Epidemiology of soil transmitted Helminth infections in the middle-belt of Ghana, Africa

Prevalence of Plasmodium and Soil-Transmitted Helminth Coinfection and Associated Factors among Malaria-Suspected Patients Attending Shewa Robit Health Center, North-Central Ethiopia

Plasmodium and soil-transmitted helminth (STH) coinfection is a major public health problem in developing countries. Its prevalence and associated factors are poorly addressed in the available research. Therefore, this study aimed to assess Plasmodium-STH coinfection prevalence and associated factors among malaria-suspected patients attending Shewa Robit Health Center, north-central Ethiopia. A cross-sectional study was conducted among 379 malaria-suspected patients attending Shewa Robit Health Center from April to May 2023. Stool and blood samples were collected from each participant. Plasmodium and STHs were detected from blood and stool samples by using blood film and the Kato-Katz method, respectively. Data were entered into Epi Info version 7 and analyzed by SPSS version 26. Descriptive statistics were used to compute Plasmodium-STH coinfection. Logistic regression was used to identify associated factors. Variables with a P-value <0.05 were considered statistically significant. Among the study participants, 27.9%, 20.3%, and 13.4% were positive for Plasmodium, STHs, and Plasmodium-STH coinfection, respectively. The prevalence of Plasmodium-Ascaris lumbricoides coinfection was high (7.6%). Unavailability of insecticide-treated bed nets (ITNs), improper use of ITNs, absence of indoor residual spraying, presence of stagnant water, and previous malaria infection were significantly associated (P <0.01) with Plasmodium infection. Being illiterate, using an unimproved latrine, having an untrimmed fingernail, and practicing open defecation were also significantly associated (P <0.03), with STH infection. Being male, illiterate, and living in rural areas were significantly associated (P <0.03) with Plasmodium-STH coinfection. The prevalence of Plasmodium-STH coinfection was high in malaria-endemic areas. Therefore, malaria-suspected cases should be checked for STH infection.

Side Effects following School Deworming among School-Age Children in Oti Region, Ghana

Background

Preventive chemotherapy with anthelminthic drugs is meant to control soil-transmitted helminthiases, but some children may experience adverse reactions.

Objective

This study investigated why some school-age children did not receive the medication as well as the side effects experienced by those who did during the 2019 preventive chemotherapy in Krachi East Municipal, Oti Region, Ghana.

Methods

Using a two-stage stratified sampling, a community-based cross-sectional study was conducted among 352 school-age children and their caregivers living in three urban and five rural communities.

Results

Most children (93.8%) were in primary school, aged 11 to 12 years (28.1%), male (53.1%), and resided in an urban area (83.8%). Due to concerns about side effects (28.1%), absenteeism (25.0%), and sickness (9.4%), 32 (9.09%) children did not receive the anthelminthic medication. Of the 320 children who received and ingested the anthelmintic drug, 50.3% experienced at least one side effect. Common side effects included dizziness (58.4%), feeling weak (27.3%), and stomach issues such as vomiting (17.4%), abdominal pain (11.8%), and nausea (6.2%). In adjusted analyses, children aged 11-12 years had higher odds of side effects (aOR: 2.40, 95% CI: 1.22-4.76) than children aged 7-8 years. Male children were also less likely than female children to experience adverse effects (aOR: 0.43, 95% CI: 0.27-0.68). Discussion. Ghana's national goal of 100% therapeutic coverage was unmet. Medication consumption during prophylactic chemotherapy may be hampered due to the high prevalence of side effects among school-age children. It is necessary to educate caregivers on how to handle these negative effects.

Helminthiasis and malaria co-infection among women of reproductive age in a rural setting of Kilifi County, coastal Kenya: A mixed method study

Soil transmitted helminthiasis (STH), Schistosoma haematobium and malaria co-infection lead to increased susceptibility to other infections and poor pregnancy outcomes among women of reproductive age (WRA). This study sought to establish risk factors, burden of co-infection with STH, S. haematobium and Plasmodium sp. among WRA in Kilifi County, Kenya.A mixed method cross-sectional study was conducted on 474 WRA in 2021. Simple random sampling was used to select WRA from four villages in two purposively sampled sub-counties. Study participants were interviewed, and stool samples collected and analysed using Kato-Katz technique for STH. Urine samples were collected for examination of S. haematobium while malaria microscopic test was done using finger prick blood samples. Further, 15 focus group discussions (FGDs) were conducted with purposively selected WRA and qualitative data analyzed thematically using Nvivo software. Quantitative and qualitative methods were triangulated to comprehensively strengthen the study findings. Prevalence of S. haematobium was 22.3% (95%CI: 13.5-36.9), any STH 5.2% (95%CI: 1.9-14.3) and malaria 8.3% (95%: 3.8-18.2). Co-infections between any STH and S. haematobium was 0.8% (95%CI: 0.2-3.2) and between S. haematobium and malaria 0.8% (95%CI: 0.2-3.1). Multivariable analysis showed increased odds of any STH infections among participants in Rabai Sub-County, (aOR = 9.74; p = 0.026), businesswomen (aOR = 5.25; p<0.001), housewives (aOR = 2.78; p = 0.003), and casual laborers (aOR = 27.03; p<0.001). Qualitative analysis showed that the three parasitic diseases were common and responsible for possible causes of low birth weight, susceptibility to other infections and complications such as infertility and cancer later in life.The study demonstrated that STH, S. haematobium and malaria are still a public health problem to WRA. Some of the associated risks of infection were geographical location, socio-economic and WASH factors. Hence the need to implement integrated control efforts of the three parasitic infection.

Improved household flooring is associated with lower odds of enteric and parasitic infections in low- and middle-income countries: A systematic review and meta-analysis

Enteric and parasitic infections such as soil-transmitted helminths cause considerable mortality and morbidity in low- and middle-income settings. Earthen household floors are common in many of these settings and could serve as a reservoir for enteric and parasitic pathogens, which can easily be transmitted to new hosts through direct or indirect contact. We conducted a systematic review and meta-analysis to establish whether and to what extent improved household floors decrease the odds of enteric and parasitic infections among occupants compared with occupants living in households with unimproved floors. Following the PRISMA guidelines, we comprehensively searched four electronic databases for studies in low- and middle-income settings measuring household flooring as an exposure and self-reported diarrhoea or any type of enteric or intestinal-parasitic infection as an outcome. Metadata from eligible studies were extracted and transposed on to a study database before being imported into the R software platform for analysis. Study quality was assessed using an adapted version of the Newcastle-Ottawa Quality Assessment Scale. In total 110 studies were eligible for inclusion in the systematic review, of which 65 were eligible for inclusion in the meta-analysis after applying study quality cut-offs. Random-effects meta-analysis suggested that households with improved floors had 0.75 times (95CI: 0.67-0.83) the odds of infection with any type of enteric or parasitic infection compared with household with unimproved floors. Improved floors gave a pooled protective OR of 0.68 (95CI: 0.58-0.8) for helminthic infections and 0.82 OR (95CI: 0.75-0.9) for bacterial or protozoan infections. Overall study quality was poor and there is an urgent need for high-quality experimental studies investigating this relationship. Nevertheless, this study indicates that household flooring may meaningfully contribute towards a substantial portion of the burden of disease for enteric and parasitic infections in low- and middle-income settings.

Spatial parasitology and the unmapped human helminthiases

Helminthiases are a class of neglected tropical diseases that affect at least 1 billion people worldwide, with a disproportionate impact on resource-poor areas with limited disease surveillance. Geospatial methods can offer valuable insights into the burden of these infections, particularly given that many are subject to strong ecological influences on the environmental, vector-borne or zoonotic stages of their life cycle. In this study, we screened 6829 abstracts and analysed 485 studies that use maps to document, infer or predict transmission patterns for over 200 species of parasitic worms. We found that quantitative mapping methods are increasingly used in medical parasitology, drawing on One Health surveillance data from the community scale to model geographic distributions and burdens up to the regional or global scale. However, we found that the vast majority of the human helminthiases may be entirely unmapped, with research effort focused disproportionately on a half-dozen infections that are targeted by mass drug administration programmes. Entire regions were also surprisingly under-represented in the literature, particularly southern Asia and the Neotropics. We conclude by proposing a shortlist of possible priorities for future research, including several neglected helminthiases with a burden that may be underestimated.

Intestinal Helminth Infections in Ghanaian Children from the Ashanti Region between 2007 and 2008—A Retrospective Cross-Sectional Real-Time PCR-Based Assessment

In spite of ongoing eradication programs, helminth infections are still a medical issue in Ghana. For follow-up assessments on the decline of regional helminth infections, historic baseline prevalence values obtained with standardized diagnostic procedures can be helpful. In this retrospective cross-sectional study, real-time PCR targeting the nematodes Ancylostoma spp. (ITS2), Ascaris lumbricoides (ITS1), Enterobius vermicularis (ITS1), Necator americanus (ITS2), Strongyloides stercoralis (18S rRNA) and Trichuris trichiura (18S rRNA), the trematodes Schistosoma spp. (ITS2) as well as the cestodes Hymenolepis nana (ITS1), Taenia saginata (ITS1) and Taenia solium (ITS1) was applied with 2046 DNA eluates from stool samples of Ghanaian children from the Ashanti region collected between 2007 and 2008 in order to retrospectively define prevalence values. The overall prevalence was low with 3.8% (n = 77) and only 0.1% (n = 2) double infections with helminths were recorded. The three most frequently detected enteric helminth species comprised 2% S. stercoralis (n = 41), 0.8% H. nana (n = 16), and 0.7% N. americanus (n = 14), while only sporadic infection events were recorded for other helminth species comprising 0.1% E. vermicularis (n = 2), 0.1% Schistosoma spp. (n = 2), 0.1% T. saginata (n = 1) and 0.1% T. trichiura (n = 1). A. lumbricoides, Ancylostoma spp. and T. solium were not detected at all. In conclusion, the retrospective assessment suggests a low prevalence of enteric helminth infections in Ghanaian children from the Ashanti Region within the assessment period between 2007 and 2008.

Prevalence and intensity of soil-transmitted helminth infections and associated risk factors among household heads living in the peri-urban areas of Jimma town, Oromia, Ethiopia: A community-based cross-sectional study

Background

Ethiopia has set national targets for eliminating soil-transmitted helminths (STH) as public health problems by 2020 and for breaking their transmission by 2025 using periodic mass treatment of children in endemic areas. However, the status of STH infection among the adults living in the same communities remains unknown. The aim of this study, therefore, was to determine the prevalence and intensity of STH infections and associated factors among the household heads in the peri-urban areas of Jimma town, Oromia, Ethiopia.

Methods

A community-based cross-sectional study was conducted in five peri-urban kebeles (smallest administrative unit in Ethiopia) of Jimma town from May to July 2021. A semi-structured questionnaire was used to collect data on socio-demographic and predisposing factors. The Kato-Katz concentration technique was utilized to detect and quantify the STH in stool samples. Both bivariate and multivariate analyses were done. P-value <0.05 was considered statistically significant.

Results

A total of 376 household heads (19.9% women and 80.1% men) from peri-urban areas were included in the study. The overall STH prevalence was 18.1% (95% CI: 14.6–22.1) with A. lumbricoides being the predominant species (11.4%) followed by T. trichiura (7.2%) and hookworm (2.1%). Most of the STH positive household heads had single infections (85.3%) and light-intensity infections (88.5%). Wealth status (AOR = 2.7; 95% CI: 1.31–5.50, P = 0.007), hand washing habits before meals (AOR = 7.07; 95% CI: 1.79–27.88, p = 0.005), fingernails status (AOR = 2.99; 95% CI: 1.59–5.65, p = 0.001), and toilet facility type (AOR = 2.06; 95% CI: 1.13–3.76, p = 0.017) were found to have statistically significant associations with the STH infection.

Conclusion

The findings of this study showed a nearly moderate level of STH prevalence among household heads in the peri-urban community. This could serve as an important reservoir for reinfection of the treated children and other at-risk groups in the community.

Urogenital schistosomiasis transmission, malaria and anemia among school-age children in Northern Ghana

Background

In sub-Saharan Africa, co-morbidity with malaria, schistosomiasis, and soil transmitted helminths (STH) is common among young children. The current study investigated malaria, urinary schistosomiasis and their co-infection and anemia among school-age children in an endemic community, Nakolo in the Kassena-Nankana East District of northern Ghana.

Methods

A cross-sectional survey of 336 school-age children, 5–16 years was undertaken. Urine samples were examined for Schistosoma haematobium ova using microscopy. Finger prick blood samples were examined for Plasmodium parasites using microscopy and haemoglobin concentration measured with HemoCue Hb301 photometer.

Results

The mean age was 10.52 (Standard deviation: ±2.27; range: 5–16 years), of which 50.6% (170/336) were males. The overall prevalence of urinary schistosomiasis and Plasmodium (P.) falciparum was 12.8% (43/336) and 37.8% (127/336), respectively with 6.0% (20/336) coinfection. Participants with only P. falciparum infection had 17.8% (19/107) of moderate anemia whilst 21.7% (5/23) of children infected with only S. haematobium had moderate anemia and 4.3% (1/23) had severe anemia. 5.0 % (1/20) of moderate anemia was observed in concurrent infections of P. falciparum and S. haematobium. Use of open water bodies was associated with increased risk of S. haematobium infection (OR = 1.21; 95% CI = [1.06–1.39]; p = 0.001), with females being at reduced risk (OR = 0.93; 95%CI = [0.87–0.99]; p = 0.005). Absence of self-reported haematuria had 0.81 times reduced odds of S. haematobium infection (OR = 0.81; 95%CI = [0.74–0.87]; p < 0.001).

Conclusion

This study has revealed that urinary schistosomiasis remains prevalent in Kassena-Nankana East district and suggests that urinary schistosomiasis may contribute to moderate anemia among school-age children as compared to asymptomatic malaria infection. These findings call for an evaluation of the annual mass drug administration of Praziquantel among in-school children to ascertain its impact on urinary schistosomiasis prevalence across the district.

Application of multiplex amplicon deep-sequencing (MAD-seq) to screen for putative drug resistance markers in the Necator americanus isotype-1 β-tubulin gene

Global control of hookworm infections relies on periodic Mass Drug Administration of benzimidazole drugs to high-risk groups, regardless of infection status. Mutations in the isotype-1 β-tubulin gene have been identified in veterinary nematodes, resulting in structural changes and reduced drug-binding. In Ghana, previous studies have demonstrated significant variability in albendazole effectiveness among people infected with the hookworm Necator americanus, although the mechanisms underlying deworming response have not been defined. Using hookworm egg samples from a cross-sectional study in Ghana, we developed a multiplex amplicon deep sequencing (MAD-seq) method to screen genomic regions encapsulating putative drug-resistance markers in N. americanus isotype-1 β-tubulin gene. Three single nucleotide polymorphisms (SNPs) corresponding to resistance-associated mutations (F167Y, E198A, F200Y) within the coding region of the isotype-1 β-tubulin gene were characterized using MAD-seq in 30 matched pre- and post-treatment samples from individuals with persistent infection following therapy. Post-sequence analysis showed that the highest mean alternative nucleotide allele at each PCR amplicon was 0.034% (167amplicon) and 0.025% (198/200amplicon), suggesting minimal allelic variation. No samples contained the F167Y SNP, while one contained low-frequency reads associated with E198A (3.15%) and F200Y (3.13%). This MAD-seq method provides a highly sensitive tool to monitor the three putative benzimidazole resistance markers at individual and community levels. Further work is required to understand the association of these polymorphisms to treatment response.

Intestinal Parasitic Infections Among Pediatric Patients in a Metropolitan City of Bangladesh With Emphasis on Cryptosporidiosis

Introduction Gastrointestinal parasitic infections are one of the global health concerns in developing countries like Bangladesh. Among them, Cryptosporidium spp. plays an essential role in causing diarrhea, malnutrition, and poor cognitive function, especially in children. This study was conducted to identify the frequency of Cryptosporidium cases and other parasitic agents.  Methods A cross-sectional observational study was conducted among 219 hospitalized children with diarrhea. The conventional microscopic technique was applied for parasitic detection. Particular staining (modified Ziehl-Neelsen) procedure was performed to identify oocysts of Cryptosporidium spp. A polymerase chain reaction (PCR) was performed to determine the SSU rRNA and gp60 gene of Cryptosporidium.  Results Cysts of Giardia duodenalis (2.3%), ova of Ascaris lumbricoides (1.4%,), Trichuris trichiura (0.5%), and both A. lumbricoides and T. trichiura (0.9%) were identified in samples through wet mount preparation. The distribution of Cryptosporidium spp. as detected by the staining method and nested PCR was 1.4% and 4.1%, respectively.  Conclusion Factors independently associated with Cryptosporidium infection are unsafe water, lack of regular hand washing, and insufficiency of exclusive breastfeeding. This study reports, presumably for the first time, the detection of Cryptosporidium oocysts in Chattogram metropolitan city of Bangladesh.

Evidence of reduced academic performance among schoolchildren with helminth infection

Background

Soil-transmitted helminths (STHs) pose a formidable health risk to school-age children in resource-limited settings. Unfortunately, mass deworming campaigns have been derailed since the onset of the coronavirus disease 2019 pandemic. The present study assessed the cross-sectional associations between STHs, nutritional status and academic performance of schoolchildren in the Banda District of Ghana.

Methods

Schoolchildren (5–16 y of age; n=275) were recruited through both school and household visits by community health workers using a multistage cluster sampling technique. In addition to school microscopy, anthropometric records were also taken.

Results

The prevalence of geohelminthiasis was 40.4% (95% confidence interval 34.6 to 46.2). STHs targeted for elimination by the World Health Organization and national programmes were detected among schoolchildren. Children with intestinal parasite infection (53.7 [standard deviation {SD} 11.5]) had lower mean academic scores compared with uninfected children (59.6 [SD 16.9]) (p=0.034). In multiple regression analysis, intestinal parasite infection status and z-scores for weight-for-age showed a collective significant effect on the academic score (F₁₁₁₇=8.169, p<0.001, R²=0.125).

Conclusions

Schoolchildren with STHs had poorer academic performance compared with uninfected children, despite their nutritional status. In addition to school feeding programmes, school-based mass drug administration campaigns may be critical for improving learning outcomes in young schoolchildren.

[School-age children'S knowledge and perceptions concerning Soil-transmitted Helminthiases and Targeted Preventive Chemotherapy in Ghana's Oti Region]

Background

The Ghana Neglected Tropical Diseases control program aimed to raise population awareness on soil-transmitted helminth (STH) infections and achieve a 100% coverage of preventive chemotherapy (PCT) by 2020. This study aims at determining the factors associated with the knowledge of school-age children and describing their perceptions at Krachi East Municipal in Ghana.

Patients and methods

It was a cross-sectional study. Children and their caregivers were selected from 8 communities following a two-stage stratified sampling. Descriptive statistics and binary logistic regression were performed at a 5% significance level.

Results

352 children and their caregivers were surveyed, mainly from Dambai (66.48%). The median age was 11 (IQR: 9-12) years and the children aged 7-14 years. About half of the children were males (53.13%) and most caregivers were females (66.48%). Most children perceived a benefit associated with PCT (94.89%). The proportion of children perceiving a health risk did not differ significantly from those not perceiving a risk (49.72% vs 50.28%; p=0.8802). In general, children had poor knowledge (91.19% vs 8.81%; p<0.0001). Good knowledge was associated with ethnic group [Guan: aOR=3.96 95%CI 1.11-14.12; p=0.034], child age [(11-12 years: aOR=6.05 95%CI 1.21-30.22; p=0.026); (13-14 years: aOR=8.19 95%CI 1.64-40.89; p=0.010)] and caregivers' sex (Female: aOR=2.97 95%CI 1.02-8.66; p=0.046) in the adjusted model.

Conclusion

Younger children and male caregivers seem to have low knowledge of intestinal worms and PCT. Therefore, they must get more attention regarding health education.

Role of seasonal variation on the prevalence and risk factors of trichuriasis among the aboriginal community in Malaysia

Trichuris trichiura is a soil-transmitted helminth prevalent in developing countries with poor, inadequate sanitation and unsafe water sources. In Malaysia, the prevalence of trichuriasis is relatively high among the aboriginal community due to poverty and poor sanitation. However, there are few studies to determine the seasonal variation on the prevalence and risk factors to acquire Trichuris trichiura infection in Malaysia. The present study found higher Trichuris trichiura infection during the dry season (63.6%; 138/217) in comparison to the wet season (55.5%; 142/256). Low household income, low education level and practice of open defecation were significant risk factors to acquire Trichuris trichiura infection during the wet season. Usage of untreated water supplies for daily activities was a risk factor to acquire trichuriasis during the dry season. This study highlighted that poverty and poor sanitation practices as well as drinking untreated water put the aborigines at high risk to acquire trichuriasis. Therefore, health education, improved sanitation and provision of treated water supply are recommended for the prevention and control of Trichuris trichiura infections in the aboriginal community.

Prevalence and effect of Plasmodium spp. and hookworm co-infection on malaria parasite density and haemoglobin level: a meta-analysis

The dual effects of co-infection of Plasmodium spp. and hookworm on malaria remain under debate. This study investigated prevalence, prevalence odds ratio (POR) of co-infection and impact of co-infection on malaria parasite density and haemoglobin levels in comparison to Plasmodium mono-infection. The protocol for this systematic review and meta-analysis is registered at PROPERO under ID: CRD42020202156. Relevant literatures were obtained from PubMed, ISI Web of Science, and Scopus on 25 December 2020. Mean difference (MD) and confidence interval (CI) of malaria parasite density and haemoglobin were compared using a random effect model. Heterogeneity was assessed using Cochrane Q and I2 statistics. Publication bias was determined by visualising funnel plot asymmetry. Of 1756 articles examined, 22,191 malaria cases across 37 studies included 6096 cases of co-infection of Plasmodium spp. and hookworm. The pooled prevalence was 20% (95% CI 15-26%, I2 99.6%, 37 studies) and was varied in terms of geographical region. Co-infection occurred by chance (OR 0.97, p 0.97, 95% CI 0.73-1.27, I2 95%, 30 studies). The mean malaria parasite density for co-infection (478 cases) was similar to Plasmodium mono-infection (920 cases) (p 0.24, MD 0.86, 95% CI - 0.58-2.29, I2 100%, 7 studies). The mean haemoglobin level for co-infection (90 cases) was similar to Plasmodium mono-infection (415 cases) (p 0.15, MD - 0.63, 95% CI - 1.49-0.23, I2 98%, 4 studies). Co-infection was common and occurred by chance but varied by geographic region. Further studies are required to investigate the mechanism of hookworm infection on malaria severity. Additionally, detection of hookworm infections among patients with malaria in endemic areas of both diseases is recommended to prevent severe malaria.

Evaluation of five diagnostic methods for Strongyloides stercoralis infection in Amhara National Regional State, northwest Ethiopia

Background

Strongyloides stercoralis is an intestinal parasite that can cause chronic infection, hyperinfection and/or a dissemination syndrome in humans. The use of techniques targeting ova fails to detect S. stercoralis, as only larvae of the parasite are excreted in faeces. Due to the absence of “Gold” standard diagnostic method for S. stercoralis, there is a paucity of reported data worldwide.

Objective

This study aimed to evaluate the performance of diagnostic methods of S. stercoralis infection by taking the composite reference as a “Gold” standard.

Methods

A cross-sectional study was conducted among 844 schoolchildren in Amhara Region, Ethiopia, from April to December 2019. Stool samples were collected and processed with formol-ether concentration technique (FECT), spontaneous tube sedimentation technique (STST), Baermann concentration technique (BCT), agar plate culture (APC) and real-time polymerase chain reaction (RT-PCR). Sensitivity, specificity, positive predictive value, and negative predictive value of each diagnostic method were computed against the composite reference. The agreements of diagnostic methods were evaluated by Kappa value at 95% CI.

Results

The composite detection rate of S. stercoralis by the five diagnostic methods was 39.0% (329/844). The detection rate of the parasite from stool samples by FECT, STST, BCT, APC and RT-PCR was 2.0% (17/844), 4.0% (34/844), 10.2% (86/844), 10.9% (92/844) and 28.8% (243/844), respectively. The highest detection rate (37.8%; 319/844) of S. stercoralis was recorded by a combination of BCT, APC, and RT-PCR followed by a combination of STST, BCT, APC and RT-PCR (37.3%; 315/844). The sensitivity of FECT, STST, BCT, APC and RT-PCR against the composite reference was 5.2%, 10.3%, 26.4%, 28.0% and 73.9%, respectively. The diagnostic agreements of RT-PCR, APC, BCT, STST and FECT with the composite reference in detection of S. stercoralis were substantial (0.775), fair (0.321), fair (0.305), slight (0.123), and slight (0.062), respectively.

Conclusion

RT-PCR detected the highest number of S. stercoralis infections. A combination of RT-PCR with APC and/or BCT better detected S. stercoralis from stool samples compared to other combinations or single diagnostic methods. Therefore, RT-PCR and combination of RT-PCR with APC and/or BCT diagnostic methods should be advocated for detection of S. stercoralis infection.

Evaluation of the efficiency of some disinfectants on the viability of Hymenolepis nana eggs isolated from wastewater and faecal sludge in Yaounde (Cameroon): importance of some abiotic variables

Hymenolepis nana is responsible for many parasitic infections in tropical areas, with its persistence in aquatic environments as major contributory factor. A study aimed at demonstrating the effectiveness of some disinfectants on the viability of Hymenolepis nana eggs was conducted in microcosm. Sampling consisted of taking wastewater and sewage sludge samples in sterilized containers and then transporting to the laboratory of Hydrobiology and Environmental Sciences for the determination of Hymenolepis nana eggs using standard protocols. The experimental set-up consisted of five replicates, four tests and a control. The test samples were successively treated with four disinfectants (calcium chlorite, hydrogen peroxide, gypsum and sodium hypochlorite). The physico-chemical parameters were measured before and after disinfection. The samples were then observed under an optical microscope after concentration of the sample through sedimentation and McMaster technique. The viability of the eggs was determined using incubation and staining techniques. The analysis revealed that the selected disinfectants significantly reduced the physico-chemical parameters (with an average yield ranging from 79.24 ± 19.43% to 99.24 ± 1.47%). These physico-chemical parameters can significantly influence the treatment of Hymenolepis nana eggs either by absorbing the disinfectant or by constituting a protective barrier for the eggs, and the physico-chemical nature of the disinfectant strongly influences the formation of disinfection by-products. Calcium chlorite showed a greater effectiveness in reducing egg viability with efficiency rates of 93.12 ± 9.12% followed by hydrogen peroxide (89.57 ± 14.55%), sodium hypochlorite (82.51 ± 14.39%) and gypsum (80.85 ± 12.88%). The results obtained with gypsum are almost similar to those obtained with other disinfectants (calcium chlorite, hydrogen peroxide and sodium hypochlorite) and clearly show that this disinfectant can be used in water treatment because, unlike other chemical disinfectants, it has no known toxic effects.

Seroprevalence of Taenia solium and Trichinella spiralis among Humans and Pigs in Ghana

In this study, the seroprevalence of the intestinal worms Taenia solium and Trichinella spiralis in humans and pigs was assessed. A cross-sectional serological study design was performed. Blood samples were collected from 322 humans and 245 pigs used in the study. These were tested for markers of antibodies for Taenia solium and Trichinella spp. Demographic data such as sex, age, education, pig farming practices, and water source used were also obtained. An overall seroprevalence of 3.1% was recorded for Taenia solium in humans. There was also a statistical association between pig management system employed by pig farmers and seropositivity to Taenia solium (p = 0.005). Factors such as mode of waste disposal (p = 0.003) and water source used statistically correlated with Taenia solium seroprevalence among humans. For the pig samples, a Taenia solium seroprevalence of 24.9% was recorded. All the pig samples which tested positive for Taenia solium were reared on the free-ranged system. This study also recorded a seroprevalence of 0.31% for Trichinella spp. for humans and a seroprevalence of 4.5% for Trichinella spp. for pigs. Again, all the samples that showed serological evidence of Trichinella spp. among pigs came from those pigs which were raised on the free-ranged system. Proper pig management practice is a very important tool for controlling these intestinal parasites in both humans and animals. This study recommends public health education among the general public and good pig farming practices.

Resource-Efficient Characterisation of Pit Latrine Sludge for Use in Agriculture

Resource recovery through reuse of by-products of the sanitation chain presents a great potential towards ensuring universal access to safely managed sanitation. Many developing countries are faced with uncertainty over public and environmental health concerns associated with use of faecal sludge in agriculture. Due to resource constraints, limited data exists on the characteristics of faecal sludge to inform proper and safe use in agriculture. Despite predictive characterisation being demonstrated to be a resource-efficient approach to generate data in other fields, its application in agricultural resource recovery from faecal sludge is lacking in the literature. This paper explored predictive modelling as a less resource-intensive approach for characterisation of nutrients and pathogens in faecal sludge. Specifically, it investigated the extent to which gravimetric parameters could predict nutrients and pathogens in pit latrine sludge from informal settlements in the cities of Malawi. The study explored predictive models to estimate total ammoniacal nitrogen (TAN), total phosphorus (TP), E.coli and helminth eggs from gravimetric parameters (total solids [TS] and total volatile solids [TVS]) in pit latrine sludge. The models developed in the study allow substantially reliable estimation of TAN (R2pred = 75.4%) and TP (R2pred = 78.2%); they also provide moderately reliable predictions for E.coli (R2pred = 69.1%) and helminth eggs (R2pred = 74.3%) from total solids. Since total solids are easy and inexpensive to measure, the models present an option that can reduce resource requirement for characterisation of pit latrine sludge for informed decision-making when using pit latrine sludge in agriculture. In the absence of data on faecal sludge characteristics at the national level, the models provide a starting point for estimation of pathogens and nutrients in sludge for agricultural use. However, stepwise refinement of the models needs to be done through their validation for different types of sludge and inclusion of spatially available demographic, technical and environmental (SPA-DET) data.

The Incidence, Intensity, and Risk Factors for Soil Transmissible Helminthes Infections among Waste Handlers in a Large Coastal Periurban Settlement in Southern Ghana

Soil-transmissible helminthes (STH) infections are among the most common sanitation-related public health problems in poor periurban settlements of tropical regions of low- and middle-income countries. In Ghana, research studies documenting the incidence rate, intensity, and occupational risk factors of STH infections among adults are scanty. A prospective cohort study of 261 waste handlers was conducted to investigate this. Stool samples were collected after 90 and 180 days of treatment with albendazole (400 mg per dose). The geometric mean intensity of STH among waste handlers after 180 days of treatment was 2.8 eggs/gram (light intensity), with an incidence rate of 1.5%. The proportion of waste handlers with light intensity STH infections was 4.8%. The odds of STH infection among female waste handlers were 80% lower when compared with male waste handlers (aOR = 0.2; 95% CI: 0.0-0.8). Waste handlers who used rubber gloves when working were 80% (aOR = 0.2: 95% CI: 0.2-1.9) protected from STH infections compared with those who did not use gloves. Infections with STH among the 261 waste handlers significantly correlated with the type of waste handling activities (LR χ 2 = 15.3; p=0.033) with the highest proportion of infection found among transporters, 2 (40%). Waste handlers should receive periodic antihelminthic treatment, at least once every six months, practice adequate hand hygiene, and use suitable personal protective equipment during work.

Strongyloidiasis in Africa: Systematic Review and Meta-Analysis on Prevalence, Diagnostic Methods, and Study Settings

BACKGROUND

Strongyloidiasis is an intestinal parasitic infection mainly caused by Strongyloides stercoralis. Although it is a predominant parasite in tropics and subtropics where sanitation and hygiene are poorly practiced, the true prevalence of strongyloidiasis is not known due to low-sensitivity diagnostic methods.

OBJECTIVE

This systematic review and meta-analysis is aimed at determining the pooled prevalence of strongyloidiasis in African countries, stratified by diagnostic methods, study settings, and patients.

METHODS

Cross-sectional studies on strongyloidiasis published in African countries from the year 2008 up to 2018 in PubMed and Google Scholar databases and which reported at least one Strongyloides spp. infection were included. Identification and screening of eligible articles were also done. Articles whose focus was on strongyloidiasis in animals, soil, and foreigners infected by Strongyloides spp. in Africa were excluded. The random effects model was used to calculate the pooled prevalence of strongyloidiasis across African countries as well as by diagnostic methods and study settings. The heterogeneity between studies was also computed.

RESULT

A total of 82 studies were included. The overall pooled prevalence of strongyloidiasis was 2.7%. By individual techniques, the pooled prevalence of strongyloidiasis was 0.4%, 1.0%, 3.4%, 9.3%, 9.6%, and 19.4% by the respective direct saline microscopy, Kato-Katz, formol ether concentration, polymerase chain reaction, Baermann concentration, and culture diagnostic techniques. The prevalence rates of strongyloidiasis among rural community, school, and health institution studies were 6.8%, 6.4%, and 0.9%, respectively. The variation on the effect size comparing African countries, diagnostic methods, study settings, and patients was significant (P ≤ 0.001).

CONCLUSIONS

This review shows that strongyloidiasis is overlooked and its prevalence is estimated to be low in Africa due to the use of diagnostic methods with low sensitivity. Therefore, there is a need for using a combination of appropriate diagnostic methods to approach the actual strongyloidiasis rates in Africa.

Does suboptimal household flooring increase the risk of diarrhoea and intestinal parasite infection in low and middle income endemic settings? A systematic review and meta-analysis protocol

BACKGROUND

Water, sanitation, and hygiene interventions often fail to show long-term impact on diarrhoeal and/or intestinal parasite risk in many low- and middle-income countries. Less attention has been paid to wider contextual factors that may contribute to high levels of contamination in the domestic environment such as household flooring. The purpose of this study will be to assess the association between diarrhoeal and/or intestinal parasite infection status and unimproved/unfinished flooring in low- and middle-income countries.

METHODS

We will conduct a comprehensive search of published studies (randomized controlled trials, non-randomized controlled trials, and observational studies) that examined the association between unimproved/unfinished household flooring and diarrhoeal and/or intestinal parasite infection status from January 1, 1980, onwards with no language restriction. The primary outcome will include diarrhoeal and/or intestinal parasite infection status. Databases to be searched include EMBASE, MEDLINE, Web of Science, and Google Scholar. The secondary outcome will be the association between specific pathogens (laboratory confirmed) and unimproved/unfinished household flooring. Independent screening for eligible studies using defined criteria and data extraction will be completed in duplicate and independently. Any discrepancies between the two reviewers will be resolved by consensus and/or arbitration by a third researcher. If data permits, random effects models will be used where appropriate. Subgroup and additional analyses will be conducted to explore the potential sources of heterogeneity (e.g. age group, geographical region) and potential risk of bias of included studies.

DISCUSSION

This review will provide a comprehensive examination of a possible association between suboptimal household flooring and increased risk of enteric pathogen infection, highlight gaps for future research in high risk areas, and inform intervention design for future planned studies in Kenya and/or elsewhere in the region.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number: CRD42019156437.

Soil transmitted helminth infections in Ghana: a ten year review

For more than a decade, intervention programs have been instituted in Ghana to combat soil transmitted helminth (STHs) infections. Knowledge of the trend of the infection in the country is needed for evaluation and modification of existing control programs to achieve national targets. The objective of this review is to examine the pattern of soil transmitted infections in Ghana between 2009-2018. We searched and reviewed published literature on soil transmitted helminths in Ghana in PubMed, Medline, Google Scholar and Institutional Repositories of Kwame Nkrumah University of Science and Technology, University of Ghana, University of Cape Coast, and University for Development Studies-Tamale. We observed paucity of research work on STHs in Ghana over the period of this review. Twenty-nine studies consisting of 24 published works in peer reviewed journals and five graduate theses were included in the study. Hookworm was the most prevalent of STHs recorded followed by roundworm, threadworm, and whipworm. Pinworm was very rarely reported. These infections were reported from different regions and ecological zones of the country and among children, pregnant women, farmers, food vendors, children in orphanage home and psychiatric institution. Although there is some downward trend over the period, soil transmitted helminths are still prevalent in Ghana. This is an indication of some hope of eventual control and elimination of these diseases in the country if control measures are optimised. Further research particularly population studies into soil transmitted helminths in Ghana is needed.

Changes in the epidemiological profile of intestinal parasites after a school-based large-scale treatment for soil-transmitted helminths in a community in northeastern Brazil: Epidemiological profile after large-scale school-based treatment for STH

Intestinal parasites cause a significant public health problem worldwide due to the associated morbidities, mainly in infected school-aged children (SAC). The strategy of large-scale deworming in SAC to control the transmission of soil-transmitted helminths (STH) has been advocated by the World Health Organization and was recently adopted in Brazil; however, the long-term effects of mass deworming on the larger parasitological profile have been less studied. After a five-year period of school-based large-scale treatment for STH using an annual single dose of albendazole in a community of Sergipe state, Brazil, a marked reduction in prevalence was observed (15.4%% vs.7.4% for Ascaris sp., 6.0%%  vs. 0.4% for hookworm, and 12.8%%  vs. 4.5%% for Trichuris trichiura), with the exception of Strongyloides stercoralis, which had no statistically significant change in prevalence. There was, however, an increase in the prevalence of intestinal protozoans, specifically Entamoeba histolytica/E. dispar (0.0%% vs. 36.0%), Blastocystis hominis (0.0%%  vs. 40.1%), and Giardia duodenalis (5.6%% vs. 14.5%). Although the findings showed a dramatic reduction in the prevalence of STH after four rounds of preventive chemotherapy, there was an increase in intestinal protozoan infections, indicating a change in the epidemiological profile.

PCR-RFLP screening of polymorphisms associated with benzimidazole resistance in Necator americanus and Ascaris lumbricoides from different geographical regions in Brazil

Ascaris lumbricoides and Necator americanus are soil-transmitted parasites with global geographic distribution, and they represent some of the most common and neglected infections in the world. Periodic treatment with mass drug administration (MDA) in endemic areas is the recommended action put forth by the World Health Organization. However, MDA can cause the selection of subpopulations that possess the genetic ability to overcome the mechanism of drug action. In fact, beta-tubulin gene mutations (codons 167, 198 and 200) are correlated with benzimidazole resistance in nematodes of veterinary importance. It is possible that these SNPs also have strong correlation with treatment resistance in the human geohelminths A. lumbricoides, Trichuris trichiura and hookworms. Here, we aimed to investigate the presence of some of these canonical molecular markers associated with parasite resistance to benzimidazole in N. americanus and A. lumbricoides collected from six Brazilian states. Nested-PCR and PCR-RFLP were used to detect mutations at codons 167 and 198 in 601 individual eggs of A. lumbricoides collected from 62 human stool samples; however, no mutations were found. Codons 198 and 200 were tested in 552 N. americanus eggs collected from 48 patients using the same methodology, which presented a relative frequency of 1.4% and 1.1%, respectively. The presence of these SNPs in N. americanus eggs is an important finding, indicating that with high benzimidazole drug pressure there is potential for benzimidazole resistance to be selected in this hookworm. However, at these low frequencies it does not indicate that there is at present any benzimidazole resistance problem. This is the first systematic study performed in South America, and the study yielded a landscape of the genetic variants in the beta-tubulin gene and anthelmintic resistance to soil-transmitted parasites detected by a simple, rapid and affordable genotyping assay of individual eggs.