Lydia N. Abia-Bassey

Neonatal septicaemia in Calabar, Nigeria.

SUMMARY A three-year survey of neonatal septicaemia (363 bacteriologically proven cases) in the University of Calabar Teaching Hospital, Calabar, has demonstrated that the dominant blood isolate was Staphylococcus aureus (53%) followed by unclassified Coliforms (20%), an unexpected Chromobacterium violaceum (5%). The incidence of neonatal septicaemia was 54.9 per 1000 live births for inborn infants. The predominant organisms were largely susceptible to gentamicin, ceftriazone and cefuroxime with a mortality rate of 19% with most (60.9%) of the fatalities being due to Gram-negative organisms.

Molecular epidemiology and genetic diversity of Mycobacterium tuberculosis complex in the Cross River State, Nigeria

This study provides with a first insight on Mycobacterium tuberculosis complex epidemiology and genetic diversity in the Cross River State, Nigeria. Starting with 137 smear positive patients recruited over a period of 12months (June 2008 to May 2009), we obtained 97 pure mycobacterial isolates out of which 81 (83.5%) were identified as M. tuberculosis complex. Genotyping revealed a total of 27 spoligotypes patterns with 10 clusters (n=64% or 79% of clustered isolates, 2-32 isolates/cluster), with patients in the age group range 25-34 years being significantly associated with shared-type pattern SIT61 (p=0.019). Comparison with SITVIT2 database showed that with the exception of a single cluster (SIT727/H1), all other clusters observed were representative of West Africa; the two main lineages involved were LAM10-CAM (n=42/81% or 51.8%) of M. tuberculosis and AFRI_2 sublineage of Mycobacterium africanum (n=27/81% or 33.3%). Subsequent 12-loci MIRU typing resulted in a total of 13 SIT/MIT clusters (n=52 isolates, 2-9 isolates per cluster), with a resulting recent n-1 transmission rate of 48.1%. Available drug-susceptibility testing (DST) results for 58/81 clinical isolates revealed 6/58% or 10.4% cases of multiple drug-resistance (MDR); 5/6 MDR cases were caused by strains belonging to LAM10-CAM lineage (a specific cluster SIT61/MIT266 in 4/6 cases, and an orphan spoligotype pattern in 1/6 case). Additionally, MIT266 was associated with streptomycin resistance (p=0.016). All the six MDRTB isolates were concomitantly resistance to streptomycin and ethambutol; however, 4/6 MDR strains with identical MIRU patterns were characterized by consecutive strain numbers hence the possibility of laboratory cross contamination could not be excluded in 3/4 serial cases. The present preliminary study underlines the usefulness of spoligotyping and 12-loci MIRU-VNTRs to establish a baseline of circulating genotypic lineages of M. tuberculosis complex in Nigeria.

The relationship between opportunistic pulmonary fungal infections and CD4 count levels among HIV-seropositive patients in Calabar, Nigeria

BACKGROUND Most HIV-seropositive people who develop AIDS die from an opportunistic infection, such as pulmonary mycosis, rather than the HIV infection itself. Data on the pattern of respiratory mycoses and the immunological profile of HIV-seropositive patients in Nigeria are scarce and uncoordinated, so we investigated respiratory mycosis and CD4 count among HIV-seropositive and AIDS patients attending the antiretroviral clinics at the University of Calabar Teaching Hospital and Lawrence Henshaw Hospital in Calabar, Nigeria. METHOD From May 2009 to July 2010 we carried out a prospective study of 331 individuals with respiratory symptoms, of whom 272 were HIV seropositive, aged 17-75 years and able to produce sputum and 59 were HIV non-reactive. Relevant samples were collected and subjected to direct microscopy, fungal culture and serology. RESULTS The overall prevalence of pulmonary mycoses was 36.0%, the most prevalent fungal pathogen being Candida albicans (11.8%). Pneumocystis jirovecii (7.4%) was confirmed as an important opportunistic fungal agent in HIV-infected individuals in Calabar. Patients aged 25-34 years were at the highest risk of pulmonary mycosis (43.9%). HIV-positive patients with mycoses had lower mean CD4 counts (142.3 ± 100.1 cells µl⁻¹) than those without mycoses (435.4 ± 249.1 cells µl⁻¹) (t = 10.5, p = 0.00). CONCLUSION Opportunistic pulmonary infections arise more frequently in HIV patients with lower CD4 counts. A more detailed comparative study with other opportunistic infections may help formalize the use of CD4 count as an indicator of HIV/AIDS with opportunistic mycoses.

Yeast associated with human infections in south-eastern Nigeria.

A total of 1921 specimens from nine clinical sources were examined by direct microscopy and culture to recover yeast associated with human infection. Identification of yeast was based on their carbon assimilation patterns, using API 20C AUX and ID 32 C (bioMérieux, France) commercial kits. A total of 178 specimens (9.3%) were positive for yeast. Most of the yeast isolates were recovered from urine samples and genital swabs. Prevalence was significantly higher in women (14.7%) than in men (1.4%) (P < 0.05). The age group 21–30 years recorded the highest prevalence of yeast infection (65.2%) followed by age group 11–20 years (16.9%) and >40 years (9.0%). When genital samples were considered, prevalence was significantly higher in the age group 21–30 years than that in older ones (P < 0.05). Isolates recovered included seven species of Candida and Trichosporon inkin. C. albicans accounted for the highest number of isolates (128) followed by C. tropicalis (23) and C. parapsilosis (9). Two isolates each of C. famata and C. norvegensis were recorded and are reported for the first time in Nigeria. The two isolates of T. inkin were recovered from perianal lesions and are also reported for the first time from Nigeria. C. albicans, C. glabrata, C. parapsilosis and C. krusei were found to be the most common yeast species that act as agents of human disease in south‐eastern Nigeria.

Multidrug resistance and demography of newly diagnosed tuberculosis patients in Cross River State, Nigeria

SETTING Nigeria has the worlds fourth largest tuberculosis burden, and multidrug resistant tuberculosis (MDR-TB) represents a serious public health problem. OBJECTIVES To describe the demography of TB patients and determine the susceptibility of Mycobacterium tuberculosis isolates to the major TB drugs. METHODS One hundred and thirty-seven newly diagnosed TB patients (26 (19%) being HIV positive) from all age groups were recruited into the study. Each specimen was cultured using BACTEC MGIT960, followed by inoculation and growth on Lowenstein-Jensen (LJ) medium. Primary identification was carried out using an immunochromatographic technique (Capilia TB-Neo), and further confirmed by genotyping. Drug susceptibility testing (DST) was carried out by the agar proportion method. RESULTS Of the 97 pure mycobacterial cultures on LJ medium, 81 (83.5%) isolates were identified as M. tuberculosis complex, while 16 (16.5%) were Capilia negative. DST was carried out on 58 isolates. The drug susceptibility pattern showed that resistance occurred in 16 (27.6%) for streptomycin, 11 (19%) for isoniazid, 9 (16%) for rifampicin, and 10 (17.2%) for ethambutol. Rifampicin monoresistance occurred in 2 (3.4%) cases. MDR (combined resistance to isoniazid and rifampicin), also involving resistance to streptomycin and ethambutol, occurred in 6/58 (10.3%) isolates; although laboratory cross-contamination could not be excluded in 4/6 MDR strains with identical MIRU patterns characterized by consecutive strain numbers. Considering that first out of these 4 isolates was not due to laboratory carryover, the results of this study still report a minimal MDR-TB rate of 3/58 (5.2%) among newly diagnosed TB patients in Cross River State, Nigeria. CONCLUSIONS An increase in drug resistance was observed in this study as compared with previous studies in the country. Hence, introduction of culture in routine diagnostic mycobacteriology laboratories will prevent the emergence and dissemination of MDR-TB, while improved quality control strategies would in parallel prevent laboratory cross-contamination, thereby reducing mislabeling, unnecessary treatment, and drug toxicity for patients.

Haematological Profile of HIV Infected Patients with Opportunistic Respiratory Mycoses in Relation to Immune Status-A Hospital Based Cohort from Calabar, Nigeria

Objectives: To study the spectrum of hematological manifestations and evaluate the relationship between various hematological manifestations and CD4 cell count among opportunistic respiratory mycoses positive adult HIV patients in Calabar, Nigeria. Materials and methods: The hematological and mycological profiles of the 272 HIV infected patients with respiratory symptoms attending the Anti Retroviral (ARV) and Infectious disease clinics in Calabar, from May 2009 to July 2010 were recorded. The relationship between hematological manifestations and CD4 counts among the respiratory mycoses positive subjects were analyzed. Results: The most common haematological abnormality was anaemia with 129(47.2%) subjects affected. Also among the mycoses positive subjects’ anaemia was more prevalent in females 32(43.8%) than males 26(46.4%), but there was no relationship between mycoses and anaemia among subjects (X2=4.3, p=0.6). All subjects infected with fungal pathogens had CD4 counts below 200 cells/μl of blood. Conclusion: Subjects with mycoses are more likely to develop haematological abnormalities like anaemia, neutropenia and lymphopenia due to further suppression of their immune status. This suggests that respiratory mycoses may affect haematological parameters of patients especially the lymphocytes and CD4 counts.

Utility and diagnostic performance of Mycobacterium tuberculosis complex by two immunochromatographic assays as compared with the molecular Genotype assay in Nigeria

Among the disadvantages of smear microscopy for detection of tuberculosis cases is its inability to differentiate between Mycobacterium tuberculosis (MTB) and non-tuberculous mycobacteria (NTM). This study evaluated two, new immunochromatographic assays - Capilia TB-Neo and SD Bioline - on unheated and heated cultures at 80°C for 30min respectively for their ability to discriminate between MTB complex and NTM as compared with the molecular Genotype assay. Mycobacteria used in the study were obtained from smear-positive specimens collected from patients at four major hospitals in Cross River State, Nigeria. Capilia TB-Neo and SD Bioline showed sensitivities of 98.8% and 93.8% respectively and 100% specificity for both assays. Heating the isolates did not significantly impact the test performance. Both tests are recommended for use in rapid differentiation of strains isolated in Nigeria.

Tuberculin Skin Test (TST) Indurations in Smear Positive TB Patients and Healthy Individuals in Calabar, Nigeria

Abstract The tuberculin skin test (TST) is used to detect latent Mycobacterium tuberculosis infection. WHO guidelines recommend 10mm as tuberculosis (TB) infection threshold for high risk individuals and 15mm for persons with no risk factors for TB. Nigeria is one of the 22 high burden countries for TB and her population is at risk of exposure to the TB germ. In an attempt to investigate indigenous TST indurations in a local population, 200 apparently healthy new students of tertiary institutions and other residents of Calabar - Nigeria metropolis that required the test for routine medical examination were examined. Each subject was injected intradermally with 0.1mL of 5TU of purified protein derivative (PPD) into the dorsal surface of the forearm. Indurated areas were measured after 48-72 hours of administration and results expressed in millimeters. 200 smear positive TB patients receiving treatment at the treatment center of the National TB Control program were used as the reference group. Results were statistically analysed using Chi square and T-test. Data obtained from the apparently healthy group show that approximately 31% of the individuals had indurations measuring 5-7mm while 29% were non-reactive. At least 25% of these individuals had indurations of >10mm compared to 95% of TB patients. Nine (4.5%) of TB patients have indurations <10mm. The results of this study imply that at least 25% of the healthy subjects are at risk of progressing to active disease when exposed to conditions that lower the individual’s immune status.