Pathology of congenital Zika syndrome in Brazil: a case series

Zika virus is an arthropod-borne virus that is a member of the family Flaviviridae transmitted mainly by mosquitoes of the genus Aedes. Although usually asymptomatic, infection can result in a mild and self-limiting illness characterised by fever, rash, arthralgia, and conjunctivitis. An increase in the number of children born with microcephaly was noted in 2015 in regions of Brazil with high transmission of Zika virus. More recently, evidence has been accumulating supporting a link between Zika virus and microcephaly. Here, we describe findings from three fatal cases and two spontaneous abortions associated with Zika virus infection.

Long lasting protection against canine kala-azar using the FML-QuilA saponin vaccine in an endemic area of Brazil (São Gonçalo do Amarante, RN).

Naturally exposed dogs of an endemic area were vaccinated with the fucose mannose ligand (FML) antigen of Leishmania donovani in formulation with QuilA saponin. The 100% of vaccinees were seropositive to FML and showed intradermal reaction to L. donovani lysate, 2 months after vaccination. The absorbency values and size of intradermal reaction were both significantly higher in vaccinees than in controls along a 3.5 years period (ANOVA, P<0.0001). The 25% of the control animals (two dogs on the first year and six dogs on the fourth year, respectively) and 5% of the vaccinees (one dog during the fourth year) developed clinical and fatal disease until the end of experiment. This difference was significant (chi(2)=3.93, P<0.05). This means that 95% protection against kala-azar was achieved in vaccinees, after FML-QuilA vaccination (80% of vaccine efficacy (VE)). Leishmania infection was also confirmed, 3.5 years after vaccination, in saline controls that showed positive polymerase chain reaction (PCR) for Leishmania DNA and FML-serology with no intradermal reaction. Higher seropositivities and intradermal reactions with no Leishmanial DNA were detected in vaccinees. The FML-QuilA vaccine induced a significant, long lasting and strong protective effect against canine kala-azar in the field.

[Vitamin A serum level in children with visceral leishmaniasis]. / Nível sérico da vitamina A em crianças portadoras de leishmaniose visceral.

Vitamin A is considered an anti-infectious disease vitamin, and its deficiency is associated with severe infections such as in measles. In developing countries the low concentrations of vitamin A are a public health problem. The aim of this study is to describe serum vitamin A concentrations among children with visceral leishmaniasis (VL). Blood sample was collected from 22 children with VL, and stored in a freezer, 9 siblings, with no clinical signs of the VL patients had their blood collected for a control group. Samples were assayed by high performance liquid chromatography. The median vitamin A concentration in the LV group was 21.38 microg/100ml and in the control group it was 31.39 microg/100. The mean in the LV was statistically lower than in the control group, using Student's t test, p<0.01.

Nível sérico da vitamina A em crianças portadoras de leishmaniose visceral / Vitamin A serum level in children with visceral leishmaniasis

A vitamina A tem sido considerada uma vitamina anti-infecciosa e sua deficiência está associada a um maior risco de infecções graves, como ocorre por exemplo no sarampo. Nos países em desenvolvimento a hipovitaminose A é um grave problema de saúde pública. O objetivo deste estudo é quantificar o nível sérico da vitamina A em pacientes pediátricos portadores da leismaniose visceral (LV). Amostras de sangue foram coletadas de 22 crianças portadoras de LV, estocadas em freezer e posteriormente, quantificado o nível de vitamina A usando-se a cromatrografia líquída de alta eficiência, nove irmãos assintomáticos dos pacientes foram usados como controles. A média do nível sérico da vitamina A nos portadores de LV foi de 21,38µg/100ml e no grupo controle foi de 31,39µg/100ml. Entre os pacientes estudados com LV a média do nível sérico de vitamina A encontrado foi significativamente menor, utilizando-se o teste t de Student para um p<0,01 que dos controles.

Vitamin A is considered an anti-infectious disease vitamin, and its deficiency is associated with severe infections such as in measles. In developing countries the low concentrations of vitamin A are a public health problem. The aim of this study is to describe serum vitamin A concentrations among children with visceral leishmaniasis (VL). Blood sample was collected from 22 children with VL, and stored in a freezer, 9 siblings, with no clinical signs of the VL patients had their blood collected for a control group. Samples were assayed by high performance liquid chromatography. The median vitamin A concentration in the LV group was 21.38 microg/100ml and in the control group it was 31.39 microg/100. The mean in the LV was statistically lower than in the control group, using Student's t test, p<0.01.

Short report: occurrence of Leishmania donovani DNA in donated blood from seroreactive Brazilian blood donors.

Human visceral leishmaniasis (kala-azar) transmitted by blood transfusion has been described in previous reports. Seroprevalence of antibodies to Leishmania donovani was shown to be related to prior blood transfusions in multiply transfused hemodialysis patients in Natal, Rio Grande do Norte, Brazil. In this study, a possible correlation between seroreactivity and the presence of L. donovani DNA was investigated in asymptomatic healthy blood donors. Sera were tested using the fucose mannose ligand (FML) ELISA, which was shown to have a sensitivity of 100%, a specificity of 96-100%, reliability, and diagnostic and prognostic potential for the detection of human and canine kala-azar, respectively. Leishmanial DNA was assessed by the polymerase chain reaction (PCR) and dot-blot hybridization techniques in blood and bone marrow samples. Among 21 FML-seroreactive asymptomatic blood donors, 5 (24%) were positive by the PCR and 9 (43%) were positive in a dot-blot assay of blood samples, showing a significant correlation (chi2 = 14.24, P < 0.01). No Leishmania DNA was detected in 20 FML non-reactive blood donors. Our results point to the need for control of transmission of kala-azar by blood transfusion in areas endemic for this disease.

A phase III trial of efficacy of the FML-vaccine against canine kala-azar in an endemic area of Brazil (São Gonçalo do Amaranto, RN).

Protection against canine kala-azar was investigated in naturally exposed dogs of an endemic area, vaccinated with the fucose mannose ligand (FML)-vaccine of Leishmania donovani. A total of 97% of vaccinees were seropositive to FML and 100% showed intradermal reaction to L. donovani lysate, 7 months after vaccination. The absorbency values and size of intradermal reaction were both significantly higher in vaccinees than in controls (ANOVA, P<0.0001). After 2 years, 92% (chi(2)=6.996; P<0.0025) protection was achieved: only 8% of vaccinees showed mild signs of kala-azar with no deaths while 33% of controls developed clinical or fatal disease. The FML-vaccine induced a significant, long-lasting and strong protective effect against canine kala-azar in the field.

Prevalence of anti-Leishmania donovani antibody among Brazilian blood donors and multiply transfused hemodialysis patients.

The prevalence of anti-Leishmania donovani antibodies was investigated in 1,500 Brazilian blood donors and multiply transfused hemodialysis patients. Sera were tested using the fucose-mannose ligand (FML) ELISA, which was shown to have 100% sensitivity and 96% specificity for kala-azar. Among 1,194 volunteer blood donors, seroreactivity was 9%, increasing to 25% in a periurban kala-azar focus. However, higher positivity (37%) was found in multiply transfused hemodialysis patients from Natal, where kala-azar is constantly present in low numbers (endemic), with sporadic outbreaks in localized regions (endemic and epidemic). Risk factors included blood transfusion, which was significantly associated with the presence of anti-Leishmania antibodies (chi2 = 8.567, P < 0.005), but did not include potential exposure to sandfly bites (chi2 = 0.033, P > 0.1). The prevalence significantly decreased to 7% in hemodialysis patients from Rio de Janeiro, where kala-azar is only occasionally seen, and was 0% in patients undergoing continuous ambulatorial peritoneal dialysis. The prospective analysis of 27 FML-seroreactive donors from Natal revealed amastigotes of Leishmania in the bone marrow of one subject while four had clinical complaints, including splenomegaly and hepatosplenomegaly. Our results point to the need for control of blood transfusion as a possible route for transmission of kala-azar in endemic areas.

Transmission of visceral leishmaniasis by blood transfusion in hamsters.

We have studied the transmission of visceral leishmaniasis by blood transfusion in the CB hamster model. Five normal CB hamsters (females, 2.5 months old) received a 0.1-ml blood transfusion from a donor that had been infected with 10(7) amastigotes of Leishmania donovani 90 days prior to the blood harvest. The development of the disease in transfused animals was monitored by the increase in anti-Leishmania serum antibodies, splenomegaly, and spleen and liver parasitic burdens. The transfused hamsters developed all the typical signs of the disease, i.e., ascites, cachexia and death. The scores of anti-Leishmania antibodies (1.345) and the level of parasite load (spleen Leishman Donovan units of Stauber (LDU) = 471, liver LDU = 378) in transfuse hamsters were similar to those observed in hamsters experimentally infected with 10(7) amastigotes (P > 0.05, Student t-test). Our results demonstrate that blood transfusion is an effective route for transmission of visceral leishmaniasis, and we point out that adequate precautions should be taken at blood banks in the regions where leishmaniasis is endemic.

Transmission of visceral leishmaniasis by blood transfusion in hamsters

We have studied the transmission of visceral leishmaniasis by blood transfusion in the CB hamster model. Five normal CB hamsters (females 2.5 months old) received a 0.1 -ml blood transfusion from a donor that had been infected with 10(7) amastigotes of Leishmania donovani 90 days prior to the blood harvest. The development of the disease in transfused animals was monitored by the increase in anti-Leishmania serum antibodies, splenomegaly, and spleen and liver parasitic burdens. The transfused hamsters developed all the typical signs of the disease, i.e., ascites, cachexia and death. The scores of anti-Leishmania antibodies (1.345) and the level of parasite load (spleen Leishman Donovan units of Stauber (LDU) = 471, liver LDU = 378) in transfused hamsters were similar to those observed in hamsters experimentally infected with 10(7) amastigotes (P>0.05, Student t-test). Our results demonstrate that blood transfusion is an effective route for transmission of visceral leishmaniasis, and we point out that adequate precautions should be taken at blood banks in the regions where leishmaniasis in endemic.

An urban outbreak of visceral leishmaniasis in Natal, Brazil.

The epidemiological pattern of visceral leishmaniasis in north-eastern Brazil is changing. The disease was typically seen in rural, endemic areas, but is now occurring as an epidemic in the city of Natal where 316 cases have been reported since 1989; 49% were in children less than 5 years of age. The principle clinical and laboratory findings were weight loss, fever, hepato-splenomegaly, anaemia, leucopenia and hypergammaglobulinaemia. Elevated transaminases and hyperbilirubinaemia were also observed. The diagnosis was confirmed in 87% of cases by identifying amastigotes in aspirates from bone marrow or spleen. Five isolates were identified as Leishmania (L.) chagasi by isoenzyme analysis. The mortality rate was 9%; all deaths occurred during the first week in hospital. One person had concurrent human immunodeficiency virus infection. Among 210 household contacts and neighbours of patients from the endemic area examined for evidence of L. (L.) chagasi infection, 6 additional cases of visceral leishmaniasis were diagnosed. Thirty-eight percent of house-mates and neighbours gave a positive Montenegro skin test reaction, indicating prior subclinical infection.

Treatment of Brazilian kala-azar with a short course of amphocil (amphotericin B cholesterol dispersion).

Amphotericin B is an effective but toxic antileishmanial agent. Lipid-encapsulated amphotericin B should have a high therapeutic index for visceral leishmaniasis because reticuloendothelial cells, the sole site in which Leishmania is found, will phagocytize and concentrate the complex. Amphotericin B cholesterol dispersion (Amphocil; 2 mg/[kg.d] intravenously) was administered to 10 Brazilians with kala-azar for 10 days (cohort 1) and to 10 Brazilians with kala-azar for 7 days (cohort 2). All patients were successfully treated: 19 of the 20 patients were without visible parasites in the bone marrow; the mean time to afebrility was 4.2 days; spleen size regressed by a mean of 79% 2 months after therapy; and no patient had clinical or laboratory abnormalities by the end of 6-12 months of follow-up. Side effects were fever and chills accompanied by respiratory distress, but not nephrotoxicity, in children < 3 years of age.