The Use of Simple Laboratory Parameters in the Differential Diagnosis of Acute-Phase Zika and Dengue Viruses.

BACKGROUND: Differential diagnosis between acute-phase Zika and dengue is challenging because of a similar clinical presentation and the lack of available molecular diagnosis tools in most of endemic areas. OBJECTIVES: Our study aimed to evaluate the use of simple laboratory parameters to differentiate these infections. METHODS: We retrospectively compared simple hematology and biochemistry values in 81 and 341 patients with confirmed Zika and dengue, respectively, collected from June 2013 to March 2014 during the French Polynesia outbreaks. RESULTS: Thrombocytopenia, neutropenia, leukopenia, lymphopenia, and elevated aspartate aminotransaminases were significantly more frequent in dengue than in Zika (p < 0.001). Platelets <100 × 109/L, neutrophils <0.5 × 109/L, lymphocytes <0.5 × 109/L, and aspartate aminotransaminases >100 IU/mL were found in dengue but not in Zika. The positive predictive value of the -association of leukocytes <4 × 109/L + lymphocytes <1 × 109/L + aspartate aminotransaminases >40 IU/mL for the diagnosis of dengue was 90%, with an accuracy of 82.4%. CONCLUSION: For the differential diagnosis between acute-phase Zika and dengue, there is no specific standard laboratory pattern. We identified cutoff values and a combination of laboratory parameters that are a strong argument against Zika and in favor of dengue.

Detection of chikungunya virus in saliva and urine.

BACKGROUND: Saliva and urine have been used for arthropod-borne viruses molecular detection but not yet for chikungunya virus (CHIKV). We investigated the use of saliva and urine for molecular detection of CHIKV during the French Polynesian outbreak. METHODS: During the French Polynesian chikungunya outbreak (2014-2015), we collected the same day blood and saliva samples from 60 patients with probable chikungunya (47 during the 1st week post symptoms onset and 13 after), urine was available for 39 of them. All samples were tested using a CHIKV reverse-transcription PCR. RESULTS: Forty eight patients had confirmed chikungunya. For confirmed chikungunya presenting during the 1st week post symptoms onset, CHIKV RNA was detected from 86.1 % (31/36) of blood, 58.3 % (21/36) of saliva and 8.3 % (2/24) of urine. Detection rate of CHIKV RNA was significantly higher in blood compared to saliva. For confirmed chikungunya presenting after the 1st week post symptoms onset, CHIKV RNA was detected from 8.3 % (1/12) of blood, 8.3 % (1/12) of saliva and 0 % (0/8) of urine. CONCLUSIONS: In contrast to Zika virus (ZIKV), saliva did not increased the detection rate of CHIKV RNA during the 1st week post symptoms onset. In contrast to ZIKV, dengue virus and West Nile virus, urine did not enlarged the window of detection of CHIKV RNA after the 1st week post symptoms onset. Saliva can be used for molecular detection of CHIKV during the 1st week post symptoms onset only if blood is impossible to collect but with a lower sensitivity compared to blood.

[Pancytopenia and folate deficiency: a case report]. / Pancytopénie et carence en folates : à propos d'un cas.

Anemia is the most common pathology encountered in hematology. Etiologies are numerous, so it is important to adopt a rigorous approach. Complementary examinations must be specific to the clinical situation in order to determine the mechanisms on the one hand and decide the therapeutic management on the other. We report the observation of a case of sudden onset of profound pancytopenia. Investigation led to the diagnosis of major folic acid deficiency with favorable evolution. Through this case, we describe the diagnostic approach towards anemia and the mechanisms involved in the formation of folate deficiency.

Exposure to toxic metals and polychlorinated biphenyls of adolescents and adults from two atolls in the Tuamotu Archipelago (French Polynesia).

The atoll of Hao, part of the Tuamotu Archipelago in French Polynesia, hosted an air base which was used by France Air Force and Naval Aviation during the nuclear tests. Following the publication of a report in 2012 indicating widespread contamination of the atoll, we conducted a biomonitoring survey to assess the exposure to toxic metals and polychlorinated biphenyls (PCBs) of Hao residents and residents of Makemo, a nearby atoll without any known sources of industrial pollution. Adults and adolescents (≥12 years) randomly sampled from Hao (n = 275) and Makemo (n = 268) provided blood samples for contaminant analyses. Whole blood samples were analysed for cadmium, lead and total mercury by inductively coupled plasma mass spectrometry. Plasma concentrations of PCBs were measured by gas chromatography mass spectrometry. Face-to-face interviews were conducted to document lifestyle and a food-frequency questionnaire was used to document dietary habits. Concentrations of contaminants were compared between atolls and associations with sociodemographic and personal characteristics of the participants were investigated. A significantly higher mean (geometric) of blood lead concentration was observed in Hao compared to Makemo (3.75 vs 3.40 µg/L, P = 0.02), whereas similar concentrations were noted for cadmium (0.49 vs 0.50 µg/L, P = 0.58) and mercury (11.4 vs 11.5 µg/L, P = 0.78). Mean total PCBs plasma concentration was significantly higher in Hao than in Makemo participants (0.75 vs 0.32 µg/L, P < 0.001). A significant proportion of participants exceeded toxicological reference values for mercury and lead in both atolls. The higher body burden of PCBs and Pb in Hao compared to Makemo residents may be linked to past air base activities in Hao. According to international standards, PCBs exposure is low; however, exposure to both mercury and lead is high and further investigations are required to identify specific sources of exposure.

Evaluation of a real-time PCR assay for malaria diagnosis in patients from Vietnam and in returned travellers.

Real-time PCR diagnosis of malaria has advantages over traditional microscopic methods, especially when parasitaemia is low and when dealing with mixed infections. We have developed a new real-time PCR with specific genes in each Plasmodium species present only in one copy to identify the four pathogenic Plasmodium spp. for humans. The sensitivity was less than 25 parasites/microl. No cross-hybridisation was observed with human DNA or among the four Plasmodium spp. Using LightCycler PCR and conventional microscopy, we compared the diagnosis of malaria in patients from Vietnam and in returned European travellers with suspicion of malaria. In patients from Vietnam with suspicion of malaria, one mixed infection was observed by PCR only; the remaining data (54 of 55 patients) correlated with microscopy. In 79 patients without symptoms, low parasitaemia was detected in 7 samples by microscopy and in 16 samples by PCR. In returned travellers, PCR results were correlated with microscopy for all four species in 48 of 56 samples. The eight discrepant results were resolved in favour of real-time PCR diagnosis. This new real-time PCR is a rapid, accurate and efficient method for malaria diagnosis in returned travellers as well as for epidemiological studies or antimalarial efficiency trials in the field.

Fatal leptospirosis and chikungunya co-infection: Do not forget leptospirosis during chikungunya outbreaks.

In endemic areas, leptospirosis can be missed by erroneous clinical or laboratory diagnosis of arboviroses or co-infections with arboviruses and an increase in mortality due to leptospirosis has already been reported during arboviruses outbreaks. During the French Polynesian chikungunya virus outbreak in 2014-2015, two leptospirosis and chikungunya co-infections were reported, one of which was fatal. Diagnosis of leptospiroses was delayed in the context of chikungunya outbreak. In the context of arbovirus outbreak, the risk of misdiagnosis of leptospirosis is maximum and clinicians should initiate early antibiotic therapy if leptospirosis is suspected. A delayed diagnosis of leptospirosis can be responsible for fatal outcome. Leptospirosis should be considered even if dengue or chikungunya virus infections are confirmed by reference molecular testing.

Crossing the Gulf of Aden: cutaneous infections in African migrant shipwreck survivors.

Skin and soft tissue infections were observed in migrants from Somalia who crossed the Gulf of Aden, crowded on a drifting boat for 14 days. Thirty-three percent of survivors of this hazardous journey had skin infections. Seven were hospitalized for severe Staphylococcus aureus cutaneous infections associated with intracellular dehydration. Migrants face infectious risks during their precarious travel, including severe cutaneous infections that require specific medical and surgical treatment by the emergency services.