Cryptosporidiosis and its genotypes among children attending Moi Teaching and Referral Hospital in Eldoret, Kenya

Objectives: To determine the prevalence of cryptosporidiosis and the associated factors, and characterise the Cryptosporidium isolates from children aged five years and less with diarrhoea.Design: A prospective cross-sectional study.Setting: This was a health facility and laboratory based study. Screening forCryptosporidium oocysts was done at the Microbiology laboratory, School of Medicine, Moi University, Eldoret and genotyping and sub-genotyping at the Kenya Medical Research Institute, Nairobi, Kenya.Subjects: Children aged five years and less seen at the outpatient clinic and those admitted in the pediatric wards at MTRH were recruited into the study upon obtaining assent and written consent from the parents or guardians.Results: The prevalence of cryptosporidiosis was 9.8% (N=317). A duration of diarrhoea of more than two weeks was associated with cryptosporidiosis (OR= 1.8301) compared to those with diarrhoea for less than one week. There were no sex related differences in the cryptosporidiosis prevalence (P= 0.9752). Waste disposal, water sources and treatment, and livestock in homesteads were not associated with cryptosporidiosis. About 82% of the isolates were C. hominis and 18% were C. parvum. There were 6subtypes of C. hominis and 4 subtypes of C. parvum in circulation.Conclusion: The prevalence of cryptosporidiosis is comparable to other regions of the world with C. hominis being the most common followed by C. parvum. Human-to-human transmission is the main mode of spread of cryptosporidiosis. All the Cryptosporidium isolates were from children residing in peri-urban and rural areas

Ziehl-Neelsen microscopy in the diagnosis of tuberculosis in settings of high human immunodeficiency virus prevalence

Objective: To determine the accuracy of Ziehl-Neelsen microscopy in the diagnosis of TB in setings of high HIV prevalence.Design: Cross-sectional descriptive study.Setting: Hospitals serving areas of high human immunodeficiency virus prevalence in western Kenya. The study was conducted between September 2007 and September 2009.Results: In total, 341/872 (39.1%) of the TB suspects were positive in ZN, 53.1% (181/341) of them culture positive. Only 3.8% (20/531) of the ZN smear negatives were culture positive. Of the 695 suspects evaluated for both Mycobacterium and HIV infection, 255 (36.7%) were ZN smear positive, 42.7% of them HIV positive. Out of the 440 ZN smear negatives, 37% were HIV positive. Similarly, 168 suspects were culture positive, 46.4% of them HIV positive. The HIV infection did not significantly reduce ZN smear positivity rate (P = 0.42) and culture sensitivity (P = 0.09). The ZN sensitivity and specificity were 88.1% and 79.7%, respectively. The predictive values were 58.0 (PPV), and 95.5% (NPV), respectively. However, the area under the ROC curve was 0.84, with 95% CI between 0.80-0.87 and P< 0.001). The ZN smear microscopy had a lesser ability to distinguish between TB and non-TB cases compared to culture.Conclusion: ZN microscopy causes a significant over-diagnosis of TB in settings of high HIV/AIDS prevalence. There is need for further studies on this subject taking into consideration the various confounding factors

Molecular Technique Utilising Sputum For Detecting Wuchereria bancrofti Infections In Malindi, Kenya

Background: Lymphatic filariasis is a tropical parasitic disease which has been identified for elimination by 2020 through mass drugs administration. There is a major problem in its diagnosis and sensitive surveillance methods for monitoring the disease elimination programs need to be sought. Objectives: To establish and evaluate the usefulness of a Polymerase Chain Reaction, PCR assay employing sputum for diagnosis of Wuchereria bancrofti infections in an endemic location. Design: Community based samples collection and a molecular laboratory technologies study. Setting: Mpirani, Malindi District and Centre for Biotechnology Research and Development, Kenya Medical Research Institute. Subjects: Sputum samples were obtained from 304 willing and consenting participants, aged between 5 and 73 years resident in Mpirani, Malindi District. Results: Prevalence of W. bancrofti infection was found to be 42.8% (130/304) by PCR assay employing sputum compared with 22.0 % (67/304) and 38.8% (119/304) respectively for microfilaria counts and ICT. The sensitivity and specificity of the PCR sputum assay was 97.5 and 92.4% respectively. Predictive values were 89.2 and 98.3% for positive (PPV) and negative (NPV) respectively while accuracy was 94.4%. Conclusions: The molecular PCR assay using sputum was found to have a great potential for use in mass diagnosis and in epidemiological studies in patients with W. bancrofti infections East African Medical Journal Vol. 85 (3) 2008: pp. 118-12

Low anti tuberculosis drug resistance despite high rates of recurrent tuberculosis and HIV infection in western Kenya

Background: The high rates of recurrent tuberculosis and HIV in Kenya raised the assumption that anti -tuberculosis drug resistance may be an increasing problem. Objective: To determine whether HIV co infection and TB recurrence are associated with anti TB drug resistance. Methods: Cross sectional study in which sputa from 872 TB suspects underwent ZN smear microscopy and culture. Growth was identified using Hain molecular identification kits. Screening for HIV infection was done using Uni GoldTM rapid test and the positives confirmed with enzyme linked immunosorbent assay. Results: A total of 186 M. tuberculosis complex and 15 non tuberculous mycobacteria isolates were obtained. The tuberculosis recurrence and TB HIV co infection rates amounted to 44.8% and 41.8%, respectively. All the 186 M. tuberculosis isolates were susceptible to streptomycin and ethambutol. Only 12 (6.5%) of the isolates were mono drug resistant, nine to isoniazid and three to rifampicin. Only 3/27 isoniazid resistant isolates were from recurrent TB cases. Conclusion and recommendation: No MDR strains of M. tuberculosis were observed in the current study. However, the study suggests an association between HIV co-infection and anti TB mono drug resistance. High TB recurrence observed in the current study was not associated with anti TB drug resistance. What needs to be examined is the cause of this high TB recurrence rate in Western Kenya. Keywords: Recurrent TB; HIV co infection; antiTB drug resistance; prevalenc

Misdiagnosis and clinical significance of non-tuberculous mycobacteria in Western Kenya in the era of human immunodeficiency virus epidemic

Objectives: To determine and document the role of non-tuberculous mycobacteria (NTM) in TB-like disease morbidity and demonstrate the confusion they cause in the diagnosis of TB in western Kenya.Design: A cross-sectional study.Setting: One provincial and nine District hospitals in western Kenya.Subjects: Tuberculosis suspects.Interventions: Sputa from 872 tuberculosis suspects underwent microscopy and culture on solid and liquid media. The growth was identified using the Hain’s GenoType® Mycobacterium CM and GenoType® Mycobacterium AS kits. Consenting clients were screened for HIV infection using Trinity Biotech Uni-GoldTM test and positive cases were confirmed with the enzyme linked immunosorbent assay. A questionnaire was used to obtain demographic data.Main outcome measures: ZN smear positivity / negativity; Culture positivity or negativity; Mycobacterium species isolates (tuberculous or non-tuberculous); HIV status.                                                      Results: Sputa from 39.1% (341/872) of the participants were ZN smear positive, of these 53.1% (181/341) were culture positive. Only 3.8% (20/531) of the ZN smear negatives were culture positive. In total 41.4% (361/872) participants were infected with mycobacteria, of which 44.3% (160/361) were culture negative and 55.7% (201/361) were culture positive. The culture positives yielded 92.5% M. tuberculosis complexand 7.5% NTM. The overall prevalence of the NTM disease was 1.72% (15/872).                                                                            Conclusion: A low prevalence of NT M pulmonary disease in western Kenya is reported in this study, but some the NTM disease cases could have been misdiagnosed as TB cases

A high rate of recurrent tuberculosis in western Kenya independent of human immunodeficiency virus infection

Background: Previous studies have shown that recurrent TB develops in about 2-5% of the patients after curative treatment with short-course anti-TB chemotherapy. With the advent of HIV/AIDS, the rate TB recurrence is anticipated to rise. Objectives: To determine whether HIV infection and TB recurrence are associated with anti-TB drug resistance and the rates of ZN microscopy and culture positivity among the recurrent TB cases in western Kenya. Design and methods: A cross-sectional study was carried out between 2007 and 2009. Sputa from 872 tuberculosis suspects underwent mycobacteriologic evaluation using Ziehl Neelsen smear microscopy, LowensteinJensen and BACTEC MGIT 960 culturing, and Hain’s GenoType® Mycobacterium CM and GenoType® Mycobacterium AS molecular identification tests. Consenting participants were screened for HIV infection using Uni-Gold TM test and positives were confirmed with the enzyme linked immunosorbent assay. Results: In total, 361/872 (41%) of the suspects mycobacterial disease (346 TB, 4.2% non-tuberculous mycobacterial disease). HIV testing was accepted by 695 (79.7%) and 39.1% of these (272/695) were found positive. Recurrence of TB constituted 44.8% (155/346) of the TB cases, with 41.9% (65/155) of them co-infected with HIV. There was nosignificant difference in TB recurrence rates with HIV status [OR = 0.57; 95% CI: 0.29-1.13; P = 0.10]. Conclusions and recommendations: This study reports a much higher (44.8%) rate of recurrent TB, compared to that of National TB control Programme of 5% in 2008 and a combined retreatment rate of 14% in 2009. The HIV co-infection and TB recurrence were not associated with anti-TB drug resistance. The majority of TB recurrent cases were ZN smear negative (67.7%) and culture negative (80%). The high TB recurrence observed in this study calls for studies to determine the proportions of the disease attributable to endogenous re-activation (relapse) and exogenous re-infection. Keywords: Recurrent tuberculosis; HIV co-infectio

Switch from 200 to 350 CD4 baseline count: what it means to HIV care and treatment programs in Kenya

Introduction: With the increasing population of infected individuals in Africa and constrained resources for care and treatment, antiretroviralmanagement continues to be an important public health challenge. Since the announcement of World Health Organization recommendation andguidelines for initiation of antiretroviral Treatment at CD4 count below 350, many developing countries are adopting this strategy in their countryspecific guidelines to care and treatment of HIV and AIDS. Despite the benefits to these recommendations, what does this switch from 200 to 350CD4 count mean in antiretroviral treatment demand? Methods: A Multi-centre study involving 1376 patients in health care settings in Kenya. CD4count was carried out by flow cytometry among the HIV infected individuals in Kenya and results analyzed in view of the In-country and the newCD4 recommendation for initiation of antiretroviral treatment. Results: Across sites, 32% of the individual required antiretroviral at <200 CD4Baseline, 40% at <250 baseline count and 58% based on the new criteria of <350 CD4 Count. There were more female (68%) than Male(32%).Different from <200 and <250 CD4 baseline criteria, over 50% of all age groups required antiretroviral at 350 CD4 baseline. Age groupsbetween 41-62 led in demand for ART. Conclusion: With the new guidelines, demand for ARVs has more than doubled with variations notedwithin regions and age groups. As A result, HIV Care and Treatment Programs should prepare for this expansion for the benefits to be realized.Key words: CD4, New criteria, HIV, AIDS, care and treatment, ARV initiatio

MATERNAL IMMUNE RESPONSES AND RISK OF INFANT INFECTION WITH HIV-1 AFTER A SHORT COURSE ZIDOVUDINE IN A COHORT OF HIV-1 INFECTED PREGNANT WOMEN IN RURAL KENYA

Objective: To investigate the effects of short-course nucleoside reverse transcriptaseinhibitor (Zidovudine, ZDW/AZT) on maternal immune responses and risk of infantinfection with HIV-1 among rural-based mothers in western Kenya.Design: A prospective cohort study involving HIV-1 seropositive pregnant mothers andtheir infants.Subjects: One hundred and seven HIV-1 seropositive asymptomatic pregnant womenand their infants.Methods: After informed consent, the women were enrolled at gestation age between16-24 weeks. For cultural and economic reasons, all mothers were allowed to breastfeed their infants. Short-course antepartum regime of AZT was administered to allmothers starting at 36 weeks gestation until start of labour. Maternal absolute CD4+T cell subset assays were performed before 3rd trimester (about 36 weeks gestation)and after a 4-week therapy of AZT (at least one month post-nuptially). Infant HIV-1 status was determined by HIV-1 DNA polymerase chain reaction (PCR) on samplessequentially taken at 1, 2, 3, 4, 6 and 9 months and confirmed by serology at 18 monthsof age.Interventions: Antepartum short-course orally administered AZT: 300mg twice-dailystarting at 36 weeks gestation until start of labour, 300mg at labour onset and 300mgevery three hours during labour until delivery.Main Outcome Measures: Maternal CD4+ T cell counts before and after AZT treatment.Determination of infant HIV-1 infection status.Results: Among 107 women sampled, only 59 received full dose of AZT and thus qualifiedfor present analysis. Of these, 12 infected their children with HIV, while 47 did not.Comparison of CD4+ T cells before and after AZT treatment scored a significant risein all mothers (P = 0.01). This increase in CD4+ T cells was not significant amongmothers who infected their infants with HIV-1 (P = 0.474). However, a significant risein CD4+ T cells following AZT therapy was observed only in mothers who did nottransmit HIV-1 to their infants (P=0.014).Conclusion: These data suggest that a rise in the CD4+ T cell counts following shortAZT regimen, now widely in use in resource-weak countries, may be evidence of theactive suppression of the replication of HIV. However, further studies to examine themulti-factorial effect of CD4+ lymphocytes and pregnancy on MTCT of HIV need tobe carried out to help fully explain the effect of AZT on immune response and whetherthe CD4+T cell count can be used as a true test of immunological normalisation duringantiretroviral therapy

Role of apoptosis-inducing factor (AIF) in programmed nuclear death during conjugation in Tetrahymena thermophila

<p>Abstract</p> <p>Background</p> <p>Programmed nuclear death (PND), which is also referred to as nuclear apoptosis, is a remarkable process that occurs in ciliates during sexual reproduction (conjugation). In <it>Tetrahymena thermophila</it>, when the new macronucleus differentiates, the parental macronucleus is selectively eliminated from the cytoplasm of the progeny, concomitant with apoptotic nuclear events. However, the molecular mechanisms underlying these events are not well understood. The parental macronucleus is engulfed by a large autophagosome, which contains numerous mitochondria that have lost their membrane potential. In animals, mitochondrial depolarization precedes apoptotic cell death, which involves DNA fragmentation and subsequent nuclear degradation.</p> <p>Results</p> <p>We focused on the role of mitochondrial apoptosis-inducing factor (AIF) during PND in <it>Tetrahymena</it>. The disruption of <it>AIF </it>delays the normal progression of PND, specifically, nuclear condensation and kilobase-size DNA fragmentation. AIF is localized in <it>Tetrahymena </it>mitochondria and is released into the macronucleus prior to nuclear condensation. In addition, AIF associates and co-operates with the mitochondrial DNase to facilitate the degradation of kilobase-size DNA, which is followed by oligonucleosome-size DNA laddering.</p> <p>Conclusions</p> <p>Our results suggest that <it>Tetrahymena </it>AIF plays an important role in the degradation of DNA at an early stage of PND, which supports the notion that the mitochondrion-initiated apoptotic DNA degradation pathway is widely conserved among eukaryotes.</p