Human papillomavirus in men: comparison of different genital sites.

OBJECTIVE: To elucidate which anatomical sites need to be sampled to detect human papillomavirus (HPV) infection in the lower male genital tract. METHOD: In an HPV survey of Mexican soldiers (median age 24 years; range 16-50 years), a cell sample from 2 cm deep into the distal urethra (group 1; n = 168 men), or 0.5 cm deep into the meatus urethralis (group 2; n = 414 men) was collected, along with a sample from the external genitalia. The different samples were tested for 27 HPV types using a polymerase chain reaction based strip assay. RESULTS: HPV DNA was detected more frequently in external genitalia samples (46.4%) than in the urethra (20.8%) or meatus samples (12.1%). Lack of samples from the urethra or meatus would have led to 5.1% and 1.5% false HPV negative results, respectively. The most frequently detected high risk HPV types (HPV 59, 52, 51, and 16) were similar in different sites, whereas low risk types were found rarely in urethra samples. CONCLUSIONS: The addition of cell samples from the meatus to those from external genitalia contributed negligibly to the evaluation of the prevalence of HPV in men. HPV detection was slightly improved by the addition of urethra samples, but the gain may not justify the discomfort of the procedure in large epidemiological studies.

Cryoablation of benign breast tumors: evolution of technique and technology.

We report on improvements in cryoprobe design and techniques of cryoablation as a minimally invasive alternative to open surgery for the treatment of benign breast tumors. In the study, which was conducted in 12 centers, 124 lesions in 102 patients were monitored for a period of 12 months after cryoablation. Two different treatment techniques were used: Double HI FREEZE and Tailored Freeze. In patients treated with the Tailored Freeze technique significantly better results were recorded 12 months after the procedure: the median reduction in tumor volume was 91%, 73% of all tumors treated were nonpalpable, 84% of lesions less than 2.5 cm in maximum diameter were nonpalpable, and none of the 31 mammograms performed yielded abnormal findings. Patient satisfaction was good to excellent in 92% of the patients. The safety profile of this technique was excellent; all complications were minor. Evolution of cryoablation freezing techniques, coupled with improvements in cryoprobe design, has resulted in significant improvements in both safety and effectiveness.

A population based study of herpes simplex virus 2 seroprevalence in rural Costa Rica.

OBJECTIVES: To determine seroprevalence and determinants of herpes simplex virus 2 (HSV-2) seropositivity, in a random sample of a population based cohort of 10 049 women of Guanacaste, Costa Rica, using a highly sensitive and specific serological assay. METHODS: Seroprevalence was determined by a type specific HSV-2 ELISA assay in an age stratified random sample of 1100 women. Univariate and multivariate logistic regression was used to calculate odds ratios and 95% confidence intervals for risk factors of seropositivity. RESULTS: Overall age adjusted HSV-2 seroprevalence was 38.5% (95% CI, 37.5 to 39.5), and it was strongly associated with increasing age (p(Trend<0.0001)), both among monogamous women and women with multiple sexual partners. A greater number of lifetime sexual partners increased the risk of seropositivity, with a 28.2% (95% CI, 24.4 to 32.2) seroprevalence among monogamous women and 75% (95% CI, 65.6 to 83.0) seroprevalence for those with four or more partners (OR = 7.6 95% CI, 4.7 to 12.4 p(Trend<0.0001)). Barrier contraceptive use was negatively associated with HSV-2 seropositivity (OR 0.54, 95% CI, 0.31 to 0.94). Women with antibodies against HPV 16, 18, or 31 were 1.6 times more likely to be HSV-2 seropositive (OR 1.6, 95% CI, 1.2 to 2.1). CONCLUSIONS: HSV-2 infection is highly endemic in Guanacaste, even among lifetime monogamous women, suggesting a role of male behaviour in the transmission of the infection. Until vaccination against HSV-2 is available, education to prevent high risk sexual behaviour and the use of condoms appear as preventive measures against HSV-2.

Survey of bat populations from Mexico and Paraguay for rabies.

A mammalian survey was conducted in Mexico (October 1994-January 1996) and in Paraguay (August 1996-March 1997); a complete specimen was collected for each bat in the survey, including primary voucher specimen, ectoparasites, karyotype, and various frozen tissues. The surveys combined provided 937 brain samples (65 bat species) for rabies diagnosis. One male Lasiurus ega, collected in Paraguay, tested positive for the rabies virus (overall prevalence rate of 0.1%). Nucleotide sequence from a 300 bp region of the rabies nucleoprotein gene was compared with sequence obtained from representative rabies virus samples in the repository at the Centers for Disease Control and Prevention (Atlanta, Georgia, USA). Rabies virus extracted from the brain material of L. ega differed by only one nucleotide from a 300 bp consensus sequence (>99% homology) derived from samples for the variant of rabies virus transmitted by Lasiurus cinereus. Lasiurus ego differed by approximately 15% for the variant transmitted by Desmodus rotundus. Phylogenetic analysis found no evidence to suggest L. ego is a reservoir for rabies antigenic variant 6. The most likely explanation for rabies in L. ega was infection following contact with a rabid L. cinereus.

High prevalence of antibodies to herpes simplex virus type 2 among middle-aged women in Mexico City, Mexico: a population-based study.

BACKGROUND: Herpes simplex virus type 2 (HSV-2) is among the most prevalent sexually transmitted diseases worldwide. In Mexico there is a lack of population-based HSV-2 surveys. GOALS: To determine population-based HSV-2 seroprevalence and risk factors among women in Mexico City. STUDY DESIGN: A random sample of 730 women was identified among the residents of Mexico City. Women ages 25 to 85 years were selected from 3,694 households. Western blot serology testing was conducted on serum samples to determine HSV-2 type-specific serostatus. A structured questionnaire was administered, and multivariate analyses were performed to identify risk factors for HSV-2 seropositivity, which were stratified into two age categories: younger than 50 years of age and 50 years of age or older. RESULTS: The HSV-2 seroprevalence among female participants was 29.8%, with a significant trend of increasing HSV-2 prevalence for each higher level of age (P < 0.001). Female participants had a median age of 46 years and were predominantly monogamous (82.6%). The overall population-based seroprevalence estimated in Mexico City among women was 35.8%. The independent risk factors for HSV-2 seropositivity included a history of two or more sexual partners (odds ratio [OR], 2.2; 95% CI, 1.4-3.4), two or more sexual partners before first pregnancy (OR, 2.3; 95% CI, 1.4-3.7), cohabitation with partner (OR, 2.5; 95% CI, 1.3-4.7), and current vaginal douching (OR, 1.7; 95% CI, 1.2-2.6). CONCLUSIONS: Population-based HSV-2 seroprevalence is endemically high among middle-age women in Mexico City, and clearly is correlated with higher-risk sexual behavior. This elevated HSV-2 seroprevalence may reflect unrecognized HSV-2 transmission throughout life.

Prevalence and risk factors for herpes simplex virus type 2 infection among middle-age women in Brazil and the Philippines.

BACKGROUND: Data comparing type-specific herpes simplex virus type 2 (HSV-2) seroprevalence and risk factors between comparable populations are largely unavailable, particularly from less-developed countries. GOAL: To examine the seroprevalence of HSV-2 infection and the risk factors for this infection among women in São Paulo, Brazil, and Manila, the Philippines. STUDY DESIGN: Altogether, 552 middle-aged women participating as control subjects in two cervical cancer studies were screened for type-specific HSV-2 antibodies. RESULTS: Herpes simplex virus type 2 seroprevalence was higher in Brazil (42%) than in the Philippines (9.2%). The mean ages of Brazilian (n = 181) and Filipino (n = 371) women were 52.4 and 46.6 years, respectively. Brazilian participants had more lifetime sexual partners, less education, and more often a husband with other sexual partners than Filipino women. Herpes simplex virus type 2 was independently associated with younger age at first intercourse in both countries. More than one lifetime sexual partner, a husband with other sexual partners, urban/semi-urban residence, and no history of condom use were HSV-2 risk factors in Brazil, but not in the Philippines, where long-term hormonal contraceptive use was associated with increased risk. CONCLUSIONS: The higher HSV-2 seroprevalence in Brazil than in the Philippines may be explained largely by differences in the sexual behavior of women and their husbands. Herpes simplex virus type 2 seroprevalence data may be used as a marker of past sexual behavior for the direct comparison of different population groups.

Human papillomavirus infection and invasive cervical cancer in Paraguay.

HPV types 16 and 18 have been categorized as human carcinogens based on their strong associations with cervical cancer in previous case-control studies. Recent IARC studies in the Philippines, Thailand and Morocco show strong associations between invasive cervical cancer and less common HPV types, including HPV 31, 33, 45, 51, 52 and 58. We present results of a further IARC case-control study conducted in Asunción, Paraguay, to examine the association between specific HPV types and invasive cervical cancer as well as risk factors other than HPV. One-hundred thirteen incident histologically confirmed invasive cervical cancer cases and 91 age-matched hospital controls were recruited. A standardized questionnaire was administered to investigate known and suspected risk factors for cervical cancer. For HPV status determination, cervical biopsy specimens from case subjects and exfoliated cervical cells from control subjects were obtained. HPV DNA was ascertained using a GP5+/6+ PCR-based assay capable of detecting more than 33 HPV types. Overall HPV prevalence was 97% in the cervical cancer cases and 20% in the control subjects. As a single infection, HPV 16 was the predominant type with a prevalence of 48% among case subjects and 5.5% among control subjects. Significant associations with the risk of cervical cancer were detected as follows: any HPV type (OR = 114; 95% CI: 36-361); HPV 16 (OR = 910); HPV 18 (infinite OR); HPV 31 (OR = 110); HPV 33 (OR = 261); HPV 45 (OR = 129); and HPV 58 (OR = 36). In the multivariate model, risk factors other than HPV significantly associated with cervical cancer risk were a higher number of lifetime sexual partners, lower educational status and never having had a Pap smear. Strong associations were found between invasive cervical cancer and specific HPV types 16, 18, 31, 33, 45 and 58.

Rabies surveillance in the United States during 1998.

During 1998, 49 states, the District of Columbia, and Puerto Rico reported 7,961 cases of rabies in nonhuman animals and 1 case in a human being to the Centers for Disease Control and Prevention, a decrease of 6.5% from 8,509 cases in nonhuman animals and 4 cases in human beings reported in 1997. More than 92% (7,358 cases) were in wild animals, whereas > 7.5% (603 cases) were in domestic species (compared with 93% in wild animals and 7% in domestic species in 1997). Decreases were evident in all of the major contributing species groups, with the exception of skunks and bats. The relative contributions of the major groups to the total reported for 1998 were reccoons (44.0%; 3,502 cases), skunks (28.5%; 2,272), bats (12.5%; 992), foxes (5.5%; 435), cats (3.5%; 282), cattle (1.5%; 116), and dogs (11.5%; 113). No further discernable westward extension of the epizootic of rabies in raccoons in Ohio was reported. Twelve of the 19 states enzootic for the raccoon variant of the rabies virus and the District of Columbia reported decreased numbers of cases of rabies during 1998, compared with 13 states and the District of Columbia that reported increases during 1997. Three states, Rhode Island (143.2%), Massachusetts (77.2%), and New Hampshire (69.4%), reported increases of > 50% during 1998, compared with totals reported for 1997. In Texas, the number of cases of rabies associated with enzootic canine variants of the rabies virus remained greatly diminished; however, overall totals of reported cases of rabies increased in Texas and 12 other states where skunks are the major terrestrial reservoir of rabies. At the national level, the total of 82 reported cases of rabies among horses and mules was greater than that reported for any year since 1981 (88 cases) and represented a 74.5% increase, compared with the total for 1997. The 992 cases of rabies reported in bats during 1998 were the greatest proportionate contribution by bats since 1990. Reported cases of rabies in cats (282), dogs (113), and cattle (116) decreased 6.0%, 10.3%, and 4.9%, respectively. One indigenously acquired case of rabies reported in a human being during 1998 was the result of infection with a rabies virus variant associated with silver-haired and eastern pipistrelle bats.

Molecular characterization of rabies virus isolates from Mexico: implications for transmission dynamics and human risk.

Twenty-eight samples from humans and domestic and wild animals collected in Mexico between 1990 and 1995 were characterized by using anti-nucleoprotein monoclonal antibodies and limited sequence analysis of the nucleoprotein gene. The variants of rabies viruses identified in these samples were compared with other isolates from Mexico and the rest of the Americas to establish epidemiologic links between cases and outbreaks and to increase the understanding of rabies epidemiology in the Western Hemisphere. Antigenic and genetic diversity was found in all samples from dogs and dog-related cases, suggesting a long-term endemic situation with multiple, independent cycles of virus transmission. Two isolates from bobcats were antigenically and genetically homologous to the rabies variant circulating in the Arizona gray fox population, indicating a wider distribution of this variant than previously reported. Rabies isolates from skunks were unrelated to any variant analyzed in this study and represent a previously unrecognized cycle of rabies transmission in skunks in Baja California Sur. Two antigenic and genetic variants co-circulating in southern and eastern Mexico were found in viruses obtained from cases epidemiologically related to vampire bats. These results serve as a baseline for the better understanding of the molecular epidemiology of rabies in Mexico.

Laboratory investigation of human deaths from vampire bat rabies in Peru.

In the spring of 1996, multiple cases of an acute febrile illness resulting in several deaths in remote locations in Peru were reported to the Centers for Disease Control and Prevention (CDC). The clinical syndromes for these cases included dysphagia and encephalitis. Because bat bites were a common occurrence in the affected areas, the initial clinical diagnosis was rabies. However, rabies was discounted primarily because of reported patient recovery. Samples of brain tissue from two of the fatal cases were received at CDC for laboratory confirmation of the rabies diagnosis. An extensive array of tests on the formalin-fixed tissues confirmed the presence of both rabies viral antigen and nucleic acid. The virus was shown to be most closely related to a vampire bat rabies isolate. These results indicate the importance of maintaining rabies in the differential diagnosis of acute febrile encephalitis, particularly in areas where exposure to vampire bats may occur.

Rabies surveillance in the United States during 1997.

In 1997, 49 states, the District of Columbia, and Puerto Rico reported 8,509 cases of rabies in nonhuman animals and 4 cases in human beings to the Centers for Disease Control and Prevention. Nearly 93% (7,899) were wild animals, whereas 7% (610) were domestic species. The total number of reported cases increased 19.4% from that of 1996 (7,128 cases). Increases were apparent in each of the major species groups, with the exception of cattle. The relative contributions of these groups to the total reported for 1997 were as follows: raccoons (50.5%; 4,300 cases), skunks (24.0%; 2,040), bats (11.3%; 958), foxes (5.3%; 448), cats (3.5%; 300), dogs (1.5%; 126), and cattle (1.4%; 122). The 958 cases of rabies reported in bats represented a 29.3% increase over the total reported for 1996 and the greatest number reported since 1984, with cases reported by 46 of the 48 contiguous states. The epizootic of rabies in raccoons expanded into Ohio in 1997 and now includes 19 states and the District of Columbia. Thirteen states, where rabies in raccoons is enzootic, reported increases over 1996 in total numbers of reported cases. New York (1,264 cases), North Carolina (879), Virginia (690), and Maryland (619) reported the greatest numbers of cases [corrected]. Five states reported increases that exceeded 50%, compared with cases reported in 1996: Ohio (673.3%; 15 cases in 1996 to 116 in 1997). Massachusetts (144.3%; 115 to 281), South Carolina (97.9%; 96 to 190), Connecticut (97.4%; 274 to 541), and Maine (86.3%; 131 to 244). Cases of rabies associated with foci of rabies in foxes in west central Texas and in dogs and coyotes in southern Texas continued to decline, with this state reporting 78.3% fewer rabid foxes (13 cases), 26.7% fewer rabid dogs (11), and 63.2% fewer rabid coyotes (7) during 1997, compared with 1996. Reported cases of rabies in cats (300) and dogs (126) increased 12.8% and 13.5%, respectively, whereas cases in cattle (122) decreased by 6.9%. Thirty states, the District of Columbia, and Puerto Rico reported increases in rabies in animals during 1997, compared with decreases reported by 31 states and the District of Columbia in 1996. One state (Mississippi; 5 cases) remained unchanged. Hawaii was the only state that did not report a case of rabies in 1997. Four indigenously acquired cases of rabies reported in human beings were the result of infection with rabies virus variants associated with bats.

Rabies surveillance in the United States during 1996.

In 1996, 49 states, the District of Columbia, and Puerto Rico reported 7,124 cases of rabies in non-human animals and 4 cases in human beings to the Centers for Disease Control and Prevention. Nearly 92% (6,550 cases) were wild animals, whereas 8% (574 cases) were domestic species. The total number of reported cases decreased 9.6% from that of 1995 (7,881 cases). Although much of the decline was the result of fewer reported cases of rabies in raccoons, fewer cases were also reported among most groups of animals. Numbers of cases associated with separate epizootics of rabies in foxes in west central Texas and in dogs and coyotes in southern Texas attributable to canine variants have declined, with 56.2% fewer rabid foxes (60), 72.7% fewer rabid dogs (15), and 76.3% fewer rabid coyotes (19) during 1996, compared with cases of rabies reported among these same species during 1995. Nationally, the number of reported rabid bats (741) decreased 5.8%, with cases reported by 46 of the 48 contiguous states. Four Eastern Seaboard states, enzootic for the raccoon variant of the rabies virus, reported noteworthy increases in total numbers of reported cases: Maine (29.7%; 101 cases in 1995 to 131 in 1996), Maryland (44.2%; 441 to 636), North Carolina (59.0%; 466 to 741), and Virginia (33.3%; 459 to 612). Increases were also reported by Florida (6.4%; 251 to 267) and Georgia (3.1%; 294 to 303). Cats continued to be the domestic animal most frequently reported rabid, but reported cases of rabies in cats (266), cattle (131), and dogs (111) decreased by 7.6%, 3.7%, and 24.0%, respectively. Thirty-one states and the District of Columbia reported decreases in rabies in animals during 1996, compared with 18 states and Puerto Rico in 1995. Hawaii was the only state that did not report a case of rabies in 1996. Two indigenously acquired cases of rabies reported in human beings were the result of infection with rabies virus variants associated with bats, whereas the remaining 2 human rabies infections were acquired outside the United States, and the variants identified were consistent with those associated with rabid dogs.

Rabies surveillance in the United States during 1995.

In 1995, 49 states, the District of Columbia, and Puerto Rico reported 7,877 cases of rabies in nonhuman animals and 4 cases in human beings to the Centers for Disease Control and Prevention. Nearly 92% (7,247 cases) were wild animals, whereas 8% (630 cases) were domestic species. The total number of reported cases decreased 4.2% from that of 1994 (8,230 cases). Most of the decline was the result of 17.1% fewer reported cases of rabies in raccoons in areas of the Northeast, where rabies is now enzootic rather than epizootic. Exceptions to this decline were detected in states where the virus has only recently entered raccoon populations or where ongoing epizootics persist. States experiencing increasing epizootic activity associated with this variant include Maine (3 cases in 1993 to 101 cases in 1995), North Carolina (9 cases in 1990 to 466 cases in 1995), Rhode Island (1 case in 1993 to 324 cases in 1995), and Vermont (45 cases in 1993 to 179 cases in 1995). The raccoon variant of the rabies virus is now present in Alabama, Pennsylvania, Vermont, West Virginia, and all Atlantic Seaboard states from Florida to Maine. In Ohio, this variant, last detected in 1992 as a single case, was again detected in 1996. Epizootics of rabies in foxes in west central Texas and in dogs and coyotes in southern Texas attributable to canine variants continue, with this state reporting 137 rabid foxes, 55 rabid dogs, and 80 of the 83 cases in coyotes during 1995. The number of rabid bats (787) increased by almost 25%, with cases reported by 47 of the 48 contiguous states. Nationally, reported cases of rabies in cattle (136) and cats (288) increased by 22.5 and 7.9%, respectively, whereas cases in dogs (146) decreased by 4.6%. Cats continued to be the domestic animal most frequently reported rabid. The cases of rabies reported in human beings were all caused by viral variants associated with bats. Eighteen states and Puerto Rico reported decreases in rabies in animals in 1995, compared with 28 states and the District of Columbia in 1994. Hawaii was the only state that did not report a case of rabies in 1995.

Genetic characterization of rabies field isolates from Venezuela.

Twenty samples from cases of rabies in humans and domestic animals diagnosed in Venezuela between 1990 and 1994 and one sample from a vampire bat collected in 1976 were characterized by reactivity to monoclonal antibodies against the viral nucleoprotein and by patterns of nucleotide substitution in the nucleoprotein gene. Three antigenic variants were found: 1, 3, and 5. Antigenic variant 1 included all samples from dogs and humans infected by contact with rabid dogs. Unique substitutions permitted identification of two separate outbreaks of dog rabies in the Maracaibo Depression and Los Llanos region and in the Andean region of Venezuela. Samples from the vampire bat and two head of cattle were characterized as antigenic variant 3 and showed a nucleotide sequence homology of 96 to 98% to each other and to samples of vampire bat-associated rabies throughout Latin America. Ten of the remaining 12 samples were characterized as antigenic variant 5. Genetic studies indicated that 11 of these samples formed a highly homologous and distinctive group but were closely related to samples of vampire bat-associated rabies. The 12th sample of variant 5 (from a cat) showed only 78 to 80% genetic homology to samples of rabies associated with vampire bats. The application of antigenic and genetic typing to rabies surveillance in Latin America is essential to improve control programs. Recognition of the source of outbreaks of dog rabies and identification of wildlife species maintaining sylvatic cycles of rabies transmission permit better utilization of public health resources.

Rabies surveillance in the United States during 1994.

In 1994, 48 states, the District of Columbia, and Puerto Rico reported 8,224 cases of rabies in nonhuman animals and 6 cases in human beings to the Centers for Disease Control and Prevention. Nearly 93% (7,632 cases) were wild animals, whereas 7% (592 cases) were domestic species. The total number of reported cases decreased 13.4% from that of 1993 (9,498 cases), with most of the decline resulting from 19.2% fewer cases of rabies in raccoons. Two previously described epizootics of rabies involving the raccoon variant of the rabies virus have converged in North Carolina, and the resulting region is now continuous from Alabama and Florida in the South to Maine in the North. Epizootics of rabies in foxes in west central Texas and in dogs and coyotes in southern Texas continue to expand, with this state reporting 144 rabid foxes, 53 rabid dogs, and 77 of the 85 cases in coyotes during 1994. Maine and New Hampshire reported cases of rabies in foxes (6 and 9, respectively) for the first time in 10 years. Nationally, reported cases of rabies in dogs (153) increased by 17.7%, whereas cases in cattle (111) and cats (267) decreased by 14.6 and 8.3%, respectively. Cats continued to be the domestic animal most frequently reported rabid. Twenty-eight states and the District of Columbia reported decreases in rabies in animals in 1994, compared with 22 states, the District of Columbia, and Puerto Rico in 1993. Hawaii and Nebraska were the only states that did not report cases of rabies in 1994.

Rabies surveillance in the United States during 1993.

In 1993, 49 states, the District of Columbia, and Puerto Rico reported 9,495 cases of rabies in nonhuman animals and 3 cases in human beings to the Centers for Disease Control and Prevention. Greater than 93% (8,889 cases) were wild animals, whereas 6.4% (606 cases) were domestic species. The total number of reported cases increased 9.9% over that of 1992 (8,645 cases), with most of the increase resulting from continued spread of rabies in raccoons (37.1% increase in reported cases over 1992). The 2 epizootics of rabies in raccoons (Northeastern/mid-Atlantic and Southeastern regions) approach convergence in North Carolina (106 cases of rabies in 1993, compared with 49 in 1992). Maine, Rhode Island, and Vermont remained the only New England states without reported cases associated with the raccoon variant of the rabies virus. New York reported 2,747 cases of rabies, the largest number of cases ever reported during a single year by any state. Increases in reported cases of rabies in Texas and 8 other geographically dispersed states were attributed mainly to larger numbers of reported cases of rabies in bats. Texas reported 71 of the 74 cases in coyotes during 1993 (70 of 75 cases in 1992). Nationally, reported cases of rabies in dogs (130) and cattle (130) each decreased by 29% in 1993, whereas cats (291 cases in 1993, compared with 290 in 1992) continued to be the domestic animal most frequently reported rabid. Twenty-two states and Puerto Rico reported decreases in rabies in animals in 1993, compared with 20 states, the District of Columbia, and Puerto Rico in 1992. Hawaii was the only state that did not report a case of rabies in 1993.

Antigenic analysis of rabies-virus isolates from Latin America and the Caribbean.

A total of 288 rabies-virus samples from 17 Latin American and Caribbean countries were reacted with an array of monoclonal antibodies. Identification of eight distinct antigenic variants among these samples permitted epidemiologic studies of the geographic distribution of different concentrations of rabies in the region and of the animal species serving as maintenance sources for rabies within a concentrated area. Two variants were broadly distributed and associated with enzootic disease in dogs and vampire bats. All isolates from cases of human rabies contained one of these two variants. Two variants had a limited distribution: an outbreak in Brazil, primarily affecting dogs and believed to be maintained by dog-to-dog transmission, and nine cases of rabies in cattle in Venezuela, animal reservoir unknown. A reservoir of rabies in insectivorous bats was identified and the associated variant was found in a rabid domestic cat. The remaining three rabies variants were found in single isolates only, but due to inference from antigenic-typing data from North American samples, were believed to be maintained by reservoirs of rabies in hoary bats, foxes, and skunks.

Intestinal nematode infections in children: the pathophysiological price paid.

The mechanism by which small animals such as rodents resist or eliminate nematode parasites requires mucosal inflammation as the final effector of the immune response. The resulting freedom from chronic infection may be worth the price of short-term illness. Putative vaccines which attempt to enhance the natural effect will have to take into account the inflammatory cost to the host. Human helminthiases involve a more stable equilibrium between host and parasite. The medical literature on hookworm disease and clinical ascariasis describes, for the former, some chronic inflammatory effects correlated with worm burden, but for the latter a less quantified or predictable set of detrimental effects. We describe a current, systematic study of the inflammatory response to whipworm infection, in which anaemia, growth retardation and intestinal leakiness are viewed as predictable consequences related to infection intensity. There is evidence for the absence of cell-mediated immunopathology. However, a specific, IgE-mediated local anaphylaxis may, at least partly, mediate the deleterious effects. Increased numbers of mucosal macrophages may also contribute to the chronic, systemic effects through their output of cytokines. Similar attempts to show the mechanisms of pathogenesis and quantify the effects of hookworm disease should be undertaken.

Unexplained rabies in three immigrants in the United States. A virologic investigation.

BACKGROUND: Extensive investigation of three patients who died of rabies in the United States failed to reveal any source of exposure to the disease. The three patients had immigrated to the United States from areas in Laos, the Philippines, and Mexico where rabies is endemic. METHODS: We studied rabies viruses isolated from the three patients, other patients with a known source of exposure, and animals in the United States, Thailand (as a proxy for Laos), the Philippines, and Mexico. The viruses were characterized by indirect immunofluorescence and neutralization tests according to their reactions to panels of monoclonal antibodies. Transcribed complementary DNA from these isolates was amplified by the polymerase chain reaction; the DNA product was then analyzed by differential digestion with restriction enzymes. RESULTS: The viral isolate from each of the three patients was a rabies variant with distinctive antigenic or genetic characteristics. For each of the three isolates, identical variants were found in specimens from rabid animals obtained from or near the country in which the patient lived before immigrating to the United States. None of these variants were found among the isolates collected from rabid animals in the United States. CONCLUSIONS: Rabies infection in these three patients did not originate in the United States but resulted from exposures in Laos, the Philippines, and Mexico. Since the three patients had lived in the United States for 4 years, 6 years, and 11 months, our findings suggest that the onset of the clinical manifestations of rabies occurred after long incubation periods.

Rabies surveillance in the United States during 1989.

In 1989, 4,808 cases of rabies in animals other than human beings were reported to the Centers for Disease Control, 1.8% more (4,724 to 4,808) than in 1988. Eighty-eight percent (4,224/4,808) of those affected were wild animals and 12% (584/4,808) were domestic animals. Cases were reported from 49 states, the District of Columbia, and Puerto Rico; Hawaii remained rabies-free. Skunks (1,657) continued to be the most commonly reported rabid wild animal. For the second consecutive year, more cats (212) were reported to be infected with rabies virus than any other domestic species. Compared with their 1988 reports, 5 states reported increases of greater than 100% (Alaska, 109%; New Jersey, 233%; Ohio, 133%; Oklahoma, 168%; and Washington, 125%), and 5 states reported decreases of greater than 50% (Connecticut, 63%; Mississippi, 56%; Montana, 67%; Nevada, 55%; and West Virginia, 53%) in 1989.