Hepatitis B virus infection, associated factors, knowledge and vaccination status among household contacts of hepatitis B index cases in Mwanza, Tanzania

Objectives

To determine the prevalence of hepatitis B virus (HBV) infection, knowledge regarding HBV, vaccination status, and associated factors among household contacts of HBV index cases in Mwanza, Tanzania.

Methods

Between July and August 2023, a cross-sectional study involving 97 index cases and 402 household contacts was conducted. Data were collected using pre-tested structured questionnaire and blood samples were collected from household contacts for HBV surface antigen (HBsAg) testing.

Results

The prevalence of HBV among household contacts was 5.4% (95% confidence interval, 2.9-9.0) with a significantly high proportion observed in > 45 years (16.6%) and in males (9.9%). A total of 40.0% of the household contacts had completed the full HBV vaccination series. On multivariate analysis, being male was significantly associated with HBsAg positivity (odds ratio: 7.16, 95% confidence interval: 1.81-28.2, P = 0.005).

Conclusion

About one-tenth of adults' male household contacts were HBsAg positive. In addition, the majority of household contacts had poor to fair knowledge regarding HBV infection with more than half being unvaccinated against HBV. There is a need to enhance awareness and education regarding HBV infection among household contacts in Tanzania and other low- and middle-income countries.

Trends of measles in Tanzania: A 5-year review of case-based surveillance data, 2018-2022

OBJECTIVES

Tanzania observed a gradual increase in the number of measles cases since 2019 with a large outbreak recorded during 2022. This study describes the trend of measles in Tanzania over a 5-year period from 2018-2022.

METHODS

This was a descriptive study conducted using routine measles case-based surveillance system including 195 councils of the United Republic of Tanzania.

RESULTS

Between 2018 and 2022 there were 12,253 measles cases reported. Out of 10,691 (87.25%) samples tested by enzyme-linked immunosorbent assay, 903 (8.4%) were measles immunoglobulin M positive. The highest number of laboratory-confirmed measles cases was in 2022 (64.8%), followed by 2020 (13.8%), and 2019 (13.5%). Out of 1279 unvaccinated cases, 213 (16.7%) were laboratory-confirmed measles cases compared to 77/723 (10.6%) who were partially vaccinated and 71/1121 (6.3%) who were fully vaccinated (P < 0.001). Children aged between 1-4 years constituted the most confirmed measles cases after laboratory testing, followed by those aged 5-9 years. There was a notable increase in the number of laboratory-confirmed measles cases in children <1 year and 10-14 years during 2022 compared to previous years. The vaccination coverage of the first dose of measles-containing vaccine (MCV1) was maintained >90% since 2013 while MCV2 increased gradually reaching 88% in 2022.

CONCLUSIONS

Accumulation of susceptible children to measles due to suboptimal measles vaccination coverage over the years has resulted in an increase in the number of laboratory-confirmed measles cases in Tanzania with more cases recorded during the COVID-19 pandemic. Strengthening surveillance, routine immunization, and targeted strategies are key to achieving the immunity levels required to interrupt measles outbreaks.

The High Seropositivity of Mumps Virus IgG Antibodies among School-Aged Children in Rural Areas of the Mbarali District in the Mbeya Region, Tanzania: It Is High Time for Consideration in the National Immunization Program

Mumps is an acute contagious viral disease caused by paramyxovirus characterized by complications that include orchitis, oophoritis, aseptic meningitis, and spontaneous abortion among many others. This study reports high mumps IgG seropositivity among school-aged children in rural areas of the Mbeya region, information that might be useful in understanding the epidemiology of mumps and instituting appropriate control measures including vaccination. Between May and July 2023, a cross-sectional study involving 196 enrolled children aged 5-13 years was conducted. Sociodemographic information and other relevant information were collected using a structured data collection tool. Blood samples were collected and used to detect mumps immunoglobulin G antibodies using indirect enzyme-linked immunosorbent assay (ELISA). A descriptive analysis was performed using STATA version 15. The median age of the enrolled children was 13 (interquartile range (IQR): 8-13) years. The seropositivity of mumps IgG antibodies was 88.8% (174/196, 95% CI: 83.5-92.5). By multivariable logistic regression analysis, history of fever (OR: 5.36, 95% CI: 1.02-28.22, p = 0.047) and sharing utensils (OR: 8.05, 95% CI: 1.99-32.65, p = 0.003) independently predicted mumps IgG seropositivity. More than three-quarters of school-aged children in rural areas of the Mbeya region are mumps IgG-seropositive, which is significantly associated with the sharing of utensils and history of fever. This suggests that the virus is endemic in this region, which calls for further studies across the country so as to institute evidence-based, appropriate control measures including a vaccination program.

Rotavirus genotype diversity in Tanzania during Rotavirus vaccine implementation between 2013 and 2018

The study aims to determine Rotavirus genotypes between 2013 and 2018 during implementation of ROTARIX vaccine in Tanzania. The analysis of surveillance data obtained between 2013 and 2018 was done to determine circulating genotypes after introduction of Rotarix vaccine. From 2013 to 2018, a total of 10,557 samples were collected and screened for Rotavirus using an enzyme immunoassay. A significant decrease in Rotavirus positivity (29.3% to 17.8%) from 2013 to 2018 (OR 0.830, 95% CI 0.803-0.857, P < 0.001) was observed. A total of 766 randomly selected Rotavirus positive samples were genotyped. Between 2013 and 2018, a total of 18 Rotavirus genotypes were detected with G1P [8] being the most prevalent. The G1P [8] strain was found to decrease from 72.3% in 2015 to 13.5% in 2018 while the G9P [4] strain increased from 1 to 67.7% in the same years. G2P [4] was found to decrease from 59.7% in 2013 to 6.8% in 2018 while G3P [6] decreased from 11.2% in 2014 to 4.1% in 2018. The data has clearly demonstrated that ROTARIX vaccine has provided protection to varieties of the wild-type Rotavirus strains. Continuous surveillance is needed to monitor the circulation of Rotavirus strains during this era of vaccine implementation.

Reduction in Rubella Virus Active Cases among Children and Adolescents after Rubella Vaccine Implementation in Tanzania: A Call for Sustained High Vaccination Coverage

Rubella virus (RV) infection in susceptible women during the first trimester of pregnancy is associated with congenital Rubella syndrome (CRS). In countries where a vaccination program is implemented, active case surveillance is emphasized. This report documents the magnitude of active cases before and after vaccine implementation in Tanzania. A total of 8750 children and adolescents with signs and symptoms of RV infection were tested for Rubella IgM antibodies between 2013 and 2019 using enzyme immunoassay followed by descriptive analysis. The median age of participants was 3.8 (IQR: 2−6.4) years. About half (4867; 55.6%) of the participants were aged 1−5 years. The prevalence of RV active cases was 534 (32.6%, 95% CI: 30.2−34.9) and 219 (3.2%, 95% CI: 2.7−3.6) before and after vaccine implementation, respectively. Before vaccination, the highest prevalence was recorded in Pemba (78.6%) and the lowest was reported in Geita (15.6%), whereas, after vaccination, the prevalence ranged between 0.5% in Iringa and 6.5% in Pemba. Overall, >50% of the regions had a >90% reduction in active cases. The significant reduction in active cases after vaccine implementation in Tanzania underscores the need to sustain high vaccination coverage to prevent active infections and eventually eliminate CRS, which is the main goal of Rubella vaccine implementation.

A213 ERCP-RELATED ADVERSE EVENTS IN PRIMARY SCLEROSING CHOLANGITIS: A SYSTEMATIC REVIEW & META-ANALYSIS

Background

Endoscopic retrograde cholangiopancreatography (ERCP) is a valuable diagnostic and therapeutic tool in primary sclerosing cholangitis (PSC). Although the complications of ERCP are well known in the general population, there is conflicting data regarding complications in patients with PSC. Factors that predict ERCP-related adverse events in PSC are also unclear.

Aims

To conduct a systematic review and meta-analyses to 1. compare ERCP-related adverse events in patients with and without PSC and 2. determine risk factors associated with ERCP-related adverse events in PSC.

Methods

A systematic search was conducted in Embase, PubMed and CENTRAL for studies published from January 1, 2000 to May 12, 2021. Eligible studies included adults with PSC undergoing ERCP and reported at least one ERCP-related adverse event (bleeding, perforation, pancreatitis, cholangitis) or risk factor associated with complications. Raw event rates for adverse events and risk factors were used to calculate odds ratios (ORs) which were then pooled using random-effects models.

Results

Four studies contributed to the first meta-analysis. There was a significant three-fold increase in the 30-day odds of cholangitis in PSC compared to those without PSC (4.3% vs. 2.0%; OR 3.26, 95% CI 1.08–9.90; p=0.037; I2=73.0%) (Figure 1). However, there were no significant differences in 30-day pancreatitis (4.2% vs. 3.4%; OR 0.89, 95% CI 0.26–3.07; p=0.851; I2=87.9%), bleeding (0.3% vs. 1.1%; OR 0.36, 95% CI 0.06–2.21; p=0.272; I2=50.3%), or perforation (0.7% vs. 0.5%; OR 1.19, 95% CI 0.40–3.51; p=0.752; I2=28.5%).

In a second meta-analysis, risk factors contributing to post-ERCP pancreatitis (PEP) in PSC were pooled from five studies. While female sex was not associated with PEP, accidental passage of wire into the pancreatic duct (OR 7.44, 95% CI 3.33–16.65; p&lt;0.001; I2=65.0%) and biliary sphincterotomy (OR 4.80, 95% CI 1.92–12.03; p=0.001; I2=73.1%) were associated with higher PEP odds.

Conclusions

In the context of limited comparative data and study heterogeneity, PSC patients have higher odds of post-ERCP cholangitis despite the majority receiving antibiotics. Odds of bleeding, pancreatitis, and perforation were similar between groups. Accidental wire passage and biliary sphincterotomy increased odds of PEP, which helps identify higher-risk groups. Future studies should elucidate ERCP-related risks in PSC and guide preventive strategies.

Funding Agencies

None

Intussusception among infants in Tanzania: findings from prospective hospital-based surveillance, 2013-2016

Introduction

intussusception surveillance was initiated in Tanzania in 2013 after monovalent rotavirus vaccine was introduced, as part of the 7-country African evaluation to assess whether the vaccine was associated with an increased risk of intussusception. An increased risk from vaccine was not identified. Published data on intussusception in Tanzanian infants are limited.

Methods

prospective intussusception surveillance was conducted at 7 referral hospitals during 2013-2016 to identify all infants with intussusception meeting Brighton Level 1 criteria. Demographic, household and clinical data were collected by hospital clinicians and analyzed.

Results

a total of 207 intussusception cases were identified. The median age of cases was 5.8 months and nearly three-quarters were aged 4-7 months. Median number of days from symptom onset to admission at treatment hospital was 3 (IQR 2-5). Seventy-eight percent (152/195) of cases had been admitted at another hospital before transfer to the treating hospital. Enema reduction was not available; all infants were treated surgically and 55% (114/207) had intestinal resection. The overall case-fatality rate was 30% (62/206). Compared with infants who survived, those who died had longer duration of symptoms before admission to treatment hospital (median 4 vs 3 days; p < 0.01), higher rate of intestinal resection (81% [60/82] vs 44% [64/144], p < 0.001), and from families with lower incomes (i.e., less likely to own a television [p < 0.01] and refrigerator [p < 0.05).

Conclusion

Tanzanian infants who develop intussusception have a high case-fatality rate. Raising the index of suspicion among healthcare providers, allocating resources to allow wider availability of abdominal ultrasound for earlier diagnosis, and training teams in ultrasound-guided enema reduction techniques used in other African countries could reduce the fatality rate.

Role of VEGF in the differential growth between the fetal and placental ends of the umbilical cord

INTRODUCTION

The umbilical cord (UC) is a vital structure; its alterations affect the newborn and neurological impact can be permanent. Paradoxically, factors that determine it remain unknown. We explore the differential VEGF protein expression in the UC's proximal and distal portions in relation to the hypothesis that the UC has differential growth and that VEGF plays a role in it.

METHODS

An observational analytical study was performed. One UC segment was taken proximal to fetus and another distal; both were randomly processed; VEGF immunohistochemical analysis was performed; two blinded pathologists read results.

RESULTS

Forty-eight newborns were included. Protein expression between the two edges of the umbilical cord, in any kind of cells, was interpreted. Endothelium, amnion, and stromal cells expressed VEGF; the first two were not different between opposite ends. Stromal cells had differential expression: higher in the proximal to the fetus portion.

CONCLUSION

Knowledge of molecular factors is necessary. UC cells widely expressed VEGF, possibly contributing to UC growth. Even though stromal cell expression was different, the interaction with activity close to the fetus must be explored.

Trends in diarrhea hospitalizations among infants at three hospitals in Tanzania before and after rotavirus vaccine introduction

BACKGROUND

The Tanzania Ministry of Health introduced monovalent human rotavirus vaccine in January 2013, to be administered at ages 6 and 10 weeks. Data suggest there was high vaccine uptake. We used hospital ward registers from 3 hospitals to examine trends in diarrhea hospitalizations among infants before and after vaccine introduction.

METHODS

Ward registers from Dodoma Regional Referral Hospital (Central Tanzania), and two hospitals in Mbeya (Southwest area), Mbeya Zonal Referral Hospital and Mbalizi Hospital, were used to tally admissions for diarrhea among children by age group, month and year. Rotavirus surveillance had started at these hospitals in early 2013; the proportion of infants enrolled and rotavirus-EIA positive were examined by month to determine peak periods of rotavirus disease post-vaccine introduction.

RESULTS

Registers were available for 2-4 prevaccine years and 2-3 post introduction years. At Dodoma Regional Referral Hospital, compared with the mean of 2011 and 2012, diarrhea hospitalizations among infants were 26% lower in 2015 and 58% lower in 2016. The diarrhea peak shifted later in the year first by 1 and then by 2-3 months from prevaccine. At the Mbeya hospitals, the number of diarrhea admissions in prevaccine period varied substantially by year. At Mbeya Referral Hospital, diarrhea hospitalizations among infants were lower by 25-37% in 2014 and 11-26% in 2015, while at Mbalizi Hospital, these hospitalizations were 4% lower in 2014 and 14% higher in 2015. Rotavirus testing data demonstrated a lowering of the prevaccine peak, a shift in timing of the peak months and indicated that other diarrheal peaks in post-introduction years were not due to rotavirus.

CONCLUSIONS

In this ecological evaluation, total diarrhea hospitalizations among infants were lower (≥25% lower in ≥1 year) following introduction in 2 of 3 hospitals. There are challenges in using ward registers to ascertain possible impact of rotavirus vaccine introduction on trends in hospitalizations for treatment of all diarrheal illness.

Detection of rotavirus before and after monovalent rotavirus vaccine introduction and vaccine effectiveness among children in mainland Tanzania

BACKGROUND

Monovalent rotavirus vaccine (RV1) was introduced in Tanzania in January 2013 under the Reach Every Child initiative, to be given at ages 6 and 10 weeks. We used the sentinel hospital rotavirus surveillance system to examine the rotavirus detection rate before and after vaccine introduction and estimate vaccine effectiveness.

METHODS

Before vaccine introduction, rotavirus surveillance was established at two mainland hospitals; children admitted for acute diarrhea were eligible for enrollment and stools were tested for rotavirus antigen. We compared the rotavirus positivity rate in the pre-vaccine period (Tanga Hospital, 2009 and 2011; Bugando Medical Centre, 2012) to that from post-introduction years, 2014-2015. In 2013, surveillance was established at 9 additional hospitals. We examined rotavirus positivity among infants at these sites for 2014-2015. We obtained vaccine records and calculated vaccine effectiveness at 3 sites using case-test-negative control design.

RESULTS

At Tanga Hospital, the rotavirus positivity rate among infants was 41% (102/251) pre-vaccine and 14% (28/197) in post-vaccine years (rate ratio: 0.35 [95% CI 0.22-0.54]). At Bugando, the positivity rate was 58% (83/143) pre-vaccine, and 18% (49/277) post-introduction (rate ratio 0.30 [95% CI 0.210.44]). Results were similar among children <5 years. At the new sites, the median site rotavirus positivity rate among infants was 26% in 2014 (range 19-44%) and 18% in 2015 (range 16-33%). The effectiveness of ≥1 RV1 dose against rotavirus hospitalization among children 5-23 months was 53% (95% CI: -14, 81), and 66% (95% CI: 9-87) against hospitalization with intravenous rehydration. Following introduction, peak rotavirus activity occurred later in the year and appeared more concentrated in time.

CONCLUSION

Rotavirus surveillance data from Tanzania indicate that the rotavirus positivity rate among children hospitalized with diarrhea that were enrolled was substantially reduced after vaccine introduction. Low positivity rates among infants were detected at hospitals across the country. Overall, the data support that rotavirus vaccine has been successfully introduced and is effective in Tanzanian children.

Gamma radiation measurements and dose rates in commonly used building materials in Cyprus

A first comprehensive study is presented on radioactivity concentrations and dose rates in 87 commonly used materials, manufactured or imported in Cyprus, for building purposes. The natural radioactivity of (40)K, (232)Th, (238)U and (226)Ra is determined using high-resolution gamma-ray spectroscopy. The respective dose rates and the associated radiological effect indices are also calculated. A comparison of the measured specific activity values with the corresponding world average values shows that most of them are below the world average activity values. The annual indoor effective dose rates received by an individual from three measured imported granites and four measured imported ceramics are found to be higher than the world upper limit value of 1 mSv y(-1). Hence, these materials should have a restricted use according to their corresponding calculated activity concentration index values and the related EC 1999 guidelines.

The Antiproliferative Effect of Calcitriol on Breast Cancer Cell Lines Depends on Vitamin D Receptor Status and the Expression of Prostaglandin Metabolizing Enzymes

Background: Both first studies in prostate cancer and our results in breast cancer suggest a link between vitamin D and prostaglandin metabolism. There is a growing body of evidence that COX-2 expression is a fundamental step in breast cancer pathogenesis acting through prostaglandin-dependent and independent mechanisms. The antiproliferative effects of calcitriol (1,25(OH)2D3) mediated via the vitamin D receptor (VDR), render the biologically active form of vitamin D a promising target in breast cancer therapy.Materials and methods: The expression of VDR, COX-2 and 15 PGDH was determined by Western blot in MCF-10F cells, a human benign epithelial cell line, in MCF-7 cells, a moderate invasive and in MDA-MB-231 cells, a highly invasive breast cancer cell line. Measurement of basal PGE2 secretion was performed with ELISA. The influence of calcitriol on cell proliferation was determined by 5-bromo-2-deoxyuridine (BrDU) incorporation (BrDU ELISA). In addition we examined the effect of calcitriol on COX-2, 15 PGDH and VDR protein levels compared to untreated cells.Results: After 72 hours the proliferation of MCF-10F cells was dose-dependent inhibited to 0.83± 0.1 by 1 nM calcitriol. Concurrently, we observed a reduction of COX-2 expression to 0.63± 0.05 as compared to the untreated control group, but we also found a reduction of 15 PGDH to 0.73± 0.16. These effects were associated with a higher expression of VDR to 1.64± 0.16. Interestingly, MCF-7 cell growth was reduced to 0.52± 0.04 by 10 nM calcitriol and to 0.7± 0.06 by 1 nM. These effects do not seem to be associated with COX-2 and 15 PGDH and are independently of VDR. VDR was detected neither in stimulated nor in unstimulated cells. A PGE2 secretion could not be detected by ELISA. In contrast, we found no effect on cell growth, COX-2 and 15-PGDH expression of the MDA-MB-231 cells when treated by calcitriol (10 nM and 1 nM). Although PGE2 was synthesized 2.3-fold more by MDA-MB-231 cells than MCF-10F cells; the COX-2 expression was consistent with the MCF-10F cells, but 15-PDGH was expressed about 50 % less. As we have shown in MCF-7 cells, an expression of the VDR could not be detected.Conclusions: The growth inhibiting effect of calcitriol in MCF10F cells is associated with the increasing expression of VDR. and a remaining question is whether the loss of VDR goes along with the invasiveness of the breast cancer cell lines. Additionally, we suggest that the invasiveness of the breast cells is abetted by the increased COX-2 expression (MCF-7) or by the decreased expression of 15 PGDH (MDA-MB-231). These results suggest even more a link between vitamin D and prostaglandin metabolism and therefore a possible synergism between COX-2 inhibition and calcitriol in breast cancer cells.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5155.

Brain biopsy in Indiana AIDS patients

The neuropathologic findings of brain biopsies in a series of Indiana AIDS patients were reviewed. All subjects displayed focal lesions on radiographic studies. The three most common diagnoses were toxoplasmosis, progressive multifocal leukoencephalopathy and primary central nervous symptoms (CNS) lymphoma. These findings were consistent with previous studies elsewhere. Biopsy appears to affect the course of treatment only if CNS lymphoma is discovered. Because the value of currently available therapy for this disease in AIDS patients is controversial, there is no clear consensus regarding the indications for biopsy in this population.