Evaluation of nine HIV rapid test kits to develop a national HIV testing algorithm in Nigeria

Background: Non-cold chain-dependent HIV rapid testing has been adopted in many resource-constrained nations as a strategy for reaching out to populations. HIV rapid test kits (RTKs) have the advantage of ease of use, low operational cost and short turnaround times. Before 2005, different RTKs had been used in Nigeria without formal evaluation. Between 2005 and 2007, a study was conducted to formally evaluate a number of RTKs and construct HIV testing algorithms. Objectives: The objectives of this study were to assess and select HIV RTKs and develop national testing algorithms. Method: Nine RTKs were evaluated using 528 well-characterised plasma samples. These comprised 198 HIV-positive specimens (37.5%) and 330 HIV-negative specimens (62.5%), collected nationally. Sensitivity and specificity were calculated with 95% confidence intervals for all nine RTKs singly and for serial and parallel combinations of six RTKs; and relative costs were estimated. Results: Six of the nine RTKs met the selection criteria, including minimum sensitivity and specificity (both ≥ 99.0%) requirements. There were no significant differences in sensitivities or specificities of RTKs in the serial and parallel algorithms, but the cost of RTKs in parallel algorithms was twice that in serial algorithms. Consequently, three serial algorithms, comprising four test kits (BundiTM, DetermineTM, Stat-Pak® and Uni-GoldTM) with 100.0% sensitivity and 99.1% - 100.0% specificity, were recommended and adopted as national interim testing algorithms in 2007. Conclusion: This evaluation provides the first evidence for reliable combinations of RTKs for HIV testing in Nigeria. However, these RTKs need further evaluation in the field (Phase II) to re-validate their performance.

Improving quality in national reference laboratories: The role of SLMTA and mentorship

Background

The Nigerian Institute of Medical Research houses two reference laboratories: the virology and tuberculosis laboratories. Both were enrolled in the Strengthening Laboratory Management Toward Accreditation (SLMTA) programme.

Objective

To describe the impact of SLMTA and discuss factors affecting the results, with an emphasis on mentorship.

Methods

The SLMTA programme was implemented from April 2010 through November 2012. Participants attended three workshops and executed quality improvement projects; laboratory auditors evaluated performance using a standard checklist. The virology laboratory did not receive mentorship; however, the tuberculosis laboratory had an international mentor who visited the laboratory four times during the programme, spending two to four weeks embedded within the laboratory during each visit.

Results

There was an overall improvement in the performance of both laboratories, with the virology laboratory increasing 13% (from 80% at baseline to 93% at exit audit) and the tuberculosis laboratory increasing 29% (from 66% to 95%). These scores were maintained nine months later at the surveillance audit.

Conclusion

The SLMTA programme resulted in improved and sustained quality management performance for both laboratories. Mentoring was a possible factor in the substantial improvement made by the tuberculosis laboratory and should be considered in order to augment the training received from the SLMTA workshops.

Stroke-like syndrome in a middle aged Nigerian woman with metastatic brain cancer

BACKGROUND

Metastatic brain cancer constitutes about 24 to 25 % of brain tumours worldwide and in Nigeria it constitutes about 40% of brain tumors. The clinical presentation of metastatic tumors may be atypical.

OBJECTIVE

To present a middle aged Nigerian woman with a metastatic brain cancer who had a stroke-like syndrome.

METHODS

The patient was a 47-year old woman who presented with a two-week history of progressive weakness of the right upper and lower limbs, associated with headache, blurring of vision and slurring of speech. There was a history of weight loss but no history of cough or evening pyrexia. She was not a known hypertensive or diabetic patient though, there were positive history of diabetes mellitus in her father and elder senior brother. Her other systemic review and past medical history were not contributory.

RESULTS

Examination revealed a woman with expressive dysphasia and right spastic hemiparesis. Her pulse, blood pressure and heart sounds were normal. There was no carotid bruit. Imaging studies showed metastases in the brain, liver, chest, cervical lymph nodes and bone marrow. Cervical lymph node histology showed metastatic adenocarcinoma. She was managed with chemotherapy, steroids and other supportive therapy but she died on the 40th day of admission due to disease progression and aspiration pneumonitis.

CONCLUSION

Metastatic brain cancer may manifest atypically. Physicians should screen any patient with stroke without any apparent risk factors for possibilities of underlying metastatic brain cancer.

Immunoprotective factors in breast milk and sera of mother-infant pairs

We analysed breast milk and serum samples from 33 healthy Nigerian mother-infant pairs for concentrations of IgG, IgM, IgA, C3, C4 and lysozyme. We found that the mean IgG and IgM concentrations in maternal sera were three to four times higher than the levels in infant sera, and five to ten times higher than in breast milk. The IgA and lysozyme concentrations in breast milk were, however, slightly higher than the levels in infant sera, suggesting an active localized synthesis of these factors in the mammary gland. While 54.5% of the milk samples lacked measurable concentrations of IgM by radial immunodiffusion, IgA was consistently present in all the milk samples. The mean C3 concentration in maternal sera was 164 mg/100 ml, compared to 145 mg/100 ml and 11.5 mg/100 ml in infant sera and breast milk respectively. The C4 concentration was also considerably lower in breast milk than in maternal and infant sera.