The impact of sexually transmitted infections (STI) and genital tract inflammation on HIV-1 acquisition and rate of disease progression in subtype C infected women.

Ph. D. University of KwaZulu-Natal, Durban 2014.Introduction: Women carry more than half the burden of HIV disease globally and this burden is even higher in sub-Saharan Africa (SSA). Young women, in particular, are at disproportionate risk of HIV infection in South Africa. Understanding risk behaviours and factors associated with ability to negotiate safe sex and condom use is one of the key elements in curbing the spread of HIV. Sexually transmitted infections (STI) and bacterial vaginosis (BV), which cause female genital tract inflammation, have been identified as key drivers of the HIV epidemic. This inflammation, which is also present in the absence of symptoms, is associated with increased susceptibility to HIV infection. Although syndromic management of symptomatic STIs or BV at the first encounter with a health care provider is an important public health measure, its effectiveness is minimised because a substantial proportion of individuals have either asymptomatic infections or fail to recognise signs and symptoms of STI and are therefore excluded. Most new HIV infections in SSA occur among young people and particularly among young girls. Prompt diagnosis of acute HIV infection (AHI) is critical and benefits the individual as well as providing opportunities for public health intervention. In South Africa, the majority of HIV infections are due to infection with HIV-1 subtype C for which there is limited data compared to subtype-B HIV-1 infections. The overall aim of this study was to assess the impact of BV, STIs, and associated genital tract inflammation on acquisition of HIV-1 subtype C infections; and evaluate the rate of subsequent disease progression in women. The objectives were: i. to investigate STIs and genital tract inflammation as risk factors for HIV infection in high risk women and adequacy of syndromic management; ii. to evaluate the challenges associated with diagnosing recently acquired (acute) HIV infection in a subtype C prevalent population; iii. and to evaluate the relationship between clinical disease progression and genital and or systemic inflammation in high-risk women who became infected with HIV. We assessed the adequacy of syndromic diagnosis of STIs, compared with laboratory diagnosis of STIs, and evaluated the association between STI diagnosis and the risk of HIV acquisition in a cohort of high-risk women. Genital cytokine profiles and the degree of inflammation associated with common STIs and bacterial vaginosis were assessed. The most common signs and symptoms of acute HIV infection (AHI) were described and a clinical algorithm to identify acute HIV cases was developed. We investigated rates of HIV disease progression of subtype C–infected South African women. Methods: The CAPRISA 002 study was a prospective cohort study established to examine the pathogenesis and natural history of HIV-1 subtype C infection and to describe the immunologic, virologic and clinical characteristics of acute and early infection in KwaZulu Natal, South Africa. A total of 775 high-risk women were screened for HIV infection, and 245 HIV-uninfected women were enrolled into the study. At each monthly visit for a total of 24 months behavioural and clinical data were collected. Cervico-vaginal lavage (CVL) samples were collected at enrolment and at each six month follow-up visits and were tested for STI pathogens (including Chlamydia trachomatis, Neisseria gonorrhoeae, herpes simplex virus type 2 (HSV-2) and Trichomonas vaginalis) and bacterial vaginosis. Forty-two cytokines were measured from the CVL and 13 from the plasma samples at enrolment. All women received monthly HIV-1 antibody and RNA testing and were assessed for AHI. Signs and symptoms at the visit with HIV-1 antibody or HIV-1 RNA positive test were compared to HIV negative visits. Logistic regression identified clinical predictors of AHI and a model-based score was assigned to each predictor to create a risk score for every woman. All women who seroconverted were followed up for more than five years and monitored for HIV disease progression. Rapid disease progression was defined as CD4+ T cell count decline to <350 cells/μl within two years post-infection. Serial clinical and laboratory assessments were compared using survival analysis and logistic regression models. CAPRISA had established several cohorts of HIV negative women to determine the feasibility of establishing cohorts and sites for HIV biomedical prevention trials. Women seroconverting in these studies were referred to the CAPRISA 002 study for longitudinal follow-up for HIV post seroconversion. Results: In this study, the HIV-1 prevalence at screening was 59.6% (95% CI: 55.9% to 62.8%). During a total of 390 person-years of follow-up, 28 new infections occurred, yielding a seroincidence rate of 7.2 (95% CI: 4.5 to 9.8) per 100 person-years. A total of 62 participants, including seroconvertors from other CAPRISA cohorts, were enrolled into the acute HIV infection Women from the HIV-1 negative cohort generally demonstrated a high level of knowledge on HIV/AIDS, and 60.3% reported use of condoms. Reported condom use at last sexual encounter varied slightly by partner type (57.0% with steady versus 64.4% with casual partners; p = 0.36), whilst self-perceived ability to choose to use a condom was significantly lower with steady partners compared to casual partners (20.8% versus 53.9%; p=0.01). An important finding was that vaginal discharge was a poor predictor of laboratory-diagnosed STIs, as only 12.3% of women (25/204) who had a laboratory-confirmed discharge causing pathogen had clinical evidence of a discharge (yielding a sensitivity of 12.3% and a specificity of 93.8%). CVL cytokine concentrations did not differ between women with asymptomatic or symptomatic STIs; and were elevated in women with either asymptomatic or symptomatic STIs compared to women with no STIs or BV. Women with chlamydia or gonorrhoea had the highest genital cytokine concentrations, with 17/42 and 14/42 of the cytokines measured in CVL being up-regulated compared with women with no infections, respectively. While BV was associated with elevated pro-inflammatory cytokine concentrations in CVL, women with BV had lower levels of chemokines and haematopoietic cytokines than women with no infections or BV. HSV-2 reactivation was inflammatory, but yielded a comparatively lower level of inflammation than Chlamydia or gonnorhoea. Trichomoniasis, despite being relatively common in this cohort, did not cause significant changes in genital tract cytokine concentrations compared to women with no infections or BV. Genital infections did not influence plasma cytokine concentrations, suggesting that the compartments were not linked with respect to cytokine responses. Although laboratorydiagnosed STIs were associated with increased risk of HIV infection [hazard ratio, 3.3 (95% confidence interval, 1.5 – 7.2)], clinical symptoms were not. Of the women who became infected, factors predictive of AHI included age, 25 years (OR = 3.2; 1.4 – 7.1), rash (OR = 6.1; 2.4 –15.4), sore throat (OR = 2.7; 1.0 – 7.6), weight loss (OR = 4.4; 1.5 – 13.4), genital ulcers (OR = 8.0; 1.6 – 39.5) and vaginal discharge (OR = 5.4; 1.6 – 18.4). A risk score of 2 correctly predicted AHI in 50.0% of cases. The number of signs and symptoms correlated with higher HIV-1 RNA at diagnosis (r = 0.63; p = 0.001). The 62 acutely infected women were identified at a median of 42 days post-infection (IQR = 34 – 59). Mean CD4 count dropped by 39.6% at 3 months and 46.7% at 6 months post-infection in women with pre-infection measurements. CD4 decline to <350 cells/μL occurred in 31%, 44%, and 55% of women at 1, 2, and 3 years post-infection, respectively, and to <500 cells/μL in 69%, 79%, and 81% at equivalent time-points. Predictors of rapid progression were CD4 count at 3 months post-infection (hazard ratio [HR], 2.07; 95% confidence interval [CI], 1.31–3.28; P = .002), setpoint viral load (HR, 3.82; 95% CI, 1.51–9.67; P = .005), and hepatitis B coinfection (HR, 4.54; 95% CI, 1.31–15.69; P = .017). Conversely, presence of any of HLAB*1302, B*27, B*57, B*5801, or B*8101 alleles predicted non–rapid progression (HR, 0.19; 95% CI, .05–.74; P = .016). Discussion/Conclusion: This study showed that syndromic STI diagnosis, which is dependent on clinical signs of vaginal discharge, was poorly predictive of laboratory-diagnosed STIs or BV and missed a significant proportion of women with asymptomatic infections. However, the level of genital inflammation, as measured by cytokine concentrations in CVL, was similar in women with symptomatic and asymptomatic infections and therefore place women at increased risk for HIV infection. While laboratory-diagnosed STIs and the presence of inflammatory cytokines in the genital tract were associated with increased susceptibility to HIV acquisition, vaginal discharge was not. Chlamydial infection was associated with the highest genital cytokine concentrations, followed by gonorrhoea, HSV-2, trichomoniasis, and BV. In regions where HIV is prevalent and STIs are managed syndromically, targeted screening of populations at risk for STIs is critical and urgently needed. Recognition of signs and symptoms of AHI is important for early diagnosis of HIV infection. The proposed algorithm of risk-stratifying individuals for AHI provides a useful clinical tool especially in resource-limited settings where there are limited or no routinely available tests for AHI. However, validation of the algorithm on another cohort is needed to assess its utility further. Point-of-care HIV antigen or viral load testing is needed, to detect asymptomatic, antibody negative cases enabling early interventions and prevention of transmission. This cohort showed high rates of rapid disease progression, with nearly half of these subtype C–infected women progressing to a CD4+ T cell count of below 350 cells/μL within 2 years of infection. Implementing 2013 World Health Organization treatment guidelines (CD4+ T cell counts less than 500cells/μL) would require most individuals to start antiretroviral therapy within 1 year of HIV infection. The economic and health systems planning implicated by these findings need to be explored and addressed to guide policy makers as countries adopt the current WHO guidelines

Relationship between levels of inflammatory cytokines in the genital tract and CD4+ cell counts in women with acute HIV-1 infection.

Inflammatory responses at mucosal surfaces after human immunodeficiency virus type 1 (HIV-1) transmission may influence disease outcome. We evaluated levels of interleukin (IL)-1beta, IL-6, tumor necrosis factor-alpha, IL-8, IL-10, and IL-12 in genital tract and plasma specimens from 44 women with acute HIV infection and 29 HIV-negative control women (13 of whom were women in the acute HIV infection cohort who had preinfection samples available for analysis). Women with acute HIV infection had significantly elevated levels of IL-6, IL-10, and IL-12 in genital tract specimens and elevated levels of IL-1beta, IL-8, and IL-10 in plasma specimens, compared with HIV-negative control women. Levels of IL-1beta, IL-6, and IL-8 in cervicovaginal specimens from women with acute HIV infection showed a significant inverse correlation with systemic CD4(+) cell counts, suggesting that mucosal inflammation is associated with low CD4(+) cell counts during acute HIV infection

Empirical antimicrobial therapy for probable v. directed therapy for possible ventilator-associated pneumonia in critically injured patients

Background. Ventilator-associated pneumonia (VAP) has recently been classified as possible or probable. Although direct attributable mortality has been difficult to prove, delay in instituting appropriate therapy has been reported to increase morbidity and mortality. Recent literature suggests that in possible VAP, instituting directed therapy while awaiting microbiological culture does not prejudice outcome compared with best-guess empirical therapy.Objectives. To ascertain outcomes of directed v. empirical therapy in possible and probable VAP, respectively. Methods. Endotracheal aspirates were obtained from patients with suspected VAP. Those considered to have possible VAP were given directed therapy following culture results, whereas patients with more convincing evidence of VAP were classed as having probable VAP and commenced on empirical antimicrobials based on microbiological surveillance.Results. Pneumonia was suspected in 106 (36.8%) of 288 patients admitted during January - December 2014. Of these, 13 did not fulfil the criteria for VAP. Of the remaining 93 (32.2%), 31 (33.3%) were considered to have probable and 62 (66.7%) possible VAP. The former were commenced on empirical antimicrobials, with 28 (90.3%) receiving appropriate therapy. Of those with possible VAP, 34 (54.8%) were given directed therapy and in 28 (45.2%) no antimicrobials were prescribed. Of the latter, 24 recovered without antimicrobials and 4 died, 3 from severe traumatic brain injury and 1 due to overwhelming intra-abdominal sepsis. No death was directly attributable to failure to treat VAP. No significant difference in mortality was found between the 34 patients with possible VAP who were commenced on directed therapy and the 31 with probable VAP who were commenced on empirical antimicrobials (p=0.75).Conclusions. Delaying antimicrobial therapy for VAP where clinical doubt exists does not adversely affect outcome. Furthermore, this policy limits the use of antimicrobials in patients with possible VAP following improvement in their clinical condition despite no therapy

Hepatitis B infection in black children from residential care facilities in KwaZulu-Natal

No Abstract

Antimicrobial susceptibility patterns of uropathogens isolated from pregnant women in KwaZulu-Natal Province: 2011 - 2016

Background. Urinary tract infection (UTI) is one of the most common infections during pregnancy, which can lead to significant maternal and perinatal morbidity and mortality if left untreated. Challenges when treating UTIs in pregnancy include fetal protection and resistance development of uropathogens. Currently, the Essential Medicines List recommends nitrofurantoin to treat cystitis and ceftriaxone to treat pyelonephritis in pregnant women.Objectives. To determine common pathogens causing UTI in pregnancy and their antibiotic susceptibility patterns.Methods. A retrospective analysis was performed of laboratory data for positive urine specimens from obstetric departments of 6 KwaZulu- Natal Province hospitals during 2011 - 2016. Identification and susceptibility testing were performed using the VITEK 2 system. Results were interpreted according to the breakpoints of the Clinical and Laboratory Standards Institute, USA.Results. From 5 971 positive urine specimens, the most common isolate was Escherichia coli (n=3 236; 54.2%), followed by Klebsiella pneumoniae (n=770; 12.9%). Group B streptococcus (GBS) (n=239; 4.0%) and Enterococcus faecalis (n=251; 4.2%) were the most common Gram-positive pathogens. E. coli displayed significant resistance to trimethoprim-sulfamethoxazole (65.1%), cephalothin (38.3%), cefuroxime (27.3%), ciprofloxacin (16.9%) and amoxicillin-clavulanic acid (17.1%). Resistance to ceftriaxone and nitrofurantoin remained low ‒ 9.1% and 7.7%, respectively. Among Gram-positive pathogens, GBS displayed 100% penicillin susceptibility and E. faecalis showed 92.9% susceptibility to ampicillin.Conclusions. E. coli is unsurprisingly the most common cause of UTI in pregnancy in KwaZulu-Natal. Susceptibility to ceftriaxone and nitrofurantoin remains good. Among Gram positives, GBS is prevalent and susceptible to penicillin, while E. faecalis is susceptible to ampicillin. As antimicrobial resistance evolves, routine surveillance is necessary to modify recommended empirical antibiotic use

APOBEC3G expression is dysregulated in primary HIV-1 infection and polymorphic variants influence CD4+ T-cell counts and plasma viral load

OBJECTIVES: In the absence of HIV-1 virion infectivity factor (Vif), cellular cytosine deaminases such as apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like 3G (APOBEC3G) inhibit the virus by inducing hypermutations on viral DNA, among other mechanisms of action. We investigated the association of APOBEC3G mRNA levels and genetic variants on HIV-1 susceptibility, and early disease pathogenesis using viral load and CD4 T-cell counts as outcomes. METHODS: Study participants were 250 South African women at high risk for HIV-1 subtype C infection. We used real-time PCR to measure the expression of APOBEC3G in HIV-negative and HIV-positive primary infection samples. APOBEC3G variants were identified by DNA re-sequencing and TaqMan genotyping. RESULTS: We found no correlation between APOBEC3G expression levels and plasma viral loads (r = 0.053, P = 0.596) or CD4 T-cell counts (r = 0.030, P = 0.762) in 32 seroconverters. APOBEC3G expression levels were higher in HIV-negative individuals as compared with HIV-positive individuals (P < 0.0001), including matched pre and postinfection samples from the same individuals (n = 13, P < 0.0001). Twenty-four single nucleotide polymorphisms, including eight novel, were identified within APOBEC3G by re-sequencing and genotyping. The H186R mutation, a codon-changing variant in exon 4, and a 3' extragenic mutation (rs35228531) were associated with high viral loads (P = 0.0097 and P < 0.0001) and decreased CD4 T-cell levels (P = 0.0081 and P < 0.0001), respectively. CONCLUSION: These data suggest that APOBEC3G transcription is rapidly downregulated upon HIV-1 infection. During primary infection, APOBEC3G expression levels in peripheral blood mononuclear cells do not correlate with viral loads or CD4 T-cell counts. Genetic variation of APOBEC3G may significantly affect early HIV-1 pathogenesis, although the mechanism remains unclear and warrants further investigation

High Prevalence of inhA Promoter Mutations among Patients with Drug-Resistant Tuberculosis in KwaZulu-Natal, South Africa

Background Drug-resistant tuberculosis (TB) remains extremely difficult to treat because there are often few remaining active medications and limited diagnostic options to detect resistance. Resistance to isoniazid is typically caused by mutations in either katG or the inhA promoter. inhA mutations confer low-level resistance to isoniazid and cross-resistance to ethionamide while katG mutations confer high-level isoniazid resistance and no cross-resistance. Line Probe Assays (LPAs) that detect mutations in katG and inhA are currently performed on all positive TB cultures in KwaZulu-Natal province, South Africa, but the frequency of inhA mutations in drug-resistant TB patients has not been examined. Methods We sought to determine the proportion of patients who could potentially benefit from high-dose isoniazid and who may be resistant to ethionamide. We reviewed 994 LPA (Hain MTBDRplus) results at the TB reference laboratory in KwaZulu-Natal to determine the frequency of mutations in either katG or the inhA promoter. We stratified these results by drug-resistance category (i.e., MDR-TB, pre-XDR-TB, and XDR-TB) as determined by phenotypic drug-susceptibility testing. Results Among MDR- and XDR-TB isolates, the prevalence of inhA mutations without a concurrent katG mutation was 14.8% and 10.3% respectively. The prevalence of inhA mutations with OR without a katG mutation was 30.3% and 82.8%, respectively. Conclusion More than 10% of patients with MDR- and XDR-TB may benefit from high-dose isoniazid. Although ethionamide is empirically included in all MDR- and XDR-TB regimens, nearly a third of MDR-TB patients and a majority of XDR-TB patients likely have resistance to ethionamide. Laboratories performing line probe assays should report specific band patterns so that clinicians may adjust treatment regimens accordingly

HIV vaccine trial safety and retention among 18-20 year olds in the HVTN 503/Phambili study support the inclusion of adolescents in future trials

Worldwide, many adolescents, especially women, acquire HIV before age 18. Yet to date, no HIV vaccine trials have enrolled adolescents. Reasons for excluding adolescents from these trials include regulations protecting vulnerable subjects and concerns regarding informed consent, social harms, adverse events, and loss to follow-up

Conserved positive selection signals in gp41 across multiple subtypes and difference in selection signals detectable in gp41 sequences sampled during acute and chronic HIV-1 subtype C infection

<p>Abstract</p> <p>Background</p> <p>The high diversity of HIV variants driving the global AIDS epidemic has caused many to doubt whether an effective vaccine against the virus is possible. However, by identifying the selective forces that are driving the ongoing diversification of HIV and characterising their genetic consequences, it may be possible to design vaccines that pre-empt some of the virus' more common evasion tactics. One component of such vaccines might be the envelope protein, gp41. Besides being targeted by both the humoral and cellular arms of the immune system this protein mediates fusion between viral and target cell membranes and is likely to be a primary determinant of HIV transmissibility.</p> <p>Results</p> <p>Using recombination aware analysis tools we compared site specific signals of selection in gp41 sequences from different HIV-1 M subtypes and circulating recombinant forms and identified twelve sites evolving under positive selection across multiple major HIV-1 lineages. To identify evidence of selection operating during transmission our analysis included two matched datasets sampled from patients with acute or chronic subtype C infections. We identified six gp41 sites apparently evolving under different selection pressures during acute and chronic HIV-1 infections. These sites mostly fell within functional gp41 domains, with one site located within the epitope recognised by the broadly neutralizing antibody, 4E10.</p> <p>Conclusion</p> <p>Whereas these six sites are potentially determinants of fitness and are therefore good candidate targets for subtype-C specific vaccines, the twelve sites evolving under diversifying selection across multiple subtypes might make good candidate targets for broadly protective vaccines.</p