection Diagnosed by Real-Time PCR-RFLP

There are approximately 20 known species of the genus Cryptosporidium, and among these, 8 infect immunocompetent or immunocompromised humans. C. hominis and C. parvum most commonly infect humans. Differentiating between them is important for evaluating potential sources of infection. We report here the development of a simple and accurate real-time PCR-based restriction fragment length polymorphism (RFLP) method to distinguish between C. parvum and C. hominis. Using the CP2 gene as the target, we found that both Cryptosporidium species yielded 224 bp products. In the subsequent RFLP method using TaqI, 2 bands (99 and 125 bp) specific to C. hominis were detected. Using this method, we detected C. hominis infection in 1 of 21 patients with diarrhea, suggesting that this method could facilitate the detection of C. hominis infections.     

Mini-FLOTAC,an Innovative Direct Diagnostic Technique for Intestinal Parasitic Infections: Experience from the Field

Background

Soil-transmitted helminths and intestinal protozoa infection are widespread in developing countries, yet an accurate diagnosis is rarely performed. The aim of this study was to evaluate the recently developed mini–FLOTAC method and to compare with currently more widely used techniques for the diagnosis of intestinal parasitic infections in different settings.

Methodology/Principal Findings

The study was carried out in Dharamsala, Himachal Pradesh, India, and in Bukumbi, Tanzania. A total of 180 pupils from two primary schools had their stool analyzed (n = 80 in Dharamsala and n = 100 in Bukumbi) for intestinal parasitic infections with three diagnostic methods: direct fecal smear, formol-ether concentration method (FECM) and mini-FLOTAC. Overall, 72% of the pupils were positive for any intestinal parasitic infection, 24% carried dual infections and 11% three infections or more. The most frequently encountered intestinal parasites were Entamoeba coli, Entamoeba histolytica/dispar, Giardia intestinalis, hookworm, (and Schistosoma mansoni, in Tanzania). Statistically significant differences were found in the detection of parasitic infections among the three methods: mini-FLOTAC was the most sensitive method for helminth infections (90% mini-FLOTAC, 60% FECM, and 30% direct fecal smear), whereas FECM was most sensitive for intestinal protozoa infections (88% FECM, 70% direct fecal smear, and 68% mini-FLOTAC).

Conclusion/Significance

We present the first experiences with the mini-FLOTAC for the diagnosis of intestinal helminths and protozoa. Our results suggest that it is a valid, sensitive and potentially low-cost alternative technique that could be used in resource-limited settings — particularly for helminth diagnosis.     

DNA Extraction from Protozoan Oocysts/Cysts in Feces for Diagnostic PCR

PCR detection of intestinal protozoa is often restrained by a poor DNA recovery or by inhibitors present in feces. The need for an extraction protocol that can overcome these obstacles is therefore clear. QIAamp® DNA Stool Mini Kit (Qiagen) was evaluated for its ability to recover DNA from oocysts/cysts directly from feces. Twenty-five Giardia-positive, 15 Cryptosporidium-positive, 15 Entamoeba histolytica-positive, and 45 protozoa-free samples were processed as control by microscopy and immunoassay tests. DNA extracts were amplified using 3 sets of published primers. Following the manufacturer''s protocol, the kit showed sensitivity and specificity of 100% towards Giardia and Entamoeba. However, for Cryptosporidium, the sensitivity and specificity were 60% (9/15) and 100%, respectively. A series of optimization experiments involving various steps of the kit''s protocol were conducted using Cryptosporidium-positive samples. The best DNA recoveries were gained by raising the lysis temperature to the boiling point for 10 min and the incubation time of the InhibitEX tablet to 5 min. Also, using a pre-cooled ethanol for nucleic acid precipitation and small elution volume (50-100 µl) were valuable. The sensitivity of the amended protocol to Cryptosporidium was raised to 100%. Cryptosporidium DNA was successfully amplified by either the first or the second primer set. When applied on parasite-free feces spiked with variable oocysts/cysts counts, ≈ 2 oocysts/cysts were theoretically enough for detection by PCR. To conclude, the Qiagen kit with the amended protocol was proved to be suitable for protozoan DNA extraction directly from feces and support PCR diagnosis.     

Endemic infection reduces transmission potential of an epidemic parasite during co-infection

Endemic, low-virulence parasitic infections are common in nature. Such infections may deplete host resources, which in turn could affect the reproduction of other parasites during co-infection. We aimed to determine whether the reproduction, and therefore transmission potential, of an epidemic parasite was limited by energy costs imposed on the host by an endemic infection. Total lipids, triacylglycerols (TAG) and polar lipids were measured in cockroaches (Blattella germanica) that were fed ad libitum, starved or infected with an endemic parasite, Gregarina blattarum. Reproductive output of an epidemic parasite, Steinernema carpocapsae, was then assessed by counting the number of infective stages emerging from these three host groups. We found both starvation and gregarine infection reduced cockroach lipids, mainly through depletion of TAG. Further, both starvation and G. blattarum infection resulted in reduced emergence of nematode transmission stages. This is, to our knowledge, the first study to demonstrate directly that host resource depletion caused by endemic infection could affect epidemic disease transmission. In view of the ubiquity of endemic infections in nature, future studies of epidemic transmission should take greater account of endemic co-infections.