Helminth Co-infection Research Articles

Co-infections and Comorbidities of Multiple Parasites and Hepatitis B Virus Infections in the Lowland Area of Western Ethiopia: Implications for Integrated Approaches.

BackgroundIn the current study area, the burden of morbidities associated with S. mansoni, soil-transmitted helminths (STHs), asymptomatic malaria, and hepatitis B virus (HBV) infections and co-infection has not been known for the last 20 years. This necessitated a systematic investigation of the status of these infections and their associated morbidities in the lowland areas of the Abbey and Didessa Valleys in Western Ethiopia.MethodsWe used a cross-sectional study design in three schistosomiasis endemic areas. Systematic random sampling and simple random sampling techniques were used to select households and one study participant from each household. Each selected and consented participants were give stool sample for S. mansoni and soil-transmitted helminths screening using duplicate kato-Katz technique; blood sample for screen of asymptomatic malaria using malaria rapid diagnostic test and microscopy and hepatitis B virus using hepatitis B surface antigen kit and anthropometric measurement to assess nutritional status and digital hemoglobin meter to measure hemoglobin and interviewed using structured questionnaire to assess factors associated with infections. A descriptive statistic to summarize the data and a chi-square test, Fisher’s exact test, and binary logistic regression models were used to see the associations.ResultsThe overall prevalence of studied infections was 74.5%. It was highest for Schistosoma mansoni (53.9%), followed by asymptomatic Plasmodium falciparum infection (23.6%). The prevalence of Schistosoma mansoni co-infection with asymptomatic malaria was 8.6%, Schistosoma mansoni and soil-transmitted helminths co-infection was 6.2%, and the seroprevalence of hepatitis B virus was 2.9%. About half (49.9%) of the study participants were undernourished and about a quarter (24.4%) were anemic. Age group, the younger age group and infection status, those with multiple infections were more anemic and commonly undernourished.ConclusionThere was a high prevalence of infections in the study area. Morbidities such as undernutrition and anemia were still prominent public health problems. There was a significant association between infection status and undernutrition and anemia.

ABO Blood Groups Do Not Predict Schistosoma mansoni Infection Profiles in Highly Endemic Villages of Uganda.

Schistosoma mansoni is a parasite which causes significant public-health issues, with over 240 million people infected globally. In Uganda alone, approximately 11.6 million people are affected. Despite over a decade of mass drug administration in this country, hyper-endemic hotspots persist, and individuals who are repeatedly heavily and rapidly reinfected are observed. Human blood-type antigens are known to play a role in the risk of infection for a variety of diseases, due to cross-reactivity between host antibodies and pathogenic antigens. There have been conflicting results on the effect of blood type on schistosomiasis infection and pathology. Moreover, the effect of blood type as a potential intrinsic host factor on S. mansoni prevalence, intensity, clearance, and reinfection dynamics and on co-infection risk remains unknown. Therefore, the epidemiological link between host blood type and S. mansoni infection dynamics was assessed in three hyper-endemic communities in Uganda. Longitudinal data incorporating repeated pretreatment S. mansoni infection intensities and clearance rates were used to analyse associations between blood groups in school-aged children. Soil-transmitted helminth coinfection status and biometric parameters were incorporated in a generalised linear mixed regression model including age, gender, and body mass index (BMI), which have previously been established as significant factors influencing the prevalence and intensity of schistosomiasis. The analysis revealed no associations between blood type and S. mansoni prevalence, infection intensity, clearance, reinfection, or coinfection. Variations in infection profiles were significantly different between the villages, and egg burden significantly decreased with age. While blood type has proven to be a predictor of several diseases, the data collected in this study indicate that it does not play a significant role in S. mansoni infection burdens in these high-endemicity communities.

Malaria and Intestinal Helminth Co-infection among Pregnant Women Attending Federal Teaching Hospital Gombe, Gombe State, Nigeria

Malaria and intestinal helminth infections are of public health concern globally, particularly among the risk groups like pregnant women in developing countries. In this study the prevalence of malaria and intestinal helminth coinfection and their relationship with anaemia were assessed. Two hundred (200) pregnant women aged between 16-55 years reporting to Federal Teaching Hospital Gombe (FTHG), Gombe State for antenatal clinics were enrolled at booking. Venous blood and stool samples were collected from each participant who consented to participate in this study, for haemoglobin estimation, determination of malaria parasitaemia and intestinal helminth parasite. Microscopy and Formal-ether concentration technique (FECT) were used to estimate the prevalence of malaria and determine the presence of intestinal helminth parasite, respectively. Chi-square (χ2) test was used to analyse the relationship between prevalence of intestinal helminth infection with Malaria and Anaemia among the participant. Results obtained revealed that 107 (53.5%) who consented to participate in the study are positive for malaria, with 11 (5.5%) infected with both malaria and intestinal helminths. Findings also revealed that more women 116 (58%) had mild anaemia among the study population. Three intestinal helminths Ascaris lumbricoides, Trichiuris trichiura and Hookworms were also recovered. A significant (P≤ 0.05) correlation between the prevalence of malaria, intestinal helminth and anaemia. Findings of this study provides an insight and further improves our understanding of the some clinical factors responsible for anaemia in pregnancy.

The Influence of Helminth Immune Regulation on COVID-19 Clinical Outcomes: Is it Beneficial or Detrimental?

Immunologically, chronic worm infections prevent themselves from strong immune responses by skewing the host response towards a T helper 2 (Th2) type. The regulatory response initiated by helminth infections is supposed to temper responses to non-helminth antigens including viral infections which will, in turn, alter the clinical outcomes of infections. In view of this, recent reports highlighted the possible negative associations of severe COVID-19 and helminth co-infections in helminth-endemic regions. As the pathology of COVID-19 is primarily mediated by an excessive immune response and subsequent cytokine storm, which contributes to the poor prognosis of COVID-19, helminth-driven immune modulation will hypothetically contribute to the less severe outcomes of COVID-19. Nevertheless, emerging reports also stated that COVID-19 and helminth co-infections may have more hidden outcomes than predictable ones. Herein, the current knowledge on the interaction of COVID-19 and helminth co-infections will be discussed.

Asymptomatic Malaria and Helminths Coinfection and Its Association with Anemia among Primary School Children in Gedeo Zone, Southern Ethiopia: A Cross-Sectional Study.

Background Asymptomatic malaria and helminths coinfection occurs mainly in the tropics and subtropics where poverty and sanitary practice favor its high prevalence. In the tropics, where malaria is endemic, helminths also thrive resulting in coinfection. This study aimed to access the prevalence of asymptomatic malaria and helminths coinfection and its contribution for anemia in primary school children of Gedeo Zone, Southern Ethiopia. Methodology. This was a cross-sectional study conducted among 413 primary school children from February to April 2020. Finger-prick blood samples were used to determine asymptomatic malaria and hemoglobin concentrations. Stool samples were collected and processed through formalin-ether concentration techniques to detect the presence of intestinal helminths. Data were double entered into Epi Data version 3.1 software and exported to SPSS version 20 for analysis. Pearson's chi-square and correlation analysis were performed as part of the statistical analyses. Result A total of 413 primary school children aged 6 to 16 years (mean age ± SD: 10.7 ± 2.64years) were enrolled in the study. 159 (38.5%) of school children were infected with at least one of the parasitic diseases. The overall prevalence of asymptomatic malaria and intestinal helminths was 46 (11.1%) and 113 (27.3%) respectively. Asymptomatic malaria and helminths coinfection was 29 (7%). Total of 39.1% of asymptomatic malaria-infected school children were anemic, which is statistically significant (P < 0.05). 15.9% of helminths-infected school children were anemic, not statistically significant (P > 0.05). The prevalence of anemia was 12 (41.3%) among coinfected students, which is statistically significant (P < 0.005). Conclusion Asymptomatic malaria and helminths coinfection affects the health status of considerable number of primary school children in the study area. Therefore, simultaneous combat against the two parasitic infections is crucial to improve health of the school children.

Reduction of Ascaridia galli Pathology by Salmonella typhimurium in Broiler Chicken.

Previous studies have reported interactions between Salmonella spp. and some helminth coinfections. In this study, S. typhimurium and Ascaridia galli coinfections were analyzed, and the consequences on therapy were proposed. In a first experiment where the effect of the bacteria on the nematode was evaluated, thirty 42-day-old broiler chickens were divided into 3 groups and coinfected with both parasites. The rate of A. galli egg inoculum was kept constant at 500/ml while that of S. typhimurium varied as follows: T0 (500 A. galli eggs/ml), T104 (500 A. galli eggs/ml+104 S. typhimurium CFUs), and T106 (500 A. galli eggs/ml +106S. typhymurium CFUs). EPG and parasitic load were measured using the McMaster technic, and number of worms and their length were also measured. We observed that T106 containing 106 CFUs of Salmonella significantly reduced the EPG values, and this group recorded the lowest worm load ranging from 18 to 21 worms. Likewise, the length of the worms obtained with T104 and T106 appeared to be shorter than those of the control (T0). In a second experiment to assess the effects of the nematode on the bacteria, thirty 42-day-old broiler chickens were divided into 3 groups and coinfected with both parasites. The rate of S. typhimurium inoculum was kept constant at 106 CFUs while that of A. galli varied as follows: T0 (106CFUs), T500 (500 A. galli eggs/ml +106S. typhymurium CFUs), and T750 (750 A. galli eggs/ml +106S. typhymurium CFUs). Bacterial load was measured using Voogt technique. We observed that T500 increased the colonization time and prolonged the duration of S. typhimurium secretion. Salmonella appears to be a hyperparasite considering the deleterious effect on A. galli. Due to this, it may be prudent to combine anti-Salmonella treatment with anthelmintic so as to effectively treat pathologies caused by these two pathogens.

Helminth Coinfection Is Associated With Enhanced Plasma Levels of Matrix Metalloproteinases and Tissue Inhibitor of Metalloproteinases in Tuberculous Lymphadenitis.

Matrix metalloproteinases (MMPs) are crucial for tissue remodeling and repair and are expressed in diverse infections, whereas tissue inhibitors of metalloproteinases (TIMPs) are endogenous inhibitors of MMPs. However, the interaction of MMPs and TIMPs in tuberculous lymphadenitis (TBL), an extra-pulmonary form of tuberculosis (EPTB) and helminth (Hel+) coinfection is not known. Therefore, this present study investigates the levels of circulating MMPs (1, 2, 3, 7, 8, 9, 12, 13) and TIMPs (1, 2, 3, 4) in TBL individuals with helminth (Strongyloides stercoralis [Ss], hereafter Hel+) coinfection and without helminth coinfection (hereafter, Hel-). In addition, we have also carried out the regression analysis and calculated the MMP/TIMP ratios between the two study groups. We describe that the circulating levels of MMPs (except MMP-8 and MMP-12) were elevated in TBL-Hel+ coinfected individuals compared to TBL-Hel- individuals. Similarly, the systemic levels of TIMPs (1, 2, 3, 4) were increased in TBL-Hel+ compared to TBL-Hel- groups indicating that it is a feature of helminth coinfection per se. Finally, our multivariate analysis data also revealed that the changes in MMPs and TIMPs were independent of age, sex, and culture status between TBL-Hel+ and TBL-Hel- individuals. We show that the MMP-2 ratio with all TIMPs were significantly associated with TBL-helminth coinfection. Thus, our results describe how helminth infection has a profound effect on the pathogenesis of TBL and that both MMPs and TIMPs could dampen the immunity against the TBL-Hel+ coinfected individuals.

Effect of Helicobacter pylori and Helminth Coinfection on the Immune Response to Mycobacterium tuberculosis.

Tuberculosis remains one of the main causes of morbidity and mortality worldwide despite decades of efforts to eradicate the disease. Although the immune response controls the infection in most infected individuals (90%), the ability of the bacterium to persist throughout the host's life leads to a risk of reactivation. Underlying conditions including human immunodeficiency virus (HIV) infection, organ transplantation, and immunosuppressive therapies are considered risk factors for progression to active disease. However, many individuals infected with Mycobacterium tuberculosis may develop clinical disease in the absence of underlying immunosuppression. It is also possible that unknown conditions may drive the progression to disease. The human microbiota can be an important modulator of the immune system; it can not only trigger inflammatory disorders, but also drive the response to other infectious diseases. In developing countries, chronic mucosal infections with Helicobacter pylori and helminths may be particularly important, as these infections frequently coexist throughout the host's life. However, little is known about the interactions of these pathogens with the immune system and their effects on M. tuberculosis clinical disease, if any. In this review, we discuss the potential effects of H. pylori and helminth co-infections on the immune response to M. tuberculosis. This may contribute to our understanding of host-pathogen interactions and in designing new strategies for the prevention and control of tuberculosis.

Malaria and Helminth Coinfection among Children at the Douala Gyneco-Obstetric and Pediatric Hospital.

Background Malaria and helminth infections are major public health issues in sub-Saharan Africa including Cameroon. This study was aimed at determining the prevalence and risk factors associated with malaria and helminth coinfection among children in the Douala Gyneco-Obstetric and Pediatric Hospital (HGOPED) in Douala, southwestern Cameroon. Material and Methods. The study was a hospital-based cross-sectional study that took place from January to July 2020 where 203 children were involved. Blood samples were collected from the children and thick blood smears were prepared and examined microscopically for malaria parasites. Stool samples were also collected and examined through the Kato-Katz technique for the identification of helminth eggs. Demographic and socioeconomic data and information of participant's knowledge on the transmission of malaria and helminth infections were collected with the use of a well-structured questionnaire. Results The overall prevalence of P. falciparum infection was 28.8%, while the overall prevalence of helminth was 9.36%. The only species of helminth identified were Ascaris lumbricoides and Trichuris trichiura with a prevalence of 4.26% and 2.95%, respectively, and mixed infection of both A. lumbricoides and T. trichiura with a prevalence of 1.47%. Coinfection of malaria and helminth was observed with a prevalence of 6.90%. Associations of malaria-helminth coinfection with age groups, parent's educational level, type of latrine, and source of water factors were not statistically significant (p > 0.05), while the prevalence of the coinfection with respect to parent's occupation, presence of stagnant water around homes, washing of hands after using the toilet, and washing of fruits before eating was statistically significant (p < 0.05). Conclusion The findings suggest that helminths and malaria infections tend to occur in children. Not washing hands after using the toilet, not washing fruits before eating, the presence of stagnant water around homes, and parents' occupation were found to be strongly associated with coinfection. Health education on the importance of better sewage disposal, draining of stagnant water around homes, and other sanitary practices is recommended.

SARS-CoV-2 and helminth co-infections, and environmental pollution exposure: An epidemiological and immunological perspective.

Soil-transmitted helminths infect billions of people globally, particularly those residing in low- and middle-income regions with poor environmental sanitation and high levels of air and water pollution. Helminths display potent immunomodulatory activity by activating T helper type 2 (Th2) anti-inflammatory and Th3 regulatory immune responses. The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the virus that causes Coronavirus disease 2019 (COVID-19), can exacerbate Th1/Th17 pro-inflammatory cytokine production in humans, leading to a cytokine storm. Air pollutants (particulate matter, oxygen radicals, hydrocarbons and volatile organic compounds) and water pollutants (metals and organic chemicals) can also intensify Th1/Th17 immune response and could exacerbate SARS-CoV-2 related respiratory distress and failure. The present review focused on the epidemiology of SARS-CoV-2, helminths and fine particulate matter 2.5 µm or less in diameter (PM2.5) air pollution exposure in helminth endemic regions, the possible immunomodulatory activity of helminths against SARS-CoV-2 hyper-inflammatory immune response, and whether air and water pollutants can further exacerbate SARS-CoV-2 related cytokine storm and in the process hinder helminths immunomodulatory functionality. Helminth Th2/Th3 immune response is associated with reductions in lung inflammation and damage, and decreased expression levels of angiotensin-converting enzyme 2 (ACE2) receptors (SARS-CoV-2 uses the ACE2 receptors to infect cells and associated with extensive lung damage). However, air pollutants are associated with overexpression of ACE2 receptors in the epithelial cell surface of the respiratory tract and exhaustion of Th2 immune response. Helminth-induced immunosuppression activity reduces vaccination efficacy, and diminishes vital Th1 cytokine production immune responses that are crucial for combating early stage infections. This could be reversed by continuous air pollution exposure which is known to intensify Th1 pro-inflammatory cytokine production to a point where the immunosuppressive activities of helminths could be hindered. Again, suppressed activities of helminths can also be disadvantageous against SARS-CoV-2 inflammatory response. This “yin and yang” approach seems complex and requires more understanding. Further studies are warranted in a cohort of SARS-CoV-2 infected individuals residing in helminths and air pollution endemic regions to offer more insights, and to impact mass periodic deworming programmes and environmental health policies.

Differential drivers of intraspecific and interspecific competition during malaria-helminth co-infection.

Various host and parasite factors interact to determine the outcome of infection. We investigated the effects of two factors on the within-host dynamics of malaria in mice: initial infectious dose and co-infection with a helminth that limits the availability of red blood cells (RBCs). Using a statistical, time-series approach to model the within-host ‘epidemiology’ of malaria, we found that increasing initial dose reduced the time to peak cell-to-cell parasite propagation, but also reduced its magnitude, while helminth co-infection delayed peak cell-to-cell propagation, except at the highest malaria doses. Using a mechanistic model of within-host infection dynamics, we identified dose-dependence in parameters describing host responses to malaria infection and uncovered a plausible explanation of the observed differences in single vs co-infections. Specifically, in co-infections, our model predicted a higher background death rate of RBCs. However, at the highest dose, when intraspecific competition between malaria parasites would be highest, these effects of co-infection were not observed. Such interactions between initial dose and co-infection, although difficult to predict a priori, are key to understanding variation in the severity of disease experienced by hosts and could inform studies of malaria transmission dynamics in nature, where co-infection and low doses are the norm.

Intestinal helminth co-infection is an unrecognised risk factor for increased pneumococcal carriage density and invasive disease

Infection with Streptococcus pneumoniae is the leading cause of death in children and burden of disease is greatest where helminth infections are also common. We investigated the impact of intestinal helminth co-infection on pneumococcal carriage; a risk factor for invasive disease. We used a mouse co-infection model and clinical data to assess the impact of co-infection on carriage density. Co-infection in mice was associated with increased pneumococcal carriage density and dissemination into lungs. Helminth-infected children also exhibited increased carriage density as compared to uninfected children. Anthelmintic treatment may be a cost-effective method of reducing pneumococcal disease burden in lower-income countries.

Environmental Sanitation, Personal Hygiene, STH Co-infection in TB Patients

Globally, helminthiasis is one of the infectious diseases that are often associated with the incidence of tuberculosis. Helminth co-infection modulates the immune system of TB patients by reducing Th-1 response that functions as protector against Mycobacterium tuberculosis. This condition disrupts the process of eliminating bacteria so that its development becomes more progressive. The impact is the activation of latent TB and the success of TB treatment. A Soil-transmitted Helminth (STH) is a group of intestinal worms that often infect humans. Previous studies prove that environmental sanitation and personal hygiene are risk factors associated with STH infection. The study to determine the relationship of environmental sanitation and personal hygiene with the incidence of STH co-infection in TB patients at Puskesmas Puger, Jember in September until December 2019. This study uses a cross-sectional design. The sampling technique uses total sampling. A total of 32 TB patients met the criteria as study sample. The data analysis uses Fisher Test. Results showed the prevalence of STH co-infection was relatively low (18.8%); most of the respondents had good environmental sanitation and personal hygiene conditions. Bivariate analysis showed p-value (0,476) for environmental sanitation and p-value (1,000) for personal hygiene. This study concludes that there is no correlation between environmental sanitation, personal hygiene, and STH co-infection in TB patients at Public health center in Puger.

Prevalence, Risk Factors, and Coinfection of Urogenital Schistosomiasis and Soil-Transmitted Helminthiasis among Primary School Children in Biase, Southern Nigeria.

Schistosomiasis and soil-transmitted helminthiasis (STH) are neglected tropical diseases (NTDs) that cause chronic infections and ill health. The study was carried out to determine the current infection status and risk factors associated with Schistosoma haematobium and soil-transmitted helminth (STH) coinfection among school children in Biase Local Government Area (LGA), Cross River State, Nigeria. A cross-sectional study was carried out. Urine and fecal samples were randomly collected from 630 school children in six villages of Biase LGA. Urine sedimentation and Kato-Katz techniques were used to diagnose urogenital schistosomiasis and STHs, respectively. A structured questionnaire was used to collect demographic information and risk factors. The prevalence of S. haematobium in Biase LGA was 6.03%, with males (27 pupils, 9.00%) significantly more (χ2 = 8.903, p value = 0.003, C.I. = −82.650–120.650) infected than the females (11 pupils, 3.33%), while the prevalence of STH infection was 11.27% with no significant difference (χ2 = 0.002, p value = 0.962, C.I. = −16.441–54.559) in prevalence between males (34 pupils, 11.33%) and females (37 pupils, 11.21%). Prevalence of S. haematobium and STHs ranged from 1.82 to 19.13% and from 4.55 to 19.05% within the communities, respectively, with Abini (22 pupils, 19.13%) and Adim (20 pupils, 19.05%) communities having the highest prevalence for S. haematobium and STHs, respectively. The most infected age group was 11–13 years (21 pupils, 9.68%) for S. haematobium and 14–16 years (5 pupils, 21.74%) for STHs. Ascaris lumbricoides, hookworms, and Trichuris trichiura had prevalence of 5.56%, 3.02%, and 2.70%, respectively. An overall prevalence of 7.14% and 8.41% was observed for haematuria and proteinuria, respectively. Prevalence of coinfection among the parasites was 4.76%. Male pupils (OR = 2.868, C.I.: 1.397–5.889), pupils of the age group of 11–13 years (OR = 2.496, C.I.: 1.287–4.838), school children that swim (OR = 1.527, C.I.: 0.784–2.974), those that cross streams to farm (OR = 25.286, C.I.: 4.091–156.283), those that visit stream or river severally (OR = 3.077, C.I.: 1.204–7.863), and those whose home is 1 km (OR = 3.116, C.I.: 1.292–7.518) from the stream are at higher odds of infection with S. haematobium. For STHs, male pupils (OR = 1.012, C.I.: 0.617–1.659), pupils of the age group of 11–13 years (OR = 2.609, C.I.: 1.582–4.302), pupils that walk barefoot (OR = 18.746, C.I.: 6.786–51.783), those that do not wash fruits and vegetables before eating (OR = 2.334, C.I.: 1.400–3.892), those that do not wash hands after using the toilet (OR = 1.200, C.I.: 0.730–1.973), those that eat soils (OR = 2.741, C.I.: 1.533–4.902), those that drink water from streams or rivers (OR = 189.509, C.I.: 24.807–1447.740), and those that use pit latrine (OR = 2.920, C.I.: 1.746–4.885) and/or open defecation (OR = 2.552, C.I.: 1.454–4.479) are at high odds of being infected with STHs. Urogenital schistosomiasis and soil-transmitted helminthiasis are still endemic diseases in Biase LGA. Although the degree of infection is quite low or moderate, there is a need to intensify and sustain control measures such as provision of sustainable clean water supply, health education intervention, and chemotherapy.

Enteric helminth coinfection enhances host susceptibility to neurotropic flaviviruses via a tuft cell-IL-4 receptor signaling axis

Although enteric helminth infections modulate immunity to mucosal pathogens, their effects on systemic microbes remain less established. Here, we observe increased mortality in mice coinfected with the enteric helminth Heligmosomoides polygyrus bakeri (Hpb) and West Nile virus (WNV). This enhanced susceptibility is associated with altered gut morphology and transit, translocation of commensal bacteria, impaired WNV-specific Tcell responses, and increased virus infection in the gastrointestinal tract and central nervous system. These outcomes were due to type 2 immune skewing, because coinfection in Stat6-/- mice rescues mortality, treatment of helminth-free WNV-infected mice with interleukin (IL)-4 mirrors coinfection, and IL-4 receptor signaling in intestinal epithelial cells mediates the susceptibility phenotypes. Moreover, tuft cell-deficient mice show improved outcomes with coinfection, whereas treatment of helminth-free mice with tuft cell-derived cytokine IL-25 or ligand succinate worsens WNV disease. Thus, helminth activation of tuft cell-IL-4-receptor circuits in the gut exacerbates infection and disease of a neurotropic flavivirus.

Malaria and helminth co-infections in children living in endemic countries: A systematic review with meta-analysis

Current knowledge on the burden of, and interactions between malaria and helminth co-infections, as well as the impact of the dual infections on anaemia, remains inconclusive. We have conducted a systematic review with meta-analysis to update current knowledge as a first step towards developing and deploying coordinated approaches to the control and, ultimately, elimination of malaria-helminth co-infections among children living in endemic countries. We searched Medline, Embase, Global Health and Web of Science from each database inception until 16 March 2020, for peer-reviewed articles reporting malaria-helminth co-infections in children living in endemic countries. No language restriction was applied. Following removal of duplicates, two reviewers independently screened the studies for eligibility. We used the summary odds ratio (OR) and 95% confidence intervals (CI) as a measure of association (random-effects model). We also performed Chi-square heterogeneity test based on Cochrane's Q and evaluated the severity of heterogeneity using I2 statistics. The included studies were examined for publication bias using a funnel plot and statistical significance was assessed using Egger's test (bias if p<0.1). Fifty-five of the 3,507 citations screened were eligible, 28 of which had sufficient data for meta-analysis. The 28 studies enrolled 22, 114 children in 13 countries across sub-Saharan Africa, Southeast Asia and South America. Overall, the pooled estimates showed a prevalence of Plasmodium-helminth co-infections of 17.7% (95% CI 12.7-23.2%). Summary estimates from 14 studies showed a lower odds of P. falciparum infection in children co-infected with Schistosoma spp (OR: 0.65; 95%CI: 0.37-1.16). Similar lower odds of P. falciparum infection were observed from the summary estimates of 24 studies in children co-infected with soil transmitted helminths (STH) (OR: 0.42; 95%CI: 0.28-0.64). When adjusted for age, gender, socio-economic status, nutritional status and geographic location of the children, the risk of P. falciparum infection in children co-infected with STH was higher compared with children who did not have STH infection (OR = 1.3; 95% CI 1.03-1.65). A subset of 16 studies showed that the odds of anaemia were higher in children co-infected with Plasmodium and STH than in children with Plasmodium infection alone (OR = 1.20; 95% CI: 0.59-2.45), and were almost equal in children co-infected with Plasmodium-Schistosoma spp or Plasmodium infection alone (OR = 0.97, 95% CI: 0.30-3.14). The current review suggests that prevalence of malaria-helminth co-infection is high in children living in endemic countries. The nature of the interactions between malaria and helminth infection and the impact of the co-infection on anaemia remain inconclusive and may be modulated by the immune responses of the affected children.

Mycobacterium leprae–helminth co-infections and vitamin D deficiency as potential risk factors for leprosy: A case–control study in south-eastern Brazil

BackgroundEvidence suggests that biological mechanisms involved in helminth infections and vitamin deficiencies increase susceptibility to other infections. The aim of this study was to investigate the associations of helminth co-infection and select micronutrient deficiencies with leprosy using a case–control design. MethodsFrom 2016 to 2018, individuals aged ≥3 years were recruited at clinics in and around Governador Valadares, Minas Gerais, Brazil in three groups: cases of leprosy, household contacts and community-matched (non-contact) controls. Helminths were diagnosed through stool Kato Katz examination and serum reactivity to anti-soluble adult worm antigen preparation IgG4. Serum ferritin, 25-OH vitamin D and retinol concentrations were measured. Multi-variate logistic regression was conducted to identify associations with active leprosy. ResultsSeventy-nine cases of leprosy, 96 household contacts and 81 non-contact controls were recruited; 48.1% of participants were male with a median age of 40 years. Helminths were found in 7.1% of participants on Kato Katz test, all but one of which were Schistosoma mansoni, and 32.3% of participants were positive for S. mansoni serology. On multi-variate analysis, cases were more likely to be infected with helminths (diagnosed by stool) than household contacts [adjusted odds ratio (aOR) 8.69, 95% confidence interval (CI) 1.50–50.51]. Vitamin D deficiency was common, and was more likely in cases compared with non-contact controls (aOR 4.66, 95% CI 1.42,–15.33). Iron deficiency was not associated with leprosy, and vitamin A deficiency was not detected. ConclusionThese associations suggest that the immune consequences of schistosomiasis and vitamin D deficiency may increase the risk of active leprosy. Comorbid conditions of poverty deserve further study as addressing co-infections and nutritional deficiencies could be incorporated into programmes to improve leprosy control.

Impaired host resistance to Salmonella during helminth co-infection is restored by anthelmintic treatment prior to bacterial challenge.

Intestinal helminth infection can impair host resistance to co-infection with enteric bacterial pathogens. However, it is not known whether helminth drug-clearance can restore host resistance to bacterial infection. Using a mouse helminth-Salmonella co-infection system, we show that anthelmintic treatment prior to Salmonella challenge is sufficient to restore host resistance to Salmonella. The presence of the small intestine-dwelling helminth Heligmosomoides polygyrus at the point of Salmonella infection supports the initial establishment of Salmonella in the small intestinal lumen. Interestingly, if helminth drug-clearance is delayed until Salmonella has already established in the small intestinal lumen, anthelmintic treatment does not result in complete clearance of Salmonella. This suggests that while the presence of helminths supports initial Salmonella colonization, helminths are dispensable for Salmonella persistence in the host small intestine. These data contribute to the mechanistic understanding of how an ongoing or prior helminth infection can affect pathogenic bacterial colonization and persistence in the mammalian intestine.

Comorbidity of Geo-Helminthes among Malaria Outpatients of the Health Facilities in Ethiopia: Systematic Review and Meta-Analysis.

Background: Coinfection of malaria and intestinal helminths affects one third of the global population, largely among communities with severe poverty. The spread of these parasitic infections overlays in several epidemiological locations and the host shows different outcomes. This systematic review and meta-analysis determine the pooled prevalence of malaria and intestinal helminthiases coinfections among malaria suspected patients in Ethiopia. Methods: Primary studies published in English language were retrieved using appropriate search terms on Google Scholar, PubMed/MEDLINE, CINHAL, Scopus, and Embase. The Joanna Briggs Institute Meta-Analysis of Statistics Assessment and Review Instrument (JBI-MAStARI) was used for critical appraisal of studies. A pooled statistical meta-analysis was conducted using STATA Version 14.0 software. The heterogeneity and publication bias were assessed using the I2 statistics and Egger’s test, respectively. Duval and Tweedie’s nonparametric trim and fill analysis using the random-effect analysis. The Random effects model was used to estimate the summary prevalence of comorbidity of malaria and soil transmitted helminthiases and the corresponding 95% confidence intervals (CI). The review protocol has registered in PROSPERO number CRD42019144803. Results: We identified ten studies (n = 6633 participants) in this study. The overall pooled result showed 13% of the ambulatory patients infected by malaria and intestinal helminths concurrently in Ethiopia. The pooled prevalence of Plasmodium falciparum and Plasmodium vivax, and mixed infections were 12, 30, and 6%, respectively. The most common intestinal helminth parasites detected were Hookworm, Ascaris lumbricoides, and Tirchuris trichiura. Conclusions: The comorbidity of malaria and intestinal helminths causes lower hemoglobin level leading to maternal anemia, preterm delivery, and still birth in pregnant women and lactating mother. School-aged children and neonates coinfected by plasmodium species and soil transmitted helminths develop cognitive impairment, protein energy malnutrition, low birth weight, small for gestational age, and gross motor delay. The Ministry of Health of Ethiopia and its international partners working on malaria elimination programs should give more emphasis to the effect of the interface of malaria and soil transmitted helminths, which calls for an integrated disease control and prevention.

Variation in helminth infection prevalence, abundance, and co-infection in an intermediate host across a large spatial scale

Parasites are often distributed heterogeneously across host populations, but the controls of this heterogeneity across regional scales often remain unclear. Here, we test the relative importance of natural and anthropogenic environmental factors and biological attributes of host populations on the large-scale variability in infection probability and parasite abundance. We quantified a larval acanthocephalan parasite (Profilicollis altmani), as well as the trematodeMaritremasp. and the nematodeProleptussp., infection of mole crabsEmerita analogausing a hierarchical design at 8 sites spanning 500 km of the south-central shoreline of Chile. At each site, we measured the variables of beach size, morphodynamics, distance to nearest port, distance to tributaries, mole crab density, seagull density, and host body size. Using mixed-effects models, we analysed the associations of acanthocephalan infection probability and parasite abundance in mole crabs as functions of body size and the environmental site-level factors. Models accounted for 20 and 61% of variation in acanthocephalan infection probability and abundance, respectively, with mole crab body size exclusively accounting for nearly all of the model fits. Also, acanthocephalan abundance decreased with increasing mole crab density, suggesting a possible encounter-dilution effect. Co-infection was strong, with the 2 other larval parasite species correlated positively with acanthocephalan parasites. The low influence of environmental variables on acanthocephalan infection could be because spatial variability in these factors is relatively low or their influences are quick to saturate. Therefore, in this system, parasite infection is apparently more strongly related to the duration of host exposure than spatially variable environmental factors, even across large spatial scales.