[Lymphatic filariasis transmission assessment survey in schools three years after stopping mass drug treatment with albendazole and ivermectin in the 7 endemic districts in Togo]. / Enquête d'évaluation de la transmission de la filariose lymphatique en milieu scolaire, 3 ans après l'arrêt du traitement de masse à l'albendazole et à l'ivermectine dans les 7 districts endémiques du Togo.

The aim of this study is to verify the level of transmission of lymphatic filariasis three years after stopping mass drug treatment in the 7 endemic districts in Togo. The survey was conducted in 2012 in Togo's 7 endemic districts grouped into four evaluation units (EU) using the WHO-recommended transmission assessment survey (TAS) protocol. Children aged 6-7 years were screened for Wuchereria bancofti antigen using the immunochromatographic card (ICT) method. A cluster sampling method was used to select eligible children in schools as the net primary-school enrolment ratio is greater than or equal to 75% in each of the four EUs. The number of children and schools to be selected in each EU, the randomization list for the selection of these children and the critical cut-off number of positive cases not to exceed were automatically generated using the Survey Sample Builder (SSB) tool, (NTD Support Center, Atlanta, Ga, USA). For confirmation, positive cases were subsequently tested for microfilaremia using nocturnal thick blood smear and for filarial antigen using Og4C3 antigen ELISA (TropBio ELISA Kit®, Townsville, Queensland, Australia). An EU is considered to have passed the test successfully (it is assumed that transmission can no longer be sustained), when the number of positive cases is below the critical cut-off number set by the SSB, which is roughly equivalent to 2% prevalence. Of the 1 706 children surveyed in Kpendjal-Tone's EU, 1 549 in Binah-Doufelgou's EU, 1 550 in Kozah's EU and the 1 575 in Amou-Haho's EU, 8 (0.46%), 1 (0.08%), 0 (0.00%) and 4 (0.25%) ICT positive cases respectively were detected. The number of positive ICT tests was well below 18, the critical cut number for each of the 4 EUs. All 13 ICT positive cases tested negative for nocturnal microfilaremia and Og4C3 ELISA. We conclude that all four EU passed the TAS with success, and the transmission of Wuchereria bancrofti is no longer likely to be sustained in the 7 endemic districts in Togo 3 years after stopping the MDA. A new TAS will be carried out in 2015, after which, if the results are still good, the country will submit a dossier to WHO for verification of the elimination of lymphatic filariasis.

Nationwide integrated mapping of three neglected tropical diseases in Togo: countrywide implementation of a novel approach.

OBJECTIVE: To conduct a nationwide integrated neglected tropical disease (NTD) prevalence survey to define the need for public health interventions using an innovative mapping protocol. METHODS: Two villages were selected in every peripheral health unit in endemic districts: 29 districts for schistosomiasis and STH, 15 of them for trachoma. In each village, 15 children aged 6-9 years at a randomly selected school were tested. An additional convenience sample of 35 children aged 1-5 years underwent an eye examination for trachoma. This integrated mapping was followed by a 20-cluster trachoma survey in each district that surpassed the WHO-defined threshold of 10% prevalence of trachomatous inflammation-follicular (TF). RESULTS: A total of 1096 villages were surveyed in <6 weeks. The district prevalence of schistosomiasis ranged from 2 to 49% and of STH from 5 to 70%, with prevalence at the village level ranging from 0 to 100% for both diseases. Two districts passed the threshold of 10% for active trachoma, but the cluster survey indicated this was because of misclassification bias and that the real prevalence was <1%. CONCLUSION: Results of this mapping were used by the MoH and partners to plan integrated mass drug administration (MDA). Mass drug administration for trachoma was not implemented as no district passed the threshold requiring public health intervention.

Identification of women at unsuspected risk of primary infection with herpes simplex virus type 2 during pregnancy.

BACKGROUND: Primary infections with herpes simplex virus type 2 (HSV-2) acquired by women during pregnancy account for about half of the morbidity and mortality from HSV-2 among neonates. The other half results from reactivation of old infections. Better methods are needed to identify which women are at risk for primary HSV-2 infection. METHODS: We prospectively studied HSV-2 infections among pregnant women who were patients in private obstetrical practices. Using an enzyme-linked immunosorbent assay that detects type-specific antibodies to HSV-2 glycoprotein G, we determined the prevalence at base line of HSV-2 infections among pregnant women and their husbands, the frequency of discordance for infection between partners, and the risk of seroconversion during pregnancy among the seronegative women whose husbands were seropositive. RESULTS: The seroprevalence of HSV-2 was 32 percent among the 277 women followed throughout their pregnancies and 25 percent among the 190 husbands studied. Two thirds of the HSV-2-seropositive women had no history of genital herpes. Of the 190 couples, 139 (73 percent) were serologically concordant for HSV-2 antibodies (57 percent being seronegative and 16 percent being seropositive), whereas 51 couples (27 percent) were discordant, despite having been sexually intimate for a mean of 6.1 years. Eighteen women who were seronegative for HSV-2 (9.5 percent) had seropositive partners, of whom 10 (56 percent) had no history of genital herpes. Thus, approximately 5 percent of these pregnant women had an unsuspected risk of contracting a primary HSV-2 infection. One of the 18 seronegative women with a seropositive husband seroconverted to HSV-2 during pregnancy; none of the other women seroconverted. CONCLUSIONS: In this study about 10 percent of pregnant women were at risk of contracting a primary HSV-2 infection from their HSV-2-seropositive husbands. In addition, about a third of these women were seropositive for HSV-2 and thus at risk for asymptomatic, reactivated infections. Serologic testing of couples can identify women who are at risk for primary or reactivated HSV-2 infections during pregnancy.

Use of polymerase chain reaction for successful identification of asymptomatic genital infection with herpes simplex virus in pregnant women at delivery.

The polymerase chain reaction was adapted to the amplification of a herpes simplex virus (HSV) DNA sequence, common to HSV types 1 and 2 (HSV-1, HSV-2). The amplified product was detectable by ethidium-bromide staining or Southern hybridization of gels and by dot hybridization. The HSV polymerase chain reaction detected HSV DNA in samples obtained from eight patients with genital lesions from which HSV-2 was isolated in tissue culture and from four patients with labial lesions from which HSV-1 was isolated. The HSV polymerase chain reaction identified HSV in clinical specimens obtained from 11 women who had asymptomatic genital HSV infections at delivery. None of 11 samples obtained at delivery from women who had antibodies to HSV-2, but whose delivery cultures were negative, were positive by polymerase chain reaction and no false-positive reactions were obtained when the reaction mixture contained human cell DNA or varicella-zoster virus, cytomegalovirus, Epstein-Barr virus, or human papillomavirus DNA.

A prospective evaluation of primary genital herpes simplex virus type 2 infections acquired during pregnancy.

In order to study the epidemiology of herpes simplex type 2 (HSV-2) infections during pregnancy, we used an enzyme immunoassay to detect type-specific antibodies to HSV-2 glycoprotein G in serial blood samples obtained from a cohort of 1891 pregnant women. Blood samples obtained at about 17 and 32 weeks of gestation and at the time of delivery were assessed for antibody to HSV-2 glycoprotein G in order to evaluate the prevalence of past infections with HSV-2 and the rate of acquisition of HSV-2 infection during pregnancy. Three hundred eleven pregnant women (16.5%) were found to have had past infections with HSV-2. Four of the 1580 women who were initially seronegative developed antibodies to HSV-2 during pregnancy. The annualized rate of acquisition of HSV-2 infection in pregnant women was 0.58%. Three of four women had asymptomatic primary infections; all of the women had preexisting HSV-1 immunity. None of the women or their infants experienced any adverse consequences of gestational herpes. Based upon our very limited number of observations to date, asymptomatic primary episodes occurring in women with previous HSV-1 immunity may be of less consequence to the fetus and neonate than symptomatic true primary HSV-2 infections.