Burden and factors associated with onchocerciasis transmission among school-aged children after more than 20 years of Community Directed Treatment with Ivermectin in Ulanga district, Tanzania: A school-based cross-sectional study.

Onchocerciasis transmission in the Ulanga District of Morogoro-Tanzania is still ongoing despite more than 20 years of Community Directed Treatment with Ivermectin (CDTI) in the area. Even though surveys conducted over the years in the area have revealed a decrease in the prevalence of onchocerciasis, the prevalence of comorbidities suggested to be associated with this filarial infection, as epilepsy, is rising in endemic regions. This fact suggests continued transmission of Onchocerca volvulus and emphasizes the need for the evaluation of factors associated with it among school aged children. Therefore, this study determined the current burden of onchocerciasis in children aged 6 to 12 years and factors associated with continued transmission despite more than 20 years of CDTI in Ulanga District, Morogoro Region-Tanzania. A school-based cross-sectional study was conducted among 270 children aged 6 to 12 years in Ulanga District. Participants were tested using the OV-16 IgG4 Rapid Test. An interview-administered questionnaire was used to assess disease-associated symptoms, knowledge of onchocerciasis, and factors associated with continued transmission of the disease among participants. Descriptive statistics, chi-square test, and logistic regression were performed during data analysis. The prevalence of onchocerciasis was 19.6% (53/270), with boys being more infected; prevalence increased with increasing age groups and was higher in rural areas. Sex (AOR = 2.2, 95% CI: 1.13-4.28), age group of 11-12 years (AOR = 31.45, 95% CI: 2.73-362.27), and not taking ivermectin (AOR = 3.17, 95% CI: 1.53-6.58) were the only significant factors identified to be associated with the transmission of onchocerciasis in this study. The high prevalence of onchocerciasis among school age children in Ulanga district suggests continued transmission in the area. Therefore, a need to integrate CDTI with health education on the importance of ivermectin uptake.

Subclinical vascular damage in Schistosoma spp. endemic regions.

Background: Cardiovascular abnormalities have been described in patients with schistosomiasis. Their true prevalence and clinical features in endemic settings are unknown. Patients and methods: The study aimed to assess the prevalence of subclinical cardiovascular damage in a population endemic to schistosomiasis. A cross-sectional study was conducted using colour-ultrasound assessment of abdominal and carotid arteries among adults aged >18 years living in Kome Island, Tanzania. Carotid intimal medial thickness, carotid plaque, mean abdominal aortic diameter, and presence of aneurysms were assessed. Anamnestic data on previous Schistosoma infection was collected; the actual prevalence of Schistosoma mansoni and Schistosoma haematobium was also assessed through stool and urine investigations. Results: A total of 264 participants (166 female, 98 male) were enrolled (mean age of 50±15.5 years). The history of previous schistosomiasis was 27.3%, and actual positivity for Schistosoma mansoni was 5.9%. The Latero-lateral Abdominal Aortic Diameter was significantly increased among participants with a previous history of schistosomiasis (16.7±2.8 mm vs. 17.6±3 mm; p=0.02), with an aOR of 1.15 [CI 1.04-1.28]; p=0.007]. Conclusions: The significant difference in the Latero-lateral Abdominal Aortic Diameter in participants with previous Schistosomiasis history schistosomiasis, suggests the need for further investigations on aortic damage in endemic populations, independently from the positive laboratory investigations.

Burden and risk factors for Schistosoma mansoni infection among primary school children: A quantitative school-based cross-sectional survey in Busega district, Northern Tanzania.

BACKGROUND: Intestinal schistosomiasis is one of the most common neglected tropical diseases in Tanzania. Despite massive praziquantel administration, data from Northern Tanzania have reported a prevalence of up to 93.2%. Because the disease is focal, depending on host, environmental and intermediate host factors, there is a need to acquire data in specific settings to better tailor interventions. Therefore, the study assessed the prevalence and factors associated with persistent transmission of intestinal schistosomiasis among school-age children in Busega district, Northern Tanzania. METHODS: A school-based cross-sectional study was conducted among 363 primary school children, randomly selected from school clusters in the Busega district. A single stool sample was collected from each child for S. mansoni ova and infection intensity examination using Kato-Katz. Factors related to intestinal schistosomiasis transmission were acquired through a questionnaire. A malacological survey was carried out to determine the Biomphalaria infectivity rate. Descriptive statistics and logistic regression analysis were conducted to analyse the association between schistosoma infection and factors related to transmission in this setting. RESULTS: The prevalence of S. mansoni infection was 41.3% (95% CI: 36.3-46.5), statistically significantly higher among the younger group aged less than 11 years (46.4% vs 35.3%, p = 0.032). The intensity of infection was heavy in 1.6% of participants, moderate in 9.6%, and light in 30.9%. Studying at Mwamayombo Primary School (AOR = 2.50, 95% CI: 1.12-5.60) was the only factor significantly associated with S. mansoni infestations. The snail intermediate host belonged to Biomphalaria sudanica species, whose infectivity rate was quantified as 0.97%, thus confirming ongoing transmission in the area. CONCLUSIONS: There was a high prevalence of S. mansoni infection among school-age children in the Busega district. The presence of the infected Biomphalaria sudanica in the area documents the persistent transmission of the disease, favored by low knowledge and negative attitudes among school-aged children. Hence, the need for multi-approach intervention for schistosomiasis prevention and elimination.

Blood Flukes and Arterial Damage: A Review of Aneurysm Cases in Patients with Schistosomiasis.

Introduction: Schistosomiasis, caused by trematode worms of the genus Schistosoma, has organ-specific morbidity due to host's inflammatory response to the oviposition of parasite eggs in vessels and organs. Damage to the cardiovascular system, including aneurysms, has been described in patients. Aims and Methods. Aims of the review of case reports and series published in literature were to describe the occurrence of aneurysm in patients with schistosomiasis. Investigation Outcomes. A total of 13 cases (seven males and six females) with a mean age of 41.3 ± 14.9 years were included. Aneurysm occurred in patients with active or previous infection. In more than half of the cases, an intestinal or hepato-splenic involvement was reported, followed by pulmonary schistosomiasis and urinary or testicular involvement. The most frequently involved arterial district was the pulmonary artery. Immunomodulation and thrombophilia were featuring challenging surgery. Conclusions: More studies are needed to shed light on the vascular complications of schistosomiasis, to ascertain the true burden of aneurysms in patients with schistosomiasis, to establish the pathophysiology of vessel damage and aneurysm formation, and to assess if there is an association between schistosomiasis and aneurysm formation in line with WHO 2021-2030 NTD Roadmap.