Field Epidemiology and Laboratory Training Program, Where Is the L-Track?

Background: Modifications of the Field Epidemiology Training Program (FETP) curricula to include a laboratory track (L-Track), to become Field Epidemiology and Laboratory Training Program (FELTP), began in 2004 in Kenya. The L-Track offered candidates training on laboratory competencies in management, policy, quality systems, and diagnostic methods as well as epidemiology, disease surveillance and outbreak response. Since then several FELTPs have discontinued the L-Track and instead offer all candidates, epidemiologists and laboratorians, a single FETP curriculum. Reasons for these changes are reported here.

Methods: A questionnaire was sent to directors of 13 FELTP programs collecting information on the status of the programs, reasons for any changes, basic entry qualifications, source institutions and where residents were post enrollment or after graduation. Data from previous CDC internal assessments on FELTP L-Track was also reviewed.

Results: Out of the 13 FELTPs included, directors from 10 FELTPs sent back information on their specific programs. The FELTPs in Kenya, Mozambique, Cameroon and Kazakhstan and Mali have discontinued a separate L-Track while those in Ghana, Georgia, Nigeria, Rwanda, and Tanzania continue to offer the separate L-Track. Reasons for discontinuation included lack of standardized curriculum, unclear strategies of the separate L-Track, and funding constraints. Two countries Kenya and Tanzania reported on the career progression of their graduates. Results show 84% (Kenya) and 51% (Tanzania) of candidates in the FELTP, L-Track were recruited from national/regional medical health laboratories. However post-graduation, 56% (Kenya) and 43% (Tanzania) were working as epidemiologists, program managers, program coordinators, or regulatory/inspection boards. Professional upward mobility was high; 87% (Kenya) and 73% (Tanzania) residents, reported promotions either in the same or in new institutions.

Conclusions: The FELTP L-Track residents continue to offer critical contributions to public health workforce development with high upward mobility. While this may be a reflection of professional versatility and demand of the FELTP graduates, the move from core laboratory services underscores the challenges in filling and retaining qualified staff within the laboratory systems. Results suggest different strategies are needed to strengthen laboratory management and leadership programs with a clear focus on laboratory systems and laboratory networks to meet current and future clinical and public health laboratory workforce demands.

Nanopore Sequencing as a Rapidly Deployable Ebola Outbreak Tool

Rapid sequencing of RNA/DNA from pathogen samples obtained during disease outbreaks provides critical scientific and public health information. However, challenges exist for exporting samples to laboratories or establishing conventional sequencers in remote outbreak regions. We successfully used a novel, pocket-sized nanopore sequencer at a field diagnostic laboratory in Liberia during the current Ebola virus outbreak.

The Merits of Malaria Diagnostics during an Ebola Virus Disease Outbreak

Malaria is a major public health concern in the countries affected by the Ebola virus disease epidemic in West Africa. We determined the feasibility of using molecular malaria diagnostics during an Ebola virus disease outbreak and report the incidence of Plasmodium spp. parasitemia in persons with suspected Ebola virus infection.

Ebola Laboratory Response at the Eternal Love Winning Africa Campus, Monrovia, Liberia, 2014-2015

West Africa experienced the first epidemic of Ebola virus infection, with by far the greatest number of cases in Guinea, Sierra Leone, and Liberia. The unprecedented epidemic triggered an unparalleled response, including the deployment of multiple Ebola treatment units and mobile/field diagnostic laboratories. The National Institute of Allergy and Infectious Diseases and the Centers for Disease Control and Prevention deployed a joint laboratory to Monrovia, Liberia, in August 2014 to support the newly founded Ebola treatment unit at the Eternal Love Winning Africa (ELWA) campus. The laboratory operated initially out of a tent structure but quickly moved into a fixed-wall building owing to severe weather conditions, the need for increased security, and the high sample volume. Until May 2015, when the laboratory closed, the site handled close to 6000 clinical specimens for Ebola virus diagnosis and supported the medical staff in case patient management. Laboratory operation and safety, as well as Ebola virus diagnostic assays, are described and discussed; in addition, lessons learned for future deployments are reviewed.

Ebola Virus Diagnostics: The US Centers for Disease Control and Prevention Laboratory in Sierra Leone, August 2014 to March 2015

In August 2014, the Viral Special Pathogens Branch of the US Centers for Disease Control and Prevention established a field laboratory in Sierra Leone in response to the ongoing Ebola virus outbreak. Through March 2015, this laboratory tested >12 000 specimens from throughout Sierra Leone. We describe the organization and procedures of the laboratory located in Bo, Sierra Leone.

Clinical inquiries regarding Ebola virus disease received by CDC--United States, July 9-November 15, 2014

Since early 2014, there have been more than 6,000 reported deaths from Ebola virus disease (Ebola), mostly in Guinea, Liberia, and Sierra Leone. On July 9, 2014, CDC activated its Emergency Operations Center for the Ebola outbreak response and formalized the consultation service it had been providing to assist state and local public health officials and health care providers evaluate persons in the United States thought to be at risk for Ebola. During July 9-November 15, CDC responded to clinical inquiries from public health officials and health care providers from 49 states and the District of Columbia regarding 650 persons thought to be at risk. Among these, 118 (18%) had initial signs or symptoms consistent with Ebola and epidemiologic risk factors placing them at risk for infection, thereby meeting the definition of persons under investigation (PUIs). Testing was not always performed for PUIs because alternative diagnoses were made or symptoms resolved. In total, 61 (9%) persons were tested for Ebola virus, and four, all of whom met PUI criteria, had laboratory-confirmed Ebola. Overall, 490 (75%) inquiries concerned persons who had neither traveled to an Ebola-affected country nor had contact with an Ebola patient. Appropriate medical evaluation and treatment for other conditions were noted in some instances to have been delayed while a person was undergoing evaluation for Ebola. Evaluating and managing persons who might have Ebola is one component of the overall approach to domestic surveillance, the goal of which is to rapidly identify and isolate Ebola patients so that they receive appropriate medical care and secondary transmission is prevented. Health care providers should remain vigilant and consult their local and state health departments and CDC when assessing ill travelers from Ebola-affected countries. Most of these persons do not have Ebola; prompt diagnostic assessments, laboratory testing, and provision of appropriate care for other conditions are essential for appropriate patient care and reflect hospital preparedness.

Recombinant viruses initiated the early HIV-1 epidemic in Burkina Faso

We analyzed genetic diversity and phylogenetic relationships among 124 HIV-1 and 19 HIV-2 strains in sera collected in 1986 from patients of the state hospital in Ouagadougou, Burkina Faso. Phylogenetic analysis of the HIV-1 env gp41 region of 65 sequences characterized 37 (56.9%) as CRF06_cpx strains, 25 (38.5%) as CRF02_AG, 2 (3.1%) as CRF09_cpx, and 1 (1.5%) as subtype A. Similarly, phylogenetic analysis of the protease (PR) gene region of 73 sequences identified 52 (71.2%) as CRF06_cpx, 15 (20.5%) as CRF02_AG, 5 (6.8%) as subtype A, and 1 (1.4%) was a unique strain that clustered along the B/D lineage but basal to the node connecting the two lineages. HIV-2 PR or integrase (INT) groups A (n = 17 [89.5%]) and B (n = 2 [10.5%]) were found in both monotypic (n = 11) and heterotypic HIV-1/HIV-2 (n = 8) infections, with few HIV-2 group B infections. Based on limited available sampling, evidence suggests two recombinant viruses, CRF06_cpx and CRF02_AG, appear to have driven the beginning of the mid-1980s HIV-1 epidemic in Burkina Faso.

HIV-2 protease sequences of subtypes A and B harbor multiple mutations associated with protease inhibitor resistance in HIV-1

BACKGROUND

HIV-1 protease inhibitors (PI) have been used for treating HIV-2-infected persons but little is known about amino acid mutations associated with PI resistance in HIV-2 and whether they are similar to those seen in HIV-1.

OBJECTIVE

To determine the frequency of HIV-1 PI resistance-associated mutations in PI-naive HIV-2-infected individuals.

DESIGN

Using PCR, protease genes were amplified from 76 individuals, directly sequenced, phylogenetically subtyped, and translated into amino acids to analyze PI-associated major and minor mutations.

RESULTS

Of the 76 HIV-2 sequences, 68% belonged to subtype A and 32% to subtype B. All sequences contained at least four codon changes giving substitutions at 10, 30, 32, 36, 46, 47, 71 or 77. The frequency of these mutations was similar in subtype A and B viruses. Two major resistance-conferring mutations, 30N and 46I, were identified in one (1%) and 68 (89%) specimens, respectively. Minor mutations 10V/I, 32I, 36I, 47V, and 71V were predominant (89%-100%), followed by the rare mutation 77I (1%). Of the 76 strains, 89% harbored multiple PI resistance-associated substitutions comprising both the major 46I and minor mutations: 10V/I, 32I, 36I, 46I, 47V, 71V (76%); 10V, 32I, 36I, 46I, 47V (9%); and 10V, 32I, 36I, 46I, 47V 71V, 77I (1.3%), 10V, 32I, 46I, 47V, 71V (1.3%), and 10V, 30N, 32I, 36I, 46I, 47V, 71V (1.3%). The remaining 11% of the sequences had patterns with only minor mutations: 10V, 32I, 36I, 47V, 71V (9%) and 10V, 32I, 36I, 47V (1.3%).

CONCLUSIONS

The high frequency of multiple PI-associated substitutions represent natural polymorphisms occurring in HIV-2 strains of subtypes A and B. Phenotypic and clinical studies are needed to determine the relevance of these substitutions.

Human immunodeficiency virus type 1 group m protease in cameroon: genetic diversity and protease inhibitor mutational features

To establish a baseline for monitoring resistance to protease inhibitors (PIs) and examining the efficacy of their use among persons in Cameroon infected with human immunodeficiency virus type 1 (HIV-1), we analyzed genetic variability and PI resistance-associated substitutions in PCR-amplified protease (PR) sequences in strains isolated from 110 HIV-1-infected, drug-naïve Cameroonians. Of the 110 strains, 85 were classified into six HIV-1 PR subtypes, A (n = 1), B (n = 1), F (n = 4), G (n = 7), H (n = 1), and J (n = 7), and a circulating recombinant form, CRF02-AG (n = 64). PR genes from the remaining 25 (23%) specimens were unclassifiable, whereas 2% (7 of 301) unclassifiable PR sequences were reported for a global collection. Two major PI resistance-associated mutations, 20M and 24I, were detected in strains from only two specimens, whereas secondary mutations were found in strains from all samples except one strain of subtype B and two strains of CRF02-AG. The secondary mutations showed the typical PI resistance-associated pattern for non-subtype B viruses in both classifiable and unclassifiable PR genes, with 36I being the predominant (99%) mutation, followed by 63P (18%), 20R (15%), 77I (13%), and 10I or 10V (11%). Of these mutations, dual and triple PI resistance-associated substitutions were found in 38% of all the Cameroonian strains. Compared with classifiable PR sequences, unclassifiable sequences had significantly more dual and triple substitutions (64% versus 30%; P = 0.004). Phenotypic and clinical evaluations are needed to estimate whether PI resistance during antiretroviral drug treatment occurs more rapidly in individuals infected with HIV-1 strains harboring multiple PI resistance-associated substitutions. This information may be important for determination of appropriate drug therapies for HIV-1-infected persons in Cameroon, where more than one-third of HIV-1 strains were found to carry dual and triple minor PI resistance-associated mutations.

Presence of diverse human immunodeficiency virus type 1 viral variants in Cameroon

Phylogenetic analysis of the gp41 region of 123 HIV-1-seropositive specimens from Cameroon showed that 89 were subtype A (71% of these sequences were IbNg-like), 12 (10%) were subtype D, 11 (9%) were subtype G, 5 (4%; closely related to subtype F2) were subtype F, 1 was subtype H, 2 (1.6%) remained unclassifiable, while 3 were group O. Further analysis of the two unclassifiable specimens in gag(p24), pol(prot), and env (C2V3 or gp41) showed that one (98CM19) was a complex mosaic between subtype A in p24 and subtype J prot, and unclassifiable in env (C2V3 or gp41). The second, 98CM63, clustered distinctly from all known subtypes in p24, prot, C2V3, or gp41. 98CM63 clustered with a specimen from Cyprus and these two geographically and epidemiologically unlinked specimens, with their distinct clustering pattern, may represent a new subcluster of subtype A. In conclusion, these findings confirm the high HIV-1 genetic variability and further suggest the continuous appearance of new viral strains in this population.

Protease sequences from HIV-1 group M subtypes A-H reveal distinct amino acid mutation patterns associated with protease resistance in protease inhibitor-naive individuals worldwide. HIV Variant Working Group

BACKGROUND

Although numerous mutations that confer resistance to protease inhibitors (PRI) have been mapped for HIV-1 subtype B, little is known about such substitutions for the non-B viruses, which globally cause the most infections.

OBJECTIVES

To determine the prevalence of PRI-associated mutations in PRI-naive individuals worldwide.

DESIGN

Using the polymerase chain reaction, protease sequences were amplified from 301 individuals infected with HIV-1 subtypes A (79), B (95), B' (19), C (12), D (26), A/E (23), F (26), A/G (11), and H (3) and unclassifiable HIV-1 (7). Amplified DNA was directly sequenced and translated to amino acids to analyze PRI-associated major and accessory mutations.

RESULTS

Of the 301 sequences, 85% contained at least one codon change giving substitution at 10, 20, 30, 36, 46, 63, 71, 77, or 82 associated with PRI resistance; the frequency of these substitutions was higher among non-B (91%) than B (75%) viruses (P < 0.0005). Of these, 25% carried dual and triple substitutions. Two major drug resistance-conferring mutations, either 20M or 30N, were identified in only three specimens, whereas drug resistance accessory mutations were found in 252 isolates. These mutations gave distinct prevalence patterns for subtype B, 63P (62%) > 77I (19%) > 10I/V/R (6%) = 361 (6%) = 71T/V (6%) > 20R (2%), and non-B strains, 36I (83%) > 63P (17%) > 10I/V/R (13%) > 20R (10%) > 77I (2%), which differed statistically at positions 20, 36, 63, 71, and 77.

CONCLUSIONS

The high prevalence of PRI-associated substitutions represent natural polymorphisms occurring in PRI-naive patients infected with HIV-1 strains of subtypes A-H. The significance of distinct mutation patterns identified for subtype B and non-B strains warrants further clinical evaluation. A global HIV-1 protease database is fundamental for the investigation of novel PRI.

Distribution of HIV-1 subtypes among HIV-seropositive patients in the interior of Côte d'Ivoire

Limited data exist on the distribution of HIV-1 subtypes in Côte d'Ivoire. The aim of this study is to describe the distribution of genetic subtypes of HIV-1 strains in six regions of Côte d'Ivoire. In 1997, we consecutively collected blood from 172 HIV-1-infected patients from six regional tuberculosis treatment centers. Peripheral blood mononuclear cells (PBMCs) from these people were analyzed by a restriction fragment-length polymorphism (RFLP) assay that involves a sequential endonuclease digestion of a 297-base pair polymerase chain reaction (PCR) fragment; plasma samples were tested by a V3-loop peptide enzyme immunoassay (PEIA). DNA sequencing of the protease or env genes was performed on all samples discordant in the two assays as well as a random sample of the concordant subtyped samples. Of 172 specimens, 3 were PCR-negative, and 169 were putatively classified as subtype A by RFLP. The 3 PCR-negative samples were unequivocally subtyped A by PEIA. Of the 169 RFLP subtype A samples, 159 (94%) were subtyped A by PEIA. Of the 10 discordant samples, PEIA testing classified 3 as subtype C, 2 as D, and 5 as F. Sequencing of the env gene classified these samples as 1 subtype A, 4 Ds, and 5 Gs. Thus, 163 (95%) of the specimens were subtype A, 3 subtype D, 4 subtype G, 1 A/D, and 1 A/G (IbNG) circulating recombinant forms (CRF). In conclusion, most HIV-1-infected tuberculosis patients throughout the interior of Côte d'Ivoire are infected with HIV-1 subtype A, which are very likely the A/G (IbNG) CRF. The uniform distribution of this subtype makes Côte d'Ivoire a potential site for vaccine trials.

Quantification of RNA in HIV type 1 subtypes D and G by NucliSens and Amplicor assays in Abidjan, Ivory Coast

We have compared the performance of the NucliSens and the standard and modified HIV Monitor assays to quantify HIV-1 RNA plasma viral load in 12 tuberculosis patients infected with HIV-1 env subtype D (n = 3) and env subtype G (n = 9) in Ivory Coast. RNA was quantified in all nine subtype G specimens by the modified Amplicor HIV Monitor (mean, 4.6 log10 copies/ml; range, 3.1-6.3 log10/ml), in seven specimens by NucliSens (mean, 4.4 log10 copies/ml; range, 2.7-5.5 log10 copies/ml), and in 6 specimens by the standard Amplicor HIV Monitor assay (mean, 4.2 log10 copies/ml; range, 3.5-5.0 log10 copies/ml). All three subtype D samples were amplified by both the modified Amplicor HIV Monitor (mean, 4.5 log10 copies/ml; range, 3.8-5.1 log10 copies/ml) and NucliSens (mean, 3.8 log10 copies/ml; range, 2.8-5.0 log10 copies/ml); two samples were quantified by the standard Amplicor HIV Monitor assay (mean, 3.0 log10 copies/ml; range, 2.4-3.6 log10 copies/ml). Our preliminary results suggest that the modified Amplicor HIV Monitor can accurately quantify HIV-1 RNA viral load in persons infected with subtype D and G strains.

HIV-1 subtypes among blood donors from Rio de Janeiro, Brazil

The prevalence of HIV infection in Brazil is one of the highest in the world. In addition, transfusion-transmitted HIV accounts for 2.3% of all AIDS cases in Brazil. The objective of this study was to evaluate genetic diversity and distribution of HIV-1 strains circulating in the blood-donor population. We characterized 43 seropositive blood units collected from volunteer blood donors residing throughout Rio de Janeiro, Brazil. Viral RNA was extracted from plasma, reverse transcribed, and amplified by nested polymerase chain reaction (PCR) using HIV group M degenerate primers. Genetic heterogeneity was evaluated by direct automated cycle sequencing of the following gene fragments: gag p24 (399 bp), env C2V3 (345 bp), and env gp41 (369 bp). Phylogenetic analysis reflected the complexity of the Brazilian HIV epidemic: the majority of specimens, 33 of 43 (76.7%) were subtype B, and 6 of 43 (14%) were subtype F. The remaining 4 samples (9.3%) involved potential mosaic viruses of subtypes B and F or B and D. This survey is the first to document HIV-1 genetic variation in the Brazilian blood-donor population.

Genetically divergent strains of human immunodeficiency virus type 2 use multiple coreceptors for viral entry

Several members of the seven-transmembrane chemokine receptor family have been shown to serve, with CD4, as coreceptors for entry by human immunodeficiency virus type 1 (HIV-1). While coreceptor usage by HIV-1 primary isolates has been studied by several groups, there is only limited information available concerning coreceptor usage by primary HIV-2 isolates. In this study, we have analyzed coreceptor usage of 15 primary HIV-2 isolates, using lymphocytes from a donor with nonfunctional CCR5 (CCR5 -/-; homozygous 32-bp deletion). Based on the infections of PBMCs, seven of these primary isolates had an absolute requirement for CCR5 expression, whereas the remaining eight exhibited a broader coreceptor usage. All CCR5-requiring isolates were non-syncytium inducing, whereas isolates utilizing multiple coreceptors were syncytium inducing. Blocking experiments using known ligands for chemokine receptors provided indirect evidence for additional coreceptor utilization by primary HIV-2 isolates. Analysis of GHOST4 cell lines expressing various chemokine receptors (CCR1, CCR2b, CCR3, CCR4, CCR5, CXCR4, BONZO, and BOB) further defined specific coreceptor usage of primary HIV-2 isolates. The receptors used included CXCR4, CCR1-5, and the recently described receptors BONZO and BOB. However, the efficiency at which the coreceptors were utilized varied greatly among the various isolates. Analysis of V3 envelope sequences revealed no specific motif that correlated with coreceptor usage. Our data demonstrate that primary HIV-2 isolates are capable of using a broad range of coreceptors for productive infection in vitro. Additionally, our data suggest that expanded coreceptor usage by HIV-2 may correlate with disease progression.

Presence of human immunodeficiency virus (HIV) type 1 subtype A infection in a New York community with high HIV prevalence: a sentinel site for monitoring HIV genetic diversity in North America. Centers for Disease Control and Prevention-Bronx Lebanon HIV Serosurvey Team

To determine whether US residents are infected with subtypes of human immunodeficiency virus (HIV) type 1 other than subtype B (Western), the predominant North American subtype with a unique GPGR genetic sequence in the V3 loop, viruses from 22 HIV-infected adults were serotyped and subtyped. Twenty patients had subtype B (Western), of whom 15 had serotype B (Western), 3 had serotype A/C, 1 had serotype B (Thai), and 1 had a nontypeable serotype. Two had subtype A, both serotype A/C. Both subtype A-infected patients, only 1 of whom had been outside the United States, reported sex with persons traveling abroad, suggesting possible acquisition in the United States. Because US residents are infected with non-subtype B (Western) strains, US surveillance for HIV-1 diversity is needed to elucidate subtype-specific transmission patterns and pathogenesis and to guide evaluation and development of HIV diagnostic tests and vaccines.

Absence of detectable antibody in a patient infected with human immunodeficiency virus

Infection with human immunodeficiency virus (HIV) is routinely and easily diagnosed with use of enzyme immunoassay (EIA) test kits. We describe an unusual patient who developed AIDS despite testing negative for antibodies to HIV 35 times over a 4-year period. HIV infection was confirmed by the results of p24-antigen assays and polymerase chain reaction amplification of proviral DNA. Sequence analysis of the virus demonstrated that it was closely related to a strain obtained from the patient's sexual partner. The explanation for this patient's persistently negative EIA results is unclear. However, this case does suggest that physicians who treat patients with AIDS-defining conditions but for whom standard HIV antibody testing is negative should consider the possibility that HIV infection is present and may be identified by additional testing procedures.

Detection of genetically diverse human immunodeficiency virus type 1 group M and O isolates by PCR

A panel of 136 genetically diverse group M and 5 group O adult isolates from outside the United States and Europe were evaluated by PCR with the Roche AMPLICOR HIV-1 test, a modified version of the AMPLICOR HIV-1 test, and a new primer pair/probe system. Detection of some of these isolates was less efficient with the AMPLICOR HIV-1 test; however, the assay was significantly improved by reducing the sample input and lowering the annealing temperature. The new primer pair/probe set detected 140 of 141 isolates, including the 5 group O isolates that were not detected with either of the AMPLICOR HIV-1 test formats.

Oligomeric nature of transmembrane glycoproteins of HIV-2: procedures for their efficient dissociation and preparation of Western blots for diagnosis

Western blot (WB) analysis of various strains of HIV-2 indicated that transmembrane glycoprotein (TMP) of HIV-2 exists as trimers. These trimers have molecular weights and electrophoretic mobilities in the region of the major external glycoprotein, gp120, resulting in WB misidentification during diagnosis. A simple and rapid procedure was developed using trichloroacetic acid (TCA) to efficiently dissociate oligomeric forms of the TMP to monomers prior to the preparation of WB. This procedure permitted the unambiguous identification of antibodies to gp120 and to the TMP. Use of HIV-2 WB strips without any oligomeric forms of the TMP demonstrated (1) that cross reactivity of HIV-1-positive specimens on HIV-2 WB was mainly directed to Gag and Pol proteins, with some reactivity to gp36/gp41 TMP, but none to gp120; (2) that these strips can substantially reduce the number of specimens falsely identified as dually (HIV-1 and HIV-2) reactive; and (3) that HIV-2-positive specimens reacted to viral gp120 in a strain-specific manner, demonstrating high antigenic variation in this glycoprotein. It is recommended that this general procedure of viral protein dissociation be used for HIV-2 WB preparation.

Isolation and characterization of human HSP70 expressed in Escherichia coli

A plasmid containing the human HSP70 gene was used to transfect and express the protein in Escherichia coli. The bacterial product was a fusion protein containing 640 amino acids of HSP70, plus 33 additional NH2 terminal amino acids; 12 from the bacterial expression vector and 21 from a 5' human sequence that is not normally translated. It was partially purified by ion-exchange and ATP-Sepharose affinity column chromatography. The bacterially produced human HSP70 protein was then compared with HSP70 obtained from cultured 293 cells. Both shared the same staphylococcal V8 protease peptide fragment pattern, ATP binding, and a weak ATPase activity (about 10-15 nmol ATP hydrolyzed per milligram protein per minute at 30 degrees C). The bacterially produced human HSP70 protein differed in its V8 protease pattern with an E. coli ATP-binding protein that corresponded in molecular mass to the E. coli dnaK gene product. Mutants in the human HSP70 gene were constructed which significantly reduced a predicted major alpha-helical domain in the HSP70 molecule that has partial homology to an ATP-binding site of several protein kinases. One HSP70 mutant clone contained a deletion of 20% at the NH2 terminus, and expressed a 57-kDa product, while the other was missing the middle 50% of the gene (40-kDa product). Neither protein fragment bound to an ATP affinity column, suggesting that ATP binding to HSP70 may be conformationally affected by a region about 20% internal to the NH2 terminal end of the molecule. Recently, a similar location of the ATP-binding site has been reported by Milarski and Morimoto (27).

Differential growth of human enteric adenovirus 41 (TAK) in continuous cell lines

Differing reports exist about the replication of human enteric adenoviruses (EnAds) in various cell lines. There was a suggestion that EnAds are defective, do not grow on primary human diploid cells, and behave like Ad host-range mutants, i.e., they require early gene products from other Ad types for efficient growth. Thus, initially the Graham-293 cell line, which contains the E1 region (E1A, E1B) of Ad5, was thought to be an ideal host for EnAds, because it provided the needed functions. Our findings, however, question this contention and show that Ad41 strain TAK, cultured on 293 cells, rapidly loses its infectivity (greater than 90% on the first and 100% by the second passage). In contrast to the results with 293 cells, we found that Ad41 strain TAK can be serially grown to high titers on several continuous cell lines: namely, HeLa, HI407, or HEp-2 cells. In order to investigate the basis for the rapid loss of the Ad41 infectivity upon passaging in 293 cells, Ad41 virions were purified from 293, as well as from HEp-2 cells, and their composition was analyzed. When structural proteins of the complete virions (rho = 1.34 g/cm3) were compared by Western blot analysis using polyclonal antibodies to HEp-2-grown virus, only traces of protein V (Mr 46,000 Da) could be detected in particles from 293 cells. In contrast, Ad41 particles obtained from HEp-2 cells exhibited a strong band at the position of protein V. Further, if polyclonal antibodies to 293-grown Ad41 were used in the Western blot, no protein V band was detected in HEp-2-grown virus. Finally, we note that new protein bands (Mr 25,000-35,000 Da) could be observed upon Western blot analysis of 293-derived complete and incomplete Ad41 particles. All of these observations taken together suggest that the low infectivity of Ad41 particles, prepared from 293 cells, could be due to a defect in assembly.

HIV-1 and HIV-2 infection associated with AIDS in Abidjan, Côte d'Ivoire

In September 1987, a seroprevalence study of HIV-1 and HIV-2 infection was conducted among 956 people from different groups in Abidjan, Côte d'Ivoire. Groups examined were hospitalized patients (Internal Medicine and Infectious Disease Departments, Centre Hospitalier Universitaire de Treichville, Abidjan), outpatients at tuberculosis treatment centers, blood donors, women attending an antenatal clinic, and patients attending sexually transmitted disease (STD) clinics. Total HIV infection prevalence ranged from 10% in STD clinic patients and pregnant women to 45% in hospitalized patients on an infectious diseases service. Within groups, HIV-1 infection was 2-6.5 times more prevalent than infection with HIV-2. One-quarter of HIV-seropositive people were serologically reactive to both HIV-1 and HIV-2 on enzyme-linked immunosorbent assay and Western blot. Clinical conditions previously observed in patients with HIV-1 infection were observed in people infected with HIV-2 only, as well as in those with HIV-1 infection and dual serologic reactivity. An isolate of HIV-2 was obtained on culture from a person with wasting disease and chronic fever. The results of this study suggest that infection with HIV-1 and HIV-2 is epidemic in Côte d'Ivoire, and that HIV-2 may be associated with AIDS.

Use of the polymerase chain reaction for early detection of the proviral sequences of human immunodeficiency virus in infants born to seropositive mothers. New York City Collaborative Study of Maternal HIV Transmission and Montefiore Medical Center HIV Perinatal Transmission Study Group

The early diagnosis of infection with human immunodeficiency virus (HIV) in infants born to infected mothers is essential for early treatment, but current tests cannot detect HIV infection in newborns because of the presence of maternal antibodies. We used the polymerase chain reaction, a new technique that amplifies proviral sequences of HIV within DNA, to detect HIV infection in peripheral-blood mononuclear cells obtained from infants of seropositive women during the neonatal (age less than 28 days) and postneonatal periods. In blood obtained during the neonatal period, the polymerase chain reaction was positive in five of seven infants in whom the acquired immunodeficiency syndrome (AIDS) later developed (a mean of 9.8 months after the test). The test was also positive in one of eight newborns who later had nonspecific signs and symptoms suggestive of HIV infection (mean follow-up, 12 months). No proviral sequences were detected in neonatal samples from nine infants who remained well (mean follow-up, 16 months). HIV proviral sequences were detected in samples obtained during the postneonatal period (median age, five months) in all of 6 infants tested who later had AIDS and in 4 of 14 infants with nonspecific findings suggestive of HIV infection. No proviral sequences were detected in 25 infants who remained well (mean follow-up, 17 months) after being born to HIV-seropositive mothers, or in 15 infants born to HIV-seronegative mothers. We conclude that the polymerase chain reaction will be a useful technique to diagnose HIV infection in newborns and to predict the subsequent development of AIDS. However, larger studies will be required to determine the sensitivity and specificity of the test.

Perinatal transmission of the human immunodeficiency virus type 1 to infants of seropositive women in Zaire

To examine perinatal transmission of the human immunodeficiency virus type 1 (HIV-1) in Zaire, we screened 8108 women who gave birth at one of two Kinshasa hospitals that serve populations of markedly different socioeconomic status. For up to one year, we followed the 475 infants of the 466 seropositive women (5.8 percent of those screened) and the 616 infants of 606 seronegative women matched for age, parity, and hospital. On the basis of clinical criteria, 85 of the seropositive women (18 percent) had the acquired immunodeficiency syndrome (AIDS). The infants of seropositive mothers, as compared with those of seronegative mothers, were more frequently premature, had lower birth weights, and had a higher death rate in the first 28 days (6.2 vs. 1.2 percent; P less than 0.0001). The patterns were similar at the two hospitals. Twenty-one percent of the cultures for HIV-1 of 92 randomly selected cord-blood samples from infants of seropositive women were positive. T4-cell counts were performed in 37 seropositive women, and cord blood from their infants was cultured. The cultures were positive in the infants of 6 of the 18 women with antepartum T4 counts of 400 or fewer cells per cubic millimeter, as compared with none of the infants of the 19 women with more than 400 T4 cells per cubic millimeter (P = 0.02). One year later, 21 percent of the infants of the seropositive mothers had died as compared with 3.8 percent of the control infants (P less than 0.001), and 7.9 percent of their surviving infants had AIDS. We conclude that the mortality rates among children of seropositive mothers are high regardless of socioeconomic status, and that perinatal transmission of HIV-1 has a major adverse effect on infant survival in Kinshasa.

Mixed human immunodeficiency virus (HIV) infection in an individual: demonstration of both HIV type 1 and type 2 proviral sequences by using polymerase chain reaction

Sera from persons seroreactive to both human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2), by whole-virus (VEIA) enzyme immunoassays (EIAs) for each virus, were selected from a seroprevalence study of 944 persons in Abidjan, Cote d'Ivoire, West Africa, in 1987. These sera were subsequently tested for HIV-1 and HIV-2 antibody specificity by type-specific peptide EIAs (PEIA) and western blot (WB) analysis for both viruses. Peripheral blood monocytes (PBMCs) from representative individuals were cultured in the presence of phytohemagglutinin-stimulated normal donor PBMCs. These cultures were periodically monitored for HIV-1 and HIV-2 proviral sequences by using the selective DNA amplification technique polymerase chain reaction (PCR). As an outgrowth of this study, we report the case of a person dually reactive by various serological techniques in whom proviral sequences from HIV-1 and HIV-2 were detected by PCR. This is the first confirmed case of a mixed HIV-1 and HIV-2 infection in a single individual.

Comparison of the DNA sequence and secondary structure of the herpes simplex virus L/S junction and the adeno-associated virus terminal repeat

The defective parvovirus Adeno-associated virus (AAV) is absolutely dependent upon coinfection with either Adenovirus or Herpes Simplex Virus (HSV) for its multiplication. We have compared the terminal repeats of HSV-1F strain DNA with the terminal 200 nucleotides of AAV DNA. Our findings demonstrate similarities between portions of the HSV inverted repeats found at the L/S junction and the termini of AAV. By computer analysis we have determined potential secondary folding patterns for both genomes. The following points can be made about the a, b, and c repeats in HSV: (1) Regions b and c are complementary over a significant portion of their length. (2) The ends of a can fold back on themselves to form large secondary structures. Moreover, when the b and c homology is used to align the ends of a, the b/a and c/a junctions are within 1 base of each other. (3) The short direct repeats within a are essentially a large loop with little secondary structure. The potential implications of this structure are discussed and a model for HSV DNA replication is presented.

Herpes simplex virus latency in the rabbit trigeminal ganglia: ganglionic superinfection

It has been confirmed and further documented that infection of the rabbit cornea with the E-43 strain of HSV-1 precludes superinfection of the corresponding trigeminal ganglia by another HSV strain, i.e., the challenging virus does not establish latency and can not be recovered from the ganglia. It was shown that after primary infection, a state of resistance is established in the neuronal cells of the ganglia, and although the challenging strain reaches the ganglia, it does not cause discernible acute infection, and does not displace the resident virus in the ganglia. This protection was present 6 months after primary infection, was independent of immune factors such as circulating or secretory antibodies, and was localized to the point of entry of the primary infecting strain and the sensory neurons that innervate that site. The smallest inoculum that provided protection from ganglionic superinfection was that which produced overt disease in the eye, although different degrees of disease resulted from varying inocula above this minimum. Asymptomatic primary infections produced by subminimal inocula of the E-43 strain or by the HSV recombinant strain, F(MP)F, which is avirulent for the rabbit eye, protected against severe disease and death, but the degree of protection against ganglionic superinfection was variable and depended on the time of challenge. These findings suggest that susceptible neurons in the trigeminal ganglion, when "occupied" by an infecting strain, cannot be superinfected by a second strain.