Serotyping of Toxoplasma gondii: striking homogeneous pattern between symptomatic and asymptomatic infections within Europe and South America.

Field isolates of Toxoplasma gondii in Europe and North America have been grouped into three clonal lineages that display different virulence in mice. Whether the genetic structure of the parasite is related to clinical expression in humans has not yet been demonstrated. We developed an enzyme-linked immunosorbent assay which uses lineage-specific, polymorphic polypeptides derived from the dense granule antigens, GRA5 and GRA6. Our goal was to compare serotypical patterns observed in asymptomatic versus symptomatic (ocular disease and severe infection in human immunodeficiency virus (HIV)-positive patients) infections among patients from Europe and South America. Independent of the clinical presentation of the disease, serotypes differed according to geographical origin, with a homogeneous distribution of serotype II in Europe and of serotypes I and III in South America. We conclude that GRA5-GRA6 serotyping is an interesting tool to study serotype prevalence in populations but it is not an accurate marker of pathogenicity of Toxoplasma infection in humans.

Molecular and serological investigation of Trypanosoma cruzi infection in dogs in French Guiana.

Clinical cases of Chagas disease, an infection caused by the parasite Trypanosoma cruzi, have been recently described in humans and dogs in French Guiana, a French overseas department located in South America. Elsewhere in endemic countries for this disease, cases of asymptomatic infections have been described. We performed a prevalence survey of the infection in dogs in Cayenne and Kourou, the main cities of French Guiana. In 2014 and 2016, blood samples were taken from 153 dogs from Cayenne and Kourou. All dogs were apparently healthy at the time of sampling. Sex and age of the dogs were recorded as well as the location where they lived. Serum samples from dogs were screened using a rapid immunochromatographic test (Chagas Stat-Pak®Assay, Chembio, USA) detecting anti-T. cruzi antibodies. Simultaneously, a real-time PCR targeting T. cruzi kDNA was performed on the blood samples of the dog. Six dogs (3.9%) were positive only in serology and one (0.6%) only in qPCR. Two dogs were positive for both tests. The prevalence of infection (positivity for one of the two tests) was 5.8% (9/153). There was no significant difference (χ2 test) between Cayenne (5/100) and Kourou (4/53), between males (3/60) and females (6/93), or between 2014 (2/55) and 2016 (7/98). Canine surveillance is a useful tool for the public health risk assessment of Chagas disease. Positive dogs, even when asymptomatic, should be treated as they can serve as a reservoir for T. cruzi.

Histoplasmosis and acquired immunodeficiency syndrome: a study of prognostic factors.

We aimed to identify prognostic factors for AIDS-associated disseminated histoplasmosis. In a multivariate analysis, we found that dyspnea, a platelet count of <100,000 platelets/mm3, and lactate dehydrogenase levels of >2 times the upper limit of the normal range were significantly independently associated with the death of the patient during the first 30 days of antifungal treatment.

Safety of mefloquine in infants with acute falciparum malaria.

We evaluated retrospectively the safety of mefloquine (25 mg/kg) for the curative treatment of uncomplicated Plasmodium falciparum malaria in 26 infants weighing <15 kg and managed during a 5-year period. Side effects were recorded in 30.8% of patients and consisted chiefly of mild and transient gastrointestinal symptoms. Mefloquine was safe in infants weighing <15 kg in our experience.