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J K Carr,
M Avila,
M Gomez Carrillo,
H Salomon,
J Hierholzer,
V Watanaveeradej,
M A Pando,
M Negrete, K L Russell,
J Sanchez,
D L Birx,
R Andrade,
J Vinoles,
F E McCutchan
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ABSTRACT: To describe the genetic diversity of HIV-1 in South America by full genome sequencing and analysis.
Purified peripheral blood mononuclear cell DNA from HIV-infected individuals in Argentina, Uruguay and Bolivia was used to amplify full HIV-1 genomes. These were sequenced using the ABI 3100 automated sequencer and phylogenetically analysed.
Twenty-one HIV-1 strains from three South American countries, 17 of which were pre-screened by envelope heteroduplex mobility assay (HMA), were studied. Ten out of 10 HMA subtype F and four out of seven HMA subtype B strains were actually BF recombinants upon full genome analysis. Two BF recombinants from Argentina and two from Uruguay had the same structure, representing a new circulating recombinant form termed CRF12_BF(ARMA159). Twelve other BF recombinants had structures related to CRF12 but with additional segments of subtype B; each was unique. BF recombinants were temporally and geographically widespread, found as early as 1986-1987 in vertically infected Argentinian children and in Argentina, Uruguay, and Bolivia.
AIDS 11/2001; 15(15):F41-7. · 6.24 Impact Factor
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A C Moncayo,
C L Hice,
D M Watts,
A P Travassos de Rosa,
H Guzman, K L Russell,
C Calampa,
A Gozalo,
V L Popov,
S C Weaver,
R B Tesh
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ABSTRACT: Allpahuayo virus was initially isolated from arboreal rice rats (Oecomys bicolor and Oecomys paricola) collected during 1997 at the Allpahuayo Biological Station in northeastern Peru. Serological and genetic studies identified the virus as a new member of the Tacaribe complex of the genus Arenavirus. The small (S) segment of the Allpahuayo virus prototype strain CLHP-2098 (Accession No. AY012686) was sequenced, as well as that of sympatric isolate CLHP-2472 (Accession No. AY012687), from the same rodent species. The S segment was 3382 bases in length and phylogenetic analysis indicated that Allpahuayo is a sister virus to Pichinde in clade A. Two ambisense, nonoverlapping reading frames were identified, which result in two predicted gene products, a glycoprotein precursor (GPC) and a nucleocapsid protein (NP). A predicted stable single hairpin secondary structure was identified in the intergenic region between GPC and NP. Details of the genetic organization of Allpahuayo virus are discussed.
Virology 07/2001; 284(2):277-86. · 3.35 Impact Factor
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A C Shurtleff,
D W Beasley,
J J Chen,
H Ni,
M T Suderman,
H Wang,
R Xu,
E Wang,
S C Weaver,
D M Watts, K L Russell,
A D Barrett
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ABSTRACT: The 3' non-coding region (3'NCR) of strains of dengue 1 (DEN 1), DEN 2, DEN 3, and DEN 4 viruses, isolated in different geographical regions, was sequenced and compared to published sequences of the four dengue viruses. A total of 50 DEN 2 strains was compared: 7 West African strains, 3 Indonesian mosquito strains, 1 Indonesian macaque isolate, and 39 human isolates from Southeast Asia, the South Pacific, and the Caribbean and Americas. Nucleotide sequence alignment revealed few deletions and no repeat sequences in the 3' NCR of DEN 2 viruses and showed that much of the 3' NCR was well conserved. The strains could be divided into two groups, sylvatic and human/mosquito/macaque, based on nucleotide sequence homology. A hypervariable region was identified immediately following the NS5 stop codon, which involved a 2-10 nucleotide deletion in human, mosquito, and macaque isolates compared with the sylvatic strains. The DEN 2 3'NCR was also compared with 3'NCR sequences from strains of DEN 1, DEN 3, and DEN 4 viruses. DEN 1 was found to have four copies of an eight nucleotide imperfect repeat following the NS5 stop codon, while DEN 4 virus had a deletion of 75 nucleotides in the 3'NCR. We propose that the variation in nucleotide sequence in the 3'NCR may have evolved as a function of DEN virus transmission and replication in different mosquito and non-human primate/human host cycles. The results from this study are consistent with the hypothesis that DEN viruses arose from sylvatic progenitors and evolved into human epidemic strains. However, the data do not support the hypothesis that variation in the 3'NCR correlates with DEN virus pathogenesis.
Virology 04/2001; 281(1):75-87. · 3.35 Impact Factor
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K L Russell,
C Carcamo,
D M Watts,
J Sanchez,
E Gotuzzo,
A Euler,
J C Blanco,
A Galeano,
A Alava,
J I Mullins,
K K Holmes,
J K Carr
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ABSTRACT: Genotype determination and risk group analysis of HIV-1 infected individuals in selected regions of South America.
Cross-sectional convenience sampling of HIV-1-positive individuals in Peru, Ecuador, Uruguay and Paraguay from March, 1994 through September, 1998.
HIV-1-positive subjects were identified through the national AIDS surveillance program in each country. A standardized questionnaire was used to obtain demographic, clinical and risk factor data on each study subject. Viral DNA was extracted from participants' peripheral blood mononuclear cells either directly or after co-cultivation. A nested PCR was used to obtain selected fragments of the envelope genes for genotyping by the heteroduplex mobility assay (HMA). A 600 bp sequence encompassing the V3 loop was sequenced from a selection of 23 of these samples for phylogenetic analysis and confirmation of HMA genotype.
Among the 257 successfully genotyped HIV-1-positive samples, genotype B was found in 98.3% (228/232) of those obtained from subjects in Peru, Ecuador, and Paraguay. In contrast, 56% (14/25) of the samples from Uruguay were genotype F, and the remainder were genotype B. Genotype F was detected for the first time in Peru (2/224) and Paraguay (1/4), and genotype A for the first time in Peru (1/224). Phylogenetic analysis confirmed the genotype identified by HMA in the 23 samples sequenced. There was no detectable genetic clustering of HIV-1 within the different high-risk groups or geographic locations.
These findings verify and extend the presence of several different HIV-1 genotypes in South America.
AIDS 09/2000; 14(12):1785-91. · 6.24 Impact Factor
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ABSTRACT: A DNA vaccine that expresses the premembrane/membrane (prM) and envelope (E) genes of dengue virus serotype-1 was tested for immunogenicity and protection against dengue-1 virus challenge in Aotus nancymae monkeys. The vaccine, in 1 mg doses, was administered intradermally (i.d.) to three monkeys and intramuscularly (i.m.) to three others. For controls, a 1 mg dose of vector DNA was administered i.d. to two monkeys and i.m. to one. All animals were primed and then boosted at one and five months post priming. Sera were collected monthly and analyzed for dengue-1 antibodies by enzyme linked immunosorbent assay (ELISA) and plaque reduction neutralization test (PRNT). Dengue-1 antibodies were detectable in the sera from i.d. and i.m. vaccine inoculated animals one month after the first boost and peaked one month after the second boost. The antibody levels from sera of animals that received the vaccine via the i.d. route were twice those from sera of animals that received the vaccine via the i.m. route. Six months after the second boost all inoculated and two naive monkeys were challenged with 1.25x10(4) plaque forming units (PFU) of dengue-1 virus. Two vaccine immunized animals were protected from viremia while the others showed a reduction in viremia. The mean days of viremia were 1 and 1.3 for the animals that were immunized with the vaccine via the i.d. or i.m. route, respectively vs 4 and 2 mean days of viremia in the animals inoculated with control DNA. Naive animals were viremic for an average of 4 days. All of the three control monkeys that received control DNA inoculum by either the i.d. or i.m. route had an intermittent viremia pattern with one or more negative days interspersed between the positive days. This pattern was not observed in any of the vaccine recipients or the naïve control monkeys. These results demonstrate that DNA immunization is a promising approach for the development of dengue vaccines and that A. nancymae monkeys are suitable for dengue vaccine trials.
Vaccine 08/2000; 18(27):3166-73. · 3.77 Impact Factor
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ABSTRACT: Specific and sensitive reverse transcription-PCR (RT-PCR) assays were developed for the detection of eastern, western, and Venezuelan equine encephalitis viruses (EEE, WEE, and VEE, respectively). Tests for specificity included all known alphavirus species. The EEE-specific RT-PCR amplified a 464-bp region of the E2 gene exclusively from 10 different EEE strains from South and North America with a sensitivity of about 3,000 RNA molecules. In a subsequent nested PCR, the specificity was confirmed by the amplification of a 262-bp fragment, increasing the sensitivity of this assay to approximately 30 RNA molecules. The RT-PCR for WEE amplified a fragment of 354 bp from as few as 2,000 RNA molecules. Babanki virus, as well as Mucambo and Pixuna viruses (VEE subtypes IIIA and IV), were also amplified. However, the latter viruses showed slightly smaller fragments of about 290 and 310 bp, respectively. A subsequent seminested PCR amplified a 195-bp fragment only from the 10 tested strains of WEE from North and South America, rendering this assay virus specific and increasing its sensitivity to approximately 20 RNA molecules. Because the 12 VEE subtypes showed too much divergence in their 26S RNA nucleotide sequences to detect all of them by the use of nondegenerate primers, this assay was confined to the medically important and closely related VEE subtypes IAB, IC, ID, IE, and II. The RT-PCR-seminested PCR combination specifically amplified 342- and 194-bp fragments of the region covering the 6K gene in VEE. The sensitivity was 20 RNA molecules for subtype IAB virus and 70 RNA molecules for subtype IE virus. In addition to the subtypes mentioned above, three of the enzootic VEE (subtypes IIIB, IIIC, and IV) showed the specific amplicon in the seminested PCR. The practicability of the latter assay was tested with human sera gathered as part of the febrile illness surveillance in the Amazon River Basin of Peru near the city of Iquitos. All of the nine tested VEE-positive sera showed the expected 194-bp amplicon of the VEE-specific RT-PCR-seminested PCR.
Journal of Clinical Microbiology 05/2000; 38(4):1527-35. · 4.15 Impact Factor
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R B Tesh,
D M Watts, K L Russell,
C Damodaran,
C Calampa,
C Cabezas,
G Ramirez,
B Vasquez,
C G Hayes,
C A Rossi,
A M Powers,
C L Hice,
L J Chandler,
B C Cropp,
N Karabatsos,
J T Roehrig,
D J Gubler
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ABSTRACT: This report describes the clinical, laboratory, and epidemiological findings on 27 cases of Mayaro virus (MV) disease, an emerging mosquito-borne viral illness that is endemic in rural areas of tropical South America. MV disease is a nonfatal, dengue-like illness characterized by fever, chills, headache, eye pain, generalized myalgia, arthralgia, diarrhea, vomiting, and rash of 3-5 days' duration. Severe joint pain is a prominent feature of this illness; the arthralgia sometimes persists for months and can be quite incapacitating. Cases of two visitors from the United States, who developed MV disease during visits to eastern Peru, are reported. MV disease and dengue are difficult to differentiate clinically.
Clinical Infectious Diseases 02/1999; 28(1):67-73. · 9.15 Impact Factor
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A P Travassos da Rosa,
M J Turell,
D M Watts,
A M Powers,
P F Vasconcelos,
J W Jones,
T A Klein,
D J Dohm,
R E Shope,
N Degallier,
V L Popov, K L Russell,
S C Weaver,
H Guzman,
C Calampa,
A C Brault,
A P Lemon,
R B Tesh
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ABSTRACT: This report describes Trocara virus, a newly recognized member of the genus Alphavirus, that has been isolated from Aedes serratus mosquitoes collected at two widely separated sites in the Amazon Basin. Biological, antigenic and genetic characteristics of the new virus are given. Results of these studies indicate that Trocara virus is the first member of a newly discovered antigenic complex within the family Togaviridae genus Alphavirus. The public health and veterinary importance of Trocara virus is still unknown.
The American journal of tropical medicine and hygiene 64(1-2):93-7. · 2.59 Impact Factor
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S R Manock,
P M Kelley,
K C Hyams,
R Douce,
R D Smalligan,
D M Watts,
T W Sharp,
J L Casey,
J L Gerin,
R Engle,
A Alava-Alprecht,
C M Martínez,
N B Bravo,
A G Guevara, K L Russell,
W Mendoza,
C Vimos
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ABSTRACT: An outbreak of delta hepatitis occurred during 1998 among the Waorani of the Amazon basin of Ecuador. Among 58 people identified with jaundice, 79% lived in four of 22 Waorani communities. Serum hepatitis B surface antigen (HBsAg) was found in the sera of 54% of the jaundiced persons, and 14% of asymptomatic persons. Ninety-five percent of 105 asymptomatic Waorani had hepatitis B core (HBc) IgG antibody, versus 98% of 51 with jaundice. These data confirm that hepatitis B virus (HBV) infection is highly endemic among the Waorani. Sixteen of 23 (70%) HBsAg carriers identified at the onset of the epidemic had serologic markers for hepatitis D virus (HDV) infection. All 16 were jaundiced, where as only two of seven (29%) with negative HDV serology were jaundiced (P = .0006). The delta cases clustered in families, 69% were children and most involved superinfection of people chronically infected with HBV. The data suggest that HDV spread rapidly by a horizontal mode of transmission other than by the sexual route.
The American journal of tropical medicine and hygiene 63(3-4):209-13. · 2.59 Impact Factor
