Household carbon monoxide (CO) concentrations in a large African city: an unquantified public health burden?

Carbon monoxide (CO) is a poisonous gas produced by incomplete combustion of carbon-based fuels that is linked to mortality and morbidity. Household air pollution from burning fuels on poorly ventilated stoves can lead to high concentrations of CO in homes. There are few datasets available on household concentrations of CO in urban areas of sub-Saharan African countries. CO was measured every minute over 24 hours in a sample of homes in Nairobi, Kenya. Data on household characteristics were gathered by questionnaire. Metrics of exposure were summarised and analysis of temporal changes in concentration was performed. Continuous 24-hour data were available from 138 homes. The mean (SD), median (IQR) and maximum 24-hour CO concentration was 4.9 (6.4), 2.8 (1.0-6.3) and 44ppm, respectively. 50% of homes had detectable CO concentrations for 847 minutes (14h07m) or longer during the 24-hour period, and 9% of homes would have activated a CO-alarm operating to European specifications. An association between a metric of total CO exposure and self-reported exposure to vapours >15 h per week was identified, however this were not statistically significant after adjustment for the multiple comparisons performed. Mean concentrations were broadly similar in homes from a more affluent area and an informal settlement. A model of typical exposure suggests that cooking is likely to be responsible for approximately 60% of the CO exposure of Nairobi schoolchildren. Household CO concentrations are substantial in Nairobi, Kenya, despite most homes using gas or liquid fuels. Concentrations tend to be highest during the evening, probably associated with periods of cooking. Household air pollution from cooking is the main source of CO exposure of Nairobi schoolchildren. The public health impacts of long-term CO exposure in cities in sub-Saharan Africa may be considerable and should be studied further.

Improving access to affordable quality-assured inhaled medicines in low- and middle-income countries

BACKGROUND: Access to affordable inhaled medicines for chronic respiratory diseases (CRDs) is severely limited in low- and middle-income countries (LMICs), causing avoidable morbidity and mortality. The International Union Against Tuberculosis and Lung Disease convened a stakeholder meeting on this topic in February 2022.METHODS: Focused group discussions were informed by literature and presentations summarising experiences of obtaining inhaled medicines in LMICs. The virtual meeting was moderated using a topic guide around barriers and solutions to improve access. The thematic framework approach was used for analysis.RESULTS: A total of 58 key stakeholders, including patients, healthcare practitioners, members of national and international organisations, industry and WHO representatives attended the meeting. There were 20 pre-meeting material submissions. The main barriers identified were 1) low awareness of CRDs; 2) limited data on CRD burden and treatments in LMICs; 3) ineffective procurement and distribution networks; and 4) poor communication of the needs of people with CRDs. Solutions discussed were 1) generation of data to inform policy and practice; 2) capacity building; 3) improved procurement mechanisms; 4) strengthened advocacy practices; and 5) a World Health Assembly Resolution.CONCLUSION: There are opportunities to achieve improved access to affordable, quality-assured inhaled medicines in LMICs through coordinated, multi-stakeholder, collaborative efforts.

Clinical standards for drug-susceptible pulmonary TB

BACKGROUND: The aim of these clinical standards is to provide guidance on 'best practice´ for diagnosis, treatment and management of drug-susceptible pulmonary TB (PTB).METHODS: A panel of 54 global experts in the field of TB care, public health, microbiology, and pharmacology were identified; 46 participated in a Delphi process. A 5-point Likert scale was used to score draft standards. The final document represents the broad consensus and was approved by all 46 participants.RESULTS: Seven clinical standards were defined: Standard 1, all patients (adult or child) who have symptoms and signs compatible with PTB should undergo investigations to reach a diagnosis; Standard 2, adequate bacteriological tests should be conducted to exclude drug-resistant TB; Standard 3, an appropriate regimen recommended by WHO and national guidelines for the treatment of PTB should be identified; Standard 4, health education and counselling should be provided for each patient starting treatment; Standard 5, treatment monitoring should be conducted to assess adherence, follow patient progress, identify and manage adverse events, and detect development of resistance; Standard 6, a recommended series of patient examinations should be performed at the end of treatment; Standard 7, necessary public health actions should be conducted for each patient. We also identified priorities for future research into PTB.CONCLUSION: These consensus-based clinical standards will help to improve patient care by guiding clinicians and programme managers in planning and implementation of locally appropriate measures for optimal person-centred treatment for PTB.

Consensus statement on measures to promote equitable authorship in the publication of research from international partnerships

Despite the acknowledged injustice and widespread existence of parachute research studies conducted in low‐ or middle‐income countries by researchers from institutions in high‐income countries, there is currently no pragmatic guidance for how academic journals should evaluate manuscript submissions and challenge this practice. We assembled a multidisciplinary group of editors and researchers with expertise in international health research to develop this consensus statement. We reviewed relevant existing literature and held three workshops to present research data and holistically discuss the concept of equitable authorship and the role of academic journals in the context of international health research partnerships. We subsequently developed statements to guide prospective authors and journal editors as to how they should address this issue. We recommend that for manuscripts that report research conducted in low‐ or middle‐income countries by collaborations including partners from one or more high‐income countries, authors should submit accompanying structured reflexivity statements. We provide specific questions that these statements should address and suggest that journals should transparently publish reflexivity statements with accepted manuscripts. We also provide guidance to journal editors about how they should assess the structured statements when making decisions on whether to accept or reject submitted manuscripts. We urge journals across disciplines to adopt these recommendations to accelerate the changes needed to halt the practice of parachute research.

Tuberculosis treatment outcomes among hospital workers at a public teaching and national referral hospital in Kenya

SETTING

Kenyatta National Hospital (KNH), Nairobi, Ken-ya, a large referral and teaching hospital.

OBJECTIVE

1) To document tuberculosis (TB) case notification rates and trends; 2) to describe demographic, clinical and workplace characteristics and treatment outcomes; and 3) to examine associations between demographic and clinical characteristics, HIV/AIDS (human immunodeficiency virus/acquired immune-deficiency syndrome) treatment and anti-tuberculosis treatment outcomes among hospital workers with TB at KNH during the period 2006-2011.

DESIGN

A retrospective cohort study involving a review of medical records.

RESULTS

The TB case notification rate among hospital staff ranged between 413 and 901 per 100 000 staff members per year; 51% of all cases were extra-pulmonary TB; 74% of all cases were among medical, paramedical and support staff. The TB-HIV coinfection rate was 60%. Only 75% had a successful treatment outcome. Patients in the retreatment category, those with unknown HIV status and those who were support staff had a higher risk of poor treatment outcomes.

CONCLUSION

The TB case rate among hospital workers was unacceptably high compared to that of the general population, and treatment outcomes were poor. Infection control in the hospital and management of staff with TB requires urgent attention.

Is introducing rapid culture into the diagnostic algorithm of smear-negative tuberculosis cost-effective?

SETTING

In 2007, the World Health Organization recommended introducing rapid Mycobacterium tuberculosis culture into the diagnostic algorithm of smear-negative pulmonary tuberculosis (TB).

OBJECTIVE

To assess the cost-effectiveness of introducing a rapid non-commercial culture method (thin-layer agar), together with Löwenstein-Jensen culture to diagnose smear-negative TB at a district hospital in Kenya.

DESIGN

Outcomes (number of true TB cases treated) were obtained from a prospective study evaluating the effectiveness of a clinical and radiological algorithm (conventional) against the alternative algorithm (conventional plus M. tuberculosis culture) in 380 smear-negative TB suspects. The costs of implementing each algorithm were calculated using a 'micro-costing' or 'ingredient-based' method. We then compared the cost and effectiveness of conventional vs. culture-based algorithms and estimated the incremental cost-effectiveness ratio.

RESULTS

The costs of conventional and culture-based algorithms per smear-negative TB suspect were respectively €39.5 and €144. The costs per confirmed and treated TB case were respectively €452 and €913. The culture-based algorithm led to diagnosis and treatment of 27 more cases for an additional cost of €1477 per case.

CONCLUSION

Despite the increase in patients started on treatment thanks to culture, the relatively high cost of a culture-based algorithm will make it difficult for resource-limited countries to afford.

Antiretroviral treatment uptake and attrition among HIV-positive patients with tuberculosis in Kibera, Kenya

Using data of human immunodeficiency virus-positive patients with tuberculosis from three primary care clinics in Kibera slums, Nairobi, Kenya, we report on the proportion that started antiretroviral treatment (ART) and attrition (deaths, lost to follow-up and stopped treatment) before and while on ART. Of 427 ART eligible patients, enrolled between January 2004 and December 2008, 70% started ART, 19% were lost to attrition and 11% had not initiated ART. Of those who started ART, 14% were lost to attrition, making a cumulative pre-ART and ART attrition of 33%. ART uptake among patients with TB was relatively good, but programme attrition was high and needs urgent addressing.

Tuberculosis transmission in Kenya: results of the third National Tuberculin Survey

SETTING

Kenya, a country with a high burden of tuberculosis (TB) and human immunodeficiency virus (HIV) infection.

OBJECTIVES

To assess the prevalence of TB infection, bacille Calmette-Guérin (BCG) coverage and the annual risk of tuberculosis infection (ARTI), and to compare estimates with previous findings.

METHODS

A sample of primary school children aged 6-14 years from the same study districts sampled in previous surveys were tuberculin skin tested using the Mantoux method from September 2004 to July 2007. The prevalence of TB infection was estimated by the mirror method, with the mode at 17 mm.

RESULTS

Of the 94 771 registered children, 76 676 (80.9%) completed the survey investigations, 12 107 (15.8%) of whom had no BCG scar. The prevalence of TB infection was estimated at 10.2%, with a corresponding ARTI of 1.1%. The ARTI obtained from the current survey is comparable to that of the 1994-1996 survey and higher than that of the 1986-1990 survey. The BCG coverage was comparable with the 1994-1996 survey and higher than in the 1986-1990 survey.

CONCLUSION

TB transmission in Kenya has remained the same over the last decade, which suggests that activities undertaken by the TB control programme have been sufficient to hold TB transmission steady, but insufficient to reduce it.

Public-private mix for control of tuberculosis and TB-HIV in Nairobi, Kenya: outcomes, opportunities and obstacles

SETTING

Nairobi, the capital of Kenya.

OBJECTIVE

To promote standardised tuberculosis (TB) care by private health providers and links with the public sector.

DESIGN AND METHODS

A description of the results of interventions aimed at engaging private health providers in TB care and control in Nairobi. Participating providers are supported to provide TB care that conforms to national guidelines. The standard surveillance tools are used for programme monitoring and evaluation.

RESULTS

By the end of 2006, 26 of 46 (57%) private hospitals and nursing homes were engaged. TB cases reported by private providers increased from 469 in 2002 to 1740 in 2006. The treatment success rate for smear-positive pulmonary TB treated by private providers ranged from 76% to 85% between 2002 and 2005. Of the 1740 TB patients notified by the private sector in 2006, 732 (42%) were tested for human immunodeficiency virus (HIV), of whom 372 (51%) were positive. Of the 372 HIV-positive TB patients, 227 (61%) were provided with cotrimoxazole preventive treatment (CPT) and 136 (37%) with antiretroviral treatment (ART).

CONCLUSION

Private providers can be engaged to provide TB-HIV care conforming to national norms. The challenges include providing diagnostics, CPT and ART and the capacity to train and supervise these providers.

Evaluation of the FluoreslenS and fluorescence microscopy blinded rechecking trial, Nairobi, Kenya

SETTING

Three busy laboratories in Nairobi, Kenya.

OBJECTIVES

To determine the performance of an affordable fluorescence system (FluoreslenS) for tuberculosis microscopy, and to test an auramine-smear rechecking system.

DESIGN

Alternating routine use of Ziehl-Neelsen (ZN) and fluorescence microscopy (FM) was performed to compare detection and errors found while rechecking.

RESULTS

Overall, 19.5% of 25,250 ZN and 23% of 21,104 FM smears were positive (P < 10(-3)). The proportional increment of FM over ZN was 18% (range -6%-29%), with one centre detecting fewer positives (non-significant, NS). The average error frequencies were comparable (1.8% vs. 2.6% false-negative and 0.2% vs. 0.4% high false-positive for ZN and FM, respectively, NS). The superior performance of controllers and the overall equal ZN/FM quality in the laboratories could be demonstrated only after converting error percentages to relative sensitivity (RS).

CONCLUSIONS

FM with the FluoreslenS system considerably improved sensitivity without loss of specificity in two of the busy routine laboratories, but the system is not sufficiently practical or user-friendly. Rechecking by FM can be done using guidelines for ZN smears, provided that routine ZN confirmation of positives is omitted. Calculation of RS allows an objective comparison of microscopy quality, independent of the variable prevalence of positives and sample size.

Provider-initiated HIV testing and counselling for TB patients and suspects in Nairobi, Kenya

SETTING

Integrated tuberculosis (TB) and human immunodeficiency virus (HIV) services in a resource-constrained setting.

OBJECTIVE

Pilot provider-initiated HIV testing and counselling (PITC) for TB patients and suspects.

DESIGN

Through partnerships, resources were mobilised to establish and support services. After community sensitisation and staff training, PITC was introduced to TB patients and then to TB suspects from December 2003 to December 2005.

RESULTS

Of 5457 TB suspects who received PITC, 89% underwent HIV testing. Although not statistically significant, TB suspects with TB disease had an HIV prevalence of 61% compared to 63% for those without. Of the 614 suspects who declined HIV testing, 402 (65%) had TB disease. Of 2283 patients referred for cotrimoxazole prophylaxis, 1951 (86%) were enrolled, and of 1727 patients assessed for antiretroviral treatment (ART), 1618 (94%) were eligible and 1441 (83%) started treatment.

CONCLUSIONS

PITC represents a paradigm shift and is feasible and acceptable to TB patients and TB suspects. Clear directives are nevertheless required to change practice. When offered to TB suspects, PITC identifies large numbers of persons requiring HIV care. Community sensitisation, staff training, multitasking and access to HIV care contributed to a high acceptance of HIV testing. Kenya is using this experience to inform national response and advocate wide PITC implementation in settings faced with the TB-HIV epidemic.

Is cough alone adequate to screen HIV-positive persons for tuberculosis preventive therapy in developing countries?

Although the efficacy of isoniazid in the prevention of tuberculosis in HIV-infected persons with a positive tuberculin skin test is proven, several feasibility issues remain unanswered. In resource poor settings where a chest radiograph may not be readily available, the question of whether cough alone is an adequate screening tool needs to be considered. We analysed screening data collected as part of an isoniazid efficacy study. Although the study was not designed specifically to answer this question, the data suggests that cough alone may be inadequate for screening patients for potential tuberculosis preventive therapy, and that a chest radiograph may be necessary. Feasibility studies are needed.