Neuropsychiatric Aspects of Parasitic Infections-A Review.

Neuropsychiatric disorders, ranging from mild cognitive impairment to frank psychosis, have been associated with certain parasitic infections. The parasite may cause damage to the central nervous system in several ways: as a space-occupying lesion (neuro-cysticercosis), alteration of neurotransmitters (toxoplasmosis), generation of the inflammatory response (trypanosomiasis, schistosomiasis), hypovolemic neuronal injury (cerebral malaria), or a combination of these. Certain drugs like quinacrine (mepacrine), mefloquine, quinolone, and interferon alpha which are used to treat these parasitic infections can further cause neuropsychiatric adverse effects. This review summarizes the major parasitic infections that are associated with neuropsychiatric disorders and the pathogenesis involved in their processes. A high index of suspicion for parasitic diseases, especially in endemic areas, should be kept in patients presenting with neuropsychiatric symptoms. A multidimensional approach to identification of the offending parasite using serological, radiological, and molecular tests is required not only to ensure proper and prompt treatment of the primary parasitic infection but also to improve the prognosis of patients by complete resolution of neuropsychiatric symptoms.

Mortality associated with cysticercosis in a historical cohort from Britain.

BACKGROUND: The burden of premature mortality associated with human cysticercosis is largely ignored mainly due to poor record-keeping in Taenia solium endemic regions. OBJECTIVE: To document mortality and survival characteristics of an historical cohort with cysticercosis. METHODS: The years of onset of symptoms and death untill 1957 were extracted from published reports of a British military cohort (n=450) examined in London in the early twentieth century. Data were entered into a Kaplan Meier survival analysis with the presence (or absence) of clinical manifestations as independent variables, which were then fitted into a Cox proportional hazards model to determine their significance. RESULTS: Cysticercosis was responsible for 24 (52.2%) of 46 deaths in the first 15 years of follow-up in comparison to 7 (19.4%) of 36 deaths in the 20-40 years of follow-up period. In the univariate and Cox analyses, intracranial hypertension (hazard ratio [HR]: 8.26; CI: 4.71, 14.49), ocular cysticercosis (HR: 6.60; CI: 3.04, 14.33), and mental disorder (HR: 3.98; CI: 2.22, 7.13) but not epilepsy (HR: 0.66; CI: 0.20, 2.18) were associated with mortality. Over half of all deaths in the first 15 years of follow-up were attributed to cysticercosis. CONCLUSIONS: Several deaths occurred early after acquiring cysticercotic infection. Intracranial hypertension, ocular cysticercosis, and mental disorder but not epilepsy were predictors of mortality in this cohort.

Neurocysticercosis control for primary epilepsy prevention: a systematic review.

Neurocysticercosis (NCC) is a leading cause of preventable epilepsy in lower- and upper- middle-income countries (LMICs/UMICs). NCC is a human-to-human transmitted disease caused by ingestion of Taenia solium eggs from a Taenia carrier. T. solium infection control is the key to reduce NCC incidence. This systematic review aims to identify T. solium control programs that can provide frameworks for endemic areas to prevent NCC-related epilepsy. A systematic search was conducted in PubMed/Medline, Embase, Web of Science, and Cochrane Library databases in March 2021. After title and abstract review, full texts were screened for qualitative analysis. Additional articles were identified via citation search. Of 1322 total results, 34 unique studies were included. Six major intervention types were identified: national policy (8.8%), community sanitation improvement (8.8%), health education (8.8%), mass drug administration (29.4%), pig vaccination and treatment (32.4%), and combined human and pig treatment (11.8%). Overall, 28 (82.4%) studies reported decreased cysticercosis prevalence following the intervention. Only health education and combined human and pig treatment were effective in all selected studies. NCC causes preventable epilepsy in LMICs/UMICs and its incidence can be reduced through T. solium control. Most interventions that disrupt the T. solium transmission cycle are effective. Long-term sustained results require comprehensive programs, ongoing surveillance, and collaborative effort among multisectoral agencies.

Neglected Parasitic Infections: What Family Physicians Need to Know-A CDC Update.

Chagas disease, cysticercosis, and toxoplasmosis affect millions of people in the United States and are considered neglected parasitic diseases. Few resources are devoted to their surveillance, prevention, and treatment. Chagas disease, transmitted by kissing bugs, primarily affects people who have lived in Mexico, Central America, and South America, and it can cause heart disease and death if not treated. Chagas disease is diagnosed by detecting the parasite in blood or by serology, depending on the phase of disease. Antiparasitic treatment is indicated for most patients with acute disease. Treatment for chronic disease is recommended for people younger than 18 years and generally recommended for adults younger than 50 years. Treatment decisions should be individualized for all other patients. Cysticercosis can manifest in muscles, the eyes, and most critically in the brain (neurocysticercosis). Neurocysticercosis accounts for 2.1% of all emergency department visits for seizures in the United States. Diagnosing neurocysticercosis involves serology and neuroimaging. Treatment includes symptom control and antiparasitic therapy. Toxoplasmosis is estimated to affect 11% of people older than six years in the United States. It can be acquired by ingesting food or water that has been contaminated by cat feces; it can also be acquired by eating undercooked, contaminated meat. Toxoplasma infection is usually asymptomatic; however, people who are immunosuppressed can develop more severe neurologic symptoms. Congenital infection can result in miscarriage or adverse fetal effects. Diagnosis is made with serologic testing, polymerase chain reaction testing, or parasite detection in tissue or fluid specimens. Treatment is recommended for people who are immunosuppressed, pregnant patients with recently acquired infection, and people who are immunocompetent with visceral disease or severe symptoms.

Guideline for preventive chemotherapy for the control of Taenia solium Taeniasis

The larval stage of the parasite Taenia solium can encyst in the central nervous system causing neurocysticercosis, which is the main cause of acquired epilepsy in the countries in which the parasite is endemic. Endemic areas are those with the presence (or likely presence) of the full life cycle of Taenia solium. The parasite is most prevalent in poor and vulnerable communities in which pigs roam free, open defecation is practiced, basic sanitation is deficient, and health education is absent or limited. Several tools are available for the control of Taenia solium. Preventive chemotherapy for Taenia solium taeniasis, which is directed at the adult tapeworm, is one of them. Other tools focus on pig management, pig vaccination and treatment, sanitation and hygiene, and community education. Three potential drugs­niclosamide, praziquantel, and albendazole­have been considered for use for preventive chemotherapy in Taenia solium taeniasis control programs through mass drug administration or targeted chemotherapy. In this Guideline, we provide recommendations for preventive chemotherapy in Taenia solium-endemic areas using niclosamide, praziquantel, or albendazole, including at which dose and in which population groups. The development of this Guideline is based on the latest standard World Health Organization methods for guideline development, including the use of systematic search strategies, synthesis, quality assessment of the available evidence to support the recommendations, and participation of experts and stakeholders in the Guideline Development Group and External Review Group. The recommendations are intended for a wide audience, including policymakers and their expert advisers, and technical and program staff at governmental institutions and organizations involved in the planning, implementation, monitoring, and evaluation of preventive chemotherapy programs for the control of Taenia solium. Guideline for Preventive Chemotherapy for the Control of Taenia solium Taeniasis

Case Report: Molecular Identification of Larval Taenia martis Infection in the Pouch of Douglas.

Taenia martis is a tapeworm dwelling in the intestine of mustelids and a rare zoonotic cysticercosis pathogen in its larval stage. The metacestode is morphologically very similar to more prevalent cysticercosis parasites, such as the larvae of Taenia solium and Taenia crassiceps, and may be indistinguishable from other metacestodes on histological sections. However, the epidemiology of human T. martis infections is different, and for prognosis, prevention, and detection of natural parasite reservoirs, the species should be identified. We here report the molecular identification of a T. martis larva located in the pouch of Douglas in a female German patient who underwent surgery for endometriosis. This case represents the fifth human infection described worldwide; all previous cases were also in European women, involving the eye, brain, and the peritoneum.

Taenia solium cysticercosis and taeniasis in urban settings: Epidemiological evidence from a health-center based study among people with epilepsy in Dar es Salaam, Tanzania.

In Africa, urbanization is happening faster than ever before which results in new implications for transmission of infectious diseases. For the zoonotic parasite Taenia solium, a major cause of acquired epilepsy in endemic countries, the prevalence in urban settings is unknown. The present study investigated epidemiological, neurological, and radiological characteristics of T. solium cysticercosis and taeniasis (TSCT) in people with epilepsy (PWE) living in Dar es Salaam, Tanzania, one of the fastest growing cities worldwide. A total of 302 PWE were recruited from six health centers in the Kinondoni district of Dar es Salaam. Serological testing for T. solium cysticercosis-antigen (Ag) and -antibodies (Abs) and for T. solium taeniasis-Abs was performed in all PWE. In addition, clinical and radiological examinations that included cranial computed tomography (CT) were performed. With questionnaires, demographic data from study populations were collected, and factors associated with TSCT were assessed. Follow-up examinations were conducted in PWE with TSCT. T. solium cysticercosis-Ag was detected in three (0.99%; 95% CI: 0-2.11%), -Abs in eight (2.65%; 95% CI: 0.84-4.46%), and taeniasis-Abs in five (1.66%; 95% CI: 0.22-3.09%) of 302 PWE. Six PWE (1.99%; 95% CI: 0.41-3.56%) were diagnosed with neurocysticercosis (NCC). This study demonstrates the presence of TSCT in Dar es Salaam, however, NCC was only associated with a few cases of epilepsy. The small fraction of PWE with cysticercosis- and taeniasis-Abs may suggest that active transmission of T. solium plays only a minor role in Dar es Salaam. A sufficiently powered risk analysis was hampered by the small number of PWE with TSCT; therefore, further studies are required to determine the exact routes of infection and risk behavior of affected individuals.

Influence of the interaction between cysticercosis and obesity on rabbit behavior and productive parameters.

Parasites induce behavioral changes in the host and obesity is a health problem affecting different animal species. Cysticercosis caused by Taenia pisiformis affects some behavior of rabbits and reproductive behavior of does. Rabbits do not escape from metabolic disorders, being long-live animals useful in breeding, research and companion animals. Here, we addressed the interaction between parasitosis and obesity, and studied how these conditions or the comorbidity affect behavioral and productive parameters in bucks infected with 3000 T. pisiformis eggs. We found that the chronic infection reduced locomotor activity by 28.5% in obese, 18.5% in infected and 47% in obese-infected group (comorbid). The exploratory activity reduced by 42% in obese, 48% in infected and 68% in comorbid rabbits (P ≤ 0.001). Chinning was not affected by obesity, while infection decreased it by 25%. Behavioral reproductive parameters like response time, the mount latency and number of ejaculates were affected by infection and obesity. Furthermore, obesity seems to increase the parasite load promoting the formation of liver granulomas (16% granulomas compared with normal weight), with a higher number of cysticerci in obese animals (86% more than normal weight). Infection decreases body weight, body mass index and the zoometric index BW/LV in obese and normal weight rabbits. In conclusion, infection with T. pisiformis altered behavioral and productive parameters, and obesity magnifies the impact caused by the infection. Also, obesity leads to major susceptibility to infection with T. pisiformis.

A rare case of giant subretinal migration of cysticercosis cyst with extensive epiretinal membrane and subretinal fibrosis.

Cysticercosis is caused by cysticercus cellulosae, the larval form of pork tapeworm. In intraocular cysticercosis the cyst enters the subretinal space via the choroid and then gains entry into the vitreous cavity by piercing the retina. It is well established that the cyst can incite extensive intraocular inflammation. Other complications such as epiretinal membrane and cataract have been reported in the literature. Thus far, epiretinal membrane in intraocular cysticercosis has been reported at the site of entry of the cyst into the vitreous cavity. The data on the extent of epiretinal membrane is sparse. We report a rare case of migrating subretinal cysticercosis with extensive epiretinal membrane and subretinal fibrosis.

The monetary burden of cysticercosis in Mexico.

BACKGROUND: Taenia solium cysticercosis is a public health and agricultural problem in many low and middle-income countries where health education, sanitation, pig management practices and meat inspection infrastructure are insufficient. Cysticercosis affects both human and animal health and has important economic consequences. Very few studies have been conducted to evaluate the monetary burden of cysticercosis. This study aimed at estimating the 2015 costs associated with cysticercosis in humans and pigs in Mexico. METHODS: The monetary burden of human cysticercosis was estimated based on costs incurred by living with and treating epilepsy and severe chronic headaches associated with neurocysticercosis (NCC). The estimated cost of porcine cysticercosis took into consideration losses due to the reduction in the price of cysticercosis-infected animals. Epidemiologic and economic data were obtained from the published literature, government reports, and setting-specific questionnaires. Latin hypercube sampling methods were employed to sample the distributions of uncertain parameters and to estimate 95% credible regions (95% CRs). All results are reported in 2015 U.S.$. FINDINGS: The overall monetary burden associated with NCC morbidity was estimated at U.S.$215,775,056 (95% CR U.S.$109,309,560 -U.S.$361,924,224), with U.S.$436 (95% CR: U.S.$296 -U.S.$604) lost per patient. If loss of future years of income and productivity due to NCC-associated deaths was included, this value increased by U.S.$54.26 million, assuming that these individuals earned Mexico's median wage salary. An additional U.S.$19,507,171 (95% CR U.S.$5,734,782 -U.S.$35,913,487) was estimated to be lost due to porcine cysticercosis. CONCLUSIONS: This study suggests that T. solium cysticercosis results in considerable monetary losses to Mexico.

Orbital apex syndrome secondary to optic nerve cysticercosis.

A 22-year-old male presented to us with complaints of sudden painful loss of vision in left eye 10 days ago along with inward deviation of the left eye. Best-corrected visual acuity (BCVA) in right eye was 20/20 and 20/50 in left eye. Left eye showed limitation of abduction, a relative afferent pupillary defect, normal anterior segment with optic disc oedema. Contrast-enhanced MRI of the brain and orbit showed thickening of left optic nerve along with a cystic lesion near the orbital apex with a central iso- to hyperintense spot resembling a scolex. A diagnosis of left orbital apex syndrome secondary to optic nerve cysticercosis was made. Patient was treated with oral albendazole and intravenous corticosteroids for 3 days followed by oral corticosteroids. Ten weeks post-treatment, his BCVA in the left eye improved to 20/20 and colour vision and visual fields improved. Pallor of the left optic disc was noted, and ocular motility improved completely. MRI after treatment showed a decreased thickness of left optic nerve with disappearance of the cystic lesion.

[Impact of the neglected Cysticercus cellulose infection on mental health among school-aged children in Tibetan agricultural areas].

OBJECTIVE: To determine the impact of Cysticercus cellulose (C. cellulose) infection on mental health among school-aged children in Tibetan agricultural areas of Sichuan Province.
 Methods: In October 2015, all primary schools located in Tibetan agricultural areas in Yajiang, Ruoergai, and Muli county of Sichuan Province were selected as the research sites. All school-aged children at five- and six-grade were enrolled for the study by a multistage stratified cluster sampling method. Antibodies against C. cellulose were detected. Mental Health Test and questionnaire survey were conducted for school-aged children to collect data. The impact of C. cellulose infection on mental health among school-aged children was analyzed with the multilevel linear regression.
 Results: A total of 2 453 school-aged children were investigated. The C. cellulose seropositive rate was 6.03% (148/2 453). There were 0.16% (4/2 453) patients with seropositive accompanied by seizure, 2.28% (56/2 453) with seropositive accompanied by headache, 2.08% (51/2 453) with seropositive accompanied by frequent weak, and 0.41% (10/2 453) were seropositive accompanied by frequent nausea. The rate of C. cellulose infection was 4.53% (111/2 453). The mean score of the mental health test was 6.59±2.61. There were significant difference in score of mental health test in children whose demographic characteristics were different. The mental health scores of school-aged children were clustered at the school level. After controlling the factors of demographic characteristics, the result of multilevel model demonstrated that the factor of school-aged children with C. cellulose seropositive accompanied by headache was statistically significant (ß=1.14, P=0.017).
 Conclusion: The status of C. cellulose infection among school-aged children in Tibetan agricultural areas is not optimistic. C. cellulose infection has impacted on mental health of local school-aged children. It is necessary to strengthen the prevention and control of C. cellulose infection in epidemic area.

Case Report: Cysticercosis: Sonographic Diagnosis of a Treatable Cause of Epilepsy and Skin Nodules.

A case of disseminated cysticercosis of brain, muscle subcutaneous tissue is reported and the use of musculoskeletal ultrasound in the diagnosis of the condition emphasized.