Evaluation of the sensitivity and specificity of rapid human immunodeficiency virus (HIV)1 and 2 test kits commonly used in Nigeria

The sensitivity and specificity of five rapid HIV antibody test kits commonly used in Nigeria were evaluated. The kits were selected based on their high percentage frequency of use as compared to others. A total of 100 EIA HIV-1and RNA HIV-1 positive sera were used as positive gold standard; while 100 EIA HIV-1 and RNA HIV-1 negative sera were used as negative gold standard. The positive gold standard sera were pooled; serially diluted and analysed to determine the sensitivities of the kits. The methods used were strictly as provided by the manufacturers. Of the 100 positive gold standard serum samples used; Immunocomb-II gave false negative results with 10 (Sensitivity = 90); while HIV-SAV; Hexagon; Determine and SD-Bioline were false negative with 12 specimens; representing 88 sensitivity for each. On the other hand; of the 100 negative gold standard sera; Immunocomb-II gave 6 false positive results (Specificity = 94); HIV-SAV 12 (Specificity = 88); Hexagon 2 (Specificity = 98); Determine 12 (Specificity = 88); while SD-Bioline had no false positive result (specificity = 100). In analytical sensitivity; Immunocomb-II detected the highest serum titre of 30 000; making it the most sensitive. Two of the five test kits (Immunocomb and SD-Bioline) demonstrated excellent analytical sensitivity and specificity respectively. The two could be recommended for use as combination test algorithms instead of EIA/Western Blot algorithm; which is time-consuming; expensive and often not technically feasible in a developing country like ours. This study shows that not all the analytical performance indices cited in the literature from the manufacturers of diagnostic kits are necessarily reproducible in end-user laboratories

Chloroquine prophylaxis associated with high prevalence of Plasmodium falciparum pfcrt K76T mutation in people with sickle-cell disease in Benin City, Nigeria.

BACKGROUND & OBJECTIVES: High mortality and morbidity in sickle-cell disease has been associated with malaria infection especially in countries where chloroquine is used. Chloroquine resistance has been associated with the emergence of Pfcrt mutant genes. This study aimed at comparing the prevalence rate of Pfcrt T76 mutation in Plasmodium falciparum isolates from infected individuals with sickle-cell disease and sickle-cell trait. This study was carried out in Benin City between the months of April and June 2006. This period is marked with high transmission rate of malaria. METHODS: The genotype of the subjects was screened using haemoglobin electrophoresis system and the P. falciparum. Pfcrt genotyping was carried out using PCR-restriction fragment length polymorphism (RFLP). RESULTS: Four hundred and twenty-four subjects comprising of 207 haemoglobin AA, 136 haemoglobin AS and 81 haemoglobin SS typed individuals were enrolled for this study. No significant difference existed in the prevalence rate of malaria in the three groups (p > 0.05). However, the prevalence rate of Pfcrt K76T mutant gene was higher in the haemoglobin SS genotyped individuals than the haemoglobin AA and AS subjects (p < 0.05). INTERPRETATION & CONCLUSION: An uncontrolled use of chloroquine has been incriminated as the major cause of chloroquine resistance in Nigeria. Therefore, rapid intervention measures are needed as a matter of urgency to curb the up rise in the prevalence of the chloroquine resistant genes in our environment.

Prevalence of Chlamydia in Patients Attending Gynecological Clinics in South Eastern Nigeria

"Background: Chlamydia infections have been reported to cause silent infections in communities which becomes endemic and could remain unnoticed for a very long time. In most parts of Nigeria these organisms are not screened for; and hence relative information about frequencies of the organisms are sparse. Method: Five hundred and sixty five blood samples and ten umbilical cord fluids were collected from various patients attending clinics in South Eastern Nigeria and were screened for Chlamydia Complement Fixing Antibody (CCFA). Endocervical swabs and urethral discharges or swabs were collected from patients whose serum was positive and were cultured into embryonic eggs which was later observed; harvested and stained using the Romanowsky - Giemsa staining techniques. The positive sera were further confirmed by distinguishing the species of Chlamydia using the monoclonal antibody spot test kit. Result: Of the five hundred and sixty five (565) samples collected only three hundred and forty were positive to CCFA; of which 141 were males and 204 females. From the cultured samples 230 were positive for Chlamydia trachomatis and 99 positive to Chlamydia pneumoniae. Statistical analysis using the student's t test at 95confidence interval shows that there was no significant difference between the number of females and males that presented themselves for screening. Conclusion: Proper screening of patients to include Chlamydia should be encouraged at all levels of medical diagnosis in the country so as to proffer treatment. Otherwise the infection will remain a ""silent epidemic""; as is the case currently."