Prevalence of soil-transmitted helminths infections among preschool and school-age children in Ethiopia: a systematic review and meta-analysis.

BACKGROUND: There is a lack of comprehensive national data on prevalence, geographical distribution of different species, and temporal trends in soil-helminthiasis (STHs). Therefore, this study aimed to provide a summary and location of the available data on STHs infection among preschool and school-age children in Ethiopia. METHODS: The search was carried out in Medline via PubMed, Scopus, Science Direct, Web of Science, and Google Scholar on data published between 1997 to February 2020 for studies describing the rate of STHs infection among preschool and school-age in Ethiopian. We followed the Patient, Intervention, Comparison, and Outcome (PICO) approach to identify the studies. Meta-regression was performed to understand the trends and to summarize the prevalence using the "metaprop" command using STATA software version 14.0 RESULTS: A total of 29,311 of the 61,690 children examined during the period under review were infected with one or more species of intestinal parasites yielding an overall prevalence of 48% (95% CI: 43-53%). The overall pooled estimate of STHs was 33% (95% CI: 28-38%). The prevalence was 44% (95% CI: 31-58%) in SNNPR, 34% (95% CI: 28-41%) in Amhara region, 31% (95% CI: 19-43%) in Oromia region and 10% (95% CI: 7-12%) in Tigray region. Soil-transmitted helminths infection rate has been decreasing from 44% (95% CI: 30-57%) pre-Mass Drug Administration (MDA) era (1997-2012) to 30% (95% CI: 25-34%) post-MDA (2013-2020), although statistically not significant (p = 0.45). A lumbricoides was the predominant species with a prevalence of 17%. CONCLUSION: Southern Nations Nationalities and Peoples Region, Amhara, and Oromia regions carry the highest-burden and are categorized to Moderate Risk Zones (MRZ) and therefore, requiring MDA once annually with Albendazole or Mebendazole. The prevalence of STHs decreased after MDA compared to before MDA, but the decline was not statistically significant. A. lumbricoides was the predominant species of STHs among preschool and school-age children in Ethiopia. The high prevalence of STHs observed in this review, underscores the need for better control and prevention strategies in Ethiopia.

Epidemiology of intestinal parasitic infections in preschool and school-aged Ethiopian children: a systematic review and meta-analysis.

BACKGROUND: Numerous studies have been carried out on assessing the prevalence of intestinal parasites infections (IPIs) amongpreschool and school-age children in Ethiopia, but there is lack of study systematically gathered and analyzedinformation for policymakers. Therefore, the aim of this systematic review and meta-analysis was to provide a summary on prevalence, geographical distribution and trends of IPIs among preschool and school-age childrenin Ethiopia. METHODS: The search were carried out in Medline via PubMed, Scopus, Science Direct, Web of Science, and Google Scholar from 1996to July2019 for studies describing prevalence of IPIs among preschooland school-age children. We conducted meta-regression to understand the trends and the source of heterogeneity and pooled the prevalence using 'metaprop' command using STATA software version 14. RESULTS: Eighty-three(83) studies examining 56,786 fecal specimens were included. The prevalence of IPIs was 48%(95%CI: 42 to 53%) and showedsignificantly decreasing trends 17% (95% CI: 2.5 to 32%) for each consecutive 6 years) and was similar in males and females. The pooled prevalence in years 1997-2002, 2003-2008, 2009-2014 and > 2014 was 71% (95% CI: 57 to 86%), 42% (95% CI: 27 to 56%), 48% (95% CI: 40 to 56%) and 42% (95% CI: 34 to 49%), respectively. Poly-parasitism was observed in 16% (95% CI: 13 to 19%,) of the cases. CONCLUSION: Intestinal parasite infections are highly prevalent among preschool and school-age children and well distributed across the regional states of Ethiopia. Southern and Amhara regional states carry the highest burden. We observed significant decreasing trends in prevalence of IPIs among preschool and school-ageEthiopian children over the last two decades. Therefore, this study is important to locate the geographical distribution and identified high risk areas that should be prioritized further interventions, which complement global efforts towards elimination of IPIs infections by 2020.

Anopheline mosquitoes behaviour and entomological monitoring in southwestern Ethiopia.

BACKGROUND & OBJECTIVES: Despite a tremendous expansion in the financing and coverage of malaria control programmes, the disease continues to be a global health threat. This study was conducted to assess the entomological parameters of anopheline mosquitoes, viz. species composition, abundance, longevity, behaviour and infectivity rates in Kersa district, Jimma zone, southwestern Ethiopia. METHODS: Mosquito collection was carried out from each selected household in each of the nine selected study villages of Kersa district, using CDC light-traps and pyrethrum spray catches (PSCs) for seven months (June to December 2014). Mosquito count data were log transformed before analysis and the data were analyzed using SPSS software package version 16.0. Analysis of variance (ANOVA) was employed to compare means and Tukey's post-hoc test was used for mean separation. RESULTS: In total, 1559 adult female anopheline mosquitoes, representing at least three species were collected from the study villages. Of these, 1122 were collected by CDC light-traps and the rest 437 were collected by PSCs. Anopheles gambiae s.1. (71.8%) was the most abundant species, followed by An. coustani s.1. (22%) and An. pharoensis (6.2%). The mean monthly density of anopheline mosquito species was highly significant (p < 0.001). Significantly (p <0.05) higher population of An. gambiae s.1. were trapped indoor than outdoor. However, outdoor mean densities of An. pharoensis and An. coustani s.1. were significantly (p < 0.001) higher than indoor mean densities. The longevity of An. gambiae s.1. was higher in the months of June, July and August (mean 7.32 days) and lower in the months of October, November and December (mean 2.94 days). Two An. gambiae s.1. specimens were found positive for Plasmodium vivax 210 polymorphs and the overall infectivity rate was estimated to be 1.04%. INTERPRETATION & CONCLUSION: This study could contribute to the understanding of anopheline mosquitoes with respect to their composition, dynamics, distribution and behaviour in Kersa district, for evidence based malaria vector control programmes, mainly in the appropriate timing of the indoor residual spray programme.

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.

Prevalence of Schistosoma mansoni infection and the therapeutic efficacy of praziquantel among school children in Manna District, Jimma Zone, southwest Ethiopia.

BACKGROUND: Intestinal schistosomiasis is one of the neglected tropical parasitic diseases caused by Schistosoma mansoni. Currently, the control measures for the disease are mainly based on mass drug administration (MDA) with praziquantel (PZQ) targeting the school-age children. In Ethiopia, the potential foci for schistosomiasis and therapeutic efficacy of PZQ among school-age children remain poorly explored. Therefore, we determined both the prevalence and intensity of S. mansoni infection and the therapeutic efficacy of PZQ among school children in the Manna District (new foci for S. mansoni), Jimma Zone, southwest Ethiopia. METHODS: A cross-sectional study was conducted among the school children aged between 6 and 18 years in three primary schools in Manna district from March to April 2014. For diagnosis of S. mansoni, a single stool sample was obtained from each child and processed using single Kato Katz and examined under light microscopy. A questionnaire was used to collect demographic information of the school children participated in the study. School children excreting eggs of S. mansoni were administered with 40 mg/kg of PZQ and re-examined after three weeks post-treatment. The therapeutic efficacy of PZQ against S. mansoni was evaluated by means of cure rate and egg reduction rate. RESULTS: The overall prevalence of S. mansoni among the school children in the three primary schools in Manna District was 24.0 %. Higher prevalence was recorded for males 25.6 % (61/238) than for females 22.5 % (59/262). Majority (27.5 %) of infection intensity was light with mean faecal egg count (FEC) of 202 eggs per gram (EPG). The therapeutic efficacy of PZQ at a dose of 40 mg/kg was highly efficient (cure rate of 99.1 % and egg reduction rate of 99.9 %) among the school children in the three primary schools in Manna District. CONCLUSIONS: The school children in the three primary schools of Manna District, Jimma Zone were at moderate risk of the morbidity caused by S. mansoni (prevalence > 10 % and < 50 % according to WHO threshold), and hence a biannual MDA with PZQ is required. PZQ available on the local market was found efficient and can be recommended for individual treatment in absence of MDA. The therapeutic efficacy of PZQ at 40 mg/kg against S. mansoni was high in the study area.

Seasonal Dynamics, Longevity, and Biting Activity of Anopheline Mosquitoes in Southwestern Ethiopia.

Continuous monitoring of vector species composition, abundance, dynamics, feeding pattern, and host finding strategy is the base to determine when, what, and how control should be implemented. Thus, this study was conducted to assess entomological parameters of anopheline mosquitoes in nine villages in Seka district, southwestern Ethiopia, from June to December 2012. Mosquito collection was carried out from selected households in each of the nine study villages using light trap catches from June to December 2012. Differences in mean mosquito density, parity rates before, and after indoor residual spraying (IRS) operation were compared. In total, 1,136 adult female anopheline mosquitoes were collected during the study period. All anopheline mosquitoes collected belong to three species. Anopheles gambiae senso lato Giles was the most predominant (69.7%) followed by Anopheles coustani s.l. Laveran (22.7%) and Anopheles pharoensis Theobald (7.6%). There was significant variation in mean mosquito density among An. gambiae s.l., An. coustani s.l., and An. pharoensis. Parity rate of An. gambiae s.l. before spray operation was significantly higher than after spray operation. The highest peak biting activity of An. gambiae s.l. was between 1800 and 2100 hours. The longevity of An. gambiae s.l. ranged from 3.4 to 12.5 d. The highest vector abundance and parity rate were recorded in July and August. In conclusion, the behavioral plasticity and early biting activity of An. gambiae s.l. could affect current vector control tools (IRS and long lasting insecticidal nets). Hence, it is imperative to explore intervention tools for outdoor malaria vector control in addition to the existing IRS and long-lasting insecticidal nets.

Malaria incidence and assessment of entomological indices among resettled communities in Ethiopia: a longitudinal study.

BACKGROUND: Population resettlement has been considered among factors that may increase risk of malaria transmission. This study reports, the impact of resettlement on malaria incidence and entomological indices among communities resettled in suburbs of Jimma town, southwestern Ethiopia. METHODS: A cohort of 604 study participants (302 resettlers and 302 non-resettlers) was monthly followed-up from September to November 2013 using active case detection. Moreover, longitudinal entomological study was conducted from June to November 2013. Anopheline mosquitoes were collected using CDC light traps and pyrethrum spray catches. Sporozoite ELISA was performed to determine Plasmodium infection rates. RESULTS: Overall, 112 malaria cases were recorded during the three-month follow-up, of which 74.1% of the cases were from resettlement villages. Plasmodium falciparum incidence from resettlement and non-resettlement villages was 52.5 and 14.5/1,000 person-months at risk, respectively. Resettlement villages were three times at higher risk of Plasmodium infection (OR = 2.8, 95% CI: 1.22-6.48). Anopheles gambiae s.l. was the predominant (86.6%) of all the collected anopheline mosquito species. Plasmodium sporozoite rate in the resettlement and non-resettlement villages was 2.1 and 0.72%, respectively. Plasmodium falciparum entomological inoculation rate (EIR) for An. gambiae s.l. in the resettlement and non-resettlement villages was 13.1 and 0 infective bites/person/night, respectively. Both sporozoite rate and EIR were significantly higher in the resettlement villages (p < 0.05). CONCLUSION: Resettled communities were at higher risk of malaria infection as compared to non-resettled communities. Special attention should be given to malaria control interventions during resettlement programmes.

Prevalence and intensity of soil-transmitted helminth infections among pre-school age children in 12 kindergartens in Jimma Town, southwest Ethiopia.

BACKGROUND: Pre-school age children (preSAC) remain difficult to reach in mass drug administration (MDA) programmes to control soil-transmitted helminth (STH) infections. Kindergartens provide a unique platform to increase the coverage of MDA in preSAC in Ethiopia, but surveys assessing STHs among preSAC in kindergartens are scarce. METHODS: We report the prevalence and intensity of STH infections among 622 preSAC in 12 kindergartens in Jimma, Ethiopia. RESULTS: STHs were found in all kindergartens, with prevalence exceeding 50% in 8 kindergartens. The majority of the infections were of low intensity. CONCLUSIONS: This study highlights the importance of kindergartens as an additional opportunity for MDA in Ethiopia.