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Biomedical subjects

K C Hyams

Publications and source records attributed to K C Hyams.

At least 19 recordsLinked to original sources
PubMed2000

Norwalk-like virus infection in military forces: epidemic potential, sporadic disease, and the future direction of prevention and control efforts.

The impact of Norwalk-like virus (NLV) infection on military forces is evaluated in this report. NLVs were a major cause of both outbreaks and sporadic disease among crowded US ground troops in the 1991 war with Iraq. NLVs also have been found to be a cause of acute gastroenteritis in other ground and shipboard deployments. Four large outbreaks of acute gastroenteritis were investigated aboard US Navy aircraft carriers between 1992 and 1997. In these outbreaks, NLVs were identified as the probable cause, and crowding was a major risk factor for transmission. An evaluation of a routine shipboard deployment also suggests that NLVs cause sporadic gastroenteritis. These data indicate that NLV infection is a major cause of acute morbidity in military forces. Because of the limitations of available prevention and control methods, development of a vaccine against these viruses may be the best solution in the military environment.

Caliciviridae Infections↗
PubMed2000

Chronic liver disease among U.S. military patients: the role of hepatitis C and G virus infection.

Thirty-nine patients with chronic liver disease who were being evaluated in a U.S. military treatment facility were tested for antibody to hepatitis C virus (anti-HCV) and for hepatitis G virus (HGV) RNA by reverse transcriptase-polymerase chain reaction. Serum samples from 20 patients (51%) were positive for anti-HCV by immunoblot assay. HGV RNA was found in the sera of only two patients, both of whom were also positive for anti-HCV. HGV appears to have a limited role in causing chronic liver disease in this population of military patients, many of whom had traveled outside the United States. However, HCV infection was commonly associated with chronic hepatitis and cirrhosis, as in civilian patients.

Adult↗
PubMed1999

Remote village survey for agents causing hepatosplenic disease in the Republic of Yemen.

The objective of this study was to epidemiologically describe potential infectious agents among rural people in the Republic of Yemen. This would aid clinicians in designing empirical therapy and public health officials in planning disease prevention. We sought to examine evidence for the geographical distribution of pathogens causing human hepatic and splenic disease among villagers and domestic animals living in three remote areas with differing altitudes. In June 1992, a cross-sectional survey was conducted at three survey sites of differing altitudes: 3080, 1440 and 250 m above sea level. Questionnaires, parasitic and serological tests were administered to 627 human volunteers. Additionally 317 domestic animals were studied. Malaria, schistosomiasis, and hepatitis B and C infections were found to be likely causes of human hepatic or splenic disease. Additionally, evidence of human and animal infections with the agents of brucellosis and Q fever was found: IgG antibodies against hepatitis E virus were discovered in two (2.0%) of the 100 volunteers. The prevalence of markers for human and animal disease was often lowest at the village of highest elevation, suggesting that increasing altitude, as a surrogate or a true independent risk factor, was protective against infection with the agents studied.

Adolescent↗
PubMed1999

Risk of Helicobacter pylori infection among long-term residents in developing countries.

The seroprevalence and incidence of Helicobacter pylori infection were determined among 312 North American missionaries who were serving in developing countries between 1967 and 1984. The majority (81%) resided in sub-Saharan Africa. When initially evaluated, the missionaries had a mean age of 40 years, 65% were female, and all were of white race/ethnicity. An ELISA showed that the initial prevalence of IgG antibody to H. pylori was 17%. After a mean of 7.4 years of service (1917 person-years of exposure), 37 (14%) of 259 initially seronegative subjects seroconverted to anti-H. pylori, giving an annual incidence of 1.9%. These data indicate a relatively higher risk of H. pylori infection among missionaries compared with an annual incidence of seroconversion of 0.3-1.0% in industrialized nations. Long-term residents in developing countries should be evaluated for H. pylori infection when gastrointestinal symptoms develop.

Adult↗
PubMed1999

Prevalence of enteric hepatitis A and E viruses in the Mekong River delta region of Vietnam.

A study of antibody prevalence for hepatitis A virus (HAV) and hepatitis E virus (HEV) was carried out in southwestern Vietnam in an area adjacent to a known focus of epidemic HEV transmission. The purpose of this investigation was first to provide a prevalence measure of hepatitis infections, and second to determine the outbreak potential of HEV as a function of the susceptible population. Blood specimens collected from 646 persons in randomly selected village hamlets were examined by an ELISA for anti-HEV IgG and anti-HAV IgG. The prevalences of anti-HEV IgG and anti-HAV IgG were 9% and 97%, respectively. There was a significant increase (P < 0.01) in age-specific anti-HEV IgG. A notable increase in anti-HAV IgG prevalence (P < 0.0001) occurred between child populations 0-4 (64%) and 5-9 (95%) years of age. No evidence of familial clustering of anti-HEV IgG-positive individuals was detected, and household crowding was not associated with the spread of HEV. Boiling of water was found to be of protective value against HEV transmission. A relatively low prevalence of anti-HEV indicates considerable HEV outbreak potential, against a background of 1) poor, water-related hygiene/sanitation, 2) dependence on a (likely human/animal waste)-contaminated Mekong riverine system, and 3) periodic river flooding.

Adolescent↗
PubMed1999

Seroprevalence of Helicobacter pylori among Egyptian newborns and their mothers: a preliminary report.

Helicobacter pylori is one of the most common human bacterial infections in the world and children in the developing countries acquire H. pylori infection early in life. We prospectively evaluated the prevalence of serum antibodies to H. pylori in a cohort of pregnant women and their offspring. Mothers' sera were collected during the third trimester of pregnancy and sera from their offspring were collected when they were 7-9 months and 18 months of age. Pylori-Stat, a commercially available ELISA kit, was used to detect antibodies to H. pylori in the serum of the subjects tested. Sera from 169 mothers were available for testing and 88% of these samples were positive for anti-H. pylori IgG. Of the 169 children tested, 13% of the infants 7-9 months of age and 25% of the children 18 months of age had serologic evidence of H. pylori infection. These data indicate that infection with H. pylori is common in Egypt and acquisition of infection occurs at a very young age.

Adolescent↗
PubMed1998

Acute jaundice in Vientiane, Lao People's Democratic Republic.

Analysis of serum samples from patients with acute jaundice by means of enzyme-linked immunosorbent assay and polymerase chain reaction testing provided the first profile of this condition in Vientiane, Lao PDR, in 1995 and 1996. In a case-control, hospital-based study, evidence of acute infections due to hepatitis A and B viruses was found in 14% and 10% of cases, respectively. Hepatitis E virus, however, did not appear to contribute to clinically recognized acute jaundice. Similarly, antibody to hepatitis C virus was recognized in almost equal proportions of cases (8%) and controls (6%), thus representing probable background infections. The detection of hepatitis G virus marks the first report of this virus in Lao PDR. The large proportion (21%) of new leptospiral infections in cases without acute hepatitis A or B was notable. This finding suggests significant regional underreporting of leptospirosis as a cause of acute jaundice. The limited laboratory diagnostic capabilities for confirming a differential diagnosis of leptospirosis contribute to the lack of attention paid to this important health problem.

Acute Disease↗
PubMed1998

A survey of women's health care needs on U.S. Navy ships.

A total of 628 female and 526 male U.S. military personnel completed a health survey questionnaire at the completion of four shipboard deployments lasting 10 to 180 days (mean, 57 days). During deployment, women visited clinic (sick call) at significantly higher rates than men: 189 versus 117 visits per week per 1,000 personnel. Except for generally minor gynecological conditions, women and men had similar medical problems. Upper respiratory complaints and requests for contraceptive pills were the most common reasons for clinic visits among women. The majority of sailors felt that they had received appropriate medical care, although fewer women (66%) than men (78%) were satisfied. Levels of cigarette and alcohol use and sexual activity were comparable among women and men and corresponded to those of the general U.S. population of young adults. Because of high levels of health, most medical needs of women sailors can be managed readily by providing routine gynecological care and by minor additions to the shipboard pharmacy.

Adolescent↗
PubMed1997

Oropouche virus transmission in the Amazon River basin of Peru.

Seroepidemiologic studies were conducted to determine the prevalence of Oropouche (ORO) viral antibody, risk factors, and the incidence of infection among residents of the Amazon region of Peru. Blood samples, as well as demographic, cultural, and medical history data, were collected from residents in a sector of the city of Iquitos and in an adjacent rural and three neotropical rain forest communities. Blood specimens were obtained approximately one year later from a cohort of the same study subjects who were negative for ORO antibody on the initial cross-sectional survey. Sera were tested for ORO IgG antibody by an enzyme-linked immunosorbent assay. Antibody prevalences were 35% for residents of the urban population, 24-46% for the forest communities, and 18% for the rural community. Antibody prevalence increased with age, and subjects who were seropositive were significantly (P = 0.001) older (mean = 33 years) than the seronegative subjects (mean = 15 years). Multivariate analysis revealed that only age, urban and forest residence, and occupation as a farmer or housekeeper remained significantly associated with seropositivity. Seroconversion data for the same populations one year later demonstrated evidence of ORO viral infection among 28% of the residents in the rural community and 2% or less in the forest and urban communities. Oropouche virus infection was significantly associated with older age (P = 0.04) in the rural community (P < 0.001). These data support prior evidence of ORO viral infection among residents of Iquitos and surrounding villages and suggest that transmission of this virus occurs continuously in the population of this area of the Amazon basin.

Adolescent↗
PubMed1997

Immunogenicity of recombinant hepatitis B vaccine among infants of mothers with active schistosomiasis.

A study of the immunogenicity of a recombinant hepatitis B vaccine was conducted among 385 Egyptian infants, 191 (49.6%) of whom were born to mothers with moderately active Schistosoma mansoni infection (mean egg count = 224 eggs/g of feces). All mothers were seronegative for hepatitis B surface antigen (HBsAg) and hepatitis B e antigen. Infants were vaccinated with a 2.5-microg dose of this vaccine, given along with diphtheria, tetanus, and pertussis (DTP) vaccine, at the ages of two, four, and six months. Serum samples taken from each infant at nine months of age were tested for HBsAg, antibody to hepatitis B core antigen, and quantitatively for antibody to hepatitis B surface antigen (anti-HBs). There was no significant difference (P = 0.1) between anti-HBs titers in infants of S. mansoni-infected mothers (mean = 539 mIU/ml) and in infants of noninfected mothers (mean = 377 mIU/ml). This study shows that there was no apparent effect of maternal schistosomiasis infection on the immune response of these infants to vaccination.

Adult↗
PubMed1997

Short report: evidence of worldwide transmission of hepatitis G virus.

Hepatitis G virus (HGV) has been recently documented in the Americas, Europe, and Australia. Distinct risk populations from North Africa, South America, and Southeast Asia were screened for HGV, in addition to hepatitis B and C viruses. First time recognition of HGV is described from Egypt and Indonesia. Notable is the high proportion of HGV positive individuals among multiply transfused children, ranging from 24% of those sampled from Egypt to 32% in Indonesia. Also, data from Peru suggest the likely association of HGV infection with progressive liver disease. Hepatitis G virus should be considered a world-wide health concern.

Flaviviridae↗
PubMed1997

Epidemic and sporadic hepatitis E virus transmission in West Kalimantan (Borneo), Indonesia.

A cross-sectional survey was conducted in West Kalimantan (Borneo), Indonesia to geographically profile hepatitis E virus (HEV) prevalence in the riverine areas recognized as the foci of epidemic HEV transmission in 1987. Additionally, a contiguous, although distinct, population with no identifiable historical exposure to epidemic HEV was surveyed downstream for comparative purposes. Eight hundred eighty-five sera were assayed by enzyme immunoabsorbent assay for anti-HEV IgG and anti-hepatitis A virus (HAV) IgG markers. A very high percent (90%) of both the outbreak and comparison populations was anti-HAV IgG positive by the age of nine years. In contrast, the prevalence of anti-HEV IgG in the outbreak area (50%) was significantly higher than in the comparison area (23%) (P < 0.0001). In both the outbreak and comparison areas, anti-HEV IgG prevalence increased with age ( < 0.0001), except for the group > or = 50 years of age. The prevalence (53%) of antibody to HEV in the population > or = seven years of age from the outbreak area (alive during the actual 1987 outbreak) was significantly (P < 0.0001) greater than among the children < seven years of age (born after the outbreak) (15%). However, anti-HEV IgG prevalence among the population from the comparison area did not differ significantly between the > or = seven- (23%) and < seven- (20%) year-old age groups. The percentage of anti-HEV IgG-positive individuals among males (47%) from the outbreak area was lower (P < 0.05) compared with females (55%). While overall usage of river water for drinking purposes was not universal, dependence on river water as a primary source was significantly higher (P < 0.001) in households from the outbreak area (60%) compared with the comparison area (30%). This study indicates persistence of an anti-HEV IgG response in a large percentage of the population seven years after an epidemic of HEV infections. Also, the relatively high prevalence (15%) of anti-HEV in children < seven years of age from the outbreak area reflects continuing, sporadic infections.

Adolescent↗
PubMed1997

A survey of outpatient visits in a United States Army forward unit during Operation Desert Shield.

Reports suggest that deployed soldiers during Operations Desert Shield and Desert Storm remained healthy, but primary care data are limited. We reviewed the outpatient visit surveillance data from the 3d Armored Cavalry Regiment to obtain information regarding soldiers' health in the field. Nontraumatic orthopedic problems accounted for the highest incidence of primary health care visits, followed by unintended injuries, gastrointestinal, respiratory, and dermatologic conditions. Visits for heat injuries, sexually transmitted diseases, unexplained fever, and psychiatric problems were low, probably due to preventive measures. These results suggest that increased prevention to decrease orthopedic problems and unintended injuries may substantially reduce outpatient visits during future deployments. Medical surveillance during future deployments can be improved by taking advantage of current advances in technology to facilitate patient data retrieval and provide timely information to first- and second-echelon medical personnel.

Ambulatory Care↗