Surveillance and Selective Treatment of Brugia malayi Filariasis Eleven Years after Stopping Mass Drug Administration in Belitung District, Indonesia

Brugia malayi is the major cause of lymphatic filariasis (LF) in Indonesia. Zoophilic B. malayi was endemic in Belitung district, and mass drug administration (MDA) with diethylcarbamazine (DEC) and albendazole ceased after five annual rounds in 2010. The district passed three transmission assessment surveys (TAS) between 2011 and 2016. As part of the post-TAS3 surveillance of the national LF elimination program, we collected night blood samples for microfilaria (Mf) detection from 1,911 subjects more than 5 years of age in seven villages. A B. malayi Mf prevalence ranging from 1.7% to 5.9% was detected in five villages. Only 2 (5%) of the total 40 Mf-positive subjects were adolescents aged 18 and 19 years old, and 38 (95%) Mf-positive subjects were 21 years and older. Microfilarial densities in infected individuals were mostly low, with 60% of the subjects having Mf densities between 16 and 160 Mf/mL. Triple-drug treatment with ivermectin, DEC, and albendazole (IDA) was given to 36 eligible Mf-positive subjects. Adverse events were mostly mild, and treatment was well tolerated. One year later, 35 of the treated Mf-positive subjects were reexamined, and 33 (94%) had cleared all Mf, while the anti-Bm14 antibody prevalence remained almost unchanged. Results indicate that in B. malayi-endemic areas, post-TAS3 surveillance for Mf in the community may be needed to detect a potential parasite reservoir in adults. Selective treatment with IDA is highly effective in clearing B. malayi Mf and should be used to increase the prospects for LF elimination if MDA is reintroduced.

Country Reports on Practical Aspects of Conducting Large-Scale Community Studies of the Tolerability of Mass Drug Administration with Ivermectin/Diethylcarbamazine/Albendazole for Lymphatic Filariasis

This article is a compilation of summaries prepared by lead investigators for large-scale safety and efficacy studies on mass drug administration of IDA (ivermectin, diethylcarbamazine, and albendazole) for lymphatic filariasis. The summaries highlight the experiences of study teams that assessed the safety and efficacy of IDA in five countries: India, Indonesia, Haiti, Papua New Guinea, and Fiji. They also highlight significant challenges encountered during these community studies and responses to those challenges that contributed to success.

Status of Lymphatic Filariasis Transmission after Two Additional Rounds of Filariasis Mass Drug Administration: A Case Study in Pekalongan City, Central Java, Indonesia

BACKGROUND: Lymphatic filariasis (LF) is a neglected tropical disease caused by mosquito-containing filarial worms Wuchereria bancrofti, Brugia malayi, and Brugia timori. World Health Organization (WHO) had set up the global program to interrupt transmission with mass drug administration and manage morbidity and prevent disability. AIM: This study aimed to determine the status of LF transmission in Pekalongan City after two additional rounds of mass drug administration. A cross-sectional study was conducted in Pekalongan City, Indonesia. METHOD: Three villages had been selected purposively as study sites: free, non-endemic, and endemic of LF as more than 600 finger blood samples were taken from study participants in the night between 21:00 and 01:00. Laboratory testing for microfilaria examination was conducted in Bendan and Bedono Public Health Center Pekalongan, Indonesia. Mosquitoes were collected in three areas of the study site from the middle of the night until the morning. Identification and biomolecular examination of caught mosquitoes used a polymerase chain reaction. Statistical analysis was made using IBM SPSS Statistics 26 software. RESULT: This research found two microfilaria positive samples from 600 finger blood samples examined (microfilariae rate: 0.33%). There were four positive reactions to filaria. The identified mosquito species consisted of Culex quinquefasciatus, Culex vashnui, and Aedes aegypti. Aedes aegypti was only confirmed filaria positive. CONCLUSION: A non-endemic village was only found one blood sample positive, but blood and mosquito sample positive were found in endemic villages. It seemed that LF transmission was still in running di endemic village in Pekalongan City.  

IgG4 antibodies against Bm14 as an evaluation tool of mass drug administration in a co-endemic area of Brugia timori and Wuchereria bancrofti

To evaluate the success of mass drug administration for lymphatic filariasis, WHO has recommended two rapid tests, Brugia Rapid (BR) to detect the presence of IgG4 antibodies against Brugia sp and Filariasis Test Strip (FTS) to detect antigens of Wuchereria bancrofti. As a country co-endemic for Brugia sp. and W. bancrofti, Indonesia needs a single diagnostic tool that can detect the exposure to both species. This study aimed to evaluate the efficacy of mass drug administration by measuring Bm14-specific IgG4 levels in blood samples of the population living in a co-endemic area of B. timori and W. bancrofti in Southwest Sumba Regency. A total of 132 plasma samples obtained before and one year after DEC-albendazole administration, which have been previously tested with BR and FTS, were examined for IgG4 against Bm14 using enzyme-linked immunosorbent assay. The results showed that before treatment all 32 individuals (100%) with BR+/ FTS+ were also positive for Bm14-specific IgG4, while in BR+ or FTS+ group there were >90% samples detected positive. At one year after treatment, positive results for Bm14-specific IgG4 were still detected in 96.9% samples with BR+/ FTS+, 78.8% samples with BR+/ FTS- and 82.9% samples with BR-/ FTS+. On the other hand, the BR-/ FTS- group also had high rate of Bm14-specific IgG4 positivity either before treatment (62,5%) and at one year after treatment (43.8%). The lowest decrease of Bm14-specific IgG4 positivity at one year after treatment was shown in the double positive group (3.1%), while the highest was in the double negative group (18.7%). The measurement of IgG4 against Bm14 has the potential as a sensitive diagnostic tool to evaluate the success of MDA in the areas co-endemic for B. timori and W. bancrofti.

The associations of leptin and adiponectin with the metabolic syndrome in an Indonesian and a Dutch population

BACKGROUND AND AIMS

At the same BMI, Asian populations develop cardiometabolic complications earlier than Western populations. We hypothesized that a different secretion of the adipocyte-derived hormones leptin and adiponectin plays a role and investigated the associations of the two hormones with the metabolic syndrome (MetS) in an Indonesian and a Dutch population.

METHODS AND RESULTS

We performed cross-sectional analyses of the Netherlands Epidemiology of Obesity Study (n = 6602) and the SUGAR Scientific Programme Indonesia-Netherlands Study (n = 1461). We examined sex-stratified associations of leptin and adiponectin with MetS, using multivariate logistic regression including adjustment for total body fat. The mean (SD) leptin (mcg/L) were 4.7 (6.0) in Indonesian men, 18.6 (12.0) in Indonesian women, 9.1 (7.7) in Dutch men, and 23.4 (17.4) in Dutch women. The mean (SD) adiponectin (mg/L) were 5.7 (5.4), 7.5 (7.1), 6.6 (3.3), and 11.3 (4.9), respectively. Within the same BMI category, leptin concentrations were similar in the two populations, whereas adiponectin was lower in the Indonesian population. Per SD of leptin, adjusted prevalence odds ratios (ORs, 95%CI) of MetS were 0.9 (0.6-1.2) in Indonesian men, 1.1 (0.9-1.4) in Indonesian women, 2.2 (1.6-2.8) in Dutch men, and 1.2 (1.0-1.5) in Dutch women. Per SD of adiponectin, the ORs were 0.9 (0.7-1.2), 0.8 (0.7-1.0), 0.6 (0.6-0.8), and 0.4 (0.4-0.5), respectively.

CONCLUSIONS

Despite lower adiponectin levels, adiponectin was not related to the MetS in the Indonesian population and can not explain their increased cardiometabolic risk at the same BMI.

Stunting Among Children in Rural Area of Indonesia: Five-Year Follow-Up Study

Objectives

To follow-up the situation of stunting among children in Nangapanda, a subdistrict in East Nusa Tenggara, Indonesia after 5 years.

Methods

The design was 5-year follow-up study in rural area of Indonesia. A total of 89 children aged 6–9 years were included. Structured interview, nutritional assessment, blood and stool collection were performed to the subjects who had the same measurement in 2014. Socio-demography characteristics, weight, height, hemoglobin level, serum ferritin, serum zinc, CRP, worm infection and household food security were collected. To compare the baseline and 5-year follow-up data wilcoxon test, paired t-test, and Mc-Nemar test were used.

Results

After 5 years, stunting prevalence dropped considerably from 49.4% to 21.3%. There were 34.1% children remain stunted after 5 years. Among the stunted children, 80% remained underweight, 33.3% remained anemia, and 16.7% still had worm infection. According to sociodemographic data, those who remain stunted had low mother's education (66%), lived with 5–8 household members (53.3%), experienced household food insecurity (53.3%), and consumed unsafe drinking water (46.7%). Compared to their nutritional status in 2014, there are improvements in their HAZ-score and hemoglobin level (P < 0.0001). In addition, worm infection rate reduced although the reduction was not significant (P = 0.077). Children whose HAZ-score improved were comparable in their sociodemographic status with those children who remained stunted children.

Conclusions

Within five year period, there was reduction in stunting prevalence which was accompanied by increase in HAZ-score, hemoglobin level and reduction in worm infection rate. No difference was found in characteristics of children who recovered and remained stunted.

Funding Sources

Pintermidi Grant from Universitas Indonesia with contract number 1908/UN2.R3.1/HKP.05.00/2019.

Soil-transmitted helminth infection, anemia, and malnutrition among preschool-age children in Nangapanda subdistrict, Indonesia

BACKGROUND

Soil-transmitted helminth (STH) infections are still prevalent in Indonesia, with roughly one-third of infected population being preschool-age children (PSC), which are generally at higher risk of morbidity such as malnutrition and anemia. This study aimed to investigate the association of STH infections with nutritional status and anemia among PSC in Nangapanda subdistrict, Ende, East Nusa Tenggara.

METHODS

A cross-sectional survey involving PSC ranging from 12 to 59 months old from Nangapanda subdistrict, Ende district, East Nusa Tenggara was performed. Socio-demographic, breastfeeding, and complementary feeding information was obtained from structured questionnaires, while nutritional and anemia status was determined from anthropometry and hemoglobin measurements, respectively. Anthropometric z-scores were calculated based on the World Health Organization 2006 standards and stool samples were examined using Kato-Katz method.

RESULTS

A total of 393 PSC randomly selected from 22 villages were examined. The prevalence of underweight, stunting, wasting, and anemia were 33.1%, 40.2%, 17.1%, and 60.3%, respectively. STH infection, predominated by Ascaris lumbricoides, was found in 160 (58.8%) PSC. Single STH infection, but not multiple infection, was independently associated with a lower risk of anemia (odds ratio [OR] 0.320, 95% confidence interval [CI]: 0.126-0.809, p = 0.016). Similar association with anemia was also found on mild STH infection (OR 0.318 [95% CI: 0.114-0.887], p = 0.029). On the other hand, younger children were found to have a higher risk of anemia and stunting. None of the examined variables were independently associated with underweight and wasting.

CONCLUSION

STH infection as well as anemia and malnutrition were prevalent in this region. However in this study, current STH infections seemed to have minimal negative impact on children's nutritional status.

An open label, randomized clinical trial to compare the tolerability and efficacy of ivermectin plus diethylcarbamazine and albendazole vs. diethylcarbamazine plus albendazole for treatment of brugian filariasis in Indonesia

Improved treatments for lymphatic filariasis (LF) could accelerate the global elimination program for this disease. A triple drug combination of the anti-filarial drugs ivermectin, diethylcarbamazine (DEC) and albendazole (IDA) has been shown to be safe and effective for achieving sustained clearance of microfilariae (Mf) of the filarial parasite Wuchereria bancrofti from human blood. However, the triple drug combination has not been previously been evaluated for treatment of brugian filariasis, which accounts for about 10% of the global LF burden. This hospital-based clinical trial compared the safety and efficacy of IDA with that of the standard treatment (DEC plus albendazole, DA) in persons with Brugia timori infections on Sumba island, Indonesia. Fifty-five asymptomatic persons with B. timori Mf were treated with either a single oral dose of IDA (28 subjects) or with DEC plus albendazole (DA, 27 subjects). Participants were actively monitored for adverse events (AE) for two days after treatment by nurses and physicians who were masked regarding treatment assignments. Passive monitoring was performed by clinical teams that visited participant’s home villages for an additional five days. Microfilaremia was assessed by membrane filtration of 1 ml night blood at baseline, at 24h and one year after treatment. IDA was more effective than DA for completely clearing Mf at 24 hours (25/28, 89% vs. 8/27, 30%, P < 0.001). By 12 months after treatment, only one of 27 IDA recipients had Mf in their blood (4%) vs. 10 of 25 (40%) in persons treated with DA (P = 0.002). Approximately 90% of participants had antibodies to recombinant filarial antigen BmR1 at baseline. Antibody prevalence decreased to approximately 30% in both treatment groups at 12 months. About 45% of persons in both treatment groups experienced AE such as fever, muscle aches, lower back, joint and abdominal pain. These were mostly mild and most common during the first two days after treatment. No participant experienced a severe or serious AE. This study showed that IDA was well-tolerated and significantly more effective for clearing B. timori Mf from the blood than DA. Larger studies should be performed to further assess the safety and efficacy of IDA as a mass drug administration regimen to eliminate brugian filariasis.

Trial Registration:NCT02899936.

Improved treatments for lymphatic filariasis (LF) could accelerate the global elimination program for this disease. A triple drug combination of the anti-filarial drugs ivermectin, diethylcarbamazine (DEC) and albendazole (IDA) has been shown to be safe and effective for achieving sustained clearance of microfilariae (Mf) of the filarial parasite Wuchereria bancrofti from human blood. However, the triple drug combination has not been previously been evaluated for treatment of brugian filariasis, which accounts for about 10% of the global LF burden. This hospital-based clinical trial compared the safety and efficacy of IDA with that of the standard treatment (DEC plus albendazole, DA) in persons with Brugia timori infections on Sumba island, Indonesia. Fifty-five asymptomatic persons with B. timori Mf were treated with either a single oral dose of IDA (28 subjects) or with DA (27 subjects). Adverse events (AE) were assessed in the hospital for two days after treatment and for another five days in participants’ home villages. IDA was much more effective than DA for clearing Mf from the blood at 24 hr. Only 1 person (4% of those treated) had Mf in their blood one year after IDA, while 10 persons (40%) treated with DA were Mf positive at that time. About 45% of persons in both treatment groups experienced mostly mild AE as fever, muscle aches, lower back, joint and abdominal pain (mostly during the first two days after treatment). This study showed that IDA was well-tolerated and significantly more effective than DA for clearing B. timori Mf from the blood. Larger studies should be performed to further assess the safety and efficacy of IDA as a mass drug administration regimen to eliminate brugian filariasis.

Whipworm-Associated Intestinal Microbiome Members Consistent Across Both Human and Mouse Hosts

The human whipworm Trichuris trichiura infects 289 million people worldwide, resulting in substantial morbidity. Whipworm infections are difficult to treat due to low cure rates and high reinfection rates. Interactions between whipworm and its host's intestinal microbiome present a potential novel target for infection control or prevention but are very complicated and are identified using inconsistent methodology and sample types across the literature, limiting their potential usefulness. Here, we used a combined 16S rRNA gene OTU analysis approach (QIIME2) for samples from humans and mice infected with whipworm (T. trichiura and T. muris, respectively) to identify for the first time, bacterial taxa that were consistently associated with whipworm infection spanning host species and infection status using four independent comparisons (baseline infected vs uninfected and before vs after deworming for both humans and mice). Using these four comparisons, we identified significant positive associations for seven taxa including Escherichia, which has been identified to induce whipworm egg hatching, and Bacteroides, which has previously been identified as a major component of the whipworm internal microbiome. We additionally identified significant negative associations for five taxa including four members of the order Clostridiales, two from the family Lachnospiraceae, including Blautia which was previously identified as positively associated with whipworm in independent human and mouse studies. Using this approach, bacterial taxa of interest for future association and mechanistic studies were identified, and several were validated by RT-qPCR. We demonstrate the applicability of a mouse animal model for comparison to human whipworm infections with respect to whipworm-induced intestinal microbiome disruption and subsequent restoration following deworming. Overall, the novel cross-species analysis approach utilized here provides a valuable research tool for studies of the interaction between whipworm infection and the host intestinal microbiome.

A multicenter, community-based, mixed methods assessment of the acceptability of a triple drug regimen for elimination of lymphatic filariasis

Background

Many countries will not reach elimination targets for lymphatic filariasis in 2020 using the two-drug treatment regimen (diethylcarbamazine citrate [DEC] and albendazole [DA]). A cluster-randomized, community-based safety study performed in Fiji, Haiti, India, Indonesia and Papua New Guinea tested the safety and efficacy of a new regimen of ivermectin, DEC and albendazole (IDA).

Methodology/Principal findings

To assess acceptability of IDA and DA, a mixed methods study was embedded within this community-based safety study. The study objective was to assess the acceptability of IDA versus DA. Community surveys were performed in each country with randomly selected participants (>14 years) from the safety study participant list in both DA and IDA arms. In depth interviews (IDI) and focus group discussions (FGD) assessed acceptability-related themes. In 1919 individuals, distribution of sex, microfilariae (Mf) presence and circulating filarial antigenemia (CFA), adverse events (AE) and age were similar across arms. A composite acceptability score summed the values from nine indicators (range 9–36). The median (22.5) score indicated threshold of acceptability. There was no difference in scores for IDA and DA regimens. Mean acceptability scores across both treatment arms were: Fiji 33.7 (95% CI: 33.1–34.3); Papua New Guinea 32.9 (95% CI: 31.9–33.8); Indonesia 30.6 (95% CI: 29.8–31.3); Haiti 28.6 (95% CI: 27.8–29.4); India 26.8 (95% CI: 25.6–28) (P<0.001). AE, Mf or CFA were not associated with acceptability. Qualitative research (27 FGD; 42 IDI) highlighted professionalism and appreciation for AE support. No major concerns were detected about number of tablets. Increased uptake of LF treatment by individuals who had never complied with MDA was observed.

Conclusions/Significance

IDA and DA regimens for LF elimination were highly and equally acceptable in individuals participating in the community-based safety study in Fiji, Haiti, India, Indonesia, and Papua New Guinea. Country variation in acceptability was significant. Acceptability of the professionalism of the treatment delivery was highlighted.

The acceptability of a new combination treatment regimen for lymphatic filariasis (ivermectin, plus DEC and albendazole, or IDA) was assessed as part of a larger community-based safety study in Fiji, Haiti, India, Indonesia and Papua New Guinea. To understand how trial participants and communities felt about the new treatment, a survey was carried out with people who had participated in the safety study receiving either the standard treatment [DEC plus albendazole (DA)] or the new treatment regimen (IDA). Focus group discussions and in-depth interviews were performed in the same communities. Results showed that there was no difference in acceptability between the DA and IDA. Adverse events and presence of filarial infection did not affect acceptability. The most important indicator associated with acceptability was country. All countries accepted the treatment regimens. Fiji had the highest acceptability scores, followed by Papua New Guinea, Indonesia, Haiti and India. Results from the qualitative research showed that study participants appreciated the professionalism of the drug delivery team and the support offered for the management of any adverse events.

The Effect of Helminths on Granulocyte Activation: A Cluster-Randomized Placebo-Controlled Trial in Indonesia

BACKGROUND

Eosinophils are a prominent cell type in the host response to helminths, and some evidence suggests that neutrophils might also play a role. However, little is known about the activation status of these granulocytes during helminth infection.

METHODS

We analyzed the expression of eosinophil and neutrophil activation markers in peripheral blood by flow cytometry and measured serum levels of eosinophil granule proteins in 300 subjects residing in an area endemic for soil-transmitted helminths (STH). The data generated are on samples before and after 1 year of 3-monthly albendazole treatment.

RESULTS

Anthelmintic treatment significantly reduced the prevalence of STH. While eosinophil numbers were significantly higher in STH-infected compared to uninfected subjects and significantly decreased following albendazole treatment, there was no effect exerted by the helminths on either eosinophil nor neutrophil activation. Although at baseline eosinophil granule protein levels were not different between STH-infected and uninfected subjects, treatment significantly reduced the levels of eosinophil-derived neurotoxin (EDN) in those infected at baseline.

CONCLUSIONS

These results show that besides decreasing eosinophil numbers, anthelmintic treatment does not significantly change the activation status of eosinophils, nor of neutrophils, and the only effect seen was a reduction in circulating levels of EDN.

CLINICAL TRIALS REGISTRATION

http://www.isrctn.com/ISRCTN75636394.

Helminth infections drive heterogeneity in human type 2 and regulatory cells

Helminth infections induce strong type 2 and regulatory responses, but the degree of heterogeneity of such cells is not well characterized. Using mass cytometry, we profiled these cells in Europeans and Indonesians not exposed to helminths and in Indonesians residing in rural areas infected with soil-transmitted helminths. To assign immune alteration to helminth infection, the profiling was performed before and 1 year after deworming. Very distinct signatures were found in Europeans and Indonesians, showing expanded frequencies of T helper 2 cells, particularly CD161+ cells and ILC2s in helminth-infected Indonesians, which was confirmed functionally through analysis of cytokine-producing cells. Besides ILC2s and CD4+ T cells, CD8+ T cells and γδ T cells in Indonesians produced type 2 cytokines. Regulatory T cells were also expanded in Indonesians, but only those expressing CTLA-4, and some coexpressed CD38, HLA-DR, ICOS, or CD161. CD11c+ B cells were found to be the main IL-10 producers among B cells in Indonesians, a subset that was almost absent in Europeans. A number of the distinct immune profiles were driven by helminths as the profiles reverted after clearance of helminth infections. Moreover, Indonesians with no helminth infections residing in an urban area showed immune profiles that resembled Europeans rather than rural Indonesians, which excludes a major role for ethnicity. Detailed insight into the human type 2 and regulatory networks could provide opportunities to target these cells for more precise interventions.

Comparison of the Impact of Annual and Semiannual Mass Drug Administration on Lymphatic Filariasis Prevalence in Flores Island, Indonesia

We compared the impact of annual and semiannual mass drug administration (MDA) on the prevalence of Brugia timori and Wuchereria bancrofti in Flores Island. Two villages (Paga, B. timori only; Lewomada, co-endemic) received annual MDA with diethylcarbamazine/albendazole and a larger village (Pruda, co-endemic) received semiannual MDA. Infection parameters (microfilariae [Mf], antibodies to recombinant filarial antigen BmR1 [Brugia Rapid (BR)], and a test for W. bancrofti antigenemia [immunochromatographic test (ICT)]) were assessed before and after treatment. The crude Mf prevalence in Pruda decreased after five semiannual treatments from 14.2% to 1.2%, whereas the Mf prevalence in the other two villages decreased after three annual treatments from 3.9% to 0% and from 5% to 0.3%, respectively. ICT positivity prevalence in Pruda and Lewomada decreased from 22.9% and 6.5% to 7% and 0.8%, respectively, whereas BR antibody prevalence in Pruda, Lewomada, and Paga decreased from 28.9%, 31.7%, and 12.5% to 3.6%, 4.1%, and 1.8%, respectively. Logistic regression analysis indicated that that Mf, BR, and ICT prevalence decreased significantly over time and that for the Mf and ICT outcomes the semiannual treatment had higher odds of positivity. Model-adjusted prevalence estimates revealed that apparent differences in treatment effectiveness were driven by differences in baseline prevalence and that adjusted prevalence declined more rapidly in the semiannual treatment group. We conclude that in this setting, annual MDA was sufficient to reduce Mf prevalence to less than 1% in areas with low to moderate baseline prevalence. Semiannual MDA was useful for rapidly reducing Mf prevalence in an area with higher baseline endemicity.

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

Intestinal 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.

Mass deworming for improving health and cognition of children in endemic helminth areas: A systematic review and individual participant data network meta-analysis

Background

Soil transmitted (or intestinal) helminths and schistosomes affect millions of children worldwide.

Objectives

To use individual participant data network meta-analysis (NMA) to explore the effects of different types and frequency of deworming drugs on anaemia, cognition and growth across potential effect modifiers.

Search Methods

We developed a search strategy with an information scientist to search MEDLINE, CINAHL, LILACS, Embase, the Cochrane Library, Econlit, Internet Documents in Economics Access Service (IDEAS), Public Affairs Information Service (PAIS), Social Services Abstracts, Global Health CABI and CAB Abstracts up to March 27, 2018. We also searched grey literature, websites, contacted authors and screened references of relevant systematic reviews.

Selection Criteria

We included randomised and quasirandomised deworming trials in children for deworming compared to placebo or other interventions with data on baseline infection.

Data Collection and Analysis

We conducted NMA with individual participant data (IPD), using a frequentist approach for random-effects NMA. The covariates were: age, sex, weight, height, haemoglobin and infection intensity. The effect estimate chosen was the mean difference for the continuous outcome of interest.

Results

We received data from 19 randomized controlled trials with 31,945 participants. Overall risk of bias was low. There were no statistically significant subgroup effects across any of the potential effect modifiers. However, analyses showed that there may be greater effects on weight for moderate to heavily infected children (very low certainty evidence).

Authors' Conclusions

This analysis reinforces the case against mass deworming at a population-level, finding little effect on nutritional status or cognition. However, children with heavier intensity infections may benefit more. We urge the global community to adopt calls to make data available in open repositories to facilitate IPD analyses such as this, which aim to assess effects for the most vulnerable individuals.

The Effect of Gut Microbiome Composition on Human Immune Responses: An Exploration of Interference by Helminth Infections

Background: Soil-transmitted helminths have been shown to have the immune regulatory capacity, which they use to enhance their long term survival within their host. As these parasites reside in the gastrointestinal tract, they might modulate the immune system through altering the gut bacterial composition. Although the relationships between helminth infections or the microbiome with the immune system have been studied separately, their combined interactions are largely unknown. In this study we aim to analyze the relationship between bacterial communities with cytokine response in the presence or absence of helminth infections.

Results: For 66 subjects from a randomized placebo-controlled trial, stool and blood samples were available at both baseline and 21 months after starting three-monthly albendazole treatment. The stool samples were used to identify the helminth infection status and fecal microbiota composition, while whole blood samples were cultured to obtain cytokine responses to innate and adaptive stimuli. When subjects were free of helminth infection (helminth-negative), increasing proportions of Bacteroidetes was associated with lower levels of IL-10 response to LPS {estimate [95% confidence interval (CI)] −1.96 (−3.05, −0.87)}. This association was significantly diminished when subjects were helminth-infected (helminth positive) (p-value for the difference between helminth-negative versus helminth-positive was 0.002). Higher diversity was associated with greater IFN-γ responses to PHA in helminth-negative (0.95 (0.15, 1.75); versus helminth-positive [−0.07 (−0.88, 0.73), p-value = 0.056] subjects. Albendazole treatment showed no direct effect in the association between bacterial proportion and cytokine responses, although the Bacteroidetes’ effect on IL-10 responses to LPS tended downward in the albendazole-treated group [−1.74 (−4.08, 0.59)] versus placebo [−0.11 (−0.84, 0.62); p-value = 0.193].

Conclusion: We observed differences in the relationship between gut microbiome composition and immune responses, when comparing individuals infected or uninfected with geohelminths. Although these findings are part of a preliminary exploration, the data support the hypothesis that intestinal helminths may modulate immune responses, in unison with the gut microbiota.

Trial Registration: ISRCTN, ISRCTN83830814. Registered 27 February 2008 — Retrospectively registered, http://www.isrctn.com/ISRCTN83830814.

Dosing pole recommendations for lymphatic filariasis elimination: A height-weight quantile regression modeling approach

BACKGROUND

The World Health Organization (WHO) currently recommends height or age-based dosing as alternatives to weight-based dosing for mass drug administration lymphatic filariasis (LF) elimination programs. The goals of our study were to compare these alternative dosing strategies to weight-based dosing and to develop and evaluate new height-based dosing pole scenarios.

METHODOLOGY/PRINCIPAL FINDINGS

Age, height and weight data were collected from >26,000 individuals in five countries during a cluster randomized LF clinical trial. Weight-based dosing for diethylcarbamazine (DEC; 6 mg/kg) and ivermectin (IVM; 200 ug/kg) with tablet numbers derived from a table of weight intervals was treated as the "gold standard" for this study. Following WHO recommended age-based dosing of DEC and height-based dosing of IVM would have resulted in 32% and 27% of individuals receiving treatment doses below those recommended by weight-based dosing for DEC and IVM, respectively. Underdosing would have been especially common in adult males, who tend to have the highest LF prevalence in many endemic areas. We used a 3-step modeling approach to develop and evaluate new dosing pole cutoffs. First, we analyzed the clinical trial data using quantile regression to predict weight from height. We then used weight predictions to develop new dosing pole cutoff values. Finally, we compared different dosing pole cutoffs and age and height-based WHO dosing recommendations to weight-based dosing. We considered hundreds of scenarios including country- and sex-specific dosing poles. A simple dosing pole with a 6-tablet maximum for both DEC and IVM reduced the underdosing rate by 30% and 21%, respectively, and was nearly as effective as more complex pole combinations for reducing underdosing.

CONCLUSIONS/SIGNIFICANCE

Using a novel modeling approach, we developed a simple dosing pole that would markedly reduce underdosing for DEC and IVM in MDA programs compared to current WHO recommended height or age-based dosing.

The mixed model for the analysis of a repeated-measurement multivariate count data

Clustered overdispersed multivariate count data are challenging to model due to the presence of correlation within and between samples. Typically, the first source of correlation needs to be addressed but its quantification is of less interest. Here, we focus on the correlation between time points. In addition, the effects of covariates on the multivariate counts distribution need to be assessed. To fulfill these requirements, a regression model based on the Dirichlet‐multinomial distribution for association between covariates and the categorical counts is extended by using random effects to deal with the additional clustering. This model is the Dirichlet‐multinomial mixed regression model. Alternatively, a negative binomial regression mixed model can be deployed where the corresponding likelihood is conditioned on the total count. It appears that these two approaches are equivalent when the total count is fixed and independent of the random effects. We consider both subject‐specific and categorical‐specific random effects. However, the latter has a larger computational burden when the number of categories increases. Our work is motivated by microbiome data sets obtained by sequencing of the amplicon of the bacterial 16S rRNA gene. These data have a compositional structure and are typically overdispersed. The microbiome data set is from an epidemiological study carried out in a helminth‐endemic area in Indonesia. The conclusions are as follows: time has no statistically significant effect on microbiome composition, the correlation between subjects is statistically significant, and treatment has a significant effect on the microbiome composition only in infected subjects who remained infected.

The profile of codon 200 β-tubulin gene of<em> Ascaris lumbricoides</em> L. and <em>Trichuris trichiura</em> L. from infected people in Nangapanda Sub-district, East Nusa Tenggara

Background: The mass administration of anthelmintic such as albendazole is one of the strategies for eliminating soil-transmitted helminth (STH) infection. The widespread and long-term use of anthelmintics can cause resistance. The research on animals shows that factor that the single-nucleotide polymorphism (SNP) codon 200 β-tubulin gene of the worms is one of the factors that can cause the decreased efficacy of anthelmintics. This study aimed to determine the bases of codon 200 in A. lumbricoides and T. trichiura, which infect the people in Nangapanda, East Nusa Tenggara.Methods: The worm samples were obtained from the intestinal helminth-infected patients from Nangapanda Sub-district. The DNA from the worm tissues were isolated, amplificated by polymerase chain reaction (PCR), and sequenced. The sequencing results were aligned to the reference sequence to obtain the codon bases in the 200 β-tubulin gene.Results: TTC constitute the codon bases in the 200 β-tubulin gene found in two A. lumbricoides and one T. trichiura.Conclusion: The SNP codon 200 β-tubulin gene was absent in A. lumbricoides or T. trichiura worms that were examined in this study.

Prevalence of Atopy following Mass Drug Administration with Albendazole: A Study in School Children on Flores Island, Indonesia

BACKGROUND

In many rural areas of tropical countries such as Indonesia, the prevalence of soil-transmitted helminths (STH) infections remains high. At the same time, the burden of allergic disorders in such rural areas is reported to be low and inversely associated with helminth infections. To reduce the morbidity and transmission of helminth infections, the world health organization recommends preventive treatment of school children by providing mass drug administration (MDA) with albendazole. Here, we had an opportunity to evaluate the prevalence of skin reactivity to allergens before and after albendazole treatment to get an indication of the possible impact of MDA on allergic sensitization.

METHODS

A study was conducted among 150 school children living in an area endemic for STH infections. Before and 1 year after anthelminthic treatment with albendazole, stool samples were examined for the presence of STH eggs, skin prick tests (SPT) for cockroach and house dust mites were performed, blood eosinophilia was assessed, and total immunoglobulin E (IgE) and C-reactive protein (CRP) were measured in plasma.

RESULTS

Anthelminthic treatment significantly reduced the prevalence of STH from 19.6 before treatment to 6% after treatment (p < 0.001). Levels of total IgE (estimate: 0.30; 95% CI 0.22-0.42, p < 0.0001), CRP (estimate: 0.60; 95% CI 0.42-0.86, p = 0.006), and eosinophil counts (estimate: 0.70; 95% CI 0.61-0.80, p < 0.001) decreased significantly. The prevalence of SPT positivity increased from 18.7 to 32.7%. Multivariate analysis adjusted for confounding factors showed an increased risk of being SPT positive to any allergen (OR 3.04; 95% CI 1.338-6.919, p = 0.008).

CONCLUSIONS

This study indicates that 1 year of MDA with albendazole was associated with a reduced prevalence of STH infections. This study shows that the prevalence of allergic sensitization increases after 1 year of albendazole treatment. Placebo-controlled and larger studies are needed to further substantiate a role of deworming treatment in an increased risk of allergic sensitization.

Dynamic changes in human-gut microbiome in relation to a placebo-controlled anthelminthic trial in Indonesia

Background

Microbiome studies suggest the presence of an interaction between the human gut microbiome and soil-transmitted helminth. Upon deworming, a complex interaction between the anthelminthic drug, helminths and microbiome composition might occur. To dissect this, we analyse the changes that take place in the gut bacteria profiles in samples from a double blind placebo controlled trial conducted in an area endemic for soil transmitted helminths in Indonesia.

Methods

Either placebo or albendazole were given every three months for a period of one and a half years. Helminth infection was assessed before and at 3 months after the last treatment round. In 150 subjects, the bacteria were profiled using the 454 pyrosequencing. Statistical analysis was performed cross-sectionally at pre-treatment to assess the effect of infection, and at post-treatment to determine the effect of infection and treatment on microbiome composition using the Dirichlet-multinomial regression model.

Results

At a phylum level, at pre-treatment, no difference was seen in microbiome composition in terms of relative abundance between helminth-infected and uninfected subjects and at post-treatment, no differences were found in microbiome composition between albendazole and placebo group. However, in subjects who remained infected, there was a significant difference in the microbiome composition of those who had received albendazole and placebo. This difference was largely attributed to alteration of Bacteroidetes. Albendazole was more effective against Ascaris lumbricoides and hookworms but not against Trichuris trichiura, thus in those who remained infected after receiving albendazole, the helminth composition was dominated by T. trichiura.

Discussion

We found that overall, albendazole does not affect the microbiome composition. However, there is an interaction between treatment and helminths as in subjects who received albendazole and remained infected there was a significant alteration in Bacteroidetes. This helminth-albendazole interaction needs to be studied further to fully grasp the complexity of the effect of deworming on the microbiome.

Trial registration

ISRCTN Registy, ISRCTN83830814.

Studying the relationship between soil-transmitted helminthiasis and gut microbiota is becoming more important as both have been implicated in modulating immune system in various inflammatory diseases. However, findings of previous studies of the effect of helminth on the microbiome are inconsistent. In this study, an optimal design, a placebo-controlled anthelminthic trial was conducted to dissect the effect of helminths and anthelminthic treatment on gut microbial profile. In addition, a novel statistical model was used to analyse the association by taking into account the correlation structures between bacterial categories by applying multivariate analysis whereby the multiple testing correction is not needed.

Effect of Anthelmintic Treatment on Insulin Resistance: A Cluster-Randomized, Placebo-Controlled Trial in Indonesia

Background

Emerging evidence suggests that helminth infections are associated with lower insulin resistance (IR). Current deworming programs might remove this helminth-associated protective effect. Therefore, we evaluated the anthelmintic treatment effect on changes in IR.

Methods

We conducted a double-blind, household-cluster-randomized, placebo-controlled clinical trial on Flores island, Indonesia, an area endemic for soil-transmitted helminths (STHs). All subjects received 4 rounds of albendazole or matching placebo with 3-month intervals, for 3 consecutive days. The primary outcome was the change in homeostatic model assessment of IR in those aged >16 years. An intention-to-treat analysis was performed involving all subjects and ad hoc in the helminth-infected subjects.

Results

We examined 797 (in 329 households) and 872 (in 353 households) subjects, who were assigned randomly into the albendazole and placebo arms, respectively. Albendazole was associated with a significant reduction in STH prevalence, total immunoglobulin E (IgE), and eosinophil count. Whereas albendazole had no effect on IR (estimated treatment effect, 0.006 [95% confidence interval, -.010 to .021]; P = .48) at the community level, it was associated with a significant increase in IR (estimated treatment effect, 0.031 [95% confidence interval, .004 to .059]; P = .04) (P value for interaction = .01) among helminth-infected subjects as detected by microscopy. Pathway analysis suggested that this might in part be due to an increased body mass index or a reduced eosinophil count.

Conclusions

Anthelmintic treatment reduces STH prevalence, total IgE, and eosinophil count but has no effect on IR at the community level. In helminth-infected subjects, treatment significantly increases IR, highlighting the need for metabolic health monitoring with ongoing deworming programs.

Clinical Trials Registration

ISRCTN 75636394.

Differential human gut microbiome assemblages during soil-transmitted helminth infections in Indonesia and Liberia

BACKGROUND

The human intestine and its microbiota is the most common infection site for soil-transmitted helminths (STHs), which affect the well-being of ~ 1.5 billion people worldwide. The complex cross-kingdom interactions are not well understood.

RESULTS

A cross-sectional analysis identified conserved microbial signatures positively or negatively associated with STH infections across Liberia and Indonesia, and longitudinal samples analysis from a double-blind randomized trial showed that the gut microbiota responds to deworming but does not transition closer to the uninfected state. The microbiomes of individuals able to self-clear the infection had more alike microbiome assemblages compared to individuals who remained infected. One bacterial taxon (Lachnospiracae) was negatively associated with infection in both countries, and 12 bacterial taxa were significantly associated with STH infection in both countries, including Olsenella (associated with reduced gut inflammation), which also significantly reduced in abundance following clearance of infection. Microbial community gene abundances were also affected by deworming. Functional categories identified as associated with STH infection included arachidonic acid metabolism; arachidonic acid is the precursor for pro-inflammatory leukotrienes that threaten helminth survival, and our findings suggest that some modulation of arachidonic acid activity in the STH-infected gut may occur through the increase of arachidonic acid metabolizing bacteria.

CONCLUSIONS

For the first time, we identify specific members of the gut microbiome that discriminate between moderately/heavily STH-infected and non-infected states across very diverse geographical regions using two different statistical methods. We also identify microbiome-encoded biological functions associated with the STH infections, which are associated potentially with STH survival strategies, and changes in the host environment. These results provide a novel insight of the cross-kingdom interactions in the human gut ecosystem by unlocking the microbiome assemblages at taxonomic, genetic, and functional levels so that advances towards key mechanistic studies can be made.

Evaluation of the Diagnostic Performance of Onchocerca volvulus Linear Epitopes in a Peptide Enzyme-Linked Immunosorbent Assay

Diagnostic tools for the detection of infection with Onchocerca volvulus are presently limited to microfilaria detection in skin biopsies and serological assessment using the Ov16 immunoglobulin G4 (IgG4) rapid test, both of which have limited sensitivity. We have investigated the diagnostic performance of a peptide enzyme-linked immunosorbent assay (ELISA) based on immunodominant linear epitopes previously discovered. Peptides that were used in these assays were designated O. volvulus motif peptides (OvMP): OvMP-1 (VSV-EPVTTQET-VSV), OvMP-2 (VSV-KDGEDK-VSV), OvMP-3 (VSV-QTSNLD-VSV), and the combination of the latter two, OvMP-23 (VSV-KDGEDK-VSV-QTSNLD-VSV). Sensitivity (O. volvulus infection), specificity (non-helminth infections), and cross-reactivity (helminth infections) were determined using several panels of clinical plasma isolates. OvMP-1 was found to be very sensitive (100%) and specific (98.7%), but showed substantial cross-reactivity with other helminths. Of the other peptides, OvMP-23 was the most promising peptide with a sensitivity of 92.7%, a specificity of 100%, and a cross-reactivity of 6%. It was also demonstrated that these peptides were immunoreactive to IgG but not IgG4, and there is no correlation with the Ov16 IgG4 status, making them promising candidates to complement this already available test. Combination of the Ov16 IgG4 rapid test and OvMP-23 peptide ELISA led to a sensitivity of 97.3% for the detection of O. volvulus infection, without compromising specificity and with minimal impact on cross-reactivity. The available results open the opportunity for a “clinical utility use case” discussion for improved O. volvulus epidemiological mapping.

The effect of three-monthly albendazole treatment on Th2 responses: Differential effects on IgE and IL-5

Helminth parasites induce a strong Th2 response, characterized by high levels of IgE and elevated signature cytokines such as IL-5. As many global deworming programmes are underway, there is concern that this might lead to emergence of Th1-mediated pathologies when the counterbalancing helminth-induced Th2 response is absent. Therefore, we assessed the effect of deworming on Th2-mediated responses in a household-clustered randomized controlled trial in Indonesia. Total plasma IgE and whole-blood IL-5 responses to mitogen phytohaemagglutinin (PHA) were measured in 1494 and 682 subjects, respectively, at baseline, 9 and 21 months after three-monthly single-dose treatment with albendazole or placebo. Anthelmintic treatment did not result in complete removal of helminth infections in the community. However, treatment significantly decreased IgE levels in albendazole- compared to placebo-treated subjects. IL-5 responses to PHA were not significantly affected by anthelmintic treatment and tended to increase in albendazole-treated subjects, indicating that intensive treatment of helminth parasites has different outcomes on B-cell (IgE levels) and T-cell (IL-5) responses. The data shows that 2 years of deworming can have differential effects on responses typified as Th2-mediated, which needs to be taken into account when examining the impact of helminths on noncommunicable diseases.

Effect of a short course of iron polymaltose on acquisition of malarial parasitaemia in anaemic Indonesian schoolchildren: a randomized trial

Background

Concern exists about the safety of iron supplementation given to individuals in malarious areas. The possible unfavourable impact of iron supplementation on malaria might be less when slow-release iron compounds are used instead of ferrous salts, because no toxic non-transferrin bound iron is formed. The aim of this study was to determine the effect of iron supplementation using the slow-release iron compound iron polymaltose (IPM) on the acquisition of malarial parasitaemia.

Methods

A randomized, placebo-controlled trial was performed in schoolchildren aged 5–18 years with mild or moderate anaemia on the Indonesian island Flores. Microscopic malaria-negative children were randomized to receive 8 weeks of IPM (6 mg elemental iron/kg/day) or placebo . The primary outcomes were the occurrence of microscopically detectable malarial parasitaemia at week 4, 8, 12 and 16 after start of treatment and the proportion of participants with real-time (RT) PCR positive malarial parasitaemia at week 16.

Results

294 Children were assigned to the IPM group and 297 to the placebo group. Whereas IPM supplementation failed to increased haemoglobin or ferritin concentrations, the IPM group had a significantly higher rate of occurrence of microscopically detectable parasitaemia [hazard ratio 2.2, 95% C.I. 1.2–4.0; P = 0.01]. This higher rate was confined to iron-replete children. At the end of the study, 89% of the children in the IPM group had remained free from microscopically detectable parasitaemia vs 95% of children in the placebo group. The proportion of plasmodial RT-PCR positive children was similar in both groups at week 16 (IPM group 16.6% vs placebo group 14.3%; P = 0.47). When analysis was restricted to iron-replete children (serum ferritin ≥30 µg/l), there was a trend for a higher proportion being RT-PCR positive at week 16 in the IPM group compared with the placebo group (20 vs 13.3%; P = 0.07). Erythrocyte microcytosis was an independent risk factor for microscopically detectable malarial parasitaemia.

Conclusions

A short course of IPM should be used cautiously in anaemic children in malaria endemic areas, as it has limited efficacy in treating iron deficiency, while it increases the rate of microscopic malarial parasitaemia in those with replete iron stores.

Trial registration ISRCTN 83091970. Registered 16 May 2012 (retrospectively registered)

Electronic supplementary material

The online version of this article (doi:10.1186/s12936-017-1691-5) contains supplementary material, which is available to authorized users.

Albendazole therapy reduces serum zinc in elementary school children with Ascaris lumbricoides infections

Background<br />Soil-transmitted helminth (STH) infection can cause malnutrition and vice versa, and decrease serum zinc concentrations. No previous studies were found on the effect of STH treatment on serum zinc concentrations in elementary school children. The objective of this study was to evalaute the effect of STH treatment on serum zinc concentration in elementary school children in Jakarta. <br /><br />Methods<br />A pre-experimental study (one group pre and post) was conducted on 3rd - 5th grade students in one elementary school in North Jakarta. FLOTAC examination was used to determine infection status and STH intensity, while serum zinc concentrations were measured by atomic absorption spectrometry. All children were given albendazole 400 mg for three consecutive days. Stool and blood samples were collected before and three weeks after treatment with albendazole. A paired t test was used to analyze the data. <br /><br />Results<br />The STH prevalence was 63.4%; these were mainly Ascaris lumbricoides and Trichuris trichiura infections. Before treatment, children infected with A.lumbricoides and T.trichiura had significantly higher serum zinc concentrations (p=0.028; p=0.014). After treatment, children with A.lumbricoides had significantly lower serum zinc concentrations (p=0.039), while children with T.trichiura had slightly lower serum zinc concentrations (p=0.659) than before treatment. <br /><br />Conclusions<br />Albendazole treatment produces lower serum zinc concentration in elementary school children with A.lumbricoides infections. A profound understanding of the interaction between helminth infections and zinc may assist in guiding integrated and sustainable intervention strategies among affected children throughout the world.

Maternal and child cytokine relationship in early life is not altered by cytokine gene polymorphisms

The development of immune responses is influenced by the interaction between environmental and genetic factors. Our previous study showed a close association between maternal and young infant's cytokine responses. The question is how this association evolves over time and the contribution of genetic polymorphisms to this association. Five cytokines in mitogen-stimulated whole blood culture were measured from pregnant mothers and their children aged 2, 5, 12, 24 and 48 months. Cytokine gene polymorphisms were determined in both mothers and children. High production of maternal interleukin (IL)-10, tumour necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) was significantly associated with higher levels of the corresponding cytokines in their children at 2 months (T2), but the association decreased over time. Maternal single-nucleotide polymorphism (SNP) in IFN-γ gene, rs3181032, was found to be associated with child's IFN-γ levels at T2 only, whereas maternal IL-10 rs4579758 and child's TNF-α rs13215091 were associated with child's corresponding cytokines at later ages but not at T2. In the final models including the gene polymorphisms, maternal cytokines were still the strongest determinant of child cytokines. Maternal cytokine during pregnancy, which could be a proxy for child's environmental factors, showed its highest impact at early age, with no or little influence from genetic factors.

Community Rates of IgG4 Antibodies to Ascaris Haemoglobin Reflect Changes in Community Egg Loads Following Mass Drug Administration

Background

Conventional diagnostic methods for human ascariasis are based on the detection of Ascaris lumbricoides eggs in stool samples. However, studies of ascariasis in pigs have shown that the prevalence and the number of eggs detected in the stool do not correlate well with exposure of the herd to the parasite. On the other hand, an ELISA test measuring antibodies to Ascaris suum haemoglobin (AsHb) has been shown to be useful for estimating transmission intensity on pig farms. In this study, we further characterized the AsHb antigen and screened samples from a population-based study conducted in an area that is endemic for Ascaris lumbricoides in Indonesia to assess changes in AsHb antibody rates and levels in humans following mass drug administration (MDA).

Methodology/Principal findings

We developed and evaluated an ELISA to detect human IgG4 antibodies to AsHb. We tested 1066 plasma samples collected at different times from 599 subjects who lived in a village in rural Indonesia that was highly endemic for ascariasis. The community received 6 rounds of MDA for lymphatic filariasis with albendazole plus diethylcarbamazine between 2002 and 2007. While the AsHb antibody assay was not sensitive for detecting all individuals with Ascaris eggs in their stools, the percentage of seropositive individuals decreased rapidly following MDA. Reductions in antibody rates reflected decreased mean egg output per person both at the community level and in different age groups. Two years after the last round of MDA the community egg output and antibody prevalence rate were reduced by 81.6% and 78.9% respectively compared to baseline levels.

Conclusion/Significance

IgG4 antibody levels to AsHb appear to reflect recent exposure to Ascaris. The antibody prevalence rate may be a useful indicator for Ascaris transmission intensity in communities that can be used to assess the impact of control measures on the force of transmission.

Ascariasis is a neglected tropical disease caused by the intestinal nematode Ascaris lumbricoides that affects hundreds of millions of people in the developing world. Current methods for diagnosis of this infection are based on detecting eggs in the stool that are excreted by adult Ascaris worms. However, these methods have limited sensitivity for recent infections, and they do not detect infections with immature parasite stages that do not always result in the establishment of adult worms in the human intestine. We have previously shown that an assay for antibodies to Ascaris hemoglobin in pig serum is useful for assessing transmission of Ascaris infections on pig farms. In this study, we developed and evaluated a similar antibody assay that is based on the detection of human IgG4 antibodies to Ascaris haemoglobin (AsHb). Community antibody rates decreased rapidly following mass drug administration of the anthelmintic drug albendazole, and this decrease reflected reduced Ascaris egg excretion at the community level. This antibody test may be a useful tool for assessing the impact of control measures on the transmission of new Ascaris infections in endemic populations.

Albendazole increases serum retinol concentration in primary schoolchildren with low serum retinol

Background<br />Soil-transmitted helminth (STH) infection is still a health problem in Indonesia. Vitamin A deficiency (VAD) is often found together with STH. The effect of the deworming program on the vitamin A status of primary school children is unknown. The objective of this study was to evaluate the effect of albendazole on serum retinol concentrations in primary school children.<br /><br />Methods<br />An experimental study of pre-post test design without control was carried out on 118 children from grades 3-5 at one primary school in North Jakarta, from July to September 2014. Flotac examination was used to determine STH infections and high performance liquid chromatography was performed to measure serum retinol concentration. Stool and blood samples were taken twice: before and three weeks after treatment with albendazole 400 mg single dose for three consecutive days given to all children either infected or uninfected. Paired t-test was used to analyze the data. <br /><br />Results<br />Of the 118 children, the prevalence of STH was 71.2%. The prevalence of low retinol serum (&lt;1.05 mmol/L) was 17 (17.2%) and of mild VAD was 2 (2.0%). Albendazole given in 3 consecutive days could not increase serum retinol concentrations (p=0.055). Serum retinol concentration significantly increased after albendazole treatment in children with low retinol serum at baseline (p=0.001). <br /><br />Conclusions<br />In children with low serum retinol concentration, treatment with albendazole increased retinol concentration. Integrated deworming and vitamin A supplementation strategies should be evaluated in this population.

Infection with Soil-Transmitted Helminths Is Associated with Increased Insulin Sensitivity

Objective

Given that helminth infections have been shown to improve insulin sensitivity in animal studies, which may be explained by beneficial effects on energy balance or by a shift in the immune system to an anti-inflammatory profile, we investigated whether soil-transmitted helminth (STH)-infected subjects are more insulin sensitive than STH-uninfected subjects.

Design

We performed a cross-sectional study on Flores island, Indonesia, an area with high prevalence of STH infections.

Methods

From 646 adults, stool samples were screened for Trichuris trichiura by microscopy and for Ascaris lumbricoides, Necator americanus, Ancylostoma duodenale, and Strongyloides stercoralis by qPCR. No other helminth was found. We collected data on body mass index (BMI, kg/m²), waist-to-hip ratio (WHR), fasting blood glucose (FBG, mmol/L), insulin (pmol/L), high sensitive C-reactive protein (ng/ml) and Immunoglobulin E (IU/ml). The homeostatic model assessment for insulin resistance (HOMAIR) was calculated and regression models were used to assess the association between STH infection status and insulin resistance.

Results

424 (66%) participants had at least one STH infection. STH infected participants had lower BMI (23.2 vs 22.5 kg/m², p value = 0.03) and lower HOMAIR (0.97 vs 0.81, p value = 0.05). In an age-, sex- and BMI-adjusted model a significant association was seen between the number of infections and HOMAIR: for every additional infection with STH species, the HOMAIR decreased by 0.10 (p for linear trend 0.01). This effect was mainly accounted for by a decrease in insulin of 4.9 pmol/L for every infection (p for trend = 0.07).

Conclusion

STH infections are associated with a modest improvement of insulin sensitivity, which is not accounted for by STH effects on BMI alone.

Helminth infections and type 2 diabetes: a cluster-randomized placebo controlled SUGARSPIN trial in Nangapanda, Flores, Indonesia

Background

Insulin resistance is a strong predictor of the development of type 2 diabetes mellitus. Chronic helminth infections might protect against insulin resistance via a caloric restriction state and indirectly via T-helper-2 polarization of the immune system. Therefore the elimination of helminths might remove this beneficial effect on insulin resistance.

Methods/Design

To determine whether soil-transmitted helminth infections are associated with a better whole-body insulin sensitivity and whether this protection is reversible by anthelmintic treatment, a household-based cluster-randomized, double blind, placebo-controlled trial was conducted in the area of Nangapanda on Flores Island, Indonesia, an area endemic for soil-transmitted helminth infections. The trial incorporates three monthly treatment with albendazole or matching placebo for one year, whereby each treatment round consists of three consecutive days of supervised drug intake. The presence of soil-transmitted helminths will be evaluated in faeces using microscopy and/or PCR. The primary outcome of the study will be changes in insulin resistance as assessed by HOMA-IR, while the secondary outcomes will be changes in body mass index, waist circumference, fasting blood glucose, 2 h-glucose levels after oral glucose tolerance test, HbA1c, serum lipid levels, immunological parameters, and efficacy of anthelmintic treatment.

Discussion

The study will provide data on the effect of helminth infections on insulin resistance. It will assess the relationship between helminth infection status and immune responses as well as metabolic parameters, allowing the establishment of a link between inflammation and whole-body metabolic homeostasis. In addition, it will give information on anthelmintic treatment efficacy and effectiveness.

Trial registration

This study has been approved by the ethical committee of Faculty of Medicine Universitas Indonesia (ref: 549/H2.F1/ETIK/2013), and has been filed by the ethics committee of Leiden University Medical Center, clinical trial number: ISRCTN75636394. The study is reported in accordance with the CONSORT guidelines for cluster-randomised trials.

Impact of six rounds of mass drug administration on Brugian filariasis and soil-transmitted helminth infections in eastern Indonesia

BACKGROUND

The lymphatic filarial parasite Brugia timori occurs only in eastern Indonesia where it causes high morbidity. The absence of an animal reservoir, the inefficient transmission by Anopheles mosquitoes and the high sensitivity to DEC/albendazole treatment make this species a prime candidate for elimination by mass drug administration (MDA).

METHODOLOGY/PRINCIPAL FINDINGS

We evaluated the effect of MDA using DEC and albendazole on B. timori and soil transmitted helminths (STH) in a cross-sectional study of a sentinel village on Alor Island annually over a period of 10 years. Pre-MDA the microfilaria (MF) prevalence was 26% and 80% of the residents had filaria-specific IgG4 antibodies. In 2010, 34 months after the 6(th) round of MDA, MF and antibody rates were only 0.17% and 6.4%, respectively. The MDA campaign had also a beneficial effect on STH. Baseline prevalence rates for Ascaris, hookworm and Trichuris were 34%, 28%, and 11%, respectively; these rates were reduced to 27%, 4%, and 2% one year after the 5(th) round of MDA. Unfortunately, STH rates rebounded 34 months after cessation of MDA and approached pre-MDA rates. However, the intensity of STH infection in 2009 was still reduced, and no heavy infections were detected.

CONCLUSIONS/SIGNIFICANCE

MDA with DEC/albendazole has had a major impact on B. timori MF and IgG4 antibody rates, providing a proof of principle that elimination is feasible. We also documented the value of annual DEC/albendazole as a mass de-worming intervention and the importance of continuing some form of STH control after cessation of MDA for filariasis.

Detection of filaria-specific IgG4antibodies and filarial DNA, for the screening of blood spots forBrugia timori

The establishment of simple, sensitive and specific tools for the diagnosis of brugian lymphatic filariasis is a prerequisite for a successful intervention to control the disease. In the simple and rapid Brugia Rapid (BR) test, an immunochromatographic dipstick is used to detect IgG(4) antibodies that are reactive with a recombinant Brugia malayi antigen. When sera from 109 individuals with Brugia microfilaraemias (12 with B. malayi and 97 with B. timori) were investigated using the BR test, all were found positive. In contrast, all of the 150 sera from individuals with Onchocerca volvulus or Mansonella infections investigated were found negative in BR tests. Some unwelcome cross-reactions were observed, however, with sera from individuals infected with Wuchereria bancrofti (three of 12 test-positive) and Dirofilaria (one of nine test-positive). In an attempt to facilitate sample collection and detect any cross-reactions, the BR dipstick was used to screen blood spots, that had been allowed to dry on filter paper, for B. timori microfilariae, before the dipstick-positive samples were tested with a PCR-based assay. Of the 66 individuals so tested, 37 (56%) were found positive by the BR test used on dry blood spots and eight (22%) by the filtration of fresh blood samples. Only nine of the 37 dipstick-positive samples were found PCR-positive. The combined use of BR tests and PCR-based assays, for testing blood spots in areas where brugian filariasis is endemic, appears to be a promising method not only for post-treatment monitoring but also for the certification activities planned within the framework of the Global Programme to Eliminate Lymphatic Filariasis.

Risk Factors Associated with the Development of Atopic Sensitization in Indonesia

Background

The prevalence of allergic diseases has increased not only in high income but also in low-to-middle income countries. However, risk factors for their development are still not well established, particularly in the latter.

Objective

To assess prevalence and identify risk factors for sensitization to two major inhalant allergens among children from semi-urban and rural areas in Indonesia.

Method

A cross-sectional survey was performed among 1,674 school children aged 5–15 years old. Information on potential risk factors and reported allergic symptoms were obtained by questionnaire. Helminth infections were assessed. Skin prick tests (SPT) were performed, total IgE as well as allergen-specific IgE for house dust mite (HDM) and cockroach were measured.

Result

The prevalence of allergic skin sensitization to both aeroallergens was significantly higher in the semi-urban than in the rural area. However, serum IgE against HDM and cockroach as well as total IgE were significantly lower in semi-urban than in rural children. In the semi-urban area, there was a significant positive association between SPT to HDM and higher paternal education but a negative one with hookworm infection. The risk factors linked to cockroach sensitization were different: being of a farmer offspring and lacking access to piped water were associated with an increased risk for a positive SPT to cockroach. No significant associations between measured risk factors and having a positive SPT were found in the rural area.

Conclusion

Sensitization to HDM and cockroach is common in Indonesia, more often translating into a positive SPT in the semi-urban than in the rural setting. Whereas high paternal education and low hookworm infection were associated with increased risk of SPT to HDM, we were surprised to find parameters of lower SES were identified as risk factor for cockroach SPT.

Epidemiology of Plasmodium infections in Flores Island, Indonesia using real-time PCR

Background

DNA-based diagnostic methods have been shown to be highly sensitive and specific for the detection of malaria. An 18S-rRNA-based, real-time polymerase chain reaction (PCR) was used to determine the prevalence and intensity of Plasmodium infections on Flores Island, Indonesia.

Methods

Microscopy and real-time multiplex PCR for the detection of Plasmodium species was performed on blood samples collected in a population-based study in Nangapanda Flores Island, Indonesia.

Results

A total 1,509 blood samples were analysed. Real-time PCR revealed prevalence for Plasmodium falciparum, Plasmodium vivax, and Plasmodium malariae to be 14.5%, 13.2%, and 1.9% respectively. Sub-microscopic parasitaemia were found in more than 80% of all positive cases. The prevalence of P. falciparum and P. vivax was significantly higher in subjects younger than 20 years (p ≤ 0.01). In the present study, among non-symptomatic healthy individuals, anaemia was strongly correlated with the prevalence and load of P. falciparum infections (p ≤ 0.01; p = 0.02) and with the load of P. vivax infections (p = 0.01) as detected with real-time PCR. Subjects with AB blood group tend to have a higher risk of being infected with P. falciparum and P. vivax when compared to other blood groups.

Conclusion

The present study has shown that real-time PCR provides more insight in the epidemiology of Plasmodium infections and can be used as a monitoring tool in the battle against malaria. The unsurpassed sensitivity of real-time PCR reveals that sub microscopic infections are common in this area, which are likely to play an important role in transmission and control.

Trial registration

Trials number ISRCTN83830814.

The development of TH2 responses from infancy to 4 years of age and atopic sensitization in areas endemic for helminth infections

Background

Helminth infections and allergies are associated with TH₂ responses. Whereas the development of TH₂ responses and allergic disorders in pediatric populations has been examined in affluent countries, no or little data exist from low income regions of the world.

The aim of this study is to examine factors influencing the development of TH₂ responses of children born in areas endemic for helminth infections and to relate these factors to atopic sensitization at 4 years of age.

Methods

Data were collected from pregnant mothers on helminth infections, education and socioeconomic status (SES). Total IgE, IL-5 in response to mitogen, and helminth antigens were measured in children at 2, 5, 12, 24 and 48 months of age. Skin prick testing (SPT) and allergen-specific IgE were determined at 4 years of age.

Results

Strong TH₂ responses were seen at 5 months of age and increased with time. Although maternal filarial infection was associated with helminth-antigen specific TH₂ responses, it was low maternal education or SES but not helminth infection, which was associated with the development of high total IgE and PHA-induced IL-5. At 4 years of age when allergen reactivity was assessed by SPT, the high general TH₂ responses did not translate into higher prevalence of SPT. The risk factor for SPT reactivity was low maternal education which decreased the risk of SPT positivity to allergens (adjusted OR, 0.32; 95% CI, 0.12 – 0.87) independently of maternal filarial infection which tended to reduce the child’s risk for being SPT positive (adjusted OR, 0.35; 95% CI, 0.07 – 1.70).

Conclusions

In areas endemic for helminths, potent TH₂ responses were seen early in life, but did not translate into a higher SPT reactivity to allergens. Therefore, in many parts of the world TH₂ responses in general and IgE in particular cannot be used for diagnosis of allergic diseases.

Asymptomatic plasmodial infection is associated with increased tumor necrosis factor receptor II-expressing regulatory T cells and suppressed type 2 immune responses

BACKGROUND

In malaria-endemic areas, a proportion of individuals becomes chronic carriers of parasites with few or no clinical signs. There is little information on cellular immune responses in asymptomatic parasite carriers.

METHODS

In 80 schoolchildren residing in a malaria-endemic area of Flores Island, Indonesia, T-helper subsets, regulatory T-cell (Treg) frequencies, tumor necrosis factor receptor type II (TNFRII) expression on Tregs, and cytokine responses induced by Plasmodium falciparum-infected red blood cells (RBCs) were measured, and values for asymptomatic infected subjects were compared to those for uninfected controls. To ascertain that alterations found were due to the presence of malaria parasites, the immune responses were analyzed in 16 children before and 1 month after antimalarial treatment.

RESULTS

TNFRII expression, a marker of activation on Tregs, was higher during infection but decreased upon treatment. GATA3-positive cells and the level of interleukin 13 secretion in response to P. falciparum-infected RBCs appeared to be suppressed by plasmodial infection, as both increased after antimalarial treatment. TNFRII expression on Tregs correlated positively with TNF in response to P. falciparum-infected RBCs, but this association disappeared following treatment.

CONCLUSIONS

Malaria parasites associated with asymptomatic infections seem to result in increased TNFRII expression on Tregs, as well as suppressed Th2 cytokine responses, features that might be important for survival of the parasites in asymptomatic carriers.

Relationship between carotid intima media thickness and helminth infections on Flores Island, Indonesia

Objective

To examine the association between helminth infections and atherosclerosis.

Background

Chronic helminth infection, which can lead to poor nutritional status and anti-inflammatory response, might protect against the development of atherosclerosis.

Methods

A cross-sectional study was performed in Flores, Indonesia, an area highly endemic for soil-transmitted helminths (STH). Stool samples from 675 participants aged 18–80 years were collected and screened for Trichuris trichiura by microscopy and for Ascaris lumbricoides, Necator americanus, Ancylostoma duodenale, and Strongyloides stercoralis by qPCR. We collected data on body mass index (BMI), waist to hip ratio (WHR), blood pressure, fasting blood glucose (FBG), lipid, high sensitive C-reactive protein (hs-CRP), total immunoglobulin-E (TIgE) and Escherichia coli lipopolysaccharide stimulated cytokines (tumor necrosis factor and interleukin-10). In a subset of 301 elderly adults (≥40 years of age) carotid intima media thickness (cIMT) was measured.

Results

Participants with any STH infection had lower BMI (kg/m2) (mean difference −0.66, 95%CI [−1.26, −0.06]), WHR (−0.01, [−0.02, −0.00]), total cholesterol (mmol/L) (−0.22, [−0.43, −0.01]) and LDL-cholesterol (mmol/L) (−0.20, [−0.39, −0.00]) than uninfected participants. After additional adjustment for BMI the association between helminth infection and total cholesterol (mean difference −0.17, 95%CI [−0.37, 0.03]) as well as LDL-cholesterol (−0.15, [−0.33, 0.04]) was less pronounced. BMI, WHR, and total cholesterol were negatively associated with number species of helminth co-infections. Participants with high TIgE, an indicator of exposure to helminths, had lower FBG, TC, and HDL. The association between TIgE and TC and HDL remained significant after adjustment with BMI. No clear association was found between STH infection or TIgE and mean cIMT.

Conclusions

This cross-sectional study presents evidence that helminth infections were negatively associated with risk factors for cardiovascular disease, an association at least partially mediated by an effect on BMI. The significance of this finding needs to be determined.

Helminth infection in populations undergoing epidemiological transition: a friend or foe?

Helminth infections are highly prevalent in developing countries, especially in rural areas. With gradual development, there is a transition from living conditions that are dominated by infection, poor sanitation, manual labor, and traditional diet to a situation where burden of infections is reduced, infrastructure is improved, sedentary lifestyle dominates, and processed food forms a large proportion of the calorie intake. The combinations of some of the changes in lifestyle and environment are expected to result in alteration of the landscape of diseases, which will become dominated by non-communicable disorders. Here we review how the major helminth infections affect a large proportion of the population in the developing world and discuss their impact on the immune system and the consequences of this for other infections which are co-endemic in the same areas. Furthermore, we address the issue of decreasing helminth infections in many parts of the world within the context of increasing inflammatory, metabolic, and cardiovascular diseases.

A longitudinal study of allergy and intestinal helminth infections in semi urban and rural areas of Flores, Indonesia (ImmunoSPIN Study)

Background

The prevalence of asthma and atopic disease has been reported to be low in low income countries, however helminth infections are likely to be high among these communities. The question of whether helminth infections play a role in allergic diseases can best be addressed by intervention studies. None of the studies so far have been based on a large scale placebo-controlled trial.

Method/Design

This study was designed to assess how intestinal helminth infections can influence the immune response and atopic and allergic disorders in children in Indonesia. The relations between allergic outcomes and infection and lifestyle factors will be addressed. This study was set up among school-age children in semi urban and rural areas, located in Ende District of Flores Island, Indonesia. A randomized placebo-controlled anthelmintic treatment trial to elucidate the impact of helminth infections on the prevalence of skin prick test (SPT) reactivity and symptoms of allergic diseases will be performed. The children living in these semi-urban and rural areas will be assessed for SPT to allergens before and after 1 and 2 years of treatment as the primary outcome of the study; the secondary outcome is symptoms (asthma and atopic dermatitis); while the tertiary outcome is immune responses (both antibody levels to allergens and cellular immune responses).

Discussion

The study will provide information on the influence of helminth infections and anthelmintic treatment on immune response, atopy and allergic disorders.

Trial registration

Current Controlled Trials ISRCTN: ISRCTN83830814

A longitudinal study of BCG vaccination in early childhood: the development of innate and adaptive immune responses

BCG vaccine drives a strong T helper 1 cellular immunity which is essential for the protection against mycobacteria, however recent studies suggest that BCG vaccination can have non-specific beneficial effects unrelated to tuberculosis. In the present cohort study the development of cytokine profiles following BCG vaccination was investigated. Immune responses to PPD were assessed before vaccination and at ages of 5 months, 1 year, and 2 years, followed by BCG scar measurement at 4 years of age. BCG was shown to induce both Th1 and Th2 type responses against PPD at about 5 months of age after vaccination, and while Th1 response was sustained, Th2 responses declined over time. However, BCG scar size was strongly correlated with Th2 responses to PPD at 5 months of age. Importantly, we observed no clear effects of BCG vaccination on innate immune responses in terms of early IL-10 or TNF-α production whereas some alterations in general adaptive immune responses to PHA were observed.