Monitoring of Insecticide Resistance in Anopheles culicifacies in Twelve Districts of Madhya Pradesh, Central India (2017–2019)

Background. Indoor residual spraying (IRS) and long-lasting insecticidal nets (LLINs) are malaria vector control measures used in India, but the development of insecticide resistance poses major impediments for effective vector control strategies. As per the guidelines of the National Vector Borne Disease Control Programme (NVBDCP), the study was conducted in 12 districts of Madhya Pradesh to generate data on insecticide resistance in malaria vectors. Methods. The susceptibility tests were conducted on adult An. culicifacies as per the WHO standard technique with wild-caught mosquitoes. The blood-fed female mosquitoes were exposed in 3 to 4 replicates on each occasion to the impregnated papers with specified discriminating dosages of the insecticides (DDT: 4%, malathion: 5%, deltamethrin: 0.05%, and alphacypermethrin: 0.05%), for one hour, and mortality was recorded after 24-hour holding. Results. An. culicifacies was found resistant to DDT 4% in all the 12 districts and malathion in 11 districts. The resistance to alphacypermethrin was also observed in two districts, and possible resistance was found to alphacypermethrin in seven districts and to deltamethrin in eight districts, while the vector was found susceptible to both deltamethrin and alphacypermethrin in only 3 districts. Conclusion. An. culicifacies is resistant to DDT and malathion and has emerging resistance to pyrethroids, alphacypermethrin, and deltamethrin. Therefore, regular monitoring of insecticide susceptibility in malaria vectors is needed for implementing effective vector management strategies. However, studies to verify the impact of IRS with good coverage on the transmission of disease are required before deciding on the change of insecticide in conjunction with epidemiological data.

Morphological and Molecular Characterization of Paragonimus Species Isolated from Freshwater Crabs in Southern Yunnan, China

Paragonimus species are highly prevalent in various regions of China. The study’s objective is to isolate and identify Paragonimus from natural habitats and compare the phylogenetic diversity of Paragonimus in southern Yunnan province, China. Metacercariae of Paragonimus was isolated from crabs, and morphologic identification was performed by microscopy. Metacercariae were injected into experimental Paragonimus free Sprague Dawley rats. After 114 days, adult worms and eggs were isolated from multiple organs. Morphologic identification confirmed the initial identification. DNA was extracted from 5 adult worms, and molecular characterization was performed by amplification and sequencing of CO1 and ITS2 regions, followed by phylogenetic analysis. Out of 447 crabs captured, 186 crabs were found to be infected. A total of 4 species of Paragonimus was observed from naturally infected crabs. Paragonimus microrchis (2), Paragonimus heterotremus (1), Paragonimus proliferus (1), and Paragonimus skrjabini (1) were isolated and identified. A total of 32 sequences were downloaded from the National Center for Biotechnology Information, and 5 sequences generated in the study were used for phylogenetic analysis. In the phylogenetic tree of the CO1 gene, Paragonimus proliferus, Paragonimus heterotremus, and Paragonimus skrjabini were clustered with the same species, and the confidence values of their branches were >95%. A congruent phylogenetic relationship was observed with the ITS2 phylogenetic tree. In the phylogenetic tree constructed with the combined dataset of CO1 and ITS2 datasets, Paragonimus proliferus, Paragonimus heterotremus, and Paragonimus skrjabini clustered with the same species, and their branch confidence values were >94%. Paragonimus microrchis clustered with Paragonimus bangkokensis in both datasets. Phylogenetic analysis revealed robustness of the double loci method as against the single-locus method with either CO1 or ITS2 alone. Paragonimus species isolated from the southern Yunnan province, China, was phylogenetically diverse, and the analysis revealed the clustering of multiple species of Paragonimus isolated from different geographic locations.

Challenges in Laboratory Diagnosis of Malaria in a Low-Resource Country at Tertiary Care in Eastern Nepal: A Comparative Study of Conventional vs. Molecular Methodologies

For ongoing malaria elimination programmes, available methods such as microscopy and rapid diagnostic tests (RDTs) cannot detect all malaria cases in acute febrile illness. These methods are entirely dependent on the course of infection, parasite load, and skilled technical resources. Our study objectives were to estimate the performance of light microscopy and a RDT as well as real-time PCR for the detection of the Plasmodium parasite. Altogether, 52 blood samples collected from patients with acute febrile illness were tested by microscopy, RDT, and real-time PCR. The results were compared in terms of sensitivity and specificity. Microscopy detected the malaria parasite in 5.8% of the blood samples whereas 13.5% were detected by the RDT and 27% by real-time PCR. Considering real-time PCR as the gold standard method, microscopy had a sensitivity of 21.4% and a specificity of 100%, and the RDT had a sensitivity of 28.6% and a specificity of 92.1%. Microscopy together with the RDT successfully detected malaria positive cases in blood samples of Ct value below 20, but both were unable to detect malaria cases between 26–40 Ct value ranges amplified by real-time PCR. Despite various diagnostic tools being available, microscopy still remains the method of choice for diagnosis, while the RDT is user-friendly when applied at the point of care. However, our preliminary results emphasize the need to implement the test with higher sensitivity and specificity in the context of a malaria elimination programme. Such programmes can be a crucial opportunity to understand the species prevalent in a low-endemic region. However, these results should be further verified with a large cohort study to document the submicroscopic infection.

Prevalence and Intensity of Soil-Transmitted Helminths and Associated Factors among Adolescents and Adults in Bibugn Woreda, Northwest Ethiopia: A Community-Based Cross-Sectional Study

Background. Soil-transmitted helminths are a common public health problem in Ethiopia, affecting all age groups. However, epidemiological studies and interventions primarily target school-age children, despite the fact that 44.6 million adults live in endemic areas. Hence, data on the prevalence and intensity of soil-transmitted helminths infections and associated factors among adolescents and adults helps to expand interventions. Objective. The aim of the study was to assess the prevalence and intensity of soil-transmitted helminths and associated factors among adolescents and adults in Bibugn Woreda, East Gojjam, Northwest Ethiopia. Methods. A community-based cross-sectional study was conducted in Bibugn Woreda from February to September 2021. Using multistage proportionate sampling technique, 641 adolescents and adults were enrolled in this study. Data on sociodemographic characteristics and factors associated with helminthic infections was collected using structured questionnaire prepared in Amharic and administered through face-to-face interview. Parasite detection in stool samples was performed using modified formol-ether concentration and Kato-Katz techniques following standard protocols. Data was entered and analyzed using Statistical Package for the Social Sciences software version 25. Multivariable logistic regression was used to assess factors associated with soil-transmitted helminths infections. P value <0.05 was considered as statistically significant. Results. The overall prevalence of soil-transmitted helminths infection was 20.9% (134/641). The most detected parasite was Ascaris lumbricoides (12.5%), followed by hookworm species (7.5%) and Trichuris trichiura (1.1%). Fecal egg counts revealed that 96.5% (112/116) of the infections were with light parasite intensity, while 3.5% (4/116) were with moderate parasite intensity. Family size >5 (AOR = 1.866; 95% CI: 1.221–2.853; P = 0.004 ), absence of latrine (AOR = 3.675; 95% CI: 1.599–8.449; P = 0.002 ), and no habit of hand washing before meal (AOR = 2.622; 95% CI: 1.073–6.405; P = 0.034 ) were significantly associated with soil-transmitted helminths infections. Conclusion. There was moderate prevalence of soil-transmitted helminths among adolescents and adults with predominance of A. lumbricoides. Family size greater than five, absence of latrine, and no hand washing habit before meal predisposed adolescents and adults for soil-transmitted helminths. The existing school-based interventions should expand to address adolescents and adults.

Temporal Validation of a Predictive Score for Death in Children with Visceral Leishmaniasis

Objectives. To perform a temporal validation of a predictive model for death in children with visceral leishmaniasis (VL). Methods. A temporal validation of a children-exclusive predictive model of death due to VL (Sampaio et al. 2010 model), using a retrospective cohort, hereby called validation cohort. The validation cohort convenience sample was made of 156 patients less than 15 years old hospitalized between 2008 and 2018 with VL. Patients included in the Sampaio et al. 2010 study are here denominated derivation cohort, which was composed of 546 patients hospitalized in the same hospital setting in the period from 1996 to 2006. The calibration and discriminative capacity of the model to predict death by VL in the validation cohort were then assessed through the procedure of logistic recalibration that readjusted its coefficients. The calibration of the updated model was tested using Hosmer–Lemeshow test and Spiegelhalter test. A ROC curve was built and the value of the area under this curve represented the model’s discrimination. Results. The validation cohort found a lethality of 6.4%. The Sampaio et al. 2010 model demonstrated inadequate calibration in the validation cohort (Spiegelhalter test: p = 0.007 ). It also presented unsatisfactory discriminative capacity, evaluated by the area under the ROC curve = 0.618. After the coefficient readjustment, the model showed adequate calibration (Spiegelhalter test, p = 0.988 ) and better discrimination, becoming satisfactory (AUROC = 0.762). The score developed by Sampaio et al. 2010 attributed 1 point to the variables dyspnea, associated infections, and neutrophil count <500/mm3; 2 points to jaundice and mucosal bleeding; and 3 points to platelet count <50,000/mm3. In the recalibrated model, each one of the variables had a scoring of 1 point for each. Conclusion. The temporally validated model, after coefficient readjustment, presented adequate calibration and discrimination to predict death in children hospitalized with VL.

Efficacy of Praziquantel for the Treatment of Human Schistosomiasis in Ethiopia: A Systematic Review and Meta-Analysis

Background. Schistosomiasis is one of the neglected tropical diseases causing a serious human health problem in Ethiopia. Praziquantel is the only drug that has been used for the treatment of human schistosomiasis in the country. In line with this, the efficacy of praziquantel has been evaluated in a few interventional studies in the country, but there is a lack in systematically gathered and analyzed information for policymakers. The aim of this systematic review and meta-analysis was to provide a summary of the efficacy of praziquantel for the treatment of human schistosomiasis in Ethiopia. Methods. We conducted a literature search from ScienceDirect, PubMed/Medlin, and Google Scholar databases. A total of 140 articles published in English from 1980 to June 2021 were accessed and 15 of them were eligible for this meta-analysis. The meta-analysis was conducted using Stata 14 software, “metan command.” The heterogeneities among studies were evaluated using I2 test. Results. A total of 140 articles were reviewed, but only 15 of them fulfilled the inclusion criteria. The polled cure rate of 40 mg/kg praziquantel was 89.2% (95% CI: 85.4–93.1) and 93.6% (95% CI: 80.6–106) among Schistosoma mansoni and S. haematobium, respectively. Similarly, the mean egg reduction rates of 40 mg/kg praziquantel were 90.2% and 85% among S. mansoni and S. haematobium infected subjects, respectively. The common adverse events observed after receiving praziquantel include abdominal pain, vomiting, headache, diarrhea, and bloody stool. Conclusion. This systematic review and meta-analysis has indicated that praziquantel is still an appropriate drug for the treatment of human schistosomiasis in Ethiopia.

Pregnant Women and Malaria Preventive Measures: A Case of Tamale Teaching Hospital, Ghana

Background. In Saharan Africa, an estimated 25 million pregnancies are all at risk of malaria every year, with substantial morbidity and death effects for both the mother and the fetus. Aim. To investigate the use of malaria preventive measures among pregnant women patronizing antenatal services of Tamale Teaching Hospital. Methodology. This study was conducted using a descriptive cross-sectional survey of 250 participants. Data analysis was done with SPSS version 20. Graphs and tables were used to present the study data. Bivariate analysis was done using Chi-square use to determine the relationships and binary logistics regression used for identification of predictor variables. Results. The mean age of the study participants was 30.0 ± 4.5 years and most of them (73.0%) were within the age group of 25–35 years. Respondents’ favorable knowledge, a favorable attitude, and favorable practice were 78.0%, 62.0%, and 57.6%, respectively. And the following variables were associated with malaria preventive practice: age of the respondent (X2 = 6.276, P = 0.043 ), religion (X2 = 6.904, P = 0.032 ), level of education (X2 = 41.482, P < 0.001 ), employment status (X2 = 20.533, P < 0.001 ), monthly income (X2 = 21.838, P < 0.001 ), and attitude level towards malaria prevention (X2 = 35.885, P < 0.001 ). Further analysis revealed educational level and attitude level as predictors of malaria preventive practice. Conclusion. This study recorded favorable knowledge, attitude, and practice with regards to malaria prevention among more than half of the study participants.

Efficiency of the Stool-PCR Test Targeting NADH Dehydrogenase (Nad) Subunits for Detection of Opisthorchis viverrini Eggs

Opisthorchis viverrini infection is the major parasitic infection problem in Southeast Asian countries, and long-term infection will lead to cholangiocarcinoma (CCA), the bile duct cancer. The early diagnosis of O. viverrini infection may interrupt the progression of the opisthorchiasis and other related illnesses, especially CCA. The current diagnostic procedure is stool examination by microscope-based methods such as direct smear and concentration techniques but it is limited by low parasite egg numbers. The molecular diagnosis prompts the chance to evaluate the light infection with low number of parasite eggs but is currently inconvenient for routine use due to special equipment requirement and unstable sensitivities. Our present study aims to establish the efficiency of OvNad subunits, the mitochondrial gene, for introducing as a potential diagnostic target by conventional PCR, the cheapest and easiest molecular procedure. A total of 166 stool samples were investigated microscopically by the PBS-ethyl acetate concentration technique (PECT); 75 samples were O. viverrini positive with 28 samples that were positive with single parasite (hookworm, A. lumbricoides, S. stercoralis, Taenia spp., and T. trichiura), 11 samples were with mixed infection, and 52 samples were without parasite detection. The detection limits of OvNad subunits were evaluated in artificially spiked samples containing 0, 1, 5, 10, 20, 50, and 100 Ov-eggs. The result suggested that the best detection efficacy was of OvNad5 that had exact detection limits at only 5 eggs. In the PCR amplification of OvNad subunits, there exist 100% specificities with varied sensitivities from 64%, 88%, 80%, and 100% of OvNad1, OvNad2, OvNad4, and OvNad5, respectively. OvNad subunits were amplified specifically without cross reactivity with the other collected parasites. Our study established that OvNad subunits, especially OvNad5, are the potent candidates for PCR amplification of stool containing Ov-eggs with high confidential sensitivity, specificity, PPV, and NPV even in the light infection that would be a benefit for developing as a routine diagnosis of O. viverrini infection.

Risk Factors and Spatial Distribution of Schistosoma mansoni Infection among Preschool-Aged Children in Blapleu, Biankouma District, Western Côte d’Ivoire

Schistosoma mansoni infection is common among school-age children (SAC) in western Côte d’Ivoire. Little is known on the infection rate of preschool-aged children (PSAC) due to epidemiological data deficiency and nonappropriate formulation of the drug. Thus, mass drug administration for schistosomiasis control mainly targets SAC. This study aims to identify the risk factors and spatial distribution of S. mansoni infection among PSAC in Blapleu, endemic foci of S. mansoni. We carried out a cross-sectional study in households with PSAC aged 1–6 years. A structured questionnaire was administered to mothers/guardians to obtain data on sociodemographics and water contact behaviour of children. Point-of-care circulating cathodic antigen (POC-CCA) immunodiagnostic test in urine and Kato-Katz (K-K) method with stool were used for S. mansoni infection diagnosis. Multiple logistic regression analysis was performed to determine the relationship between S. mansoni infection and sociodemographic data. Coordinates recorded by a Global Positioning System of households, water source points, and infected PSAC were used to map the spatial distribution of S. mansoni infection cases. This study was conducted with 350 PSAC aged 1–6 years. The overall infection prevalence of S. mansoni varies from 31.43% with the K-K method to 62.86% with the POC-CCA. PSAC aged 2–6 years were highly infected with S. mansoni than those aged 1-2 years (OR = 14.24, 95% CI: 5.85–34.64). PSAC who did not have access and who do not live close to the infected water source were at a significant lower risk of S. mansoni infection (OR = 0.13, 95% CI: 0.057–0.30). The main purpose of water contact of PSAC was to help their mother for laundry that occurs weekly. In Blapleu, a high risk of S. mansoni infection was observed among PSAC. Schistosomiasis control effort in such localities should include information, education, and communication, water, sanitation, and hygiene, and particularly chemotherapy targeting PSAC, reinforcing the need of the paediatric praziquantel formulation.

Prevalence of Helicobacter pylori among Patients with Gastrointestinal Tract (GIT) Symptoms: A Retrospective Study at Selected Africa Air Rescue (AAR) Clinics in Kampala, Uganda, from 2015 to 2019

Background. Helicobacter pylori (HP) infection is extremely common worldwide, with almost half of the world’s population infected. In Uganda, no study has been done on the trends of the prevalence of H. pylori infection in the affluent population. Therefore, this retrospective cross-sectional study aimed at determining the trend of H. pylori prevalence among affluent patients presenting with gastrointestinal (GIT) symptoms whose stool samples were tested at selected AAR clinics in Kampala area. Patients were tested for Helicobacter pylori infection using the stool antigen test between January 2015 and December 2019. Results. The overall 5-year H. pylori prevalence was 35.7% (1298/3634). The prevalence was higher in males (36.0% (736/2044)) than in females (35.4% (562/1590)), although not statistically significant (OR = 0.97, p = 0.680, 95% CI: 0.84–1.11). The prevalence of H. pylori infection was significantly higher (39.4%) among patients who belonged to the age group of 19–35 years (OR = 1.49, p < 0.001 , 95% CI: 1.22–1.82). The prevalence for H. pylori among the age group of 19–35, the most productive age, could be attributed to work-related factors such as stress. The highest prevalence (43.4%) was recorded in 2018 and the lowest (21.4%) in 2015; however, the trend of H. pylori infection in the 5 years was fluctuating. Conclusion. H. pylori infestation is a preserve of not only the poor but also the elites. Stressful factors, especially in the age group of 19–35 years, should be appropriately managed.