The China I/CDC strain of Plasmodium malariae in Aotus monkeys and chimpanzees.

Five Aotus monkeys and two chimpanzees were infected with Plasmodium malariae isolated from a patient who acquired her infection approximately 50 years ago. All animals were splenectomized. The chimpanzees supported the highest parasite densities of 22,271/microliters and 18,544/microliters. Three Aotus monkeys with a previous history of infection with P. vivax had maximum parasite counts of from 1,818/microliters to 2,909/microliters, whereas two monkeys not previously infected had maximum parasite counts of 6,908/microliters. The establishment of new isolates in these animals aides the development of diagnostic probes and the identification of areas of antigenic variation within the species.

Nosocomial transmission of hepatitis B virus associated with the use of a spring-loaded finger-stick device.

BACKGROUND AND METHODS: From June 1989 through March 1990, 26 patients, of whom 23 had diabetes, contracted acute hepatitis B virus (HBV) infection in a hospital in California. All 26 patients and one HBV carrier (also a diabetic) had been admitted to a single medical ward during the six months before the case patients became infected with HBV. To determine the source of the infection, we conducted a retrospective cohort study of the 72 patients with diabetes who had been admitted to the ward from January through December 1989 and a case-control study comparing the 3 nondiabetic patients who contracted hepatitis with 20 nondiabetic controls. RESULTS: The retrospective cohort study of all the patients with diabetes who were admitted to the ward during 1989 found that those who underwent capillary blood sampling by finger stick with a spring-loaded lancet device were more likely to contract HBV infection than those who did not have finger sticks (attack rate, 42 percent vs. 0 percent; P = 0.08). In addition, a dose-response relation was observed between the number of finger sticks received and the frequency of hepatitis B (P = 0.002). The case-control study found that all 3 of the nondiabetic patients who contracted hepatitis underwent finger-stick blood sampling with the device, as compared with none of the 20 nondiabetic controls (P = 0.0006). A review of nursing procedures indicated that the platform of the device was not routinely changed after each use; this finding suggested that contamination of the platform by HBV-infected blood was the mechanism of percutaneous transmission of HBV. CONCLUSIONS: Proper use of finger-stick devices as well as strict adherence to universal precautions to avoid contamination by blood are required to decrease the possibility of transmission of blood-borne pathogens among hospitalized patients.

Cysticercosis: first 12 months of reporting in California.

Cysticercosis, a sometimes fatal ailment caused by larvae of the pork tapeworm Taenia solium, became a reportable disease in California in 1989. During the first year, from 1 April 1989 through 31 March 1990, 134 cases were reported to the California Department of Health Services. All of the 112 patients for whom laboratory diagnostic test data were obtained had neurocysticercosis. Nearly all (117) of the 127 patients whose race and ethnic background were known had a Hispanic background, and most of the 112 patients whose country of birth or prior residence was known had immigrated from T. solium-endemic countries. However, three of 11 patients born in the United States said they had never traveled outside the country, and it appears possible that indigenous transmission has been occurring. These findings affirm that neurocysticercosis should be included in the differential diagnosis of neurologic symptoms in patients who have immigrated from or traveled to T. solium-endemic countries, and also in those who have been in close contact with immigrants from endemic countries.

An outbreak of hepatitis B associated with jet injections in a weight reduction clinic.

From January 1984 through November 1985, 31 clinical cases of hepatitis B occurred among attendees of a weight reduction clinic (clinic 1). Before the onset of illness, each case-patient had received a series of injections of human chorionic gonadotropin administered by jet injectors at clinic 1. Clinical history, risk factor assessment, serologic evaluation, and review of clinic injection records were obtained on 287 (84%) of 341 persons who had attended clinic 1 in the first 6 months of 1985. Of this cohort, 21% (60/287) had evidence of acute infection with hepatitis B virus (either documented clinical cases or antibody to hepatitis B core antigen, IgM positive). Of persons who had been given human chorionic gonadotropin at the clinic during the period studied, 24% (57/239) of those receiving human chorionic gonadotropin only by jet injector experienced acute hepatitis B virus infection. None of the 22 persons who had received injections only by syringe experienced hepatitis B virus infection. Stopping the use of the jet injectors on July 2, 1985, at clinic 1, was associated with the termination of this outbreak. This investigation demonstrated that jet injectors can become contaminated with hepatitis B virus and then may be vehicles for its transmission.

Transmission of Plasmodium vivax malaria in San Diego County, California, 1986.

Between 18 June and 20 September 1986, 28 cases of Plasmodium vivax malaria were documented in Carlsbad, California, a coastal town north of San Diego. Malaria occurred in 1 local resident who had no risk factors, a second local resident who had traveled to a malarious area 9 months earlier, and 26 Mexican migrant workers (MWs). Among the 28 cases, 27 lived in a square mile marshy area where Anopheles hermsi, a newly described American species of the Anopheles maculipennis group, was known to be breeding. An investigation of MWs residing in the affected area was done to determine the extent of the outbreak and to identify risk factors for acquiring malaria. We interviewed and drew blood from 304 healthy MWs and 17 (65%) of the MWs with malaria. Fluorescent antibody titers to P. vivax greater than or equal to 1:256 occurred in 14 (82%) of the 17 MWs with malaria tested and 9 (3%) of the healthy MWs. The principal risk factor identified for contracting malaria was sleeping outside on a hillside adjacent to the marshy area. Malaria in a local resident with no malaria risk factors and the clustering in time and place of 26 cases suggest that P. vivax malaria was introduced and local transmission was sustained through several generations, producing the largest outbreak of introduced malaria in the United States since 1952.

Transfusion-acquired hepatitis A in a premature infant with secondary nosocomial spread in an intensive care nursery.

An outbreak of hepatitis A involving 15 nurses, two premature infants, and the mother of one infant occurred in an intensive care nursery. The infants became infected after receiving blood transfusions from a donor who shortly thereafter experienced symptoms compatible with hepatitis A and was later found to have serologic evidence of acute hepatitis A. Hepatitis was not suspected clinically in the infants but was documented serologically. One of the infants had an ileostomy with liquid intestinal drainage. Her mother and most, if not all, of the nurses acquired hepatitis from this infant. All 15 nurses had contact with this infant, whereas only four nurses had contact with the second infant. The amount of contact nurses had with this infant clearly was related to their risk of infection. Nurses not actually assigned to this infant but who reported some contact had a significantly lower attack rate than those assigned to the infant. Among assigned nurses, those assigned to more than one shift had 4.7 times the risk of acquiring hepatitis than those assigned to one shift only. No specific nursing techniques or personal habits were documented as being significant risk factors in the infected group of nurses.

Human and sylvatic Trypanosoma cruzi infection in California.

In August 1982, a 56-year-old woman from Lake Don Pedro, California, developed acute Chagas' disease (American trypanosomiasis). She had not traveled to areas outside the United States with endemic Chagas' disease, she had never received blood transfusions, and she did not use intravenous drugs. Trypanosoma cruzi cultured from the patient's blood had isoenzyme patterns and growth characteristics similar to T. cruzi belonging to zymodeme Z1. Triatoma protracta (a vector of Trypanosoma cruzi) infected with T. cruzi were found near the patient's home, a trypanosome resembling T. cruzi was cultured from the blood of two of 19 ground squirrels (Spermophilus beecheyi), and six of 10 dogs had antibody to T. cruzi. A serosurvey of three groups of California residents revealed antibody to T. cruzi by complement fixation in six of 237 (2.5 per cent) individuals living near the patient and in 12 of 1,706 (0.7 per cent) individuals living in a community 20 miles northeast of the patient's home, but in only one of 637 (0.2 per cent) blood donors from the San Francisco Bay area. This is the first case of indigenously acquired Chagas' disease reported from California and the first case recognized in the United States since 1955. This investigation suggests that transmission of sylvatic Trypanosoma cruzi infection to humans occurs in California but that Chagas' disease in humans is rare.

Toxoplasmosis infection associated with raw goat's milk.

In October 1978, a large family cluster of acute toxoplasmosis was identified in northern California. Indirect fluorescent IgM antibody tests showed that ten of 24 members of an extended family had serological evidence of acute Toxoplasma infection. The index case had retinochoroiditis; the other nine persons had asymptomatic infections. All ten seropositive persons had recently consumed raw goat's milk from the family herd as compared with no consumption of raw milk by the 14 persons with negative results. No dietary item or other risk factors were as strongly associated with positive serological test results as raw milk consumption. Although ingestion of soil-transmitted oocysts could not be ruled out unequivocally as the source of infection, the data suggest that drinking raw milk from infected goats might be another possible vehicle for the transmission of toxoplasmosis.

A 27-nm virus isolated during an outbreak of acute infectious nonbacterial gastroenteritis in a convalescent hospital: a possible new serotype.

An outbreak of acute infectious nonbacterial gastroenteritis began among elderly patients in a convalescent hospital in Marin County in northern California in March 1978 and persisted through May 1978. The overall clinical attack rate was 51% of 187 residents and 12% of 180 employees. A 27-nm viruslike particle was observed by immune electron microscopy in stools obtained at or near the onset of illness from four of 32 patients. Seroresponses to the 27-nm particles were found by immune electron microscopy in 16 of 18 patients. In addition, serologic evidence of infection with this or a related agent was demonstrated in persons who developed illness in another large outbreak of acute infectious nonbacterial gastroenteritis which occurred in a nearby county. This agent is morphologically similar to but serologically unrelated to the Norwalk and Hawaii gastroenteritis agents and has been designated the Marin agent pending further classification.

An intercity outbreak of meningococcal meningitis in adults.

An intercity outbreak of meningococcal meningitis occurred in five adults, with the acute onset of symptoms developing in two of the patients after they returned to Los Angeles from the San Francisco Bay area. The secondary attack rate was 36.4 percent in this entirely adult household. The authors review reports of secondary cases in civilian epidemics, as well as recommendations for chemoprophylaxis in household contacts.

Meningococcal disease in California. Epidemiology and management.

Between 1969 and 1975 in California, 1,953 cases of meningococcal disease were reported. For cases reported in 1973, 1974 and 1975, detailed information about chemoprophylaxis of cases and contacts was obtained in addition to demographic and laboratory data. A review of data for the seven years showed a reduction in the case rate from 2.6 to 0.6 per 100,000 population, but this drop was due primarily to a very substantial decline in the military rate from 35.7 to 1.8 per 100,000 population. No reduction was apparent in the case fatality rate. Five groups of associated meningococcal disease cases were identified for a total of nine secondary or coprimary cases among 862 household contacts. Associated cases occurred in 10.4 per 1,000 household contacts-a rate several hundred times greater than that for the general population. THE STUDY FINDINGS INDICATE THAT MANY PHYSICIANS ARE UNAWARE OF THE FOLLOWING: (1) nonhousehold contacts are at little or no risk of contracting meningococcal disease; (2) prophylaxis should be offered only to household or intimate contacts immediately upon identification of an index case without waiting for test results for meningococcal carriage; (3) valid medical and epidemiologic indications exist for administering prophylaxis to household contacts who are culture negative as well as those who are culture positive; (4) the current drug of choice for prophylaxis is rifampin, but since no drug is completely effective, close medical observation remains the most important factor in the management of household or intimate contacts to meningococcal disease.

An outbreak of introduced malaria in California possibly involving secondary transmission.

During 1974, 12 cases of Plasmodium vivax malaria were reported from an agricultural area in California's Sacramento Valley. At least three of these cases resulted from local mosquito transmission. The imported cases were in Punjabi immigrants except for one in an American-born visitor to the Punjab. This is the 11th reported outbreak of introduced malaria in the United States since 1952, and the first in California since 1957. A unique aspect of this outbreak is the likelihood that secondary transmission occurred. Extensive surveillance activities, including a house-to-house case-finding survey in a 15-square-kilometer area of suspected transmission, yielded no new malaria cases, but the activities may have increased awareness of malaria among both the medical community and the public, and thus facilitated the detection of later cases. The occurrence of local malaria transmission coincided with unusually high numbers of Anopheles freeborni. The increase in imported malaria cases probably reflects a resurgence of malaria in Punjab State, India.

Occurrence and persistence of "Australia" antigen determinants.

"Australia" (Au) antigens from various groups of individuals were examined for the presence of d and y determinants. Antigens from all of the 214 individuals examined were found to possess either the d or y determinant, in addition to the a determinant. With the ay antiserum employed, antibody absorption was found to be a more effective means than demonstration of spur formation for detection of the y determinant. Antigens with ad specificity predominated in a collection of sera from non-ill Tongan children and adults, but no significant differences were noted in the specificities of antigens from individuals from four different regions. Almost all of the antigens from various groups of individuals in California, including inmates of a state hospital, a group of heroin users, and hepatitis patients from San Francisco General Hospital, were of the ay specificity. With one exception, antigenic specificities were found to persist for 3 years in a group of Tongan school children. Specificities also persisted in chronic carriers from California and in hepatitis patients over the course of antigenemia. Of 15 human and 4 animal antisera examined, antibodies to the y determinant were demonstrable only in a single (human) antiserum, and antibodies to the d determinant were demonstrable in one guinea pig antiserum and one horse antiserum.

Importation of Shiga bacillus dysentery into California. Clinical and public health significance.

Concurrent with the regional epidemic of classic Shiga dysentery in Central America during 1969 and 1970, a pronounced increase in the isolation of Shigella dysenteriae type 1 was noted in California. A retrospective study of 20 cases diagnosed in California in 1969 and 1970 revealed that 18 of the patients had traveled to Central America or Mexico during or immediately before the onset of symptoms. Sixteen were known to have been admitted to hospital; there was one death. Despite the concern that such importations might result in epidemics in this country among groups living in crowded, unsanitary settings, no definite secondary transmission was identified in this study. The problems of differential diagnosis, laboratory isolation of the agent, chemotherapy, and epidemic control are discussed.