Lessons learnt conducting minimally invasive autopsies in private mortuaries as part of HIV and tuberculosis research in South Africa

Current estimates of the burden of tuberculosis (TB) disease and cause-specific mortality in human immunodeficiency virus (HIV) positive people rely heavily on indirect methods that are less reliable for ascertaining individual-level causes of death and on mathematical models. Minimally invasive autopsy (MIA) is useful for diagnosing infectious diseases, provides a reasonable proxy for the gold standard in cause of death ascertainment (complete diagnostic autopsy) and, used routinely, could improve cause-specific mortality estimates. From our experience in performing MIAs in HIV-positive adults in private mortuaries in South Africa (during the Lesedi Kamoso Study), we describe the challenges we faced and make recommendations for the conduct of MIA in future studies or surveillance programmes, including strategies for effective communication, approaches to obtaining informed consent, risk management for staff and efficient preparation for the procedure.

Cost of point-of-care lateral flow urine lipoarabinomannan antigen testing in HIV-positive adults in South Africa

INTRODUCTION:

The World Health Organization recommends point-of-care (POC) lateral flow urine lipoarabinomannan (LF-LAM) for tuberculosis (TB) diagnosis in selected human immunodeficiency virus (HIV) positive people. South Africa had 438 000 new TB episodes in 2016, 58.9% of which were contributed by HIV-positive people. LF-LAM is being considered for scale-up in South Africa.

METHODS:

We estimated the costs of using LF-LAM in HIV-positive adults with CD4 counts ⩽ 150 cells/μl enrolled in the TB Fast Track Trial in South Africa. We also estimated costs of POC haemoglobin (Hb), as this was used in the study algorithm. Data on clinic-level (10 intervention clinics) and above-clinic-level costs were collected.

RESULTS:

A total of 1307 LF-LAM tests were performed at 10 clinics over 24 months. The mean clinic-level costs were US$12.80 per patient for LF-LAM and POC Hb; LF-LAM costs were US$11.49 per patient. The mean above-clinic-level unit costs for LF-LAM were US$12.06 for clinic preparation, training, coordination and mentoring. The mean total cost of LF-LAM was US$23.55 per patient.

CONCLUSION:

At clinic level, the cost of LF-LAM was comparable to other TB diagnostics in South Africa. It is important to consider above-clinic-level costs for POC tests, as these may be required to support roll-out and ensure successful implementation.

What causes symptoms suggestive of tuberculosis in HIV-positive people with negative initial investigations?

OBJECTIVE:

To identify the causes of symptoms suggestive of tuberculosis (TB) among people living with the human immunodeficiency virus (PLHIV) in South Africa.

METHODS:

A consecutive sample of HIV clinic attendees with symptoms suggestive of TB (⩾1 of cough, weight loss, fever or night sweats) at enrolment and at 3 months, and negative initial TB investigations, were systematically evaluated with standard protocols and diagnoses assigned using standard criteria. TB was ‘confirmed’ if Mycobacterium tuberculosis was identified within 6 months of enrolment, and ‘clinical’ if treatment started without microbiological confirmation.

RESULTS:

Among 103 participants, 50/103 were preantiretroviral therapy (ART) and 53/103 were on ART; respectively 68% vs. 79% were female; the median age was 35 vs. 45 years; the median CD4 count was 311 vs. 508 cells/mm³. Seventy-two (70%) had ⩾5% measured weight loss and 50 (49%) had cough. The most common final diagnoses were weight loss due to severe food insecurity (n = 20, 19%), TB (n = 14, 14%: confirmed n = 7; clinical n = 7), other respiratory tract infection (n = 14, 14%) and post-TB lung disease (n = 9, 9%). The basis for TB diagnosis was imaging (n = 7), bacteriological confirmation from sputum (n = 4), histology, lumbar puncture and other (n = 1 each).

CONCLUSION:

PLHIV with persistent TB symptoms require further evaluation for TB using all available modalities, and for food insecurity in those with weight loss.

An intervention to optimise the delivery of integrated tuberculosis and HIV services at primary care clinics: results of the MERGE cluster randomised trial

OBJECTIVES

To evaluate the effect of an intervention to optimize TB/HIV integration on patient outcomes.

METHODS

Cluster randomised control trial at 18 primary care clinics in South Africa. The intervention was placement of a nurse (TB/HIV integration officer) to facilitate provision of integrated TB/HIV services, and a lay health worker (TB screening officer) to facilitate TB screening for 24 months. Primary outcomes were i) incidence of hospitalisation/death among individuals newly diagnosed with HIV, ii) incidence of hospitalisation/death among individuals newly diagnosed with TB and iii) proportion of HIV-positive individuals newly diagnosed with TB who were retained in HIV care 12 months after enrolment.

RESULTS

Of 3328 individuals enrolled, 3024 were in the HIV cohort, 731 in TB cohort and 427 in TB-HIV cohort. For the HIV cohort, the hospitalisation/death rate was 12.5 per 100 person-years (py) (182/1459py) in the intervention arm vs. 10.4/100py (147/1408 py) in the control arms respectively (Relative Risk (RR) 1.17 [95% CI 0.92-1.49]).For the TB cohort, hospitalisation/ death rate was 17.1/100 py (67/ 392py) vs. 11.1 /100py (32/289py) in intervention and control arms respectively (RR 1.37 [95% CI 0.78-2.43]). For the TB-HIV cohort, retention in care at 12 months was 63.0% (213/338) and 55.9% (143/256) in intervention and control arms (RR 1.11 [95% 0.89-1.38]).

CONCLUSIONS

The intervention as implemented failed to improve patient outcomes beyond levels at control clinics. Effective strategies are needed to achieve better TB/HIV service integration and improve TB and HIV outcomes in primary care clinics.

TRIAL REGISTRATION

South African Register of Clinical Trials (registration number DOH-27-1011-3846).

Does antiretroviral treatment increase the infectiousness of smear-positive pulmonary tuberculosis?

BACKGROUND

Understanding of the effects of human immunodeficiency virus (HIV) infection and antiretroviral treatment (ART) on Mycobacterium tuberculosis transmission dynamics remains limited. We undertook a cross-sectional study among household contacts of smear-positive pulmonary tuberculosis (TB) cases to assess the effect of established ART on the infectiousness of TB.

METHOD

Prevalence of tuberculin skin test (TST) positivity was compared between contacts of index cases aged 2-10 years who were HIV-negative, HIV-positive but not on ART, on ART for <1 year and on ART for 1 year. Random-effects logistic regression was used to take into account clustering within households.

RESULTS

Prevalence of M. tuberculosis infection in contacts of HIV-negative patients, HIV-positive patients on ART 1 year and HIV-positive patients not on ART/on ART <1 year index cases was respectively 44%, 21% and 22%. Compared to contacts of HIV-positive index cases not on ART or recently started on ART, the odds of TST positivity was similar in contacts of HIV-positive index cases on ART 1 year (adjusted OR [aOR] 1.0, 95%CI 0.3-3.7). The odds were 2.9 times higher in child contacts of HIV-negative index cases (aOR 2.9, 95%CI 1.0-8.2).

CONCLUSIONS

We found no evidence that established ART increased the infectiousness of smear-positive, HIV-positive index cases.

Risk factors for Mycobacterium tuberculosis infection in 2-4 year olds in a rural HIV-prevalent setting

BACKGROUND

Mycobacterium tuberculosis infection in children acts as a sentinel for infectious tuberculosis.

OBJECTIVE

To assess risk factors associated with tuberculous infection in pre-school children.

METHOD

We conducted a population-wide tuberculin skin test (TST) survey from January to December 2012 in Malawi. All children aged 2-4 years residing in a demographic surveillance area were eligible. Detailed demographic data, including adult human immunodeficiency virus (HIV) status, and clinical and sociodemographic data on all diagnosed tuberculosis (TB) patients were available.

RESULTS

The prevalence of M. tuberculosis infection was 1.1% using a TST induration cut-off of 15 mm (estimated annual risk of infection of 0.3%). The main identifiable risk factors were maternal HIV infection at birth (adjusted OR [aOR] 3.6, 95%CI 1.1-12.2), having three or more adult members in the household over a lifetime (aOR 2.4, 95%CI 1.2-4.8) and living in close proximity to a known case of infectious TB (aOR 1.6, 95%CI 1.1-2.4), modelled as a linear variable across categories (>200 m, 100-200 m, <100 m, within household). Less than 20% of the infected children lived within 200 m of a known diagnosed case.

CONCLUSION

Household and community risk factors identified do not explain the majority of M. tuberculosis infections in children in our setting.

A cluster randomised trial to evaluate the effect of optimising TB/HIV integration on patient level outcomes: the "merge" trial protocol

INTRODUCTION

We describe the design of the MERGE trial, a cluster randomised trial, to evaluate the effect of an intervention to optimise TB/HIV service integration on mortality, morbidity and retention in care among newly-diagnosed HIV-positive patients and newly-diagnosed TB patients.

DESIGN

Eighteen primary care clinics were randomised to either intervention or standard of care arms. The intervention comprised activities designed to optimise TB and HIV service integration and supported by two new staff cadres-a TB/HIV integration officer and a TB screening officer-for 24 months. A process evaluation to understand how the intervention was perceived and implemented at the clinics was conducted as part of the trial. Newly-diagnosed HIV-positive patients and newly-diagnosed TB patients were enrolled into the study and followed up through telephonic interviews and case note abstractions at six monthly intervals for up to 18 months in order to measure outcomes. The primary outcomes were incidence of hospitalisations or death among newly diagnosed TB patients, incidence of hospitalisation or death among newly diagnosed HIV-positive patients and retention in care among HIV-positive TB patients. Secondary outcomes of the study included measures of cost-effectiveness.

DISCUSSION

Methodological challenges of the trial such as implementation of a complex multi-faceted health systems intervention, the measurement of integration at baseline and at the end of the study and an evolving standard of care with respect to TB and HIV are discussed. The trial will contribute to understanding whether TB/HIV service integration affects patient outcomes.

Spectrum of non-tuberculous mycobacteria identified using standard biochemical testing vs. 16S sequencing

Non-tuberculous mycobacterial isolates from gold miners were speciated using standard biochemical testing (SBT) and 16S rDNA sequencing. Of 237 isolates tested, SBT identified 126, compared with all 237 identified using sequencing. Of 111 isolates unspeciated by SBT but identified by sequencing, 38 (34.2%) were identified as Mycobacterium gordonae and 8 (7.2%) were new species. Of 126 isolates speciated by both methods, 37 were discordant, with 14/17 M. gordonae isolates incorrectly identified as M. scrofulaceum using SBT. The majority of these were the potentially pathogenic strain D, M. gordonae. Sequencing is preferable where available to guide treatment.

Trends in drug-resistant tuberculosis in a gold-mining workforce in South Africa, 2002-2008

SETTING AND OBJECTIVE

To describe trends in drug-resistant tuberculosis (TB) in two gold-mining workforces, South Africa, 2002-2008.

DESIGN

TB programme data analysis.

RESULTS

TB case notification rates decreased between 2002 and 2008 from 4006 to 3018 per 100,000 and from 3192 to 2468/100,000 for Companies A and B, respectively. Human immunodeficiency virus (HIV) prevalence exceeded 80% in TB episodes with known status. The proportion of TB episodes with multidrug-resistant TB (MDR-TB) increased from 6/129 (4.7%) to 17/85 (20.0%) among previously treated cases, and from 4/38 (10.4%) to 7/28 (25.0%) in Companies A and B, respectively (tests for trend, Company A, P < 0.001; Company B, P = 0.304). Case notifications of MDR-TB increased during 2002-2008 from 39.8 to 122.9/100,000/year in Company A and from 7.8 to 96.8/100,000/year in Company B. Coverage of second-line drug susceptibility testing (DST) among MDR-TB episodes was low. Previous treatment exposure was a strong risk factor for MDR-TB (prevalence ratio 8.78, 95%CI 5.94-12.97 in previously treated vs. untreated individuals).

CONCLUSION

Despite decreasing TB notifications overall, MDR-TB notifications and proportions of episodes with MDR-TB increased in the larger company. Cure must be ensured in first episodes to prevent acquired resistance. Improved coverage of culture, DST and HIV testing is required to allow treatment to be optimised.

Contribution of reinfection to recurrent tuberculosis in South African gold miners

SETTING

A gold mine in South Africa.

OBJECTIVE

To investigate incidence and risk factors for tuberculosis (TB) recurrence and the relative contribution of reinfection and relapse to recurrence.

DESIGN

Prospective cohort study.

METHODS

Employees cured of a first episode of culture-positive TB were followed up for recurrence, which was classified as reinfection or relapse by restriction fragment length polymorphism using an insertion sequence (IS) 6110 probe.

RESULTS

Among 609 patients, 57 experienced recurrence during a median follow-up period of 1.02 years, corresponding to a recurrence rate of 7.89 per 100 person-years (py). The culture positive recurrence rate was 5.79/100 py, and was higher in human immunodeficiency virus (HIV) infected patients (8.86/100 py in HIV-infected vs. 3.35/100 py in non-HIV-infected). Among HIV-infected patients, the risk of culture-positive recurrence was higher with decreasing CD4 count (compared with CD4 < 200, hazard ratios for recurrence among individuals with CD4 200-500 and CD4 > 500 were 0.40 [95%CI 0.14-1.09] and 0.14 [95%CI 0.02-1.10], respectively, Ptrend = 0.01). IS6110 genotyping was available on both the initial and subsequent isolate for 16/42 (38%, 14 HIV-infected) patients with culture-positive recurrence, and showed reinfection in 11 (69%).

CONCLUSION

HIV-infected gold miners, particularly those who are more immunosuppressed, are at higher risk of TB recurrence. TB control strategies need to take into account reinfection as an important cause of recurrent TB.

Screening for tuberculosis prior to isoniazid preventive therapy among HIV-infected gold miners in South Africa

SETTING

Human immunodeficiency virus (HIV) clinic for employees of a gold mine, Free State, South Africa.

OBJECTIVE

To evaluate the process of screening for active tuberculosis (TB) prior to commencing TB preventive therapy in HIV-infected individuals.

DESIGN

Cross-sectional study comparing performance of various combinations of screening tests for TB against a gold standard diagnosis of TB based on symptoms, chest radiograph (CXR), sputum microscopy and culture.

RESULTS

Of 899 individuals, 44 (4.9%) had TB. The most sensitive symptom combination (59.1%) was any of night sweats, new or worsening cough or reported weight loss; measured weight loss > 5% or abnormal CXR increased sensitivity to 90.9%. Sputum microscopy did not increase sensitivity further, but including World Health Organization HIV clinical staging or CD4 count did. As the specificity of all these combinations was low, many individuals required further investigation to rule out TB. TB prevalence was high (11.7%) among individuals with a CD4 count < 200/mm3.

CONCLUSION

CXR greatly increased the sensitivity of screening for TB in this population. Sputum microscopy conferred no additional benefit among asymptomatic patients with a normal CXR. The high prevalence of TB amongst those with a low CD4 count underlines the importance of screening for active TB prior to commencing TB preventive therapy, and before antiretroviral therapy.

Severe respiratory syncytial virus infection in early life is associated with increased type 2 cytokine production in Gambian children

BACKGROUND

Severe respiratory syncytial virus (RSV) infection in early childhood has been associated with subsequent wheezing and atopy. The aim of this study was to test if severe RSV infection in early life was associated with an increase in type 2 cytokine production and atopy in Gambian children 5 years later.

METHODS

A cohort of children with severe RSV infection during the first year of life ('cases', n = 66) and without ('controls', n = 122) was followed-up at 5 years of age. Immediate hypersensitivity to common allergens, airway reactivity, serum IgE concentration and the production of IFN-gamma, IL-5 and IL-13 by lymphocytes activated in vitro with RSV F-G or control antigens was determined.

RESULTS

After adjustment for confounders, cases produced significantly higher concentrations of IL-13 in response to RSV F-G and of IL-5 and IL-13 in response to tuberculin. Cases were more likely to have presented with a wheezy lower respiratory tract infection in the first 3 years of life (adjusted odds ratio = 9.9; 95% CI 1.6-61.0), but not thereafter. Cases and controls had similar skin response to allergens, airway reactivity and serum IgE concentrations.

CONCLUSION

Severe RSV infection in early life is associated with a higher production of type 2 cytokines in Gambian children at 5 years of age. However this does not appear to result in increased risk of atopy or clinical allergy at that age.

HIV infection in women: immunological markers and the influence of pregnancy

OBJECTIVE

To describe the influence of pregnancy on immunological marker paths and progression of HIV-infected women.

DESIGN

Analysis of prospectively collected immunological and clinical data collected on 145 women reviewed at the City Hospital, Edinburgh, between 1985 and 1992 using a two-level random-effects model that allows for within- and between-patient variance.

RESULTS

There were differences between the marker paths of women according to risk activity; women who had acquired HIV via injecting drug use (in addition to heterosexual intercourse) had a higher level of absolute CD4 cells, CD4% and total lymphocytes at seroconversion than those who had acquired HIV via heterosexual intercourse alone; however, immunological markers declined more steeply after seroconversion. There was no evidence that pregnancy, either before or after HIV seroconversion had an adverse effect on marker paths of HIV disease. There was a significant association between pregnancy after HIV seroconversion and post-pregnancy changes in immunological markers: an increase in the CD4% and a decrease in CD8%. However, causality cannot be implied as pregnancy itself may be associated with considerable lifestyle changes. During pregnancy the total white blood count rose due to an increase in the number of granulocytes, whereas the total lymphocyte numbers fell. The absolute CD4 lymphocyte subset counts fell progressively but the effect was due to the fall in the total lymphocyte counts, there being no influence of pregnancy on either CD4% or CD8%.

CONCLUSIONS

In asymptomatic HIV infection, changes in the absolute levels of CD4 and CD8 lymphocyte counts are primarily related to changes in the other components of the white cell count because there were no changes in CD4% and CD8%. Pregnancy itself has no adverse effect on immunological markers of HIV.

Heterosexual transmission of HIV analysed by generalized estimating equations

A longitudinal analysis of a partner study is compared with a cross-sectional analysis which identify behavioural and biological risk factors for heterosexual transmission of HIV. Using generalized estimating equations (GEEs) a random effects logistic model is used for the longitudinal analysis. These approaches are illustrated by the Edinburgh heterosexual partner study. The longitudinal analysis finds that 'high-risk' sexual practices, unprotected intercourse for HIV and a low CD4 count in the index case significantly increase the risk of HIV transmission. The cross-sectional analysis, however, only indicates 'high-risk' sexual practices as favourable for HIV transmission.

Incorporating HIV test data into forecasts of the AIDS epidemic in Scotland

For AIDS cases in Scotland the date of HIV antibody positive diagnosis (HIV test date) is recorded on the AIDS case reports. Data are also available on the total numbers of individuals with HIV positive test reports in Scottish laboratories in each year since testing became available. These data are incorporated into a model of the HIV epidemic described in terms of testing rates by calendar year. The HIV infection curve is modelled as a step function, and the testing rates are allowed to differ between steps. Results are presented for intravenous drug users (IDUs) and for homosexual/bisexual men. The estimated rates of testing for the IDUs (estimates from 19 per cent to 44 per cent per year) are considerably higher than those for homosexual/bisexual men (estimates of 10 per cent to 17 per cent per year). Data on the year of testing for AIDS diagnoses gave relatively little improvement in estimates of the HIV infection curve. However, when this information is combined with data on the total number of HIV positive diagnoses per year, there is a dramatic improvement in the estimate of the HIV infection curve. This is particularly marked for infections in the most recent period and for the estimates of cumulative infections up to the present. However, these improvements are gained at the cost of assumptions of similar testing rates applying to all sections of the HIV infected populations, which will be difficult to check in practice. This suggests that these methods should not be used in isolation but in combination with other evidence about the spread of HIV infection in a population.