Epilepsy and neurocysticercosis in rural areas of the Bolivian Chaco: What has changed during the last 30 years?

OBJECTIVE: Neurocysticercosis (NCC) is considered the major cause of epilepsy in endemic regions. In the rural areas of the Bolivian Chaco prevalence of NCC among people with epilepsy (PWE) was 27.4%, according to a population-based survey carried out in 1994. The aim of the study was to estimate the prevalence of Epilepsy Associated with Tonic-Clonic Seizures (EATCS) and to evaluate the prevalence of NCC among PWE in the rural communities of the Bolivian Chaco after 30 years. METHODS: Twenty-two rural communities (total population 12 852) were involved in the study. PWE in the study area were ascertained by multiple sources and the diagnosis was confirmed by a neurologist. All PWE identified were invited to undergo brain CT scan examination and diagnosis of NCC was sought according to the revised Del Brutto criteria. RESULTS: Seventy-eight PWE (30 men, 38.4%; mean age at onset was 12.7 ± 13.2 years) with EATCS were identified giving a crude prevalence of 6.1/1000 (95% CI: 4.7-7.3). Due to the COVID-19 lockdown, the study was interrupted in 2020 and only 36 PWE (46%) of the whole sample underwent CT scan examination. Of these, 8 (22.2%) fulfilled the criteria for NCC of whom 6 (75%) presented only single or multiple calcifications. SIGNIFICANCE: This is the first study reassessing the prevalence of NCC among PWE after 30 years, in the same rural area and using a population-based design. T. solium is still endemic in the Bolivian Chaco where more than 20% of EATCS may be attributable to NCC. Our findings show a substantially unchanged prevalence of NCC over the past 30 years despite improved knowledge, underlining the need for active intervention programs to control T. solium transmission in this area. PLAIN LANGUAGE SUMMARY: Neurocysticercosis is still endemic in the Bolivian Chaco. The proportion of epilepsy attributable to neurocysticercosis is about 22%. Systematic efforts towards elimination of neurocysticercosis in these areas should be implemented.

Yaws elimination in Ecuador: Findings of a serological survey of children in Esmeraldas province to evaluate interruption of transmission.

BACKGROUND: The WHO roadmap for neglected tropical diseases includes yaws eradication requiring certification of elimination of transmission in all endemic and formerly endemic countries worldwide. A community-based programme for yaws control was considered to have achieved elimination of the infection in the endemic focus in Ecuador after 1993. We did a serosurvey of children in this focus to provide evidence for interruption of transmission. METHODS: Survey of serum samples collected from children aged 2 to 15 years living in the formerly endemic and in geographically contiguous areas. A convenience sample of sera collected between 2005 were 2017 from non-yaws studies, were analyzed using immunochromatic rapid tests to screen (OnSite Syphilis Ab Combo Rapid Test) for Treponema pallidum-specific antibodies and confirm (DPP Syphilis Screen and Confirm) seroreactivity based on the presence antibodies to treponemal and non-treponemal antigens. RESULTS: Seroreactivity was confirmed in 6 (0.14%, 95% CI 0.06-0.30) of 4,432 sera analyzed and was similar in formerly endemic (0.11%, (95% CI 0.01-0.75) and non-endemic (0.14%, 95% CI 0.06-0.34) communities. All seroreactors were of Afro-Ecuadorian ethnicity and most were male (4/6) and aged 10 or more years (5/6), the latter possibly indicating venereal syphilis. Only 1 seroreactor lived in a community in the Rio Santiago, that was formerly hyperendemic for yaws. CONCLUSION: We observed very low levels of treponemal transmission in both formerly endemic and non-endemic communities which might be indicative of congenital or venereal syphilis and, if yaws, would likely be insufficient to maintain transmission of this endemic childhood infection. Additional surveys of children aged 1 to 5 years are planned in Rio Santiago communities to exclude yaws transmission.

[I promotori di salute come attori-protagonisti delle cure primarie nel controllo delle malattie comunicabili e non comunicabili e nell' empowerment delle comunità. Esperienza e risultati di lungo periodo in aree marginali in Ecuador dal 1980 al 2018.] / The community health promoters as protagonist actorsof primary health care and community empowerment:a long term field-report from 1980 to 2018.

. INTRODUCTION: Against the increasing recognition of the critical importance of a direct participation of community members to assure effective health care in peripheral areas of Middle and Low Income Countries (MLIC), representative field experiences of their essential role are only occasionally available. AIMS AND METHODS: We report a narrative, factual documentation of a spectrum of projects covering the basic and specific health needs of the disperse communities in Ecuador, a model MLIC, and discuss the broader implications of the role and performance of HPs over a long period, 1980-2018, in the project activation, implementation and monitoring. RESULTS: The role of 60 HPs, with the coordination of a small core group of professionals of the Centro de Epidemiologia Comunitaria y Medicina Tropical (CECOMET) is documented through their main achievements which include: infectious diseases and in particular Neglected Tropical Diseases (eradication of onchocerciasis and yaws; virtual elimination of malaria and of strongyloidiasis; identification and control of a new focus of Chagas Disease; control of tuberculosis), mother and child health, reproductive health, hypertension (as model of the emergence of non-transmissible, chronic diseases). The most effective and sustainable strategies and methods are discussed also in terms of their more general transferability, already partially tested in programs in Bolivia, Burkina Faso, undeserved areas of Argentina. CONCLUSIONS: The systematic availability of non-professional, trained HPs should be recommended as a sustainable and reliable component of health care strategies and interventions targeted to marginalized settings, to assure a concrete accessibility to the fundamental human right to life.

Community Epidemiology Approach to Parasitic Infection Screening in a Remote Community in Ecuador.

The Awa indigenous people of Ecuador live in remote areas and were included in health programs only recently. The first screening for parasitic infections in the Awa communities was implemented in the context of community epidemiology. During the site visits in each community, the health-care staff collected the samples for stool microscopy and serology for Strongyloides. A total of 705 individuals consented for the study, representing 40% of the Awa population living in the targeted communities; 184 (26%) participants supplied a stool sample. Giardia intestinalis was found in about 11% of samples. Prevalence of Ascaris lumbricoides and Trichuris trichiura was 54.9% and 36.9%, respectively. No hookworm eggs were found. In addition, Strongyloides stercoralis larvae were found in eight individuals (4.3%), whereas serology was positive in 22.7% of the individuals tested. The community-based approach resulted in an impressive participation. There was a high prevalence of parasites associated with relevant morbidity.

Comparison of S. stercoralis Serology Performed on Dried Blood Spots and on Conventional Serum Samples.

Background: Dried blood spots (DBS) are used for epidemiological surveys on infectious diseases in settings where limited resources are available. In fact, DBS can help to overcome logistic difficulties for the collection, transport and storage of biological specimens. Objective: To evaluate the accuracy of Strongyloides stercoralis serology performed on DBS. Methods: A survey was proposed to children attending a school in the village of Borbon, Ecuador, and to their parents/guardians. Each participant gave consent to the collection of both serum and DBS specimens. DBS absorbed on filter papers were analyzed with a commercially available ELISA test for S. stercoralis antibodies, as well as with standard serology. The agreement between the two methods was assessed through the Cohen's kappa coefficient. Results: The study sample was composed of 174 children and 61 adults, for a total of 235 serum and 235 DBS samples. The serology was positive in 31/235 (13%) serum samples, and in 27/235 (11%) DBS: 4 samples resulted discordant (positive at standard serology). Cohen's kappa coefficient was 0.921 (95% CI 0.845 - 0.998), indicating a high rate of concordance. Conclusion: DBS are suitable for in field-surveys requiring serological testing for S. stercoralis.