A family outbreak of toxoplasmosis: a serendipitous finding

A family outbreak of toxoplasmosis involving five members of a Lebanese family is described. We believe it to be the first reported outbreak of toxoplasmosis in Australia. Kibbi , a traditional Lebanese dish which can occasionally incorporate raw meat, may have been the source of infection. The chance occurrence of an outbreak of hepatitis A in the same family subsequently led us to discover this outbreak.

Acute Toxoplasma infection among family members of patients with acute lymphadenopathic toxoplasmosis

Studies were performed to determine how frequently acute infections with Toxoplasma gondii occur among family members of patients with acute acquired lymphadenopathic toxoplasmosis. In five of the nine families studied, more than one family member had serologic evidence of recent acute infection with T gondii. In three of the families, the immunoglobulin M and immunoglobulin G antibody titers to T gondii among infected family members were similar irrespective of whether lymphadenopathy was present. Lymphadenopathy developed in one family member in each of two families (families VIII and IX) three and eight months after lymphadenopathy had developed in the index case (proband). These results suggest that common-source outbreaks occur with surprising frequency among family members of patients with lymphadenopathic toxoplasmosis and that the humoral response is similar with different manifestations of the infection.

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.

Concomitant cases of acquired toxoplasmosis in children of a single family: evidence of reinfection

During 1979, three brothers had antibody titers for toxoplasmosis of 1:1,024, 1:64, and 1:16, respectively, by IgG indirect immunofluorescent antibody (IgG-IFA) test. The first child also had a fever and lymphadenopathy. In August 1980 the three children had lymphadenopathy and IgG-IFA test titers between 1:4,096 and 1:16,000. Two other brothers, first examined at that time, had IgG-IFA test titers between 1:1,024 and 1:4,096, one with ascending titers and the other with IgM antibodies to Toxoplasma gondii. The latter had lymphadenopathy, fever, and hepatosplenomegaly. Clinical and serologic examinations during March, April, and September 1981 revealed good health and decreasing IgG-IFA test titers in most of the brothers. The simultaneous increase of antibody titers during August 1980 in the three initial patients lead to the consideration of a probable reinfection. A simultaneous reactivation of the disease was considered less probable because acute toxoplasmosis occurred in two other brothers at the same time.

On the epidemiology of human toxoplasmosis in Scandinavia especially in children

A random sample representing approx. one-third of pre-school children and approx. 95% of school children in age groups 8, 11, 13, and 15 years in a suburb of Stockholm were examined for antibodies to Toxoplasma. Antibodies were uncommon in small children. They gradually appeared throughout childhood but especially in adolescence and adult life. Antibodies were more common in females than in males. Even small girls were more often infected than boys of corresponding age. The difference becomes marked in puberty and is significant in adults. A family study revealed evidence of familial aggregation of the infection albeit with borderline significance. No correlation was found between occurrence of antibodies and the presence of cats in the families or reported consumption of raw meat. The majority of representative samples of Lapps and Skolt Lapps in northern Scandinavia lacked antibodies to Toxoplasma.

[Role of Toxoplasma gondii in human and animal chromosomal pathology]

Toxoplasma gondii was found to cause an appearance of cells with a changed number of chromosomes in the bone marrow of infected white rats. Besides the increase of aneuploid and polyploid cells the infection with toxoplasms inhibits the mitotic activity in bone marrow of rats. The similar changes were observed in blood leucocytes of toxoplasmosis patients.

[An epidemic of familial toxoplasmosis (author's transl)]

After observation of choroiditis of toxoplasmic nature in a member of a rural family, the authors have led a clinical and serological study on other five members of the household. Three of five had antibody titers and two of these demonstrated antibody titers consistent with recent toxoplasmic infection; one of these members manifested asymptomatic choroiditis. Therefore, it would be interesting to carry out a clinical and serological study on relatives of patient with toxoplasmosis.

Acquired toxoplasmosis in children

Nine cases of acquired toxoplasmosis, 8 from rural backgrounds, are described, illustrating the wide variety of clinical pictures. Evidence of familial infection was found whenever sought, and was also found in cattle in one case. The availability of an easily performed screening test should make diagnosis of this common disease more frequent.

Outbreak of toxoplasmosis in a family and documentation of acquired retinochoroiditis

An outbreak of toxoplasmosis in one household is described. It demonstrates the potential for a common source infection with Toxoplasma gondii to cause multiple cases. Six of seven members of a household investigated for toxoplasmosis demonstrated high antibody titers consistent with recent infection; five of these members (83%) were symptomatic. The most common manifestations were fever and lymphadenopathy, which developed from seven to 18 days (mean 11 days) after a common source ingestion of infected meat. Since inadequately cooked lamb, pork and beef are probably the most common sources of infection in the United States, outbreaks of multiple cases may occur more frequently than is generally appreciated. As more outbreaks of febrile illnesses are examined, especially in families and closed communities, it is likely that more common source epidemics of toxoplasmosis will be recognized. Retinochoroiditis is an unusual manifestation of adult acquired toxoplasmosis. In the index case in this epidemic the patient manifested vision threatening retinochoroiditis 129 days after infection with toxoplasmosis. He represents the ninth well-documented case of toxoplasma retinochoroiditis associated with adult acquired disease.

Toxoplasma infection in an urban community

A survey was undertaken in an urban community to examine the intrafamilial epidemiology of toxoplasma infection and its relation to a set of environmental variables. Statistically significant relations were found with (a) ownership of a dog or cat; (b) the handling of pet food, particularly cat food; and (c) a "risk" score compounded from the handling of pet food and lack of cleanliness in the kitchen.