A decrease in mother-to-child transmission of human T lymphotropic virus type I (HTLV-I) in Okinawa, Japan

To investigate the chronologic change of mother-to-child transmission of human T lymphotropic virus type I (HTLV-I) in Okinawa, Japan, the presence of antibody to HTLV-I was tested in 4,187 healthy residents between, 4,528 nursery school children, and 3,837 pregnant women between 1968 and 2000. The chronologic change of the feeding method and the length of the breast-feeding period among 1,117 healthy mothers from 1937 to 1995 were also obtained by interview. Age-adjusted prevalence of HTLV-I among healthy residents decreased from 9.1% in 1968-1970 to 7.8% in 1981-1984 and to 6.3% in 1996-1998. The crude prevalence of antibody to HTLV-I among healthy residents less than 20 years old decreased significantly from 4.6% in 1968-1970 to 0.1% in 1996-1998 (P < 0.0001). The prevalence of antibody to HTLV-I among nursery school children decreased significantly over the study period, from a high of 1.8% in 1984 to a low of 0.2% in 1998 (P = 0.03). The prevalence among pregnant women decreased significantly from 5.6% in 1989-1992 to 3.7% in 1997-2000 (P = 0.0275). Prior to 1967, all healthy mothers breast-fed their children. After 1968, the use of bottled and mixed milk (breast milk and bottled milk) increased, with bottled milk becoming predominant after 1990 (89%). The percentage of healthy mothers breast-feeding for more than one year significantly decreased from 68.3% in 1937-1947 to 0.4% in 1990-1995 (P < 0.0001). Infection with HTLV-I in Okinawa has decreased mainly due to a reduction in the number of mothers breast-feeding and a shortening of the breast-feeding period. However, because the mother-to-child transmission rate among non-breast-feeders decreased from 12.8% in 1986-1991 to 3.2% in 1995-1999, there may be other factors involved in the decrease in mother-to-child transmission.     

Human T cell lymphotropic virus infection in Guaymi Indians from Panama

Preliminary studies found that 9% of Guaymi Indians from Bocas del Toro province have antibody to human T cell lymphotropic virus (HTLV-I/II). The present study enrolled 317 (21% of the population) Guaymi Indians from Changuinola, the capital of Bocas del Toro province and 333 (70% of the population) from Canquintu, an isolated rural village. Demographic information and family relationships were ascertained and subjects were screened for neurologic diseases. Serum specimens were screened by an enzyme-linked immunosorbent assay for HTLV-I/II antibody and positives were confirmed according to U.S. Public Health Service criteria. Twenty-five (8%) Guaymi residing in Changuinola and 7 (2.1%) from Canquintu were confirmed seropositive. In Changuinola, antibody was virtually limited to residents greater than or equal to 15 years of age (24 [16%] of 153) and rates were slightly higher in males than in females; in Canquintu, antibody rates did not increase significantly with age and appeared higher in females than in males. In Changuinola, there was no evidence for household clustering of infection. In contrast, HTLV antibody among Canquintu residents clustered significantly by household. HTLV-associated neurologic disease was not detected in either population. The atypical seroepidemiology observed in both locations might be explained if the virus endemic to the Guaymi differed from HTLV-I previously described in the Caribbean basin and Japan.     

Prevalence of complement fixing antibody to Mycoplasma pneumoniae in Thai children.

The prevalence of antibodies to Mycoplasma pneumoniae was determined in normal Thai children by means of complement fixation. There were 445 children (243 boys and 202 girls) of different ages, ranging from newborn to 15 years. The lowest frequency of complement-fixing antibody was found in children age 1-3 months, and highest in children age 6-10 years which corresponds to the age distribution of symptomatic M. pneumoniae infection. The lowest and highest titers measured were less than 1:8 and 1:512 respectively. The prevalence of complement fixing antibody of titers more than or equal to 1:8, 1:32, 1:64 and 1:128 were 61.3, 31.7, 25.4 and 10.3 per cent of total children, respectively. Among children less than one month old, the frequency of complement fixing antibody of titers greater than or equal to 1:32 was 12.2 per cent and decreased to 1.3 per cent among children from the age 1-3 months. This decrease probably represented the disappearance of maternal antibody over this period. An increase in both the frequency and the geometric mean titer was seen thereafter. The peak frequency of high titers (greater than or equal to 1:32), 81.1 per cent, occurred in children 6-10 year of age. Paired sera were obtained from 72 children with high titers of greater than or equal to 1:64, 9.7 per cent had four fold changes of titer which indicated recent infection.(ABSTRACT TRUNCATED AT 250 WORDS)     

Age specific patterns of change in the dynamics of Wuchereria bancrofti infection in Papua New Guinea

Results of a longitudinal study of the age-specific dynamics of Wuchereria bancrofti infection in a community of East Sepik Province, Papua New Guinea (PNG) are described. Microfilarial (mf) density and serum levels of W. bancrofti phosphorylcholine-containing antigen (PC-Ag) in individuals were used as indirect measures of adult worm burden. These parasitological data were collected from 126 subjects greater than 4 years of age at two time points, 12 months apart, prior to the administration of the antifilarial drug diethylcambamazine (DEC). No significant changes in levels of mf density were observed for the study population between these two time points. However, significant changes in the levels of circulating PC-Ag were noted in subjects less than or equal to 20 years of age, but not in subjects greater than 20 years of age, between these two time points. The apparent shorter half life of circulating PC-Ag compared to that of mf makes antigenemia a more sensitive measure of the dynamics of adult worm populations. These data are discussed in terms of a basic mathematical model describing the dynamics of adult worm populations in relation to their life expectancy and attrition of larvae during establishment. Consideration of these data in the context of this simple immigration/death model suggests that the differences observed in patterns of change in intensity of infection between subjects less than or equal to 20 years old and those greater than 20 years old may be consistent with the acquisition of resistance to superinfection with increasing age.     

Evaluation of a specific enzyme immunoassay for onchocerciasis using a low molecular weight antigen fraction of Onchocerca volvulus

A micro-ELISA technique has been developed for the diagnosis of onchocerciasis. With the use of a low molecular weight (LMW) fraction of a soluble, adult Onchocerca volvulus extract as an antigen, the problem of nonspecificity observed with the crude worm extract is negligible. Seventy-three sera from proven cases of other filarial infections were weakly reactive or nonreactive. From cross-sectional and longitudinal surveys in a West African village hyperendemic for onchocerciasis, we concluded that this assay detects antibodies elicited when female worms start to produce microfilariae. Thirty-two of 33 children aged less than or equal to 15 years with positive skin snips were seropositive. High antibody levels could also be found in children who only became parasitologically positive 1-4 years after seroconversion. This leads to the conclusion that serology is more sensitive than the 2-snip method. In individuals with chronic infection (exposed for greater than 15 years), antibody titers were consistently lower (independent of the density of skin microfilariae) than in the early phase of a patent infection. A comparative serological study in a mesoendemic village revealed that the assay can serve to assess onchocerciasis prevalence by testing individuals aged 5-15 years.     

Parasitologic and clinical features of bancroftian filariasis in a community in East Sepik Province, Papua New Guinea

Bancroftian filariasis has been reported in several areas of Papua New Guinea. The epidemiologic features and natural history of Wuchereria bancrofti infection in this geographic region, however, have not been well-defined. The objective of this study was to assess the parasitological and clinical features of bancroftian filariasis in a community in East Sepik Province, Papua New Guinea. In a village of 99 individuals, the overall prevalence of microfilaremia was 68%. The microfilarial carrier rate was high in those less than or equal to 10 years (62%), remained elevated in the 11-20, 21-30, and 31-40 age groups (42-55%), and peaked in subjects greater than or equal to 41 years old (90%). The geometric mean level of parasitemia in all subjects with patent infection was 3,198 microfilariae/ml blood. This value was 78 parasites/ml in the less than or equal to 10-year-old age group, increased to 1,753 in 21 to 30-year-olds and was markedly elevated in subjects greater than or equal to 41 years old (6, 792 microfilariae/ml). Acute symptoms of filariasis (lymphadenitis and lymphangitis) were initially noted in individuals between the ages of 11 and 20 years (30%). Obstructive disease, manifested as elephantiasis and hydroceles, was present in 64 and 79% of 31-40 and greater than or equal to 41-year-olds, respectively. These data suggest that intense transmission of W. bancrofti infection occurs at an early age in this area of East Sepik Province; patent infection remains high in older age groups. Irreversible lymphatic obstruction develops 20-30 years after initial infection and may be associated with either amicrofilaremia or microfilaremia.     

Sequential change of virus markers in seroconverters with community-acquired infection of human T lymphotropic virus type I

Twenty-three human T lymphotropic virus type I (HTLV-I) seroconverters were identified among 1120 HTLV-I-seronegative adults followed up for 11 years in an area of Japan endemic for HTLV-I. The geometric mean titer of anti-HTLV-I was 1:453 in the first year after seroconversion; the titer of each subject did not change significantly during 2-10 years of follow-up. HTLV-I proviral DNA load was quantified in 15 seroconverters, and a broad range of levels was observed-from <10 to >1000 copies/10(5) peripheral blood mononuclear cells. However, there was no obvious change in HTLV-I proviral DNA load over several years within individual subjects. Therefore, both proviral DNA load and humoral response in adult HTLV-I seroconverters were shown to stabilize within a few years after initial infection. In addition, 1 subject tested positive for HTLV-I proviral DNA before antibody seroconversion, which suggests the existence of a window period in community-acquired infection.     

Invasive disease due to Streptococcus pneumoniae in an area with a high rate of relative penicillin resistance

During 1984 we conducted a population-based survey of culture-confirmed invasive disease due to Streptococcus pneumoniae among persons who lived in the Oklahoma City, Oklahoma, metropolitan area (population, 846,000) through the 20 clinical laboratories in the area. There were 139 residents identified with invasive pneumococcal disease (11 with meningitis and 128 with other bacteremic infections), for an infection rate of 16.4 per 100,000 population (meningitis, 1.3 cases per 100,000; other bacteremias, 15.1 cases per 100,000). Cases peaked in January-May and December (75% of cases). Rates were highest among infants less than 12 months old (97 cases per 100,000) and persons greater than or equal to 80 years old (87 cases per 100,000). Seventeen (12.2%) of the pneumococcal isolates were relatively penicillin resistant. These isolates were most prevalent among elderly persons greater than or equal to 70 years old (six [17.6%] of 34) and young children 0-4 years old (7 [15.9%] of 44) compared with persons 5-69 years old (four [6.6%] of 61).     

Prevalence of antibodies to human immunodeficiency virus and to human T cell leukemia virus type I in transfused sickle cell disease patients

The prevalence of the human immunodeficiency virus (HIV) antibody and the human T cell leukemia virus type I (HTLV-I) antibody was examined in 116 adults with sickle cell disease. Eighty-eight of them had received a mean of 18.6 transfusions of red blood cells between 1978 and 1985, and none was positive for the HIV antibody. Of 116 patients, 9 (7.8%) tested positive for HTLV-I antibodies. HTLV-I-positive patients were similar to those without HTLV-I antibody with respect to age, number of transfusions, and proportion of patients with greater than 40 transfusions. However, 3 of the 9 HTLV-I-positive patients came from West Africa or from the Caribbean, whereas this proportion was much lower (7/107) in the HTLV-I-negative group (x2, 7.564; P less than .01). Our analysis suggests that the risk of HIV infection in transfused sickle cell disease patients is low. Although HTLV-I antibodies in these patients may not be related to blood transfusions, it seems prudent to screen blood donors for HTLV-I infection.     

Natural history of viral markers in children infected with human T lymphotropic virus type I in Jamaica

PURPOSE: We conducted a longitudinal analysis of human T lymphotropic virus type I (HTLV-I) viral markers in 28 Jamaican mothers and their children, who were monitored for a median of 6.2 years after the birth of the children. METHODS: The HTLV-I provirus DNA load was measured using the Taqman system (PE Applied Biosystems). The HTLV-I antibody titer was determined using the Vironstika HTLV-I/II Microelisa System (Organon Teknika). The HTLV-I Tax-specific antibody titers were measured using an enzyme-linked immunosorbent assay. Generalized estimating equations were used to describe the associations of exposure variables with sequentially measured levels of HTLV-I viral markers in children. RESULTS: The HTLV-I antibody titer increased significantly up to 1 year after infection, reaching equilibrium at a median titer of 1 : 7,786. The prevalence of Tax-specific antibody reached 80% at 2 years after infection. The provirus load increased up to 2 years after infection, reaching equilibrium at a median of 6,695 copies/100,000 peripheral blood mononuclear cells. The increase in the provirus load was significant only among children with eczema, but not among children without eczema. CONCLUSIONS: The provirus loads in children increased for an additional year after their antibody titers had stabilized, possibly as a result of the expansion of HTLV-I-infected clones. This effect was significant only for children with eczema. Among HTLV-I-infected children, eczema may be a cutaneous marker of the risk of HTLV-I-associated diseases developing in adulthood.     

New live attenuated influenza A/England/42/72 (H3N2) vaccine (Alice): reactogenicity,, immunogenicity, and protection efficacy.

The Alice strain of influenza A/England/42/72 (H3N2) live attenuated vaccine, when given by the intranasal route to 133 volunteers, was relatively nonreactogenic; only 12% of the vaccinees had upper respiratory tract symptoms after immunization. Seroconversion in 87.2% of subjects whose titers of humoral hemagglutination-inhibiting antibody before immunization were less than 1:8 demonstrated the immunogenicity of the vaccine. The overall seroconversion rate was 66.1% (geometric mean titer of hemagglutination-inhibiting antibody, 1:40.9). Antibody levels were unchanged at six months in 95.5% and at 12 months in 91.7% of the vaccinees. Because of the lack of natural influenza A infection during the season monitored, an experimental challenge study with homotypic virus (influenza A/Udorn/307/72 [H3N2]) was conducted eight months after immunization of a sample population of 22 subjects. Twelve of these subjects were vaccinees whose titers of hemagglutination-inhibiting antibody were greater than or equal to 1:64, and 10 were unimmunized controls whose titers of hemagglutination-inhibiting antibody were less than or equal to 1:8. The group with titers of greater than or equal to 1:64 represented 40.2% of the immunized population. The vaccine was highly effective in this selected group, with a 91% protection efficacy against illness and a 100% rate of protection against illness associated with influenza A infection.     

Protozoal enteric infections among expatriates in Bangladesh

In order to study the prevalence, incidence, and symptoms of infections with Giardia lamblia and Entamoeba histolytica, we followed 251 expatriates in Bangladesh over a 1-year period. Microscopic examination of fecal specimens was performed upon enrollment, at 3-month intervals, and during episodes of diarrhea. Specimens were cultured for bacteria and samples of serum and saliva were collected for antibody studies (IgG and SIgA). The prevalence of G. lamblia infections was 5.2% and the incidence 11.8%. Children aged less than or equal to 10 years and newcomers were most frequently infected (P less than 0.02). Symptoms were present in 37% of the subjects infected with G. lamblia. A systemic antibody response was observed in 57% of symptomatic patients and 35% of asymptomatic subjects during the first 2 months of infection. The prevalence and the incidence of E. histolytica infection were 3.2% and 8.6%, respectively. Infections with E. histolytica were correlated with the duration of stay in Bangladesh; less than 1 year 7% vs. greater than 3 years 26% (P less than 0.01). Most expatriates infected with E. histolytica were asymptomatic (90%). Three adult patients, who were resident in Bangladesh for less than 1 year, were symptomatic but none of them developed dysentery or a serological response. Four of 25 asymptomatic subjects had significant antibody titers. Three of these people were seropositive for ameba at the beginning of the study. The local immune response, reflected by specific secretory IgA in saliva samples, correlated poorly with both E. histolytica and G. lamblia infections.     

Seroprevalence of Chlamydia pneumoniae infection in Taiwan

OBJECTIVES: To survey the seroprevalence of Chlamydia pneumoniae (C. pneumoniae) infection in healthy subjects in Taiwan. MATERIALS AND METHODS: We used microimmunofluorescence antibody assay to survey the prevalence of antibodies to C. pneumoniae in 620 serum samples from healthy subjects aged 6 months to 86 years in Taiwan. RESULTS: The mean prevalence (+/-SD) of IgG antibodies against C. pneumoniae at titer greater than or equal 1:16 was 55.8% (range 7.8-81.8%). The antibody prevalence was low in children under the age of 10 years (7.8%), and increased rapidly with age. Most individual acquired infection during the second and third decades of life with highest antibody prevalence reached up to 81.8% at fifth decade of life and remained high (70%) thereafter. CONCLUSIONS: Chlamydia pneumoniae infection is highly endemic in Taiwan. These data contribute to the understanding of asymptomatic infections with C. pneumoniae in general population and should serve as a basis for studies on the role of C. pneumoniae infections and their related diseases.     

Serum antibody response to toxins A and B of Clostridium difficile

An enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies to toxins A and B of Clostridium difficile was developed. Serum samples from 340 patients were tested for determination of the age-related prevalence of antitoxin. Antibody to toxin A was present in 64% of patients more than two years old and antibody to toxin B in 66% of patients more than six months old. A strongly positive ELISA value correlated with the presence of cytotoxicity-neutralizing antibody (P less than 0.001). Strongly positive ELISA values were obtained more commonly in convalescent sera from 16 patients with C difficile-induced colitis than in sera from the control population (antibody to toxin A, P less than 0.05; antibody to toxin B, P less than 0.001). Testing of paired sera revealed significant increases in the titer of IgG antibody to toxin A or B. Ten of the 16 patients with colitis had IgM titers of greater than or equal to 1:160 to one or both toxins. The data presented suggest that antibodies to toxins A and B are present in the majority of older children and adults and that patients with C difficile-induced disease develop serologic responses to one or both toxins.     

Patterns of HIV-1 and HTLV-I/II in intravenous drug abusers from the middle atlantic and central regions of the USA

Seroprevalence of human immunodeficiency virus type 1 (HIV-1) and human T lymphotropic virus types I and II (HTLV-I/II) was determined among 1160 intravenous (iv) drug abusers from five drug treatment or medical centers (Manhattan, Brooklyn, New Jersey, Detroit, and New Orleans). HIV-1 infection ranged from 5% in New Orleans to 48% in New York City. Hispanics and blacks had a significantly higher rate of HIV-1 infection than whites (P less than .01), but within each group rates were similar between males and females and by age stratum. HTLV-I/II seroprevalence increased with age from 3% in the 20-29 year age group to 37% in the group greater than 50 years. New Orleans and Manhattan (24%) had the highest rate, and blacks (19%) had a higher rate than either Hispanics (6.3%) or whites (7.3%). No association between HIV-1 and HTLV-I/II infection was observed except in Manhattan. When compared with iv drug abusers infected only with HIV-1, dually infected subjects had more clinical symptoms related to immune deficiency but a lower prevalence of HIV antigenemia. These data document the frequent occurrence of retroviral infections in iv drug abusers. The contrast between the two classes of virus suggests that HIV-1 is more efficiently transmitted, while the age-dependent rise in HTLV-I/II seroprevalence suggests cumulative exposure of a less-transmissible agent.     

Prevalence of bacterial vaginosis and its association with genital infections, inflammation, and contraceptive methods in women attending sexually transmitted disease and primary health clinics

In an epidemiological survey of 2128 women attending a sexually transmitted diseases clinic for the first time and 200 attending two primary health clinics, 26% and 27% respectively were found to have bacterial vaginosis. The prevalence increased significantly with age, being diagnosed in 22.8% (326/1431) of women aged 14-24 years, and in 33.3% (232/697) of those aged greater than or equal to 25 years. Bacterial vaginosis was associated with gonorrhoea and with chlamydial infection, but was negatively associated with genital papillomavirus infection and yeast infection. Women using barrier contraceptives had a significantly lower prevalence of bacterial vaginosis than those using an intrauterine device or no contraceptive. Women less than or equal to 24 years old using oral contraceptives had a significantly lower prevalence of bacterial vaginosis than those not using contraceptives. Patients without gonorrhoea or chlamydial infection but with vaginal or urethral inflammatory signs had a significantly higher prevalence of bacterial vaginosis than those without inflammatory signs. These findings may have implications regarding complications associated with lower genital tract infections and may strengthen the hypothesis that bacterial vaginosis is a risk factor for pelvic inflammatory disease.     

Low prevalence of human immunodeficiency virus-1 (HIV-1), HIV-2, and human T cell lymphotropic virus-1 infection in Somalia.

A seroepidemiologic survey was conducted to determine the prevalence of human immunodeficiency virus type 1 (HIV-1), HIV-2, human T cell lymphotropic virus type I (HTLV-I), and Treponema pallidum infection among southern Somalis. Sera were collected from 1,269 study subjects in the urban area of the capital city, Mogadishu, and in the rural towns of Merka, Qoryoley, and Kismayo. The subjects included 57 prostitutes, 79 sexually transmitted disease (STD) patients, and 1,133 others, including outpatient and hospitalized patients with leprosy, tuberculosis, other infectious diseases, individuals from rehabilitation camps and secondary schools, and Ethiopian immigrants. Results indicated that none of the sera were positive for HIV-1 and HIV-2 by Western blot, but one was positive for HTLV-I. The prostitutes had a significantly higher prevalence of treponemal antibody (50.8%; P less than 0.0001) than either the STD patients (12.6%) or the other subjects (5.2%). Epidemiologic data indicated that 94% of the males and females were circumcised and only 2.6% of the males used condoms. Overall, the results of this study suggested a very low prevalence of HIV-1, HIV-2, and HTLV-I infections, especially among prostitutes and STD patients, who were considered at greatest risk of contracting these retroviral infections.     

A controlled double-blind comparison of reactogenicity, immunogenicity, and protective efficacy of whole-virus and split-product influenza vaccines in children.

A double-blind randomized study with bivalent influenza virus vaccines was conducted to compare the local and systemic reactions and immunogenicity of a whole-virus vaccine and a split-product vaccine in children. Fevers of greater than 100 F were more frequent after vaccination with whole-virus than split-product vaccine especially in children one to four years old (69% vs 22%; P less than 0.01). Fevers of greater than or equal to 103 F did not occur in children who previously had been given influenza virus vaccine, even in the absence of preexisting homologous serum antibody. The immune response to the A/Port Chalmers/1/73 antigen in the vaccine was similar after administration of either whole-virus or split-product vaccine. However, split-product vaccine induced significantly less hemagglutination-inhibiting antibody to B/Hong Kong/5/72 virus in children younger than 10 years who had not been previously immunized; only 43% developed detectable antibody vs. 100% of those vaccinated with whole virus vaccine (P less than 0.01). These studies indicate that (1) in young children whole-virus vaccine causes fever more frequently than split-product vaccine; (2) young children previously vaccinated with influenza virus vaccine are unlikely to experience fever subsequent to immunization with a related antigen; and (3) split-product vaccine induces less antibody to B/Hong Kong/5/72 virus than whole-virus vaccine in immunologically unprimed young children.     

Late seroconversion to hepatitis B in a Somali village indicates the important role of venereal transmission.

Hepatitis B virus (HBV) markers were investigated in a cross-sectional study in 1985 on sera from 84% of the 648 inhabitants in a rural Somali village. The prevalence of HBV markers increased with age, from 9.7% in subjects less than 12 years old, to 38% in the age group 12-19 years, and to 68% in adults. HBV markers were more common in boys less than 12 years old, 13%, than in girls of the same age group, 5.8% (P less than 0.05). A rapid increase of HBV markers started at adolescence in both sexes. The female cohort showed their highest seroconversion rate during their second decade of life, while the male cohort seroconverted more rapidly in the third decade. Thus, an initially more rapid seroconversion among boys was reversed when the females reached reproductive age, and no sex difference in marker frequencies was observed in the age group 12-19 years. There was a steady increase of HBV markers during the reproductive years in both sexes. The frequencies of HBsAg, as well as total markers, were significantly higher in adult males than females, 14 vs 5.6%, and 77 vs 62%, respectively. HBV markers were more frequent in wives of HBV positive husbands than in those married to HBV negative husbands. No increased marker prevalence was observed among siblings of HBV positive children, nor among their mothers, which disproved the role of vertical and early horizontal transmission. In 1989 the four-year rate of seroconversion was investigated in villagers who were seronegative in 1985. On testing 158 sera from 319 individuals, the seroconversion rate was significantly lower among those younger than 12 years in 1985 compared to those in the older age group, 5 vs 17%.(ABSTRACT TRUNCATED AT 250 WORDS)