Prevalence and predictors of asymptomatic Chlamydia trachomatis and Neisseria gonorrhoeae in a Ugandan population most at risk of HIV transmission

The aim of this study was to establish the prevalence of asymptomatic Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) in key populations at increased risk of transmission of HIV. Additionally, we aimed to identify the associated risk factors for asymptomatic sexually transmitted infections (STIs) and evaluate the acceptability of self-collected samples. Asymptomatic people living with HIV (PLHIV) in the following categories were offered testing: discordant couples, young adults, pregnant patients and those attending the 'most-at-risk-population' clinic. Patients provided first-pass urine, self-collected vaginal swabs or both to test for NG and CT by polymerase chain reaction using BD ProbeTec™. Patients also completed an acceptability questionnaire, including the negative partner of an HIV-positive participant. Three hundred and sixty-three PLHIV had an STI screen. Asymptomatic STIs were only diagnosed in women (prevalence 5.7%), overall prevalence 3.9% (n = 14). Factors independently associated with an STI in women were being under 25 years (OR 9.63 95% CI 1.56-59.5) and having more than one sexual partner (OR 8.06 95% CI 1.07-60.6). Four hundred and seven completed the acceptability questionnaire. More than 95% of patients found self-sampling easy and comfortable and 83.8% would believe the results. Women significantly preferred the option of self-sampling, 56.9% versus 29.3% of men (p < 0.001). Acceptability of self-sampling was high. Young women with or at risk of HIV are an important target for STI testing regardless of symptoms. There is need for diagnostic tests that are inexpensive, rapid and accurate especially in resource-limited settings.

Test Cost and Test Accuracy in Clinical Laboratories in Kampala, Uganda

OBJECTIVES

To assess the accuracy and costs of laboratory tests in Kampala, Uganda.

METHODS

A random selection of 78 laboratories tested external quality assurance samples at market rates. There were 40 moderate- to high-complexity and 38 low-complexity laboratories. Four percent (3/78) of these laboratories were accredited and 94% (73/78) were private. The 40 moderate- to high-complexity laboratories performed malaria blood smear, urine human chorionic gonadotropin (hCG), human immunodeficiency virus (HIV), syphilis, glucose, and three-panel tests: CBC, liver function tests, and kidney function tests. The 38 low-complexity laboratories performed malaria blood smear, urine hCG, and syphilis testing only. Hematology, HIV, syphilis, and malarial proficiency testing samples were prepared by accredited laboratories in Kampala. All other samples were provided by the Royal College of Pathologists of Australia.

RESULTS

77.1% of all results were accurate (met target values). It varied widely by laboratory (50%-100%), test identity (malaria blood smear, 96%; serum urea nitrogen, 38%), and test type (quantitative: 66% [31%-89%], qualitative: 91% [68%-97%]). Test prices varied by up to 3,600%, and there was no correlation between test cost and accuracy (r2 = 0.02).

CONCLUSIONS

There were large differences in accuracy and price across laboratories in Kampala. Price was not associated with quality.

Scaling up HIV viral load - lessons from the large-scale implementation of HIV early infant diagnosis and CD4 testing

INTRODUCTION

The scale-up of effective HIV viral load (VL) testing is an urgent public health priority. Implementation of testing is supported by the availability of accurate, nucleic acid based laboratory and point-of-care (POC) VL technologies and strong WHO guidance recommending routine testing to identify treatment failure. However, test implementation faces challenges related to the developing health systems in many low-resource countries. The purpose of this commentary is to review the challenges and solutions from the large-scale implementation of other diagnostic tests, namely nucleic-acid based early infant HIV diagnosis (EID) and CD4 testing, and identify key lessons to inform the scale-up of VL.

DISCUSSION

Experience with EID and CD4 testing provides many key lessons to inform VL implementation and may enable more effective and rapid scale-up. The primary lessons from earlier implementation efforts are to strengthen linkage to clinical care after testing, and to improve the efficiency of testing. Opportunities to improve linkage include data systems to support the follow-up of patients through the cascade of care and test delivery, rapid sample referral networks, and POC tests. Opportunities to increase testing efficiency include improvements to procurement and supply chain practices, well connected tiered laboratory networks with rational deployment of test capacity across different levels of health services, routine resource mapping and mobilization to ensure adequate resources for testing programs, and improved operational and quality management of testing services. If applied to VL testing programs, these approaches could help improve the impact of VL on ART failure management and patient outcomes, reduce overall costs and help ensure the sustainable access to reduced pricing for test commodities, as well as improve supportive health systems such as efficient, and more rigorous quality assurance. These lessons draw from traditional laboratory practices as well as fields such as logistics, operations management and business.

CONCLUSIONS

The lessons and innovations from large-scale EID and CD4 programs described here can be adapted to inform more effective scale-up approaches for VL. They demonstrate that an integrated approach to health system strengthening focusing on key levers for test access such as data systems, supply efficiencies and network management. They also highlight the challenges with implementation and the need for more innovative approaches and effective partnerships to achieve equitable and cost-effective test access.

Most clinical laboratory testing in Kampala occurs in high-volume, high-quality laboratories or low-volume, low-quality laboratories. A tale of two cities

OBJECTIVES

To describe key characteristics (laboratory quality, test volumes, and complexity) of clinical laboratories in Kampala, Uganda (population ~1.7 million).

METHODS

Cross-sectional survey using a standard questionnaire to document laboratory type and quality, as well as test menus and volumes. Quality was based on the World Health Organization-Africa Region checklist.

RESULTS

Of the 954 laboratories identified (a density of one laboratory per 1,781 persons), 779 (82%) performed only simple kit tests or light microscope examinations. The 95% (907/954) of laboratories for whom volumes were obtained performed an average aggregate of 13,189 tests daily, for a test utilization rate of around 2 tests per individual per year. Laboratories could be segregated into eight groups based on quality, test volume, and complexity. However, 90% of the testing was performed by just two groups: (1) low-volume (≤100 tests daily), low-quality laboratories performing simple tests or (2) high-volume (>100 tests daily), high-quality laboratories. Each of these two groups did 45% of the daily testing volume (90% combined).

CONCLUSIONS

Clinical laboratory density in Kampala (1/1,781 persons) is high, approaching that in the United States (1/1,347 persons). Low-volume/low-quality and high-volume/high-quality laboratories do 90% of the daily aggregate testing. Quality improvement (QI) schemes for Africa must be appropriate to low-volume laboratories as well as to the large laboratories that have been the focus of previous QI efforts.

Ebola outbreak response; experience and development of screening tools for viral haemorrhagic fever (VHF) in a HIV center of excellence near to VHF epicentres

INTRODUCTION

There have been 3 outbreaks of viral hemorrhagic fever (VHF) in Uganda in the last 2 years. VHF often starts with non-specific symptoms prior to the onset of haemorrhagic signs. HIV clinics in VHF outbreak countries such as Uganda see large numbers of patients with HIV 1/2 infection presenting with non-specific symptoms every day. Whilst there are good screening tools for general health care facilities expecting VHF suspects, we were unable to find tools for use in HIV or other non-acute clinics.

METHODS

We designed tools to help with communication to staff, infection control and screening of HIV patients with non-specific symptoms in a large HIV clinic during the outbreaks in Uganda. We describe our experiences in using these tools in 2 Ebola Virus Disease outbreaks in Uganda.

RESULTS

During the Ebola Virus Disease (EVD) outbreaks, enhanced infection control and communication procedures were implemented within 24 hours of the WHO/Ministry of Health announcement of the outbreaks. During course of these outbreaks the clinic saw 12,544 patients with HIV 1/2 infection, of whom 3,713 attended without an appointment, suggesting new symptoms. Of these 4 were considered at risk of EVD and seen with full infection procedures; 3 were sent home after further investigation. One patient was referred to the National Referral Hospital VHF unit, but discharged on the same day. One additional VHF suspect was identified outside of a VHF outbreak; he was transferred to the National Referral Hospital and placed in isolation within 2 hours of arriving at the HIV clinic.

DISCUSSION

Use of simple screening tools can be helpful in managing large numbers of symptomatic patients attending for routine and non-routine medical care (including HIV care) within a country experiencing a VHF outbreak, and can raise medical staff awareness of VHF outside of the epidemics.

Evaluation of portable point-of-care CD4 counter with high sensitivity for detecting patients eligible for antiretroviral therapy

Background

Accurate, inexpensive point-of-care CD4+ T cell testing technologies are needed that can deliver CD4+ T cell results at lower level health centers or community outreach voluntary counseling and testing. We sought to evaluate a point-of-care CD4+ T cell counter, the Pima CD4 Test System, a portable, battery-operated bench-top instrument that is designed to use finger stick blood samples suitable for field use in conjunction with rapid HIV testing.

Methods

Duplicate measurements were performed on both capillary and venous samples using Pima CD4 analyzers, compared to the BD FACSCalibur (reference method). The mean bias was estimated by paired Student's t-test. Bland Altman plots were used to assess agreement.

Results

206 participants were enrolled with a median CD4 count of 396 (range; 18–1500). The finger stick PIMA had a mean bias of −66.3 cells/µL (95%CI −83.4−49.2, P<0.001) compared to the FACSCalibur; the bias was smaller at lower CD4 counts (0–250 cells/µL) with a mean bias of −10.8 (95%CI −27.3−+5.6, P = 0.198), and much greater at higher CD4 cell counts (>500 cells/µL) with a mean bias of −120.6 (95%CI −162.8, −78.4, P<0.001). The sensitivity (95%CI) of the Pima CD4 analyzer was 96.3% (79.1–99.8%) for a <250 cells/ul cut-off with a negative predictive value of 99.2% (95.1–99.9%).

Conclusions

The Pima CD4 finger stick test is an easy-to-use, portable, relatively fast device to test CD4+ T cell counts in the field. Issues of negatively-biased CD4 cell counts especially at higher absolute numbers will limit its utility for longitudinal immunologic response to ART. The high sensitivity and negative predictive value of the test makes it an attractive option for field use to identify patients eligible for ART, thus potentially reducing delays in linkage to care and ART initiation.

Distribution of haematological and chemical pathology values among infants in Malawi and Uganda

BACKGROUND

Data on paediatric reference laboratory values are limited for sub-Saharan Africa.

OBJECTIVE

To describe the distribution of haematological and chemical pathology values among healthy infants from Malawi and Uganda.

METHODS

A cross-sectional study was conducted among healthy infants, 0-6 months old, born to HIV-uninfected mothers recruited from two settings in Blantyre, Malawi and Kampala, Uganda. Chemical pathology and haematology parameters were determined using standard methods on blood samples. Descriptive analyses by age-group were performed based on 2004 Division of AIDS Toxicity Table age categories. Mean values and interquartile ranges were compared by site and age-group.

RESULTS

A total of 541 infants were included altogether, 294 from Malawi and 247 from Uganda. Overall, the mean laboratory values were comparable between the two sites. Mean alkaline phosphatase levels were lower among infants aged ≤21 days while aspartate aminotransferase, creatinine, total bilirubin and gamma-glutamyl transferase were higher in those aged 0-7 days than in older infants. Mean haematocrit, haemoglobin and neutrophil counts were higher in the younger age-groups (<35 days) and overall were lower than US norms. Red and white blood cell counts tended to decrease after birth but increased after ∼2 months of age. Mean basophil counts were higher in Malawi than in Uganda in infants aged 0-1 and 2-7 days; mean counts for eosinophils (for age groups 8-21 or older) and platelets (for all age groups) were higher in Ugandan than in Malawian infants. Absolute lymphocyte counts increased with infant age.

CONCLUSION

The chemical pathology and haematological values in healthy infants born to HIV-uninfected mothers were comparable in Malawi and Uganda and can serve as useful reference values in these settings.