Diagnostic performance of NxTek™ Eliminate Malaria-Pf test for the detection of Plasmodium falciparum in school children with asymptomatic malaria.

BACKGROUND: One of the major roadblocks to the falciparum malaria elimination programme is the presence of a portion of the population, such as school children, with asymptomatic malaria infection. Targeting such reservoirs of infections is critical to interrupting transmission and enhancing elimination efforts. The NxTek™ Eliminate Malaria Pf test is a highly sensitive rapid diagnostic test (hsRDT) for the detection of HRP-2. However, knowledge gaps exist in Ethiopia on the diagnostic performance of hsRDT for the detection of Plasmodium falciparum in school children with asymptomatic malaria. METHODS: A school-based cross-sectional study was conducted from September 2021 to January 2022 on 994 healthy school children (aged 6-15 years). Finger-pricked whole blood samples were collected for microscopy, hsRDT, conventional RDT (cRDT or SD Bioline Malaria Ag Pf/P.v), and QuantStudio™ 3 Real-Time PCR system (qPCR). The hsRDT was compared to cRDT and microscopy. qPCR and microscopy were used as reference methods. RESULTS: The prevalence of Plasmodium falciparum was 1.51%, 2.2%. 2.2% and 4.52%, by microscopy, hsRDT, cRDT and qPCR, respectively. Using qPCR as reference, the sensitivity of hsRDT was higher (48.89%) than the microscopy (33.3%), and showed 100% specificity and a positive predictive value (PPV). Microscopy showed similar specificity and PPV as hsRDT. Using microscopy as a reference, the diagnostic perforrmances of both hsRDT and cRDT were similar. Both RDTs demonstrated identical diagnostic performances in both comparison methods. CONCLUSIONS: hsRDT has the same diagnostic performance as cRDT but improved diagnostic characteristics than microscopy for detection of P. falciparum in school children with asymptomatic malaria. It can be a useful tool for the national malaria elimination plan of Ethiopia.

Reference Intervals for Absolute and Percentage CD4+ T Lymphocytes among an Apparently Healthy Population in Addis Ababa, Ethiopia.

Background: Reference intervals for clinical laboratory parameters differ based on several factors, including age, sex, genetic variation, and geographic location. This variation influences clinical decisions and treatment monitoring. Currently, Ethiopia has used adopted reference intervals from manufacturer values derived from non-Africans. Therefore, the aim this study was to determine reference intervals for absolute and percentage CD4+ T cells for an apparently healthy population in Addis Ababa, Ethiopia. Methods: A community-based cross-sectional study was conducted on 361 apparently healthy people in four subcities in Addis Ababa from January to June 2019. Sociodemographic and clinical data were collected using a structured questionnaire after informed consent had been obtained. Blood samples were collected and CD4+ T-lymphocyte enumeration performed using a BD FACSPresto near-patient CD4 counter. Data were entered and analyzed using SPSS 20. Reference intervals were determined by a nonparametric test estimating percentiles 2.5 (lower limit) and 97.5 (upper limit) with 95% CIs. P<0.05 was considered statistically significant. Results: A total of 337 (183 female and 154 male) healthy participants of median age 28 (IQR 17-35) years were included in the final analysis. Medians of absolute and percentage CD4+ T-cell counts (932.0 and 42.9, respectively) of female participants were significantly higher than male participants (802.5 and 38.7, respectively; P<0.05). Reference intervals for absolute CD4+ T-cell count and percentages in males were 483.8-1,310 cells/µL and 18.1-57.3 and in females 447.8-1,479.8 cells/µL and 25.6-58.9, respectively. Conclusion: The CD4+ T-count reference intervals established in this study showed some inconsistency from the manufacturer's provided values and other studies and also revealed sex differences, necessitating sex-specific locally established reference intervals.

Assessment of Coverage and Quality of Selected Clinical Chemistry Tests among Medical Laboratories of Health Facilities in Jimma Zone, South West Ethiopia.

BACKGROUND: Medical laboratories play essential roles in measurement of analyte in clinical sample for the diagnosis and monitoring of diseases. Thus, data generated from the laboratory have to be reliable for which strict quality assurance is maintained. OBJECTIVE: To assess the coverage and quality of selected clinical chemistry tests among medical laboratories of health facilities in, Jimma Zone, South West Ethiopia. METHODS: A cross-sectional study was conducted at Jimma Zone on health facilities from August 15 to September 15, 2014. Eighty-six health facility laboratories were included in the study. We classified laboratories into laboratories with clinical chemistry service and those without clinical chemistry service clusters and those with clinical chemistry laboratory were again clustered according to their level. Data were collected by direct observation, interview, and proficiency testing (PT). The collected data were analyzed and compared with CLIA PT goal for TEa by considering total allowable error ± 20%, ±10%, ±15%, and ±20 for each analyte, ALT, glucose, creatinine, and total bilirubin, respectively. RESULT: From total of 86 health facilities with laboratories, 23.3% (n=20) had clinical chemistry service, of which 77.2% results were reported outside of the allowable error limit. CONCLUSION: According to this study the availability of clinical chemistry test service was very minimal and facilities giving the service do not fulfill the minimum standard for quality; thus clients were either getting wrong clinical decision or misdiagnosed. Therefore, the external and internal quality assessment programs should be reviewed very well. Those laboratories whose report was outside of the allowable error should have to report results with the appropriate reference range so that physicians consider that. Establishment of local clinical chemistry reference range can also minimize the problem.

Insecticide resistance in Anopheles arabiensis from Ethiopia (2012-2016): a nationwide study for insecticide resistance monitoring.

BACKGROUND: Indoor residual spraying (IRS) and long-lasting insecticidal nets (LLINs) remain the cornerstones of malaria vector control. However, the development of insecticide resistance and its implications for operational failure of preventative strategies are of concern. The aim of this study was to characterize insecticide resistance among Anopheles arabiensis populations in Ethiopia and describe temporal and spatial patterns of resistance between 2012 and 2016. METHODS: Between 2012 and 2016, resistance status of An. arabiensis was assessed annually during the long rainy seasons in study sites from seven of the nine regions in Ethiopia. Insecticide resistance levels were measured with WHO susceptibility tests and CDC bottle bioassays using insecticides from four chemical classes (organochlorines, pyrethroids, organophosphates and carbamates), with minor variations in insecticides tested and assays conducted between years. In selected sites, CDC synergist assays were performed by pre-exposing mosquitoes to piperonyl butoxide (PBO). In 2015 and 2016, mosquitoes from DDT and deltamethrin bioassays were randomly selected, identified to species-level and screened for knockdown resistance (kdr) by PCR. RESULTS: Intense resistance to DDT and pyrethroids was pervasive across Ethiopia, consistent with historic use of DDT for IRS and concomitant increases in insecticide-treated net coverage over the last 15 years. Longitudinal resistance trends to malathion, bendiocarb, propoxur and pirimiphos-methyl corresponded to shifts in the national insecticide policy. By 2016, resistance to the latter two insecticides had emerged, with the potential to jeopardize future long-term effectiveness of vector control activities in these areas. Between 2015 and 2016, the West African (L1014F) kdr allele was detected in 74.1% (n = 686/926) of specimens, with frequencies ranging from 31 to 100% and 33 to 100% in survivors from DDT and deltamethrin bioassays, respectively. Restoration of mosquito susceptibility, following pre-exposure to PBO, along with a lack of association between kdr allele frequency and An. arabiensis mortality rate, both indicate metabolic and target-site mutation mechanisms are contributing to insecticide resistance. CONCLUSIONS: Data generated by this study will strengthen the National Malaria Control Programme's insecticide resistance management strategy to safeguard continued efficacy of IRS and other malaria control methods in Ethiopia.

Transmission dynamics of co-endemic Plasmodium vivax and P. falciparum in Ethiopia and prevalence of antimalarial resistant genotypes.

Ethiopia is one of the few African countries where Plasmodium vivax is co-endemic with P. falciparum. Malaria transmission is seasonal and transmission intensity varies mainly by landscape and climate. Although the recent emergence of drug resistant parasites presents a major issue to malaria control in Ethiopia, little is known about the transmission pathways of parasite species and prevalence of resistant markers. This study used microsatellites to determine population diversity and gene flow patterns of P. falciparum (N = 226) and P. vivax (N = 205), as well as prevalence of drug resistant markers to infer the impact of gene flow and existing malaria treatment regimes. Plasmodium falciparum indicated a higher rate of polyclonal infections than P. vivax. Both species revealed moderate genetic diversity and similar population structure. Populations in the northern highlands were closely related to the eastern Rift Valley, but slightly distinct from the southern basin area. Gene flow via human migrations between the northern and eastern populations were frequent and mostly bidirectional. Landscape genetic analyses indicated that environmental heterogeneity and geographical distance did not constrain parasite gene flow. This may partly explain similar patterns of resistant marker prevalence. In P. falciparum, a high prevalence of mutant alleles was detected in codons related to chloroquine (pfcrt and pfmdr1) and sulfadoxine-pyrimethamine (pfdhps and pfdhfr) resistance. Over 60% of the samples showed pfmdr1 duplications. Nevertheless, no mutation was detected in pfK13 that relates to artemisinin resistance. In P. vivax, while sequences of pvcrt-o were highly conserved and less than 5% of the samples showed pvmdr duplications, over 50% of the samples had pvmdr1 976F mutation. It remains to be tested if this mutation relates to chloroquine resistance. Monitoring the extent of malaria spread and markers of drug resistance is imperative to inform policy for evidence-based antimalarial choice and interventions. To effectively reduce malaria burden in Ethiopia, control efforts should focus on seasonal migrant populations.

Relationship between exposure to malaria and haemoglobin level of children 2-9 years old in low malaria transmission settings.

In the context of reduced transmission of malaria, it is essential to examine the association between exposure to malaria and haemoglobin level. This study measured the Haemoglobin level of children 2-9 years of age and examined its association with malariometric indices. A cross sectional study was conducted, during June 2016, on 763 children 2-9 years old, recruited from ten sites representing different malaria transmission settings in Ethiopia. Haemoglobin concentration was determined using HemoCue analyzer. Malariometric indices (splenomegaly rate, parasite rate and serological marker) were measured. The overall prevalence of anaemia was 17.3% (95% CI: 14.6-19.9) in the study population. Mild, moderate and severe anaemia accounted for 7.3%, 7.2% and 2.8% respectively. Of the children with anaemia (132), only 7 (5.3%) had malaria parasitaemia. The prevalence of malaria parasitaemia was 3.6% (2/56), 9.1% (5/55) and 0.0% (0/21) among children with mild, moderate and severe anaemia, respectively. Malaria reactive antibody and anaemia co-occurred in 3.13% (21/672) of the samples. Seroprevalence and parasitaemia did not have significant association with anaemia (p>0.05). However, splenomegaly was significantly associated with increased risk of anaemia (AOR=14.93; p=0.001). Anaemia was significantly higher among children 2-4 years old (22.2%), and children living in households without any insecticide treated bed net (34.0%). The prevalence of anaemia was lower by 55.0% among children living in households with at least one net (AOR=0.45, 95% CI: 0.21-0.96). Repeated exposure to malaria infections (seropositive) and parasitaemia was less likely to contribute to development of anaemia among children 2-9 years in this study setting. Thus, in low malaria endemic settings, anaemia prevention and control program required to reconsider the historical evidence that suggests malaria is one of the major risk factor for anaemia.

Analysis of asymptomatic and clinical malaria in urban and suburban settings of southwestern Ethiopia in the context of sustaining malaria control and approaching elimination.

BACKGROUND: Malaria intervention in Ethiopia has been strengthened significantly in the past decade. The Ethiopian government recently stratified the country based upon annual parasite incidence into malaria free, low, moderate and high transmission strata. Districts with low transmission were targeted for indigenous transmission elimination. Surveillance on malaria disease incidence is needed for planning control and elimination efforts. METHODS: Clinical malaria was monitored prospectively in health facilities in Jimma town, Oromia Region, southwestern Ethiopia from July 2014 to June 2015. Seasonal cross-sectional parasite prevalence surveys in local communities were conducted in 2014 and 2015 in eight kebeles. Case report forms were administered to obtain sociodemographic and epidemiological information from patients. RESULTS: A total of 1434 suspected malaria cases were examined from the health facilities and 428 confirmed malaria cases were found. Among them, 327 (76.4 %) cases were Plasmodium vivax, 97 (22.7 %) were Plasmodium falciparum, and 4 (0.9 %) were mixed infection of P. vivax and P. falciparum. The annual malaria incidence rate was 1.7 cases per 1000 people at risk. Parasite prevalence in the community was less than 3 %. Household ownership of insecticide-treated nets (ITNs) was 47.3 % (1173/2479) and ITN usage was 37.9 %. All ITNs were long-lasting insecticidal nets, and repellent use was not found in the study area. Being male and traveling were the significant risk factors for P. falciparum malaria. For P. vivax malaria, risk factors included occupation and history of malaria illness during the preceding 30 days. CONCLUSION: Epidemiological evidence suggested low clinical malaria incidence and prevalence in Jimma town. More aggressive measures may be needed to further suppress vivax transmission. Strategies should be planned targeting sustained control and elimination.

Diagnostic detection of human immunodeficincy virus type-1 antibodies in urine, Jimma Hospital, south west Ethiopa.

BACKGROUND: Testing for human immunodeficiency virus (HIV) specific antibodies continues to be the most important measure in diagnosis and HIV intervention. Detection of anti-HIV antibodies in serum or plasma samples are common strategies. However, body fluids such as urine and saliva could serve as an alternative sample for diagnosis of HIV infection. OBJECTIVE: To determine the diagnostic accuracy of Calypte HIV-1 urine EIA test kits for detection of HIV antibodies in urine sample. METHODS: Urine and serum samples were collected from a total of 365 subjects (HIV suspected (n=156), VCT clients (n=129) and 80 known HIV positive individuals at Jimma Hospital VCT center, OSSA, Red Cross and Mekaneyessus Jimma cohort sites in unlinked anonymous testing method. Urine sample were tested using Calypte HIV-1 urine EIA kits parallel to the golden standard method of testing serum samples by combination of Determine and Vironostica (Rapid test followed by ELISA) test algorithm. All discordant samples (by urine serum tests) were resolved using urine western blot (Calypte HIV-1 urine Western Blot). RESULT: Comparing the results obtained with a golden standard (HIV test algorithm) the sensitivity and specificity of urine EIA test kit were 99.5% (187/188) and 98.3% (174/177) respectively. Beside to this kappa's test of agreement showed perfect agreement with kappa 0.98. CONCLUSION: The result showed the utility of urine test as an alternative method for HIV antibody detection. Since the method of collection of urine specimen is non-invasive, it reduces occupational exposure for health professionals involved in collecting samples. Furthermore patient's stronger acceptance to give urine samples will make this test more applicable than serum or whole blood test.