Robert Downing

Rapid Diagnosis of Ebola Hemorrhagic Fever by Reverse Transcription-PCR in an Outbreak Setting and Assessment of Patient Viral Load as a Predictor of Outcome

ABSTRACT The largest outbreak on record of Ebola hemorrhagic fever (EHF) occurred in Uganda from August 2000 to January 2001. The outbreak was centered in the Gulu district of northern Uganda, with secondary transmission to other districts. After the initial diagnosis of Sudan ebolavirus by the National Institute for Virology in Johannesburg, South Africa, a temporary diagnostic laboratory was established within the Gulu district at St. Marys Lacor Hospital. The laboratory used antigen capture and reverse transcription-PCR (RT-PCR) to diagnose Sudan ebolavirus infection in suspect patients. The RT-PCR and antigen-capture diagnostic assays proved very effective for detecting ebolavirus in patient serum, plasma, and whole blood. In samples collected very early in the course of infection, the RT-PCR assay could detect ebolavirus 24 to 48 h prior to detection by antigen capture. More than 1,000 blood samples were collected, with multiple samples obtained from many patients throughout the course of infection. Real-time quantitative RT-PCR was used to determine the viral load in multiple samples from patients with fatal and nonfatal cases, and these data were correlated with the disease outcome. RNA copy levels in patients who died averaged 2 log10 higher than those in patients who survived. Using clinical material from multiple EHF patients, we sequenced the variable region of the glycoprotein. This Sudan ebolavirus strain was not derived from either the earlier Boniface (1976) or Maleo (1979) strain, but it shares a common ancestor with both. Furthermore, both sequence and epidemiologic data are consistent with the outbreak having originated from a single introduction into the human population.

Newly discovered Ebola virus associated with hemorrhagic fever outbreak in Uganda

Over the past 30 years, Zaire and Sudan ebolaviruses have been responsible for large hemorrhagic fever (HF) outbreaks with case fatalities ranging from 53% to 90%, while a third species, Côte dIvoire ebolavirus, caused a single non-fatal HF case. In November 2007, HF cases were reported in Bundibugyo District, Western Uganda. Laboratory investigation of the initial 29 suspect-case blood specimens by classic methods (antigen capture, IgM and IgG ELISA) and a recently developed random-primed pyrosequencing approach quickly identified this to be an Ebola HF outbreak associated with a newly discovered ebolavirus species (Bundibugyo ebolavirus) distantly related to the Côte dIvoire ebolavirus found in western Africa. Due to the sequence divergence of this new virus relative to all previously recognized ebolaviruses, these findings have important implications for design of future diagnostic assays to monitor Ebola HF disease in humans and animals, and ongoing efforts to develop effective antivirals and vaccines.

Assessment of a pilot antiretroviral drug therapy programme in Uganda: patients' response, survival, and drug resistance

BACKGROUNDnLittle is known about how to implement antiretroviral treatment programmes in resource-limited countries. We assessed the UNAIDS/Uganda Ministry of Health HIV Drug Access Initiative--one of the first pilot antiretroviral programmes in Africa--in which patients paid for their medications at negotiated reduced prices.nnnMETHODSnWe assessed patients clinical and laboratory information from August, 1998, to July, 2000, from three of the five accredited treatment centres in Uganda, and tested a subset of specimens for phenotypic drug resistance.nnnFINDINGSn912 patients presented for care at five treatment centres. We assessed the care of 476 patients at three centres, of whom 399 started antiretroviral therapy. 204 (51%) received highly active antiretroviral therapy (HAART), 189 (47%) dual nucleoside reverse transcriptase inhibitors (2NRTI), and six (2%) NRTI monotherapy. Median baseline CD4 cell counts were 73 cells/microL (IQR 15-187); viral load was 193817 copies/mL (37013-651 716). The probability of remaining alive and in care was 0.63 (95% CI 0.58-0.67) at 6 months and 0.49 (0.43-0.55) at 1 year. Patients receiving HAART had greater virological responses than those receiving 2NRTI. Coxs proportional hazards models adjusted for viral load and regimen showed that a CD4 cell count of less than 50 cells/microL (vs 50 cells/microL or more) was strongly associated with death (hazard ratio 2.93 [1.51-5.68], p=0.001). Among 82 patients with a viral load of more than 1000 copies/mL more than 90 days into therapy, phenotypic resistance to NRTIs was found for 47 (57%): 29 of 37 (78%) who never received HAART versus 18 of 45 (40%) who received HAART (p=0.0005).nnnINTERPRETATIONnThis pilot programme successfully expanded access to antiretroviral drugs in Uganda. Identification and treatment of patients earlier in the course of their illness and increased use of HAART could improve probability of survival and decrease drug resistance.

Population-Based Hematologic and Immunologic Reference Values for a Healthy Ugandan Population

ABSTRACT To assess the validity of the reference values for hematologic and immunologic indices currently used in Africa, we evaluated blood samples from 3,311 human immunodeficiency virus (HIV)-negative Ugandans aged 1 week to 92 years. Erythrocyte, hemoglobin, and hematocrit levels and mean corpuscular volume all significantly increased with age (P < 0.001) and were independent of gender until the age of 13 years, after which the levels were higher in males than in females (P < 0.001). White blood cell, neutrophil, lymphocyte, basophil, and monocyte counts significantly declined with age until the age of 13 years (P < 0.001), with no differences by gender, while platelet counts declined with age (P < 0.001) and showed differences by gender only among adults older than age 24 years. CD4+- and CD8+-cell counts declined with age until the age of 18 years; thereafter, females had higher counts than males. The absolute values for many of these parameters differed from those reported for populations outside Africa, suggesting that it may be necessary to develop tables of reference values for hematologic and immunologic indices specific for the African population. This may be particularly important with regard to CD4+-cell counts among children because significant differences in absolute and percent CD4+-cell counts exist between the values for Western populations and the values for the population evaluated in our study. These differences could influence the decision to initiate antiretroviral therapy among children infected with HIV.

Undiagnosed HIV infection and couple HIV discordance among household members of HIV-infected people receiving antiretroviral therapy in Uganda.

Introduction: Systematic efforts to identify HIV-infected members and HIV-discordant couples in households of individuals taking antiretroviral therapy (ART) could theoretically reduce HIV transmission and improve ART adherence. Methods: We enrolled HIV-infected clients of an AIDS support organization in a randomized evaluation of different ART monitoring regimens that offered home-based ART care to them and their clinically eligible household members. At baseline, counselors visited participants homes and offered voluntary counseling and testing (VCT) to all household members. We assessed uptake, HIV prevalence, HIV discordance, and rate of ART eligibility. Results: Of the 2373 household members, 2348 (99%) accepted VCT. HIV prevalence among household members was 7.5% and varied by age with 9.5% among children aged 0 to 5 years, 2.9% among persons aged 6 to 24 years, and 37.1% among adults aged 25 to 44 years. Of the household members with HIV, 74% had never been previously tested, and 39% of these were clinically eligible for ART. Of the 120 spouses of ART patients that were tested for HIV, 52 (43%) were HIV negative, and of these, 99% had not been previously tested. Conclusions: Provision of home-based VCT to household members of people initiating ART was well accepted and resulted in the detection of a large number of previously undiagnosed HIV infections and HIV-discordant relationships.

Herpesvirus-like DNA sequences detected in endemic, classic, iatrogenic and epidemic Kaposi's sarcoma (KS) biopsies

The identification of Kaposis sarcoma (KS) clusters in subequatorial Africa (endemic KS, AKS) and the high frequency of KS in sexually transmitted AIDS (epidemic KS, EKS), have previously suggested a role for infectious agents in the etiopathogenesis of KS. The recent identification of herpesvirus (HHV)‐like DNA sequences in one case of EKS and their detection in >90% of all tested EKS, prompted us to determine the prevalence of these viral sequences in all types of KS, such as AKS, EKS, classic KS (CKS) and iatrogenic KS (IKS). The presence of herpesvirus (HHV)‐like DNA sequences has been examined in 61 KS skin tumors obtained from Greece, Italy, USA, Uganda and Kenya. All KS types (100%) were positive by polymerase chain reaction (PCR) and Southern‐blot analysis, while 5 out of 6 (83%) and 4 out of 7 (57%) uninvolved autologous skin biopsies from AKS and CKS patients, respectively, were positive for HHV‐like sequences. All samples from non‐KS patients were negative, i.e. 17 human biopsies from healthy individuals or patients affected by other pathologies, 5 human cell lines and 15 peripheral blood mononuclear cells (PBMC) from HIV‐positive subjects. These results suggest that HHV‐like sequences play a major role in the pathogenesis of this neoplasm.

Breastfeeding, mother-to-child HIV transmission, and mortality among infants born to HIV-Infected women on highly active antiretroviral therapy in rural Uganda.

Background:Highly active antiretroviral therapy (HAART) drastically reduces mother-to-child transmission of HIV, but where breastfeeding is the only safe infant feeding option, HAART for the prevention of mother-to-child transmission needs to be evaluated in relation to both HIV transmission and infant mortality. Design and Methods:One hundred and two ≥18-year old women on HAART in rural Uganda who delivered one or more live infants between March 1, 2003 and January 1, 2007 were enrolled in a prospective study to assess HIV transmission and infant survival. All pregnant women were counseled to exclusively breastfeed for 3-6 months according to national guidelines at the time. Infants were followed-up for ≥7 months and were offered HIV polymerase chain reaction testing quarterly from 6 weeks of age until ≥6 weeks after complete weaning. Results:Of 118 infants born during follow-up, 109 (92%) were breastfed. Median durations of exclusive and total breastfeeding were 4 months (interquartile range 3-6) and 5 months (interquartile range 3-7), respectively. None of the infants tested HIV polymerase chain reaction positive over follow-up but 16 infants died without a definitive HIV status at a median age of 2.6 months. In total, 23 (19%) infants died during follow-up at a median age of 3.7 months; 15 (65%) of whom with severe diarrhea and/or vomiting in the week preceding their death. In multivariate analysis, there was a 6-fold greater risk of death among infants breastfed for less than 6 months independent of maternal CD4 count closest to delivery, maternal marital status or maternal death (adjusted hazard ratio = 6.19; 95% confidence interval 1.41-27.0, P = 0.015). Conclusions:In resource-constrained settings, HIV-infected pregnant women should be assessed for HAART eligibility and treated as needed without delay, and should be encouraged to breastfeed their infants for at least 6 months.

Optimizing the delivery of HIV counseling and testing services : The Uganda experience using rapid HIV antibody test algorithms

The AIDS Information Center (AIC) was established in Kampala, Uganda in 1990 in response to increasing interest by members of the general public who wished to know their HIV serostatus. By 1996, >300,000 clients had been seen. HIV serologic testing was performed at a central laboratory and results reported back to AIC after 2 weeks. Approximately 25% of clients failed to learn their HIV serostatus as a result of failure to return or late arrival of results. To address these issues, AIC carried out an evaluation of 3 rapid HIV assays, Sero-Strip, SeroCard, and Capillus, against a standard criterion to identify a testing algorithm that could be used as an on-site confirmatory testing strategy. The study was carried out over a period of 5 working days and 325 clients were seen. An algorithm was identified, which gave no indeterminate results with unambiguously positive or negative specimens, which was 100% sensitive and specific, and which could be integrated with minimal disruption into existing counseling procedures. All clients left AIC knowing their HIV serostatus and having spent <2 hours at the Center. The results of this evaluation demonstrate that same-day results can be provided in counseling and testing settings without compromising the quality of counseling or the accuracy of HIV testing.

Severe malnutrition with and without HIV-1 infection in hospitalised children in Kampala, Uganda: differences in clinical features, haematological findings and CD4 + cell counts

BackgroundThe aim of this study was to describe the clinical features, haematological findings and CD4+ and CD8+ cell counts of severely malnourished children in relation to human immunodeficiency virus (HIV) infection.MethodsThe study was conducted in the paediatric wards of Mulago hospital, which is Ugandas national referral and teaching hospital. We studied 315 severely malnourished children (presence of oedema and/or weight-for-height: z-score < -3) and have presented our findings. At admission, the CD4+ and CD8+ cells were measured by the flow cytometry and HIV serology was confirmed by Enzyme linked Immunoassay for children >18 months of age, and RNA PCR was performed for those ≤18 months. Complete blood count, including differential counts, was determined using a Beckman Coulter counter.ResultsAmong the 315 children, 119 (38%) were female; the median age of these children was 17 months (Interquartile range 12–24 months), and no difference was observed in the HIV status with regard to gender or age. The children showed a high prevalence of infections: pneumonia (68%), diarrhoea (38%), urinary tract infection (26%) and bacteraemia (18%), with no significant difference with regard to the HIV status (HIV-positive versus HIV-negative children). However, the HIV-positive children were more likely to have persistent diarrhoea than the HIV-uninfected severely malnourished children (odds ratio (OR) 2.0, 95% confidence interval (CI) 1.2–3.6). When compared with the HIV-negative children, the HIV-positive children showed a significantly lower median white blood cell count (10700 versus 8700) and lymphocyte count (4033 versus 2687). The CD4+ cell percentages were more likely to be lower in children with non-oedematous malnutrition than in those with oedematous malnutrition even after controlling for the HIV infection.The novel observation of this study is that the CD4+ percentages in both HIV-positive and HIV-negative children without oedema were lower that those in children with oedema. These observations appear to imply that the development of oedema requires a certain degree of immunocompetence, which is an interesting clue to the pathophysiology of oedema in severe malnutrition.

A molecular epidemiologic survey of HIV in Uganda.

Objective:Previous data, based on a small sampling of convenience, reported subtypes A, B, C, D, and G in Uganda, but neither the extent nor the proportion of these subtypes could be evaluated. To establish correctly the prevalence and distribution of HIV-1 subtypes, we analysed viral clades in 739 HIV-1-seropositive specimens from different areas of Uganda. Methods:Blood specimens from 1100 patients were collected in five districts of Uganda. Within this collection, 929 HIV-1-seroreactive samples underwent analysis of viral DNA, and 739 were selected for further subtyping in env or pol regions. Results:Using a combination of subtype A- and D-specific probes to C2–V3 region and DNA sequencing, HIV-1 env subtypes were determined in 594 specimens: 341 were of subtype A (57.4%), 250 of subtype D (42.1%), and three of subtype C (0.5%). Sixty-two samples showed reactivity with both probes, suggesting potential mixed infections, cross-reactivity to probes, or possibly other subtypes. Subsequent sequence analysis of 19 randomly selected specimens revealed subtypes A (n = 4), D (n = 12), and C (n = 3). Sequence analysis of the 27 samples chosen from the remaining 83 samples, which could be amplified only with viral gp41 or protease gene primers, classified them as subtypes A (n = 13) and D (n = 14). No significant clinical, demographic, or geographic differences were found between HIV-1 infections with viruses of subtypes A and D, despite considerable genetic diversity within these clades. Conclusions:This is the first major population-based study of the prevalent HIV-1 strains in an African country selected for vaccine trials. The subtyping methods we describe should be of use to investigators seeking to conduct large-scale screening for HIV variants in other populations.