The pattern of epileptic seizures in rural Tanzania

Mortality among persons with epilepsy in onchocerciasis-endemic and non-endemic areas of sub-Saharan Africa: A systematic review and meta-analysis

PURPOSE

To document epilepsy-related mortality in sub-Saharan Africa (SSA) and investigate possible associations with onchocerciasis endemicity.

METHODS

Systematic review with meta-analysis. Searches were performed in PubMed and Google Scholar (search terms: 'epilepsy'; 'mortality/death'; 'sub-Saharan Africa'). Included studies were classified as high-risk or low-risk for onchocerciasis based on documented endemicity data. Pooled mortality rates and annual case fatality rates (CFR) were calculated, and risk factors for mortality among persons with epilepsy (PWE) were investigated using meta-regression analysis.

RESULTS

The 28 eligible studies reported 30 epilepsy surveys, of which 9 (30.0%) were conducted in onchocerciasis high-risk sites. The pooled epilepsy mortality rate was 20.9 (95% CI: 5.9-74.4) per 100,000 person-years, and the pooled CFR was 36.2 (95% CI: 23.9-54.4) per 1,000 PWE per year, albeit with substantial between-study heterogeneity. Compared to onchocerciasis low-risk sites, high-risk sites had higher pooled mortality (342.9 versus 10.0 per 100,000 PY; p<0.001) and CFR (57.0 versus 26.6 per 1,000 PWE per year; p = 0.001). Mortality of PWE was almost five-fold that of people without epilepsy (mortality risk ratio: 4.9; 95% CI: 3.5-6.8). Studies in onchocerciasis high-risk sites and the study which recruited only PWE with nodding syndrome were associated with higher CFR (p = 0.044 and p = 0.002, respectively). The leading causes of epilepsy-related death were status epilepticus (58.5%), drowning (15.7%), and sudden unexpected death in epilepsy (10.1%).

CONCLUSION

Epilepsy mortality remains high in SSA. Most reported causes of death among PWE might be averted by improving seizure control. Better epilepsy prevention and care are urgently needed, particularly in onchocerciasis-endemic settings.

Lifetime prevalence of epilepsy in urban Tanzania - A door-to-door random cluster survey

Objectives

Epileptic seizures and epilepsy in urban settings of low-income and middle-income countries (LMIC) are largely under-researched, but their prevalence is necessary for good healthcare planning. This study aimed to determine the lifetime prevalence of epileptic seizures and epilepsy in urban Dar es Salaam.

Methods

Nearly 50,000 people in former Kinondoni district, Dar es Salaam, were screened for epileptic seizures using a set of nine questions. Answers to these nine questions were categorized into generalized, focal, and unspecified seizures. Screening positivity rates were adjusted for questionnaire inaccuracy using two scenarios to analyse true epilepsy prevalences.

Results

Overall, 1085 (2.23%) people fulfilled the criteria for ever having had at least one type of epileptic seizure. Two-hundred-ninety-six (0.60%) people screened positive for generalized seizures, 986 (2.02%) for focal seizures, and 32 (0.07%) for unspecified seizures. Women more commonly screened positive than men (2.61% versus 1.72%, p < 0.001), particularly for focal seizures (p < 0.001). Adjusting for different degrees of accuracy of the screening questionnaire yielded true lifetime prevalences for epilepsy of any type between 1.59% and 2.41%. We furthermore observed a considerable variation of screening positivity rates between wards in Kinondoni district (p < 0.001).

Conclusion

The prevalence of epilepsy, based on a questionnaire survey in urban Tanzania, was higher than previously observed, probably due to the screening questionnaire, which contained questions specifically designed to identify focal seizures. Further studies on epileptic seizures/epilepsy are needed for urban settings in LMIC, preferably with an integrated follow-up of positive cases.

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Data on epilepsy in urban African populations are scarce

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Reliable prevalence estimates for epilepsy are important for healthcare planning but difficult to obtain

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Epilepsy screening tools need to be developed carefully in a participatory approach

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Focal and non-convulsive seizures are often overlooked in studies

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Epilepsy prevalence in urban Tanzania is similar to other parts of Africa

High frequency of Taenia solium antigen positivity in patients admitted for neurological disorders in the Rural Hospital of Mosango, Democratic Republic of Congo

Background

The epidemiology of human cysticercosis and neurocysticercosis, caused by the larval stage of the pork tapeworm Taenia solium, is not well known in the Democratic Republic of Congo (DRC). Within a multicenter etiological and diagnostic study conducted by the NIDIAG consortium (“Better Diagnosis for Neglected Infections”) and investigating several challenging syndromes, we consecutively evaluated from 2012 to 2015 all patients older than 5 years presenting with neurological disorders (neurology cohort) and with fever > 7 days (persistent fever cohort) at the rural hospital of Mosango, province of Kwilu, DRC. In both cohorts, etiological diagnosis relied on a systematic set of reference laboratory assays and on pre-established clinical case definitions. No neuroimaging was available in the study hospital. In this study, we determined the frequency of T. solium infection in both cohorts and explored in the neurology cohort its association with specific neurological presentations and final etiological diagnoses.

Methods

We conducted a post-hoc descriptive and analytic study on cysticercosis in the neurology and persistent fever cohorts, based on the presence in serum samples of circulating T. solium antigen using the B158/B60 enzyme-linked immunosorbent assay (ELISA) and of cysticercosis IgG using the LDBIO Cysticercosis Western Blot IgG assay.

Results

For the neurology cohort, 340 samples (of 351 enrolled patients) were available for analysis (males: 46.8%; mean age: 38.9 years). T. solium antigen positivity was found in 43 participants (12.6%; 95% confidence interval [CI] 9.3–16.7%), including 9 of 60 (15%) patients with epilepsy. Among the 148 samples available from the persistent fever cohort (males: 39.9%; mean age: 19.9 years), 7 were positive in the T. solium antigen ELISA (4.7%; 95% CI 1.9–9.5%; P = 0.009 when compared to the neurology cohort). No significant association was found within the neurology cohort between positivity and clinical presentation or final diagnoses. Of note, the IgG antibody-detecting assay was found positive in only four (1.3%) of the participants of the neurology cohort and in none of the persistent fever cohort.

Conclusions

T. solium antigen positivity was found in at least 10% of patients admitted with neurological disorders in the Kwilu province, DRC, with no specific pattern of presentation. Further neuroimaging studies should be used to confirm whether neurocysticercosis is prevalent in this region.

Febrile seizures in an urban Tanzanian population: lessons learned from a community-based random cluster survey

OBJECTIVE

To analyse the cumulative incidence of febrile seizures, to evaluate the accuracy of our screening questionnaire and to describe clinical characteristics of children with febrile seizure in an urban population in Tanzania.

METHODS

A large random cluster sampled population was screened for a febrile seizure history as part of a larger epilepsy study using a standardised questionnaire in a two-stage door-to-door survey in Tanzania. A subset of screen positive participants was further examined for confirmation of diagnosis and evaluation of clinical characteristics.

RESULTS

Overall, 49 697 people were screened for a febrile seizure history of whom 184 (0.4%) screened positive. Women more commonly screened positive than men (112 [0.4%] vs. 72 [0.3%]). There was no marked difference between age groups or education. The positive predictive value of the screening tool was 37% (95% CI 24-51%) but its accuracy varied with the age of interviewed individuals. Cumulative incidence rates were estimated between 1.1% and 2.0% after adjusting for the inaccuracy of the screening tool. Most febrile seizures occurred before the age of two (65%) and most children had more than one episode (80%). A large proportion of children had complex febrile seizure (65%), often caused by malaria or respiratory infections.

CONCLUSIONS

The community-based cumulative incidence of a febrile seizure history in an urban Tanzanian population was similar to rates reported from other rural populations after adjusting for the inaccuracy of our screening tool. Based on the integrated nature of the febrile seizure questionnaire, screening positivity rates may have been too low. This has implications for the design of future studies. The majority of cases had complex febrile seizures often associated with malaria. This has implications for clinical case management.

Pattern and frequency of neurological and neurosurgical care of adult inpatients and outpatients at a tertiary referral hospital in Kenya

OBJECTIVE

To describe the patterns and burden of neurological and neurosurgical disorders at a national tertiary level referral hospital in western Kenya.

METHODS

We conducted a three-month period prevalence study. We recruited consecutive adult patients seeking neurological-neurosurgical care in both inpatient and outpatient settings at Moi Teaching and Referral Hospital.

RESULTS

833 participants were included. The age range was between 19 year and 99 years (mean age = 45.3 years). The most common diagnoses among neurology inpatients were meningitis (12%), ischemic stroke (11.0%) and epilepsy/seizure (6.7%). Among neurology outpatients, epilepsy (35.1%) and ischemic stroke (18.8%) were the most common diagnoses. The most common neurosurgery inpatient diagnosis was hemorrhagic stroke (16.3%) and among outpatients, the most common diagnoses were traumatic brain injury (17.4%) and hemorrhagic stroke (16.3%). Overall, 471 (56.5%) patients underwent HIV testing, of which, 89 (18.9%) were HIV positive and 382 (81.1%) were HIV negative. Thirty-one inpatient deaths (male 58%), attributable to neurological and neurosurgical disorders, occurred during the study period. Meningitis was the most common cause of death.

CONCLUSIONS

The findings suggest that meningitis, stroke, epilepsy, and traumatic brain injury were the most common diagnosis. More resources and efforts should be directed towards prevention, diagnosis and management of these conditions in the region.

The societal cost of Taenia solium cysticercosis in Tanzania

Taenia solium is a zoonotic parasite prevalent in many low income countries throughout Latin America, Asia and sub-Saharan Africa, including Tanzania. The parasite is recognized as a public health threat; however the burden it poses on populations of Tanzania is unknown. The aim of this study was to estimate the societal cost of T. solium cysticercosis in Tanzania, by assessing both the health and economic burden. The societal cost of T. solium cysticercosis was assessed in humans and pigs based on data obtained by a systematic review. Experts' opinion was sought in cases where data were not retrievable. The health burden was assessed in terms of annual number of neurocysticercosis (NCC) associated epilepsy incident cases, deaths and disability-adjusted life years (DALYs), while the economic burden was assessed in terms of direct and indirect costs imposed by NCC-associated epilepsy and potential losses due to porcine cysticercosis. Based on data retrieved from the systematic review and burden assessments, T. solium cysticercosis contributed to a significant societal cost for the population. The annual number of NCC-associated epilepsy incident cases and deaths were 17,853 (95% Uncertainty Interval (UI), 5666-36,227) and 212 (95% UI, 37-612), respectively. More than 11% (95% UI, 6.3-17) of the pig population was infected with the parasite when using tongue examination as diagnostic method. For the year 2012 the number of DALYs per thousand person-years for NCC-associated epilepsy was 0.7 (95% UI, 0.2-1.6). Around 5 million USD (95% UI, 797,535-16,933,477) were spent due to NCC-associated epilepsy and nearly 3 million USD (95% UI, 1,095,960-5,366,038) were potentially lost due to porcine cysticercosis. Our results show that T. solium imposes a serious public health, agricultural and economic threat for Tanzania. We urge that a One Health approach, which involves the joint collaboration and effort of veterinarians, medical doctors, agricultural extension officers, researchers and relevant governmental agencies, is taken to find sustainable solutions for prevention, control and elimination of T. solium.

Recent patterns and predictors of neurological mortality among hospitalized patients in Central Ghana

BACKGROUND

Although neurological disorders are projected to escalate globally in the coming decades, there is a paucity of enumerated data on the burden, spectrum and determinants of outcomes of adult neurological admissions in resource-limited settings, especially within sub-Saharan Africa.

OBJECTIVE

To evaluate the diversity, demography, and determinants of mortality among adult patients presenting with neurological disorders over a 6-year period in a tertiary medical referral institution in the Central belt of Ghana.

METHODS

A retrospective analysis of data on neurological admissions and in-patient outcomes between 2008 and 2013 was undertaken. Data collected for analyses included age, gender, neurological diagnosis, documented comorbidities, duration of admission and vital status at discharge. Predictors of in-patient mortality were evaluated using Kaplan-Meier survival curves and Cox Proportional Hazards regression models.

RESULTS

The 6494 admissions with neurological disorders represented 15.0% of all adult medical admissions over the study period. Male-to-female ratio of admissions was 1.6:1.0 with a mean±SD age of 52.9±20 years. The commonest neurological disorders were Cerebrovascular, Infectious, Seizures/epilepsy, Alcohol-use and Spinal cord disorders representing 54.0%, 26.7%, 10.3%, 4.0% and 2.3% of admissions respectively. Despite the low national HIV prevalence of 2.0%, the frequency of HIV infection among patients with infectious disorders of the nervous system was 40.9%. Overall crude mortality rate for neurologic admissions was 30.6% being 39.1% and 33.9% for Infectious affectations of the nervous system and stroke respectively and 7.4% for seizure disorders. Probability of death was higher for females than males aHR (95% CI) of 1.53 (1.40-1.68) and increasing age aHR (95% CI) of 1.11 (1.06-1.17) for each 20-year increase in age.

CONCLUSION

Almost one in three patients admitted with neurological disease to a tertiary care center in Ghana died in the hospital, and the majority of these deaths were due to non-communicable conditions. Enhanced multi-dimensional public health disease prevention strategies and neurological inpatient care processes are warranted.

Community-based prevalence and clinical characteristics of febrile seizures in Tanzania

BACKGROUND

The prevalence of febrile seizures (FSs) and epilepsy are often reported to be higher in sub-Saharan Africa. Furthermore, several studies describe complex features of FSs as risk factors for the development of subsequent epilepsy.

METHODS

During the period from 2002 to 2004 door-to-door studies with supplementary data collection were conducted in three different areas of Tanzania, examining the prevalence of FSs in 7,790 children between the age of 2 mo and 7 y at the time of the interview. The information on the presence of FSs of 14,583 children, who at the time of the interview were younger than 15 y, was collected in order to describe reported seizures, if any.

RESULTS

Overall, 160 children between 2 mo and 7 y with a prevalence rate of 20.5/1,000 (95% confidence interval: 17.5-23.9/1,000) met the criteria for FSs. The average age at onset was 2.2 (SD: 1.8) y and ~42% had complex FSs. Respiratory tract infections and malaria were the most frequent concomitant diseases.

CONCLUSION

Our findings do not confirm the assumption of an increased prevalence of FSs in sub-Saharan Africa. However, the elevated number of complex FSs emphasizes the necessity of more reliable studies about FSs and its consequences.

Febrile seizures in rural Tanzania: hospital-based incidence and clinical characteristics

OBJECTIVE

Febrile seizures may contribute to epilepsy later in life, but data in sub-Saharan Africa are scarce. We, therefore, conducted a hospital-based study on clinical characteristics of children with febrile seizures.

METHODS

Over 2 years, we screened all pediatric admissions of Haydom Lutheran Hospital, northern Tanzania, and recruited 197 children with febrile seizures.

RESULTS

The incidence of febrile seizures was 4% of all admitted children aged <10 years, with a mortality of almost 4%. The peak age at the first febrile seizure was 2 years. One of five children experienced repeated episodes, and the majority of children showed features of complex seizures. Approximately 20% of children had a positive family history of febrile seizures or epilepsy.

CONCLUSION

Febrile seizures represent a frequent cause for admission of children, bearing a rather high mortality. Most children exhibit complex febrile seizures, which may contribute to the development of epilepsy later in life.

Belief systems of epilepsy and attitudes toward people living with epilepsy in a rural community of northern Tanzania

The social stigma toward people with epilepsy (PWE) varies greatly between cultures. In this study, 167 people (59 PWE, 62 relatives, 46 villagers) in a rural area of northern Tanzania were interviewed at the hospital and in the community regarding their prevailing beliefs about epilepsy and attitudes toward PWE. Seventy-eight of those interviewed (46.7%) thought that epilepsy was due to supernatural causes, but 86 (51.5%) assumed that epilepsy is caused by brain disorders or is inherited. According to the interviewees, epilepsy impacts on the lives of affected people. 65.3% (n=109) thought that PWE should not attend school or go to work and 38.3% (n=64) were of the opinion that PWE had decreased chances of getting married. A minority (11.4%; n=19) thought that epilepsy was a reason not to have children. In summary, supernatural and more scientific ideas about the causes of epilepsy seem to coexist. Nevertheless, there is considerable stigma toward PWE, which needs to be interpreted within the sociocultural context of the study.

Epilepsy and neurocysticercosis in sub-Saharan Africa

Over the last decades, studies in sub-Saharan Africa have indicated that epilepsy is a highly prevalent neurological disorder. Causes may be varied with infections of the central nervous system playing an important role. Neurocysticercosis (NCC) has recently been recognised as an emerging public health problem and a growing concern throughout sub-Saharan Africa and has been estimated to be responsible for 30-50% of acquired epilepsy. NCC is closely linked with porcine cysticercosis and human taeniosis, the former reaching a prevalence of almost 50% in some pig populations. In this review, we first summarize prevalence data on epilepsy and highlight some special aspects of the disorder within sub-Saharan Africa. We then focus on the prevalence of NCC, clinical signs and symptoms and diagnostic criteria for NCC with special reference to sub-Saharan Africa. This is followed by a section on the latest developments regarding serodiagnosis of cysticercosis and a section on care management of people infected with NCC. NCC clearly represents a major risk factor of epilepsy, thus detecting and treating NCC may help cure epilepsy in millions of people in sub-Saharan Africa.

Attitudes towards African traditional medicine and Christian spiritual healing regarding treatment of epilepsy in a rural community of northern Tanzania

Most people with epilepsy (PWE) live in developing countries with limited access to health care facilities. In sub-Saharan Africa with approximately 12 million PWE, 90% do not receive adequate medical treatment. In this context, traditional medicine, being easily accessible, plays an important role. However, in sub- Saharan Africa, studies on the attitude of people (both affected and not affected by epilepsy) towards traditional medicine for treatment of epilepsy are scarce. In this study, 167 people (59 PWE, 62 relatives, 46 villagers) were interviewed at the hospital and in the community with a semi-structured validated questionnaire regarding the prevailing attitude towards traditional medicine for treatment of epilepsy in a rural area of northern Tanzania. Various traditional healing methods (THM) could be ascertained, i.e. traditional herbal medicine, spiritual healing, scarifications and spitting. 44.3% (n=74/167) of the interviewed people were convinced that epilepsy could be treated successfully with THM. Interestingly, 34.1% (n=57/167) thought that Christian prayers could cure the cause and/or treat symptoms of epilepsy. Significantly more PWE and their relatives were in favour of THM compared to villagers not knowing about epilepsy or not being immediately affected by epilepsy (χ(2)-test, p=0.004). Further factors influencing people's attitudes towards THM were gender, tribe, religion and urbanity of people's dwellings. Our study demonstrates that not only THM but also prayers in the Christian sense seem to play an important role in people's beliefs regarding successful treatment of epilepsy. Factors influencing this belief system have been identified and are discussed.