5 research outputs found
Human immunodeficiency virus and human papillomavirus infections in Mozambique : from epidemiological reports to clinical trials and vaccine implementation
Human immunodeficiency virus (HIV) and human papillomavirus (HPV) are sexually transmitted
microorganisms responsible for two major infectious diseases and public health concerns,
particularly in developing countries and in sub-Saharan Africa. HIV is the causative agent of the
acquired immunodeficiency syndrome (AIDS) that has so far claimed more than 35 million lives.
HPV is responsible for virtually all cervical cancers (CC), the seventh most common cancer in the
world and the fourth in women. Mozambique is highly affected by both HIV and HPV epidemics.
The country has the fifth highest prevalence of HIV in the world and the second highest rates of CC
in Africa. The national seroprevalence of HIV in 2015 was estimated to be 13.2% in populations
aged 15-49 years. A previous report from Southern Mozambique has demonstrated a high
prevalence of HPV in women aged 14-61 years (75.9%).
This thesis aimed at describing the epidemiology of HIV and HPV infections in young adults in
Maputo city, Mozambique and to evaluate preventive strategies for control of HIV and HPV. This
thesis embraces a total of four studies (I-IV). Study I aimed at determining the HIV incidence in
youths aged 18-24 years. In this study 1380 subjects were screened for HIV, hepatitis B virus and
syphilis. HIV-uninfected individuals (n=1309) were prospectively followed for one year with
quarterly study visits to determine the HIV status. The HIV, hepatitis B and syphilis prevalence
found at baseline were 5.1%, 12.2% and 0.36%, respectively. The overall HIV incidence was
1.14/100 PY and was slightly higher in the female population (1.49/100 WY). The relatively low
prevalence and incidence of HIV and the low prevalence of syphilis described in this study
associated to the considerable stable visit retention rates, suggest that this cohort is suitable for
recruitment into phase I/II HIV vaccine trials. Study II was a phase I HIV vaccine trial that
recruited 24 healthy HIV-uninfected individuals from the cohort established in study I and aimed at
exploring the safety and immunogenicity of an HIV-DNA/HIV-MVA prime-boost strategy using a
low-dose (600 ÎĽg, 2 x 0.1 mL) and a high-dose (1200 ÎĽg, 2 x 0.2 mL) of HIV-DNA prime,
delivered intradermally using a needle-free device, the ZetajetTM. This was the first HIV vaccine
trial ever conducted in Mozambique and the first to assess the use of the ZetajetTM in a higher
injection volume. The vaccines were safe and well tolerated. After the first HIV-MVA, Env
responses were significantly higher in the high-dose group compared to the low-dose group (median
420 vs. 157.5 SFC/million PBMC, p = 0.014). Four weeks after the 2nd HIV-MVA, binding
antibodies to recombinant CN54 subtype C gp140 and to native subtype B gp160 were induced in
all vaccinees, with a median titer of 800 and 400, respectively. The findings suggest that the higher
1200 ÎĽg HIV-DNA dose should be considered in the future. Study III describes HPV genotypes in
young women and men recruited from the cohort established in study I. Cervical and urethral
samples were collected in women and men, respectively and analyzed using the Clart® Human
Papillomavirus 2 (Genomica, Madrid, Spain), a target amplification assay capable of detecting 35
different low- and high-risk HPV genotypes. The overall prevalence of HPV was 40.8% (63.6% and
10.2% in women and men, respectively). In women HPV52, 35, 16, 53, 58, 6, and 51 were the most
frequently found genotypes and HPV6, 11, 52, 59, and 70 in men. These results show a 50%
homology with the genotypes detected in CC specimens in the country. Study IV was a two-round
post-vaccination survey conducted after an HPV vaccine demonstration project (in 2014 and 2015),
in which an HPV vaccine was given to girls aged 9-10 years, in two rural districts of Mozambique
(Manica and MocĂmboa da Praia). This study aimed at assessing the HPV vaccine coverage,
awareness, knowledge, and acceptance; to explore reasons for not-vaccinating; and to identify the
best vaccine communication strategies. Parents or guardians of girls eligible for vaccination were
interviewed within 4 months after the last HPV injection had been administered to the girls.
Vaccine coverage in 2014 was 50% and 14% and in 2015 was 47% and 32% for Manica and
MocĂmboa da Praia, respectively. The most frequent reason to vaccinate the girls was the belief that
the vaccine could contribute to the girl´s health. The reasons for not vaccinating were the absence of
girls from school and the lack of knowledge about the campaign. The radio spot was the
communication strategy that reached the majority of respondents. These results show that provision
of information about the benefits of vaccines can lead to a positive decision by the
parents/guardians and improved planning and communications may increase the vaccination rates.
Lessons learned from this study may give important insights on the implementation of a future HIV
vaccine in adolescents, a group that will most likely be prioritized
Incidence of HIV and the Prevalence of HIV, Hepatitis B and Syphilis among Youths in Maputo, Mozambique: A Cohort Study
<div><p>Background</p><p>Prevalence of HIV in Mozambique among individuals aged 15–49 years is 11.5%. The HIV prevalence is higher in women than in men across the country, peaking at ages 25–29 years and 35–39 years, respectively. In this study, we aimed at determining the prevalence and incidence of HIV, prevalence of Hepatitis B (HBV), and prevalence of syphilis in youths. We also characterized a cohort of youths for future participation in phase I/II HIV vaccine trials.</p><p>Methods</p><p>The study was conducted at a youth clinic in Maputo Central Hospital from August 2009 to October 2011. Youths of both genders aged 18–24 years (n = 1380) were screened for HIV using a sequential algorithm of two immunochromatographic assays, HBV using an enzyme linked immunosorbant test, and syphilis using a treponemal immunochromatographic strip test. The HIV seronegative participants (n = 1309) were followed-up for 12 months with quarterly study visits. The clinical and behavioral data were collected using structured questionnaires. The HIV seroconversions were confirmed by a molecular assay.</p><p>Results</p><p>The study population was female dominant (76.8%). All participants had a formal education, with 44.6% studying for technical or higher education degrees. The mean age at sexual debut was 16.6 years (SD: ±1.74), with 85.6% reporting more than one sexual partner in life. The screening showed the prevalence of HIV, HBV, and syphilis at 5.1% (95% CI: 3.97–6.31), 12.2% (95% CI 10.5%–14.0%), and 0.36% (95% CI 0.15%–0.84%), respectively. The HIV incidence rate was found to be 1.14/100 person years (95% CI: 0.67–1.92). Retention rates were stable throughout the study being 85.1% at the last visit.</p><p>Conclusion</p><p>Incidence of HIV in this cohort of youths in Maputo was relatively low. Also, the prevalence of HIV and syphilis was lower than the national values in this age group. However, the HBV prevalence was higher than in previous reports in the country.</p></div