Neurocysticercosis among resettled refugees from Burma

Mass chemotherapy with niclosamide for the control of Taenia solium: population-based safety profile and treatment effectiveness

Background

Mass drug administration (MDA) with niclosamide (NSM) can be used to control taeniasis, the cause of neurocysticercosis. NSM is 84.3% effective against taeniasis and is considered safe as it is not absorbed from the intestinal tract. However, information on its safety and effectiveness during MDA is limited. We evaluated the effectiveness of NSM and reported adverse events (AEs) during a cysticercosis elimination program in Tumbes, Peru.

Methods

Three rounds of NSM at 4-month intervals were offered to 77,397 eligible residents. We revisited all participants in their homes 72 h after each round to collect information regarding AEs. We also collected post-treatment stool samples to diagnose taeniasis after the first round, followed by a second sample at 30 days from those infected to evaluate NSM's effectiveness.

Findings

During implementation, 68,751 individuals were administered at least one dose of NSM (mean age 29 years, SD 20; 52% male), and 65,551 (95.3%) were visited post-treatment. 988 (1.5%) reported experiencing at least one AE. Almost all AEs (99.2%) were of mild intensity, with no severe AEs recorded. Of 211 participants diagnosed with taeniasis, 188 provided a follow-up stool sample 30-days after treatment and 141 were cured (treatment effectiveness 75.0%). Older age and higher coproantigen levels were significantly associated with treatment failure.

Interpretation

MDA with NSM is safe in Taenia solium endemic settings. However, the effectiveness following one dose is lower than expected, which suggests additional treatment may be necessary to enhance the infection control efforts.

Funding

The Bill and Melinda Gates Foundation.

Biological Psychiatry in Displaced Populations: What We Know, and What We Need to Begin to Learn

Conflict and climate change continue to displace millions of people, who experience unique trauma and stressors as they resettle in host countries. Both children and adults who are forcibly displaced, or choose to migrate, experience posttraumatic stress disorder, anxiety, depression, and other mental health conditions at higher rates than the general population. This may be attributed to severe, cumulative stress and trauma (largely interpersonal traumas); discrimination and harassment in host countries; and structural barriers to accessing and addressing mental health concerns, including clinician availability, language barriers, cultural differences, geographic accessibility, health care access, and stigma. Despite high exposure to and clinical impact of such experiences, and despite representing 1% of the world population, forcibly displaced people are underrepresented in neuroscientific research. The availability of such literature and research findings is significant in understanding the unique genetic and cultural aspects of trauma- and stress-related mental health, advocacy, reducing stigma, informing prevention, and treatment. The present work aimed to explore how the field of neuroscience can address mental health equity for individuals who have been uprooted in relation to land, with a focus on refugee populations. We offer practical suggestions on how to improve research in this area and narrow the gap in knowledge.

Epilepsy and psychogenic non-epileptic seizures in forcibly displaced people: A scoping review

With a growing number of forcibly displaced people (FDP) globally, the focus on their medical needs has necessarily increased. Studies about the prevalence and incidence of epilepsy and psychogenic non-epileptic seizures (PNES) in this population are, though, sparse. This Review highlights the importance of exploring and managing both conditions in these vulnerable people to promote global health. We performed an exhaustive review of 10 databases, as well as a manual search of relevant websites related to global health and refugee-related organizations. We analyzed data related to the prevalence and incidence of epilepsy and PNES; health visits; costs of medical care and challenges faced by healthcare workers in relation to FDP with these conditions. Fifty six papers met our inclusion criteria. Of these, 53 reported directly or indirectly on the prevalence of epilepsy and its costs in FDP. Two articles reported on the prevalence of PNES in forcibly displaced people. The reported prevalence of epilepsy in FDP varied from 0.2% to 39.13%, being highest in people with pre-existing neurological or psychiatric comorbidities. Only one study reported on the incidence of epilepsy in internally displaced children. Data from the United Nations Relief and Works Agency for Palestine Refugees in the Near East (UNRWA) have identified a tendency to higher incidence of epilepsy in children following wars. While within displaced women without a history of sexual violence the rate of PNES was 16.7%, in FDP women with such a history the rate of PNES was 43.7% (p=0.02). The healthcare costs for epilepsy can be high, with recurrent health visits related to seizures being the most common cause of health encounters in refugee camps. Increasing awareness and further studies of multicultural aspects to improve shared understanding of seizure phenomenon in vulnerable displaced populations would seem crucial.

Genetic Diversity of Taenia solium and its Relation to Clinical Presentation of Cysticercosis

In this perspectives paper, we discuss fertilization strategies for Taenia saginata and Taenia saginata asiatica as well as heterogeneity in Taenia solium, the causative agent of human cysticercosis. Two different genotypes of T. solium (Asian and Afro/American) were confirmed by mitochondrial DNA analysis approximately two decades ago. Since then, outcrossings of the two genotypes have been identified in Madagascar where the two genotypes are distributed sympatrically. Outcrossings were confirmed by the presence of discordance between mitochondrial and nuclear DNA. Since multiple tapeworm infections are common in endemic areas, outcrossing events likely occur quite frequently. Therefore, mitochondrial DNA from T. solium specimens collected from humans and pigs in endemic areas should be analyzed. If variations are found between specimens, nuclear DNA analysis should be performed to confirm the presence of discordance between mitochondrial and nuclear genes. Additional outcrossings likely add complexity to understanding the existing genetic diversity. Serological surveys are also recommended since serodiagnostic glycoprotein can also differentiate between the two genotypes. Viable eggs from different genotypes or from hybrids of two different genotypes should be used for experimental infection of pigs or dogs in order to observe any pathological heterogeneity in cysticercosis development. Although genetic diversity of T. solium is expected to result in clinical heterogeneity of cysticercosis in humans and pigs, there is currently no evidence showing that this occurs. There are also no comparative experimental studies on this topic. Therefore, studies evaluating the link between parasite heterogeneity and clinical outcome are warranted.

Taeniasis and cysticercosis in Asia: A review with emphasis on molecular approaches and local lifestyles

Taeniasis is an important parasitic condition in Asia, especially since all three human-infecting Taenia spp., Taenia solium, Taenia saginata, and Taenia asiatica are found in this region. These three species are believed to be sympatrically distributed, with the largest disease burden found in remote and rural areas where people raise pigs and cattle in a traditional manner. Recent studies revealed that T. asiatica and T. saginata are genetically-related sister species that are not completely reproductively isolated from each other. Current evidence indicates that most T. asiatica adult worms are hybrid-derived descendants. Moving forward, nuclear DNA analysis will be critical in further assessing the species circulating locally. Lifestyle choices, such as the consumption of undercooked meat, are important in maintaining the life cycles of these parasites. In addition, poor hygiene and sanitation, in highly endemic areas, make disease control difficult, resulting in the need for sustainable education programs. An overview of the present situation of taeniasis and cysticercosis in Asia is provided, followed by a discussion of molecular approaches to species assessment and the impact of human lifestyles on parasite transmission.

Neurocysticercosis: A case study of a Mongolian traveler who visited China and India with an updated review in Asia

BACKGROUND

Neurocysticercosis (NCC) of Taenia solium has never been reported in Mongolia. A Mongolian traveler who visited China and India presented with epileptic seizures after his return to Mongolia. Magnetic resonance imaging showed multiple ring enhancing lesions with edema surrounding several lesions in his brain that were initially diagnosed to be viral encephalitis or NCC.

METHODS

Serology for cysticercosis using diagnostic antigens partially purified by cation-exchange chromatography and chimeric recombinant antigens and DNA analysis of a proglottid found in the patient's stool were applied for differential diagnosis.

RESULTS

Serology showed strong positivity for NCC, and mitochondrial cox1 gene analysis revealed Indian but not Chinese haplotype of T. solium.

CONCLUSION

This NCC case was considered to be caused by eggs released from adult tapeworm(s) established after eating uncooked or undercooked pork contaminated with cysticerci during his stay in India. This is a case report of taeniasis and secondary NCC associated with travel to India with an updated review of NCC in Asia. Molecular tracking of the specimen is highly informative as a way to identify where the infection was acquired.

Needs of exploring the burden of recent onset seizures due to neurocysticercosis and challenges in southeast Asia focusing on scenario in Malaysia

Seizures due to neurocysticercosis (NCC) is a neglected human-to-human transmitted disorder and an emerging problem worldwide. A substantial portion of recent onset seizures is known to be attributed to NCC in Taenia solium (T. solium) endemic areas where populations which neither raise pigs nor eat pig meat are also at risk. High prevalence of NCC causing epilepsy has been reported in the underdeveloped areas of Southeast Asia (SEA) however, only fragmentary information on its incidence is available in countries like Malaysia. In Malaysia T. solium infection was previously thought to be infrequent due to Muslim population majority and the religious prohibition of consuming pork, but it is not totally absent. There is an evident lack of knowledge and awareness of the actual burden, routes of transmission, and the impact of NCC in this region. The problem is assumed to be more prevalent particularly in cities because of the frequent inflow of possibly T. solium infected individuals or carriers among those who migrate from neighboring endemic countries to Malaysia. The issue of imported cases that are likely to be emerging in Malaysia is highlighted here. An accurate quantification of regional burdens of epilepsy due to NCC in Malaysia is warranted considering the disease emergence in its neighboring countries. It is suggested that the importance of NCC be recognized through quantification of its burden, and also to collect epidemiological data for its subsequent elimination in line of World Health Organization's mission for control of cysticercosis as a neglected tropical disease. In this review the need as well as a strategy for neuro-care center screening of epilepsy cases, and various issues with possible explanations are discussed. It is also proposed that NCC be declared as a reportable disease which is one of the eradicable public health problems in SEA.

Taeniasis among Refugees Living on Thailand-Myanmar Border, 2012

We tested refugee camp residents on the Thailand–Myanmar border for Taenia solium infection. Taeniasis prevalence was consistent with that for other disease-endemic regions, but seropositivity indicating T. solium taeniasis was rare. Seropositivity indicating cysticercosis was 5.5% in humans, and 3.2% in pigs. Corralling pigs and providing latrines may control transmission of these tapeworms within this camp.

The Increase of Exotic Zoonotic Helminth Infections: The Impact of Urbanization, Climate Change and Globalization

Zoonotic parasitic diseases are increasingly impacting human populations due to the effects of globalization, urbanization and climate change. Here we review the recent literature on the most important helminth zoonoses, including reports of incidence and prevalence. We discuss those helminth diseases which are increasing in endemic areas and consider their geographical spread into new regions within the framework of globalization, urbanization and climate change to determine the effect these variables are having on disease incidence, transmission and the associated challenges presented for public health initiatives, including control and elimination.

Neglected parasitic infections in the United States: cysticercosis

Cysticercosis is a potentially fatal and preventable neglected parasitic infection caused by the larval form of Taenia solium. Patients with symptomatic disease usually have signs and symptoms of neurocysticercosis, which commonly manifest as seizures or increased intracranial pressure. Although there are many persons living in the United States who emigrated from highly disease-endemic countries and there are foci of autochthonous transmission of the parasite in the United States, little is known about burden and epidemiology of the disease in this country. In addition, despite advances in the diagnosis and management of neurocysticercosis, there remain many unanswered questions. Improving our understanding and management of neurocysticercosis in the United States will require improved surveillance or focused prospective studies in appropriate areas and allocation of resources towards answering some of the key questions discussed in this report.