Unveiling P. vivax invasion pathways in Duffy-negative individuals.

Vivax malaria has long been thought to be absent from sub-Saharan Africa owing to the high proportion of individuals lacking the Duffy antigen receptor for chemokines (DARC) in their erythrocytes. The interaction between P. vivax Duffy-binding protein (PvDBP) and DARC is assumed to be the main pathway used by merozoites to invade reticulocytes. However, the increasing number of reports of vivax malaria cases in genotypically Duffy-negative (DN) individuals has raised questions regarding the P. vivax invasion pathway(s). Here, we show that a subset of DN erythroblasts transiently express DARC during terminal erythroid differentiation and that P. vivax merozoites, irrespective of their origin, can invade DARC+ DN erythroblasts. These findings reveal that a large number of DN individuals may represent a silent reservoir of deep P. vivax infections at the sites of active erythropoiesis with low or no parasitemia, and it may represent an underestimated biological problem with potential clinical consequences in sub-Saharan Africa.

Ethiopian Plasmodium vivax hypnozoites formation dynamics and their susceptibility to reference antimalarial drugs.

One of the key obstacles to malaria elimination is largely attributed to Plasmodium vivax's ability to form resilient hypnozoites in the host liver that cause relapsing infections. As a result, interruption of P. vivax transmission is difficult. P. vivax transmission occurs in Duffy-positive individuals and have been mainly thought to be absent in Africa. However, increasing studies using molecular tools detected P. vivax among Duffy-negative individuals in various African countries. Studies on the African P. vivax has been severely limited because most of malaria control program focus mainly on falciparum malaria. In addition, there is a scarcity of laboratory infrastructures to overcome the biological obstacles posed by P. vivax. Herein, we established field transmission of Ethiopian P. vivax for routine sporozoite supply followed by liver stage infection in Mali. Furthermore, we evaluated local P. vivax hypnozoites and schizonts susceptibilities to reference antimalarial drugs. The study enabled the assessment of local African P. vivax hypnozoite production dynamics. Our data displayed the ability of the African P. vivax to produce hypnozoite forms ex-vivo at different rates per field isolate. We report that while tafenoquine (1µM) potently inhibited both hypnozoites and schizont forms; atovaquone (0.25µM) and the phosphatidylinositol-4-OH kinase (PI4K)-specific inhibitor KDU691 (0.5µM) showed no activity against hypnozoites forms. Unlike hypnozoites forms, P. vivax schizont stages were fully susceptible to both atovaquone (0.25µM) and the (PI4K)-specific inhibitor KDU691 (0.5µM). Together, the data revealed the importance of the local platform for further biological investigation and implementation of drug discovery program on the African P. vivax clinical isolates.

Differential transmissibility to Anopheles arabiensis of Plasmodium vivax gametocytes in patients with diverse Duffy blood group genotypes.

BACKGROUND: Measuring risk of malaria transmission is complex, especially in case of Plasmodium vivax. This may be overcome using membrane feeding assays in the field where P. vivax is endemic. However, mosquito-feeding assays are affected by a number of human, parasite and mosquito factors. Here, this study identified the contributions of Duffy blood group status of P. vivax-infected patients as a risk of parasite transmission to mosquitoes. METHODS: A membrane feeding assay was conducted on a total of 44 conveniently recruited P. vivax infected patients in Adama city and its surroundings in East Shewa Zone, Oromia region, Ethiopia from October, 2019 to January, 2021. The assay was performed in Adama City administration. Mosquito infection rates were determined by midgut dissections at seven to 8 days post-infection. Duffy genotyping was defined for each of the 44 P. vivax infected patients. RESULTS: The infection rate of Anopheles mosquitoes was 32.6% (296/907) with 77.3% proportion of infectious participants (34/44). Infectiousness of participants to Anopheles mosquitoes appeared to be higher among individuals with homozygous Duffy positive blood group (TCT/TCT) than heterozygous (TCT/CCT), but the difference was not statistically significant. The mean oocyst density was significantly higher among mosquitoes fed on blood of participants with FY*B/FY*BES than other genotypes (P = 0.001). CONCLUSION: Duffy antigen polymorphisms appears to contribute to transmissibility difference of P. vivax gametocytes to Anopheles mosquitoes, but further studies are required.

Infectivity of Symptomatic Patients and Their Contribution for Infectiousness of Mosquitoes following a Membrane Feeding Assay in Ethiopia.

The membrane feeding assay is widely used to evaluate the efficacy of transmission-blocking interventions (TBIs) and identify the reservoir of malaria. This study aimed to determine the infectivity of blood meals from symptomatic Plasmodium-infected patients to an Anopheles arabiensis colony in Ethiopia. A membrane feeding assay was conducted on a total of 63 Plasmodium falciparum- and/or Plasmodium vivax-infected clinical patients in East Shoa Zone, Ethiopia. Detection of P. falciparum and P. vivax in blood samples was done using microscopy. Mosquito infection rates were determined by dissection of mosquitoes' midguts, while mosquito infectiousness was observed by dissection of their salivary glands. The proportion of infectious symptomatic patients was 68.3% (43/63). Using the chi-square or Fisher's exact test, the oocyst infection levels were higher among patients infected with P. vivax, females, and rural residents. Nearly 57% (56.7%, 17/30) of assays produced sporozoites in the salivary glands of mosquitoes. Both oocyst and sporozoite infection rates had positive correlations with parasitemia and gametocytemia. High infectiousness of symptomatic patients was observed, with a greater proportion of infectious mosquitoes per assay. Demonstrating oocyst infection in the mosquitoes might confirm estimates of the infectiousness of mosquitoes, although some of the oocyst-infected mosquitoes failed to produce sporozoites. IMPORTANCE Malaria remains one of the most devastating infectious diseases globally, and transmission-blocking activities are needed. Plasmodium transmission from human to mosquitoes is poorly studied, particularly in endemic countries, and the membrane feeding assay allows it to be determined. In this study, we demonstrated human infectious reservoirs of malaria. Moreover, the effect of Plasmodium-infected patients on the infectiousness of mosquitoes was also observed. These findings are therefore important for designing future evaluation of transmission-blocking interventions that will support the malaria elimination program.

Vivax malaria in Duffy-negative patients shows invariably low asexual parasitaemia: implication towards malaria control in Ethiopia.

BACKGROUND: The increase in detections of Plasmodium vivax infection in Duffy-negative individuals in Africa has challenged the dogma establishing the unique P. vivax Duffy Binding Protein-Duffy antigen receptor for chemokines (PvDBP-DARC) pathway used by P. vivax merozoites to invade reticulocytes. Information on the impact of Duffy antigen polymorphisms on the epidemiology of P. vivax malaria remains elusive. The objective of this study was to determine the distribution of asexual parasitaemia of P. vivax according to the Duffy antigen polymorphisms in Ethiopia. METHODS: DNA was extracted from dried blood spots (DBS) collected from prospectively recruited 138 P. vivax-infected patients from health centres. The identification and estimation of P. vivax asexual parasitaemia were performed by microscopic examination and quantitative real-time polymerase chain reaction (PCR). Duffy genotyping was conducted by DNA sequencing in a total of 138 P.vivax infected samples. RESULTS: The proportion of Duffy-negatives (FY*BES/FY*BES) in P. vivax infected patients was 2.9% (4/138). Duffy genotype FY*B/FY*BES (48.6%) was the most common, followed by FY*A/FY*BES genotype (25.4%). In one patient, the FY*02 W.01/FY*02 N.01 genotype conferring a weak expression of the Fyb antigen was observed. All P.vivax infected Duffy-negative patients showed low asexual parasitaemia (≤ 110 parasites/µL). The median P. vivax parasitaemia in Duffy-negative patients (53 parasites/µL) was significantly lower than those found in homozygous and heterozygous individuals (P < 0.0001). CONCLUSION: Plasmodium vivax in Duffy-negative patients shows invariably low asexual parasitaemia. This finding suggests that the pathway used by P. vivax to invade Duffy-negative reticulocytes is much less efficient than that used in Duffy-positives. Moreover, the low asexual parasitaemia observed in Duffy-negative individuals could constitute an 'undetected silent reservoir', thus likely delaying the elimination of vivax malaria in Ethiopia.

Five-Year Trend of Malaria Prevalence in Mojo Town, Central Ethiopia: Shifting Burden of the Disease and Its Implication for Malaria Elimination: A Retrospective Study.

INTRODUCTION: Malaria continues to strike hardest against the health and economic development in Ethiopia. The peak of malaria incidence follows the main rainfall season in each year; however, its transmission tends to be highly heterogeneous within or between years and from area to area. Thus, this study was aimed to determine the trend prevalence of malaria in Mojo town, central Ethiopia. METHODS: A retrospective study was conducted in Mojo town, East Shoa zone, Ethiopia from February to March 2021. Malaria cases and related data documented between 2016 and 2020 were carefully reviewed from laboratory registration logbooks. The collected data were analyzed using descriptive statistics. RESULTS: A total of 19,106 blood films were examined from malaria-suspected patients. The overall microscopically confirmed prevalence of malaria was 4.2% (793/19,106). Plasmodium vivax was the predominant species accounting for 76.2% (604/793) of positive samples. Malaria cases declined from 259 in 2016 to 77 in 2020. The proportion of malaria was higher among males (64.8%, 514/793) than females (35.2%, 279/793) (P < 0.0001). Higher malaria cases were observed from the age group 15-24 years followed by the age group of 25-34 (P < 0.0001). The number of malaria cases was at a high level from September to November and lowest from December to February. CONCLUSION: Despite a declining trend of malaria prevalence, it remains a public health burden in the area. P. vivax, the predominant species, should get attention during prevention and control strategies for the successful progress of the malaria elimination program.

Common mental illness among epilepsy patients in Bahir Dar city, Ethiopia: A cross-sectional study.

BACKGROUND: Common mental illness has a substantial impact on seizure control and negatively affects the overall quality of life among individuals with epilepsy. However, there is a dearth of studies that examined the associated factors of common mental illness among epilepsy patients in Ethiopia, particularly in the study area. This study aimed to assess the magnitude and factors associated with common mental disorders in epilepsy patients who attended government health institutions in Bahir Dar city, Ethiopia. METHOD: Health institution based cross-sectional study was conducted using a systematic sampling technique among people living with epilepsy in Bahir Dar City Administration. Common mental illness was assessed using a self-reporting questionnaire and a semi-structured questionnaire was employed to collect data on socio-demographic and clinical related characteristics. Data were analyzed using descriptive statistics, univariate logistic regression, and multivariable logistic regression. RESULTS: The magnitude of comorbid common mental illness among people living with epilepsy was found 35.4%. High magnitude of common mental illness was reported among females (39.9%) when compared to males (32.3%). The most prevalent common mental disorders symptoms include being worried, unhappy feeling, trouble thinking clearly, and difficult to enjoy daily activities. Family history of epilepsy, frequent seizures attacks, side effects of antiepileptic drugs, lack of social support and not adherent to antiepileptic drugs were factors associated with common mental illness. CONCLUSIONS: Common mental illness was found to be prevalent among people living with epilepsy. Therefore, it is recommended that great attention should be given to mental illness besides controlling seizure attacks.

Perceived stigma among non-professional caregivers of people with severe mental illness, Bahir Dar, northwest Ethiopia.

BACKGROUND: The stigmatization of mental illness is currently considered to be one of the most important issues facing caregivers of severely mentally ill individuals. There is a dearth of information about the prevalence and associated factors of perceived stigma among caregivers of people with severe mental illness in the study area. OBJECTIVE: To assess the prevalence and associated factors of perceived stigma among non-professional caregivers of people with severe mental illness, Bahir Dar, northwest Ethiopia. METHOD: Institutional based cross-sectional study was conducted from May to June, 2016 at Felege Hiwot Referral Hospital among 495 caregivers of people with the severe mental illness. Pre-tested structured family interview schedule questionnaire was used. Binary logistic regression was applied to identify factors associated with perceived stigma and interpreted using odds ratio with 95% confidence interval. Statistical significance was considered at p value < 0.05. RESULT: The overall prevalence of perceived stigma was found to be 89.3%. Being female, rural residency, lack of social support, long duration of relationship with the patient and currently not married were found significantly associated with the perceived stigma of caregivers. CONCLUSION: Prevalence of perceived stigma is very high in the current study. Thus, stigma reduction program and expanding of strong social support should better be implemented by different stakeholders for caregivers of people with severe mental illness.

Antipsychotic medication non-adherence among schizophrenia patients in Central Ethiopia.

BACKGROUND: Despite the fact that adherence to antipsychotic medications is the cornerstone in the treatment and prevention of relapse of the disease, non-adherence is a major problem among schizophrenia patients. The purpose of this study was to assess the magnitude and factors associated with antipsychotic medication non-adherence among schizophrenia patients in Amanuel Mental Specialized Hospital. METHOD: An institution-based cross-sectional study was conducted among 412 people with schizophrenia at Amanuel Mental Specialized Hospital from April to May 2014. Non-adherence was assessed using the questionnaire of Morisky medication adherence rating scale and semi-structured questions for assessment of associated factors. Logistic regression analysis was used to assess predictors of non-adherence. RESULTS: Prevalence of non-adherence was 41.0% among schizophrenia patients. Living in rural areas (adjusted odds ratio [AOR] = 2.07; 95% confidence interval [CI]: 1.31, 3.28), current substance use (AOR = 1.67; 95% CI: 1.09, 2.56), long duration of treatment (AOR = 2.07; 95% CI: 1.22, 3.50) and polypharmacy (AOR = 2.13; 95% CI: 1.34, 3.40) were found to be significantly associated with non-adherence. CONCLUSION: The results indicate that non-adherence to antipsychotic medication was a major problem among patients with schizophrenia. Reducing the number of antipsychotic medications and availing drugs in rural areas may decrease the level of non-adherence.

Chewing khat and risky sexual behavior among residents of Bahir Dar City administration, Northwest Ethiopia.

INTRODUCTION: Khat is a well-known natural stimulant and is widely used in Ethiopia, particularly in Bahir Dar city. Khat chewing is linked with risky sexual behaviors. OBJECTIVE: The study was aimed to determine the prevalence of chewing khat and its relation with risky sexual behaviors among residents of Bahir Dar City administration, Northwest Ethiopia. METHODS: A community based cross-sectional study was conducted from January to February, 2016. The data were collected using an interviewer administered structured questionnaire. Logistic regression analysis was applied to assess association between dependent and explanatory variables. RESULTS: The proportion of lifetime and current chewing khat among the study participants were 25.7 and 19.5%, respectively. Males (AOR 5.0; 95% CI 3.0-8.2) than females, merchants (AOR 4.9; 95% CI 2.6-9.3) than government employees, and those with average monthly income of ≥ 3001 Ethiopian birr (AOR 2.4; 95% CI 1.2-4.8) than ≤ 1000 had an increased current chewing khat prevalence. Having lifetime history of chewing khat was significantly associated with ever had sexual intercourse, having extra sexual partners, watching pornographic film and self-reported sexually transmitted infections. CONCLUSION: Chewing khat is associated with increment of having risky sexual behaviors and self-reported sexually transmitted infections. Harm reduction measures are needed to prevent the community from engaging in khat use and risky sexual behaviors.

Determinants of depression among people with epilepsy in Central Ethiopia.

BACKGROUND: Depression is the most frequently and highly occurring mental disorders in epilepsy patients. When depression is comorbid with epilepsy, it leads to low employment and poor quality of life. Thus, the aim of this study was to assess the prevalence and associated factors of depression among people living with epilepsy in Central Ethiopia. METHODS: Institution-based cross-sectional study was conducted from April to May 2015 at Amanuel Mental Specialized and TikurAnbesa Hospitals, Addis Ababa, Ethiopia. Samples of 422 epilepsy patients were selected, and data on depression were collected using validated questionnaire using face-to-face interview technique. Logistic regression analysis was performed to assess predictors of depression. RESULTS: The study indicated that the prevalence of depression among people with epilepsy was 43.8%. Factors associated with depression were being female (AOR 2.48; 95% CI, 1.61.3.81), being single (AOR 2.23; 95% CI 1.38-3.60), perceived stigma (AOR 2.47; 95% CI 1.59-3.83), medication adherence (AOR 2.85; 95% CI 1.64-4.96), and current substance use (AOR 2.10; 95% CI 1.34-3.30). CONCLUSION: There is a high prevalence of depression among epilepsy patients. Early detection and prompt management of depressive symptoms are critically important in reducing depression burden among people living with epilepsy.

Correction to: Suicide ideation and attempts among people with epilepsy in Addis Ababa, Ethiopia.

[This corrects the article DOI: 10.1186/s12991-018-0174-6.].

Depression among patients attending antiretroviral treatment program in public health facilities in Bahir Dar City, Ethiopia.

BACKGROUND: The magnitude of depression is not well investigated among people living with HIV/AIDS. Thus, this research aimed to assess the magnitude of depression and its influencing factors among people living with HIV/AIDS attending government institutions in Bahir Dar City, North West, Ethiopia. METHODS: institution based-cross-sectional study was done among randomly selected 415 people living with HIV/AIDS attending antiretroviral therapy program in Bahir Dar city, Ethiopia. Socio-demographic data and medical histories for all respondents were collected using interviewer-administered structured questionnaire. We assessed the odds of association of patient characteristics with depression was assessed using multiple logistic regression. The relative effect estimates of the respective factors were presented with odds ratio accompanied by their 95% uncertainty intervals. RESULTS: From 407 people living with HIV/AIDS interviewed, 198(48.6%) of them had depression. Social support, HIV clinical staging, total daily pill burden, treatment regimen and adherence to highly active antiretroviral therapy were significantly associated with depression. CONCLUSION: The magnitude of depression among people living with HIV/AIDS was found to be high. Early mental health screening should be done for people living with HIV/AIDS.

Suicide ideation and attempts among people with epilepsy in Addis Ababa, Ethiopia.

Background: Suicidal ideation and attempts are more frequent in people with epilepsy than in general population and suicide attempt increases the chance of later completed suicide. The aim of this study was to assess the prevalence and associated factors of suicidal ideation and attempt among people with epilepsy in Amanuel Mental Specialized Hospital, Addis Ababa, Ethiopia. Methods: Institution-based cross-sectional study was conducted from May to June 2014 at Amanuel Mental Specialized Hospital among people with epilepsy. The pre-tested semi-structured questionnaire was used for interviewing the study participants. Logistic regression analysis was used to assess predictors of suicidal ideation and attempt. Results: The study indicated that the prevalence of suicidal ideation and attempt among people with epilepsy were 29.8 and 14.1%, respectively. Poor social support, drug treatment for mental illness, had co-morbid depression, no seizure free within 1 year and family history committed suicide were significantly associated with suicidal ideation and attempt. Conclusion: The prevalence of suicidal ideation and attempt in people with epilepsy found to be higher when compared to general population. Therefore, screening all epilepsy patients should be done for early diagnosis and treatment.

Antipsychotic medication non-adherence among schizophrenia patients in Central Ethiopia

Background: Despite the fact that adherence to antipsychotic medications is the cornerstone in the treatment and prevention of relapse of the disease, non-adherence is a major problem among schizophrenia patients. The purpose of this study was to assess the magnitude and factors associated with antipsychotic medication non-adherence among schizophrenia patients in Amanuel Mental Specialized Hospital. Method: An institution-based cross-sectional study was conducted among 412 people with schizophrenia at Amanuel Mental Specialized Hospital from April to May 2014. Non-adherence was assessed using the questionnaire of Morisky medication adherence rating scale and semi-structured questions for assessment of associated factors. Logistic regression analysis was used to assess predictors of non-adherence. Results: Prevalence of non-adherence was 41.0% among schizophrenia patients. Living in rural areas (adjusted odds ratio [AOR] = 2.07; 95% confidence interval [CI]: 1.31, 3.28), current substance use (AOR = 1.67; 95% CI: 1.09, 2.56), long duration of treatment (AOR = 2.07; 95% CI: 1.22, 3.50) and polypharmacy (AOR = 2.13; 95% CI: 1.34, 3.40) were found to be significantly associated with non-adherence. Conclusion: The results indicate that non-adherence to antipsychotic medication was a major problem among patients with schizophrenia. Reducing the number of antipsychotic medications and availing drugs in rural areas may decrease the level of non-adherence

Community knowledge, attitude and practice about malaria in a low endemic setting of Shewa Robit Town, northeastern Ethiopia.

BACKGROUND: Since malaria is one of the foremost public health problems in Ethiopia, assessment of situation of the disease, and communities' knowledge and perceptions about malaria is necesary to institute appropriate preventive and control measures. Thus, the aim of this study was to assess malaria prevalence and knowledge, attitude and practice (KAP) about the disease among ShewaRobit Town community, northeastern Ethiopia. METHODS: A community-based cross-sectional study was conducted in Shewa Robit Town from October to November 2011. A multi-stage random sampling technique was used to select the study participants. A total of 425 individuals were examined for malaria using thin and thick Giemsa stained blood film, and 284 of the participants were interviewed to assess their KAP about malaria. Logistic regression analysis was used to assess predictor factors for malaria prevalence. RESULTS: All respondents had ever heard of malaria. Most of the respondents (85.2%) attributed the cause of malaria to mosquito bite. However, some of the respondents (>20%) mentioned lack of personal hygiene, exposure to cold weather, hunger, chewing maize stalk, body contact with malaria patient and flies as the causes of malaria. Sleeping under mosquito nets, draining stagnant water and indoor residual spraying were the most frequently mentioned malaria preventive measures perceived and practiced by the respondents. Among 425 individuals examined for malaria, only 2.8% were positive for Plasmodium parasites. Living in houses made of wall without hole, sprayed with insecticide within the last 12 hours and located at a distance of greater than 500 meters from potential mosquito breeding sites as well as knowing and using of mosquito net were significant predictors of low malaria prevalence among the study participants. CONCLUSIONS: A high level of knowledge about the cause, transmission and preventive methods of malaria was detected among the community in Shewa Robit Town. However, a considerable proportion had misconception about the cause and transmission of malaria suggesting the necessity of health education to raise the community's awareness about the disease.