Evaluation of non-instrumented nucleic acid amplification by loop-mediated isothermal amplification (NINA-LAMP) for the diagnosis of malaria in Northwest Ethiopia.

BACKGROUND: Malaria is a major public health problem in sub-Saharan African countries including Ethiopia. Early and accurate diagnosis followed by prompt and effective treatment is among the various tools available for prevention, control and elimination of malaria. This study aimed to evaluate the performance of non-instrumented nucleic acid amplification loop-mediated isothermal amplification (NINA-LAMP) compared to standard thick and thin film microscopy and nested PCR as gold standard for the sensitive diagnosis of malaria in Northwest Ethiopia. METHODS: A cross-sectional study was conducted in North Gondar, Ethiopia from March to July 2014. Eighty-two blood samples were collected from malaria suspected patients visiting Kola Diba Health Centre and analysed for Plasmodium parasites by microscopy, NINA-LAMP and nested PCR. The NINA-LAMP method was performed using the Loopamp Malaria Pan/Pf detection kits for detecting DNA of the genus Plasmodium and more specifically Plasmodium falciparum using an electricity-free heater. Diagnostic accuracy outcome measures (analytical sensitivity, specificity, predictive values, and Kappa scores) of NINA-LAMP and microscopy were compared to nested PCR. RESULTS: A total of 82 samples were tested in the primary analysis. Using nested PCR as reference, the sensitivity and specificity of the primary NINA-LAMP assay were 96.8% (95% confidence interval (CI), 83.2% - 99.5%) and 84.3% (95% CI, 71.4% - 92.9%), respectively for detection of Plasmodium genus, and 100% (95% CI, 75.1% - 100%) and 81.2% (95% CI, 69.9% - 89.6%), respectively for detection of P. falciparum parasite. Microscopy demonstrated sensitivity and specificity of 93.6% (95% CI, 78.5% - 99.0%) and 98.0% (95% CI, 89.5% - 99.7%), respectively for the detection of Plasmodium parasites. Post-hoc repeat NINA-LAMP analysis showed improvement in diagnostic accuracy, which was comparable to nested PCR performance and superior to microscopy for detection at both the Plasmodium genus level and P. falciparum parasites. CONCLUSION: NINA-LAMP is highly sensitive for the diagnosis of malaria and detection of Plasmodium parasite infection at both the genus and species level when compared to nested PCR. NINA-LAMP is more sensitive than microscopy for the detection of P. falciparum and differentiation from non-falciparum species and may be a critical diagnostic modality in efforts to eradicate malaria from areas of low endemicity.

Prevalence, intensity of infection and associated risk factors of soil-transmitted helminth infections among school children at Tachgayint woreda, Northcentral Ethiopia.

BACKGROUND: Soil-transmitted helminths (STH) are one of the most common infections affecting underprivileged populations in low- and middle-income countries. Ascaris lumbricoides, Trichuris trichiura, and hookworm are the three main species that infect people. School children are the most vulnerable groups for STH infections due to their practice of walking and playing barefoot, poor personal hygiene, and environmental sanitation. However, evidence is limited in the study area. So, this study aimed to assess the current prevalence, infection intensity, and associated risk factors of STHs among school children in Tachgayint woreda, Northcentral Ethiopia. METHODS: A cross-sectional study was conducted among school children of Tachgayint woreda from February to May 2021. The study participants were chosen via systematic random sampling. Stool samples were collected from 325 children and examined using the Kato-Katz technique. The data was analyzed using SPSS version 23. Binary and multivariable logistic regression analyses were used to identify the potential associated factors for STHs. An adjusted odds ratio (AOR) with a 95% confidence interval (CI) was used to measure the magnitude of the association. A P-value <0.05 was considered statistically significant. RESULTS: The overall prevalence of STHs in this study was 36.0% (95% CI: 30.5-41.2%). Ascaris lumbricoides are the most prevalent species 89 (27.4%) followed by hookworm 14 (4.3%) and Trichuris trichiura 10 (3.1%). All of the infected school children had light-intensity of infections with the mean of eggs per gram (EPG) being 464.53. Lack of shoe wearing habit (AOR = 4.08, 95% CI: 1.29-12.88) and having untrimmed fingernail (AOR = 1.85, 95% CI: 1.06-3.22) were identified as risk factors for STH infections. CONCLUSIONS: More than one-third of the school children were infected with at least one STH species and this indicates that STHs are still a health problem among school children in the study area. Therefore, periodic deworming, implementation of different prevention strategies, and health education programs should be regularly applied in the area.

Evaluation of urine sample for diagnosis of visceral leishmaniasis using rK-39 immunochromatographic test in Northwest Ethiopia.

BACKGROUND: Visceral leishmaniasis is the most severe form of leishmaniasis which ranks second in mortality and fourth in morbidity. Parasitological diagnostic techniques with splenic aspirate remain the gold standard. However, sample collection is risky, painful, and difficult. Alternatively, serological techniques provide good diagnostic accuracy using serum sample that is difficult for applying on small children and in the field. So, finding alternative non-invasive and self-collected samples like urine is very important. Thus, the study aimed to evaluate the diagnostic performance of the rK-39 strip test using urine for diagnosis of visceral leishmaniasis. METHODS: A multicenter institutional-based cross-sectional study was conducted from November 2019 to March 2021 at Northwest Ethiopia. Sociodemographic information was collected using a structured questionnaire. Blood sample and midstream urine sample were collected for rK-39 test. Data were entered into Epi-data version 4.2 and analyzed using SPSS version 24.0. Diagnostic performance parameters of urine-based rK-39 rapid test, i.e. sensitivity, specificity, positive and negative predictive values, positive and negative likelihood ratios (LR+/-), and diagnostic accuracy were determined on contingency table by using serum-based rK-39 test result as a reference. An agreement between urine and serum-based rK-39 test was statistically determined by kappa value. RESULT: In total, 300 subjects, age ranged between 7 and 60 years, were included in the study. The overall sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of urine-based rK-39 test were found to be 98.0% (95% CI: 93.0% - 99.8%), 95.5% (95% CI: 91.6% - 97.9%), 91.6% (95% CI: 85.2%- 95.4%), 98.9 (95% CI: 96.0%- 99.7%), and 96.33% (95% CI: 93.53-98.16%), respectively. Additionally, there was a strong agreement between the results obtained on rK-39 ICT using urine and serum samples (kappa = 0.92; P < 0.001). CONCLUSION: Urine-based rK-39 ICT had an excellent high sensitivity, specificity and strong agreement with serum-based rK-39 ICT results. This indicates that urine sample would be a promising noninvasive and easy to collect sample for diagnosis of VL in field and rural settings.

Prevalence of Intestinal Parasitosis and Its Associated Factors Among Children Aged 6 to 59 months Attending Mekane Eyesus Primary Hospital, Northcentral Ethiopia.

Background. Intestinal parasites are still a serious public health problem and important cause of morbidity and mortality all over the world, particularly in developing countries. Unfortunately, pre-school children are more susceptible to infection. However, information is scarce in the study area. Thus, this study aimed to assess the prevalence of intestinal parasitosis and associated factors among children aged 6 to 59 months in Northcentral Ethiopia. Methods. An institutional-based cross-sectional study was carried out at Mekane Eyesus primary hospital from June 10 to November 30, 2020. Stool samples were collected from 322 children and examined by using direct wet mount and formal ether concentration techniques. The data were entered and analyzed using EPI Info v7 and SPSS v23 statistical software, respectively. Both bivariable and multivariable logistic analysis was carried out and potential associated factors were identified based on adjusted odds ratio with 95% confidence interval and P-value <.05. Results. The prevalence of intestinal parasitosis was 18.0% (95% CI: 14.0%-22.0%). A total of 4 parasites were examined and the dominant parasite was E. histolytica/dispar (8.1%) followed by A. limbricoide (4.7%). Children with irregular trimming of fingernails (AOR = 3.14, 95% CI: 1.59-6.21), and child who have habit of eating unwashed fruits/vegetables (AOR = 3.80, 95% CI: 1.14-12.82) were strongly associated with IPIs. Conclusions. Protozoa parasites are most common cause of diseases in children. The study identified some preventable and modifiable factors to address the prevalence of IPIs. Additionally, improving mothers/guardians awareness about source of infection and mode of transmission is necessary.

Prevalence of intestinal parasitic infections and associated factors among patients attending at Sanja Primary Hospital, Northwest Ethiopia: An institutional-based cross-sectional study.

BACKGROUND: Intestinal Parasitic Infections are the most prevalent diseases in the world, predominantly in developing countries. It is estimated that more than two billion people are affected globally, mostly in tropical and sub-tropical parts of the world. Ethiopia is one of the countries in Africa with a high prevalence of intestinal parasites. However, there is a limited study conducted in the study area. Hence, this study was to assess the prevalence and associated factors of intestinal parasitosis among patients attending at Sanja Primary Hospital, Northwest Ethiopia. METHODS: An institutional-based cross-sectional study was conducted at Sanja Primary Hospital from January 1 to August 20, 2019. Stool samples were collected from 1240 study participants and analyzed by direct wet mount and formal ether concentration techniques. Furthermore, sociodemographic and explanatory variables were collected using a face-to-face interview. Data were entered into Epi data version 4.4.2.1 and transferred to SPSS version 23 for analysis. Bivariate and multivariate binary logistic regression models were fitted to identify associated factors of intestinal parasitic infections. Adjusted Odds Ratio (AOR) with 95% confidence interval (CI) was considered to ascertain the significance of the association. RESULTS: The overall prevalence of intestinal parasitic infection was 52.9% (95% CI: 50.2%-55.5%). Entamoeba histolytica/dispar (21.5%) was the leading cause of intestinal parasitosis followed by Hookworm species (13.3%). Furthermore, the rate of double and triple parasitic infections was observed in 6.1% and 0.5% of study participants respectively. Being Illiterate (AOR: 2.87, 95% CI: 1.06-7.47, p = 0.038), swimming habits of more than 4 times a month (AOR = 2.91, 95% CI 1.62-5.24, p< 0.001) and not washing hands before a meal (AOR: 3.92, 95% CI: 1.74-8.83, p = 0.001) were the key factors significantly associated with intestinal parasitic infection. CONCLUSIONS: The present study showed that the prevalence of intestinal parasitosis is high in the study area. Therefore, there is a need for an integrated control program, including improving personal, environmental sanitation and health education should be given to have a lasting impact on transmission.