Sero-epidemiology of Toxoplasmosis among pregnant women in the University of Port Harcourt Teaching Hospital, Nigeria

Background: The objective of this study was to determine the sero-prevalence of Toxoplasma gondii infection and associated risk factors among pregnant women in the University of Port Harcourt Teaching Hospital, Nigeria.Methods: A cross-sectional study involving two hundred and eighty-eight (288) pregnant women who gave informed consent was done. Questionnaires were administered to determine their sociodemographic and risk factors. Enzyme-linked immunosorbent assay (ELISA) was performed on all patients’ sera to detect anti-Toxoplasma Immunoglobulin G (IgG) and M (IgM). Data was analyzed using the statistical package Epi info version 6.04d.Results: A total of one hundred and eighty-nine women (65.6 %) were sero-positive for IgM and/or IgG. Thirty-three (11.5%) were positive for IgM only, one hundredand twenty-three (42.4%) for IgG only and thirty-three (11.5%) for both. Consumption of beef was a statistically significant risk factor associated.Conclusion: A significant proportion of pregnant women have been exposed to Toxoplasma gondii, with the risk factor significantly associated with infection being consumption of beef, which is a very common practice in Port Harcourt. It is therefore necessary to heighten enlightenment of the populace particularly women of child-bearing age and pregnant women on toxoplasmosis–specific preventive practices to reduce their exposure to the pathogen and its potential complications. Routine screening for Toxoplasmosis in pregnancy would be largely beneficial in its prevention and control.Keywords: Toxoplasma gondii; Pregnancy; ELISA, Risk factor

Interim data monitoring to enroll higher-risk participants in HIV prevention trials

<p>Abstract</p> <p>Background</p> <p>Lower-than-expected incidence of HIV undermines sample size calculations and compromises the power of a HIV prevention trial. We evaluated the effectiveness of interim monitoring of HIV infection rates and on-going modification of recruitment strategies to enroll women at higher risk of HIV in the Cellulose Sulfate Phase III study in Nigeria.</p> <p>Methods</p> <p>We analyzed prevalence and incidence of HIV and other sexually transmitted infections, demographic and sexual behavior characteristics aggregated over the treatment groups on a quarterly basis. The site investigators were advised on their recruitment strategies based on the findings of the interim analyses.</p> <p>Results</p> <p>A total of 3619 women were screened and 1644 enrolled at the Ikeja and Apapa clinics in Lagos, and at the Central and Peripheral clinics in Port Harcourt. Twelve months after study initiation, the overall incidence of HIV was less than one-third of the pre-study assumption, with rates of HIV that varied substantially between clinics. Due to the low prevalence and incidence rates of HIV, it was decided to close the Ikeja clinic in Lagos and to find new catchment areas in Port Harcourt. This strategy was associated with an almost two-fold increase in observed HIV incidence during the second year of the study.</p> <p>Conclusion</p> <p>Given the difficulties in estimating HIV incidence, a close monitoring of HIV prevalence and incidence rates during a trial is warranted. The on-going modification of recruitment strategies based on the regular analysis of HIV rates appeared to be an efficient method for targeting populations at greatest risk of HIV infection and increasing study power in the Nigeria trial.</p> <p>Trial Registration</p> <p>The trial was registered with the ClinicalTrials.gov registry under #NCT00120770 <url>http://clinicaltrials.gov/ct2/show/NCT00120770</url></p

Effectiveness of Cellulose Sulfate Vaginal Gel for the Prevention of HIV Infection: Results of a Phase III Trial in Nigeria

BACKGROUND: This trial evaluated the safety and effectiveness of 6% cellulose sulfate vaginal gel in preventing male-to-female vaginal transmission of HIV, gonorrhea and chlamydial infection. METHODS: This Phase III, double-blind, randomized, placebo-controlled trial was conducted between November 2004 and March 2007 in Lagos and Port Harcourt, Nigeria. We enrolled 1644 HIV-antibody negative women at high risk of HIV acquisition. Study participants were randomized 1:1 to cellulose sulfate or placebo and asked to use gel plus a condom for each act of vaginal intercourse over one year of follow-up. The participants were evaluated monthly for HIV, gonorrhea and chlamydial infection, and for adverse events. RESULTS: The trial was stopped prematurely after the data safety monitoring board of a parallel trial concluded that cellulose sulfate might be increasing the risk of HIV. In contrast, we observed fewer infections in the active arm (10) than on placebo (13), a difference that was nonetheless not statistically significant (HR = 0.8, 95% CI 0.3-1.8; p = 0.56). Rates of gonorrhea and chlamydial infection were lower in the CS group but the difference was likewise not statistically significant (HR = 0.8, 95% CI 0.5-1.1; p = 0.19 for the combined STI outcome). Rates of adverse events were similar across study arms. No serious adverse events related to cellulose sulfate use were reported. CONCLUSIONS: Cellulose sulfate gel appeared to be safe in the evaluated study population but we found insufficient evidence that it prevented male-to-female vaginal transmission of HIV, gonorrhea or chlamydial infection. The early closure of the trial compromised the ability to draw definitive conclusions about the effectiveness of cellulose sulfate against HIV. TRIAL REGISTRATION: ClinicalTrials.gov NCT00120770

What predicts non-retention in microbicide trials?

Background: Poor retention can reduce study power and thwart randomization, possibly resulting in biased estimates of effect. Some HIV prevention trials conducted in developing countries have been challenged by high loss to follow-up. Identifying factors associated with non-retention could lead to recruitment of women more likely to remain in the trial, potentially yielding greater efficiency and validity. Methods: We summarized retention rates and, using Cox regression, evaluated factors associated with non-retention in four trials of two candidate vaginal microbicides (1% C31G or SAVVY® and 6% cellulose sulfate or CS) conducted in multiple sub-Saharan African countries. We defined retention as completion of the trial, including those with an HIV outcome. Nonretention comprised participants randomized to a study arm who were either lost to follow-up or discontinued prior to infection with HIV. Results: 7367 women were enrolled and randomized in the four trials; 7086 are included in this analysis. 1514 (21.4%) participants were either lost to follow-up or had early discontinuation. In the final Cox model, the following baseline factors were associated with non-retention: younger age (hazard ratio [HR] = 0.95); less education (HR = 0.97); condom use at last sex (HR = 1.18); larger number of sex acts in a typical week (HR = 1.01); and baseline candidiasis or bacterial vaginosis (HR = 1.12). Conclusions: Younger and less educated women were more difficult to retain in these microbicide trials. But these same traits may be associated with higher HIV infection rates. Enhanced retention methods focused on those at highest risk of non-retention and possibly infection will optimize study efficiency and validity