The geographic limits and life history of the tropical brown dog tick, Rhipicephalus linnaei (Audouin, 1826), in Australia with notes on the spread of Ehrlichia canis.

The tropical brown dog tick, Rhipicephalus linnaei, is a tick of much medical, veterinary, and zoonotic importance. This tick has a nearly world-wide distribution due to its ability to survive and propagate in kennels and houses. Rhipicephalus linnaei is the vector of Ehrlichia canis, the causative agent of canine monocytic ehrlichiosis, an often debilitating disease of canids and, occasionally, humans. To prevent incursion of E. canis into Australia, dogs entering Australia have been required to have a negative immunofluorescence antibody test for E. canis. In May 2020 however, E. canis was detected in Western Australia. The detection of E. canis in Australia prompted disease investigation and concerted surveillance for R. linnaei and E. canis in regions across Australia. These investigations revealed that R. linnaei was established far beyond the previously recognised geographic range limits of this tick. In the present paper, using records from various collections, published data, and data from our network of veterinarian collaborators and colleagues, we update the current geographic range of R. linnaei in Australia. Our analyses revealed that the geographic range of R. linnaei in Australia is much wider than was previously supposed, particularly in Western Australia, and in South Australia. We also map, for the first time, where E. canis has been detected in Australia. Last, we discuss the possible routes of incursion and subsequently the factors which may have aided the spread of E. canis in Australia which led to the establishment of this pathogen in Australia.

Detection of bacterial agents in Amblyomma americanum (Acari: Ixodidae) from Georgia, USA, and the use of a multiplex assay to differentiate Ehrlichia chaffeensis and Ehrlichia ewingii.

Amblyomma americanum, the lone star tick, is the most common and most aggressive human biting tick in the Southeastern United States. It is known to transmit the agents of human ehrlichioses, Ehrlichia chaffeensis and Ehrlichia ewingii. In addition, it carries agents of unspecified pathogenicity to humans, including Rickettsia amblyommii, Borrelia lonestari, and the newly emerging Panola Mountain Ehrlichia (PME). Surveillance of these ticks for recognized or emerging pathogens is necessary for assessing the risk of human infection. From 2005 to 2009, we surveyed A. americanum ticks from four locations in the state of Georgia. Ticks (1,183 adults, 2,954 nymphs, and 99 larval batches) were tested using a multiplex real-time polymerase chain reaction (PCR) assay designed to detect and discriminate DNA from Rickettsia spp., E. chaffeensis, and E. ewingii. This assay was capable of detecting as few as 10 gene copies of the aforementioned agents. Ticks were also tested for PME and B. lonestari by nested PCR. The prevalence of infection ranged from 0 to 2.5% for E. chaffeensis, 0 to 3.9% for E. ewingii, 0 to 2.2% for PME, 17 to 83.1% for R. amblyommii, and 0 to 3.1% for B. lonestari. There were 46 (4.1%) individual adults positive for two agents, and two females that were each positive for three agents. Two larval batches were positive for both B. lonestari and R. amblyommii, indicating the potential for transovarial transmission of both agents from a single female. Although infrequent in occurrence, the dynamics of coinfections in individual ticks should be explored further, given the potential implications for differential diagnosis and severity of human illness.

Effects of homologous and heterologous immunization on the reservoir competence of domestic dogs for Rickettsia conorii (israelensis).

A number of spotted fever group (SFG) rickettsiae cause serious infections in humans. Several antigenically related rickettsial agents may coexist within the same geographical area, and humans or vertebrate hosts may be sequentially exposed to multiple SFG agents. We assessed whether exposure of a vertebrate reservoir to one SFG Rickettsia will affect the host's immune response to a related pathogen and the efficiency of transmission to uninfected ticks. Two pairs of dogs were each infected with either Rickettsia massiliae or Rickettsia conorii israelensis, and their immune response was monitored twice weekly by IFA. The four immunized dogs and a pair of naïve dogs were each challenged with R. conorii israelensis-infected Rhipicephalus sanguineus nymphs. Uninfected Rh. sanguineus larvae were acquisition-fed on the dogs on days 1, 7, and 14 post-challenge. These ticks were tested for the presence of rickettsial DNA after molting to the nymphal stage. The naive dogs became infected with R. conorii israelensis and were infectious to ticks for at least 3 weeks, whereas reservoir competence of dogs previously infected with either R. massiliae or R. conorii was significantly diminished. This opens an opportunity for decreasing the efficiency of transmission and propagation of pathogenic Rickettsia in natural foci by immunizing the primary hosts with closely related nonpathogenic SFG bacteria. However, neither homologous immunization nor cross-immunization significantly affected the efficiency of R. conorii transmission between cofeeding infected nymphs and uninfected larvae. At high densities of ticks, the efficiency of cofeeding transmission may be sufficient for yearly amplification and persistent circulation of a rickettsial pathogen in the vector population.

Outcomes and native renal recovery following simultaneous liver-kidney transplantation.

With the increase in patients having impaired renal function at liver transplant due to MELD, accurate predictors of posttransplant native renal recovery are needed to select candidates for simultaneous liver-kidney transplantation (SLK). Current UNOS guidelines rely on specific clinical criteria for SLK allocation. To examine these guidelines and other variables predicting nonrecovery, we analyzed 155 SLK recipients, focusing on a subset (n = 78) that had post-SLK native GFR (nGFR) determined by radionuclide renal scans. The 77 patients not having renal scans received a higher number of extended criteria donor organs and had worse posttransplant survival. Of the 78 renal scan patients, 31 met and 47 did not meet pre-SLK UNOS criteria. The UNOS criteria were more predictive than our institutional criteria for all nGFR recovery thresholds (20-40 mL/min), although at the most conservative cut-off (nGFR ≤ 20) it had low sensitivity (55.3%), specificity (75%), PPV (67.6%) and NPV (63.8%) for predicting post-SLK nonrecovery. On multivariate analysis, the only predictor of native renal nonrecovery (nGFR ≤ 20) was abnormal pre-SLK renal imaging (OR 3.85, CI 1.22-12.5). Our data support the need to refine SLK selection utilizing more definitive biomarkers and predictors of native renal recovery than current clinical criteria.

Crossbreeding between different geographical populations of the brown dog tick, Rhipicephalus sanguineus (Acari: Ixodidae).

Brown dog ticks are distributed world-wide, and their systematics and phylogeny are the subject of an ongoing debate. The present study evaluates the reproductive compatibility between Rhipicephalus sanguineus ticks from North America, Israel, and Africa. Female ticks of the parent generation were mated with males from the same and alternate colonies. Every pure and hybrid cohort was maintained separately into the F2 generation with F1 females being allowed to mate only with males from the same cohort. The following survival parameters were measured and recorded for every developmental stage: feeding duration and success; engorgement weight, fertility, and fecundity of females; molting and hatching success. Ticks from North American and Mediterranean populations hybridized successfully. The survival parameters of all their hybrid lines were similar to those in pure lines throughout the F1 generation, and F1 adults were fully fertile. Parent adult ticks from the African population hybridized with either North American or Mediterranean ticks and produced viable progenies whose survival parameters were also similar to those in pure lines throughout the F1 generation. However, F1 adults in the four hybrid lines that included African ancestry were infertile. No parthenogenesis was observed in any pure or hybrid lines as proportion of males in F1 generation ranged from 40 to 60 %. Phylogenetic analysis of the 12S rDNA gene sequences placed African ticks into a separate clade from those of the North American or Mediterranean origins. Our results demonstrate that Rh. sanguineus ticks from North America and Israel represent the same species, whereas the African population used in this study is significantly distant and probably represents a different taxon.

Co-feeding as a route for transmission of Rickettsia conorii israelensis between Rhipicephalus sanguineus ticks.

Rickettsia conorii is widely distributed in Europe, Asia, and Africa. The brown dog tick, Rhipicephalus sanguineus, is the recognized vector of R. conorii. In this study, we assessed the efficiency of R. conorii israelensis transmission between co-feeding Rh. sanguineus ticks. Infected Rh. sanguineus adults and uninfected nymphs were fed simultaneously upon either naïve dogs or a dog previously exposed to this agent. When ticks were placed upon naïve dogs, 92-100% of nymphs acquired the infection and 80-88% of infected engorged nymphs transmitted it transstadially. When ticks were placed upon a seropositive dog, only 8-28.5% of recipient nymphs became infected. Our results establish the first evidence for efficient natural transmission of R. conorii israelensis between co-feeding ticks upon both naïve and seropositive dogs. This route of transmission can ensure continuous circulation of R. conorii israelensis in tick vectors even in the absence of naïve reservoir hosts.

Incongruent effects of two isolates of Rickettsia conorii on the survival of Rhipicephalus sanguineus ticks.

Rickettsia conorii, the etiologic agent of Mediterranean spotted fever is widely distributed in Southern Europe, the Middle East, Africa, India and the Caspian region. In the Mediterranean region, the brown dog tick, Rhipicephalus sanguineus, is the recognized vector of R. conorii. To study tick-pathogen relationships and pathogenesis of infection caused in model animals by the bite of an infected tick, we attempted to establish a laboratory colony of Rh. sanguineus persistently infected with R. conorii. Rhipicephalus sanguineus ticks of North American and Mediterranean origin were exposed to R. conorii isolates of African (R. conorii conorii strain Malish) and Mediterranean (R. conorii israelensis strain ISTT) origin. Feeding of ticks upon infected mice and dogs, intra-hemocoel inoculation, and submersion in suspensions of purified rickettsiae were used to introduce the pathogen into uninfected ticks. Feeding success, molting success and the longevity of molted ticks were measured to assess the effects of R. conorii on the survival of Rh. sanguineus. In concordance with previously published results, Rh. sanguineus larvae and nymphs from both North American and Mediterranean colonies exposed to R. conorii conorii Malish experienced high mortality during feeding and molting or immediately after. The prevalence of infection in surviving ticks did not exceed 5%. On the other hand, exposure to ISTT strain had lesser effect on tick survival and resulted in 35-66% prevalence of infection. Rh. sanguineus of Mediterranean origin were more susceptible to infection with either strain of R. conorii than those from North America. Previous experimental studies had demonstrated transovarial and transstadial transmission of R. conorii in Rh. sanguineus; however, our data suggest that different strains of R. conorii may employ different means of maintenance in nature. The vertebrate host may be a more important reservoir than previously thought, or co-feeding transmission between different generations of ticks may obviate or lessen the requirement for transovarial maintenance of R. conorii.

Hiv-associated nephropathy occurring before HIV antibody seroconversion.

It currently is thought that human immunodeficiency virus-associated nephropathy (HIVAN) occurs late in the course of HIV infection. Although HIVAN may be the presenting manifestation of acquired immunodeficiency syndrome (AIDS), it usually occurs after a prolonged period of viral infection often associated with high levels of HIV viremia. The patient described here developed HIVAN as a manifestation of acute retroviral syndrome. A 41-year-old black man presented with nephrotic range proteinuria, renal insufficiency, and acute gastrointestinal and pulmonary symptoms. He recently had been treated for primary syphilis. Two HIV serologic tests, performed 3 months apart, were negative. Renal biopsy was consistent with HIVAN. After the biopsy, the patient was discovered to have more than 700,000 viral copies per mL in his blood. CD4(+) count was greater than 500/mm(3). Six weeks later, enzyme-linked immunosorbent assay and Western blot analyses for HIV antibody became positive. HIVAN can occur early in the course of HIV infection, even during acute infection before seroconversion, and prolonged exposure to virus is not necessary for this renal involvement to occur in the susceptible host.

The prevalence of Borrelia burgdorferi sensu lato in Ixodes persulcatus and I. ricinus ticks in the zone of their sympatry.

A total of 7210 unfed adult Ixodes persulcatus Schulze, 1930 and I. ricinus (L., 1758) ticks were collected from the vegetation by flagging in 35 study sites located in the zone of their sympatry (mainly in Leningrad region, Russia). Borrelia infection in ticks was estimated by the dark-field microscopic analysis of gut contents in standard vital preparations at a magnification of x600. No correlation was revealed between the series of parameters characterising the abundance of each tick species (tau = -0.13) and between the series of these parameters and the prevalence of Borrelia in each vector. It is concluded that in the broad zone of I. persulcatus and I. ricinus sympatry, the presence and proportion of one vector in the ecosystem does not have any significant effect on the extensity of infection and on the epizootic and epidemic significance of the other vector. Each tick species has its independent (of the other species) and relatively original functional role in the focal ecosystem.

Interference between the agents of Lyme disease and human granulocytic ehrlichiosis in a natural reservoir host.

Agents of Lyme disease (Borrelia burgdorferi) and human granulocytic ehrlichiosis (Ehrlichia phagocytophila) are perpetuated in a natural cycle involving the black-legged tick (Ixodes scapularis) and its vertebrate hosts. Using I. scapularis nymphs as the mode of infectious challenge, we studied how infection with one pathogen in white-footed mice (Peromyscus leucopus) affects their ability to acquire the other agent and subsequently to infect larvae, which these agents would do in nature. Two groups of mice were infected with either B. burgdorferi or E. phagocytophila. One week later, B. burgdorferi-infected mice were challenged with E. phagocytophila, and E. phagocytophila-infected mice were challenged with B. burgdorferi. Simultaneously, two control groups of uninfected mice were infected with each agent from the same tick cohorts used on the first groups of mice. Uninfected I. scapularis larvae were fed on all mice for xenodiagnosis at weekly intervals lasting 2 months. For the B. burgdorferi challenge, all control and E. phagocytophila-infected mice acquired B. burgdorferi. However, fewer xenodiagnostic larvae acquired B. burgdorferi from mice with mixed infections compared with mice infected with B. burgdorferi only. For the E. phagocytophila challenge, all five control mice acquired E. phagocytophila, but only two of five mice infected with B. burgdorferi subsequently acquired E. phagocytophila. Consequently, mice with both infections produced fewer xenodiagnostic ticks infected with E. phagocytophila than mice infected with E. phagocytophila only. Thus, a primary infection with either B. burgdorferi or E. phagocytophila in mice inhibited transmission of a second agent, suggesting interference between these two agents.

Acquisition of coinfection and simultaneous transmission of Borrelia burgdorferi and Ehrlichia phagocytophila by Ixodes scapularis ticks.

The agents of Lyme disease (Borrelia burgdorferi) and human granulocytic ehrlichiosis (Ehrlichia phagocytophila) are both transmitted by the tick Ixodes scapularis. In nature, ticks are often infected with both agents simultaneously. We studied whether previous infection with either Borrelia or Ehrlichia in ticks would affect acquisition and transmission of a second pathogen. Ehrlichia-infected I. scapularis nymphs were fed upon Borrelia-infected mice, and Borrelia-infected I. scapularis nymphs were fed upon Ehrlichia-infected mice. The efficiency with which previously infected nymphal ticks acquired a second pathogen from infected hosts was compared to that of uninfected ticks. An average of 51% +/- 15% of ticks acquired Ehrlichia from infected mice regardless of their prior infection status with Borrelia. An average of 85% +/- 10% of ticks acquired Borrelia from infected mice regardless of their prior infection status with Ehrlichia. Also, we assessed the efficiency with which individual nymphs could transmit either agent alone, or both agents simultaneously, to individual susceptible hosts. An average of 76% +/- 9% of Borrelia-infected ticks and 84% +/- 10% of Ehrlichia-infected ticks transmitted these agents to mice regardless of the presence of the other pathogen. There was no evidence of interaction between the agents of Lyme disease and human granulocytic ehrlichiosis in I. scapularis ticks. The presence of either agent in the ticks did not affect acquisition of the other agent from an infected host. Transmission of the agents of Lyme disease and human granulocytic ehrlichiosis by individual ticks was equally efficient and independent. Dually infected ticks transmitted each pathogen to susceptible hosts as efficiently as ticks infected with only one pathogen.

Immunity reduces reservoir host competence of Peromyscus leucopus for Ehrlichia phagocytophila.

Infection with Ehrlichia phagocytophila in white-footed mice is transient and followed by a strong immune response. We investigated whether the presence of acquired immunity against E. phagocytophila precludes white-footed mice from further maintenance of this agent in nature. Mice were infected with E. phagocytophila via tick bite and challenged either 12 or 16 weeks later by Ixodes scapularis nymphs infected with the same agent. Xenodiagnostic larvae fed upon each mouse simultaneously with challenging nymphs and 1 week thereafter. Ticks were tested for the agent by PCR, and the prevalence of infection was compared to that in ticks that fed upon nonimmune control mice. Only 30% of immunized mice sustained cofeeding transmission of E. phagocytophila between simultaneously feeding infected and uninfected ticks, compared to 100% of control mice. An average of 6.3% of xenodiagnostic ticks acquired Ehrlichia from previously immunized mice when fed 1 week after the challenge, compared to 82.5% infection in the control group. Although an immune response to a single infection with E. phagocytophila in white-footed mice provided only partial protection against reinfection with the same agent, the majority of mice were rendered reservoir incompetent for at least 12 to 16 weeks. Immunity acquired by mice during I. scapularis nymphal activity in early summer may exclude a large proportion of the mouse population from maintaining E. phagocytophila during the period of larval activity later in the season.

AIDS knowledge, condom attitudes, and risk-taking sexual behavior of substance-abusing juvenile offenders on probation or parole.

AIDS knowledge, condom attitudes, and sexual behavior were examined in a sample of 193 substance-abusing juvenile offenders on probation or parole. The majority of these youths reported being sexually active, and many admitted to early onset of sexual activity as well as unsafe sexual practices. Potential predictors of condom use by these juveniles were examined including age, condom use at first sexual experience, number of sexual partners in the last 6 months, locus of control, AIDS knowledge, condom attitudes, perceived risk for AIDS, self-efficacy for avoiding HIV, condom use by peers, delinquency risk, race, and gender. General attitudes toward condoms and the reported use of a condom at first sexual intercourse experience were the only statistically significant predictors of subsequent condom use. The relevance of these findings to the development of AIDS prevention programs for juvenile offenders is discussed.

PIP: This study examines knowledge on AIDS, condom attitudes, and sexual behavior in a sample of 193 substance-abusing juvenile offenders on probation or parole in Mississippi. The participants were paid US$10 to complete self-administered questionnaires containing items regarding the adolescent's value, parental disciplinary practices, locus of control, condom attitudes, AIDS knowledge, sexual behavior frequency for the previous 6 months, where and from whom they obtained information about sex, perception of personal AIDS risks, and their self-efficacy in avoiding HIV infection. The majority of these youths reported being sexually active, and many admitted to early onset of sexual activity as well as unsafe sexual practices. The findings also support those of others, which reports that delinquents are likely to engage in behaviors, which place them at high-risk for HIV infection and sexually transmitted diseases (STDs). Other important findings emerged regarding condom use by juvenile offenders: positive attitudes towards the use of condoms and condom use at first intercourse predict subsequent condom use. These findings are particularly relevant to the development of AIDS prevention programs with juvenile offenders having found no relationship between levels of awareness, knowledge, or concern about HIV/AIDS and risky sexual behavior. Further, juvenile offenders are unlikely to abstain from sexual activity, and once they are sexually active, consistent condom use will lower their chances of contracting HIV infection and STDs. It is therefore of paramount importance that interventions be designed and implemented in an attempt to reduce these odds.

Proximal 5p trisomy resulting from a marker chromosome implicates band 5p13 in 5p trisomy syndrome.

We describe an infant with trisomy of (5)(p10p13.1) resulting from a de novo marker chromosome. The marker's origin was identified by chromosome microdissection and reverse in situ hybridization. The clinical findings are compared to those of other partial and complete 5p duplications. This case further defines the critical region of 5p trisomy syndrome to proximal 5p.

Teenage partners' communication about sexual risk and condom use: the importance of parent-teenager discussions.

CONTEXT: Teenagers' communication with their partners about sex and their use of condoms may be influenced by the discussions teenagers have with their parents about sex. However, little is known about the process of parent-teenager communication on this topic. Understanding both what parents discuss with their children and how they discuss it may lead to a greater understanding of teenagers' sexual behavior. METHODS: Interviews were conducted with 372 sexually active black and Hispanic youth aged 14-17 from Alabama, New York and Puerto Rico. Regression analyses were used to examine parent-teenager discussions about sexuality and about sexual risk, and parental communication skills as predictors of teenagers' discussions about sexual risk with a partner and teenagers' condom use. RESULTS: Parent-teenager discussions about sexuality and sexual risk were associated with an increased likelihood of teenager-partner discussions about sexual risk and of teenagers' condom use, but only if parents were open, skilled and comfortable in having those discussions. Teenagers' communication with their partner about sexual risk also was associated with greater condom use, but the relationship between parent-teenager communication and teenagers' condom use was independent of this association. CONCLUSIONS: The influence on teenagers of parent-teenager discussions about sexuality and sexual risk depends on both what parents say and how they say it. Programs that foster parent-teenager communication about sexuality and sexual risk must emphasize both of these aspects.

PIP: Teenagers' communication with their partners about sex, an important factor in sexual risk reduction, has been shown to be influenced by discussions teens have with their parents about sex. The present study confirmed that parent-teen communication about sex does indeed promote teenagers' discussions with their partners about sex and condom use, but only when parents communicate in a skilled, comfortable, and open manner. Interviews were conducted during 1993-94 with 372 sexually active Black and Hispanic US high school students 14-17 years old from Alabama, New York, and Puerto Rico. On average, teens had first intercourse at age 13.7 years and had had 3.9 partners. The association between parent-teen discussions about sexuality and sexual risk and teenager-partner communication about sex was high when parental responsiveness (openness, skill, comfort) was rated high by the teenager, but this association was weaker and of only marginal significance when responsiveness was rated as low. Similarly, when parental responsiveness was high, sexuality and risk discussions were significantly associated with increased condom use during most recent intercourse and lifetime condom use. However, at low levels of parental responsiveness, sexuality discussions were negatively associated with most recent and lifetime condom use. The association between parent-teen communication and condom use was direct and independent. These findings highlight the importance of communication skills training for parents.

Disparity in the natural cycles of Borrelia burgdorferi and the agent of human granulocytic ehrlichiosis.

We studied the prevalence of Borrelia burgdorferi and the agent of human granulocytic ehrlichiosis (HGE) among questing nymphal and adult Ixodes scapularis ticks of the same generation and the infectivity of wild white-footed mice for ticks feeding on them. The prevalence of B. burgdorferi infection in host-seeking ticks increased less than twofold from nymphal (31% to 33%) to adult (52% to 56%) stage, and 52% of white-footed mice were infected. Prevalence of the agent of HGE increased 4.5- to 10.6-fold from nymphal (1.5% to 1.8%) to adult stage (7.6% to 19.0%), while only 18% of mice were infectious to ticks. B. burgdorferi infection was more common in mouse-fed ticks than in ticks collected from vegetation, whereas the agent of HGE was half as common in mouse-fed ticks as in ticks collected from vegetation. The different prevalence in nature of these pathogens in ticks suggests that their maintenance cycles are also different.

Comparative vector competence of Dermacentor variabilis and Ixodes scapularis (Acari: Ixodidae) for the agent of human granulocytic ehrlichiosis.

Vector competence of Ixodes scapularis Say and Dermacentor variabilis Say for the agent of human granulocytic ehrlichiosis (HGE) was compared. Five white-footed mice, Peromyscus leucopus Rafinesque, were inoculated intra-peritoneally with blood from a mouse infected with the agent of HGE. Approximately 100 I. scapularis and D. variabilis larvae were placed on each mouse and allowed to feed to repletion. Fed larvae were collected, separated according to species and allowed to molt to nymphs. Twenty-six per cent of I. scapularis (34/131) and 11% of D. variabilis (11/96) tested positive for the agent of HGE by polymerase chain reaction (PCR) after molting to nymphs. Positive I. scapularis nymphs transmitted the agent of HGE to P. leucopus mice in 5 of 5 trials. In contrast, the positive D. variabilis nymphs did not transmit the agent of agent of HGE in any of 6 trials. In a 2nd experiment, 3 P. leucopus mice were infested with I. scapularis nymphs that were infected with the agent of HGE. All 3 mice became infected with the agent of HGE and approximately 300 D. variabilis larvae were placed on each mouse and allowed to feed to repletion. Larvae were collected and allowed to molt to nymphs as before. Approximately 8% (5/60) of the nymphs became positive for the agent of HGE as determined by PCR. Twenty-five of these nymphs were then placed on each of 9 P. leucopus mice and allowed to feed to repletion. Evidence of transmission was not observed in any of 9 mice exposed to D. variabilis nymphs. These results demonstrate that although I. scapularis is a competent vector of the agent of the HGF, D. variabilis is not.

Patterns of condom use among adolescents: the impact of mother-adolescent communication.

OBJECTIVES: The association between the timing of discussions about condoms between mother and adolescent and adolescents' condom use during their first and subsequent sexual encounters was examined. METHODS: Sexually active adolescents reported whether and when they discussed condoms with their mother and answered questions about their own condom use. RESULTS: Mother-adolescent discussions about condoms that occurred prior to sexual debut were strongly associated with greater condom use during first intercourse and most recent intercourse, along with greater lifetime regular condom use. CONCLUSIONS: Discussions about condoms prior to sexual debut are important in promoting condom use among adolescents.