A study on chikungunya outbreak during 2007 in Kerala, south India.

BACKGROUND & OBJECTIVE: The first chikungunya outbreak occurred in Kerala during 2006 affecting 14 districts, followed by another during May 2007 affecting almost whole of the State. Four of the worst affected districts viz, Pathanamthitta, Idukki, Kottayam and Thrissur were surveyed during 2007 to understand the magnitude of the problem of chikungunya fever, particularly clinical signs and symptoms. METHODS: A total of 1265 persons from 310 houses were surveyed door-to-door in 20 different localities representing four affected districts. The history and examination findings from 354 clinically diagnosed chikungunya cases were recorded. The symptoms recorded were fever, headache, myalgia, arthralgia, itch/rash, oedema, eye congestion, eye pain, oral ulcers, distaste, nausea, vomiting and haemorrhage. RESULTS: The major symptoms were fever (100%), headache (97.5%), arthralgia (99.4%) and myalgia (99.4%). A significant difference was observed in oedema, distaste, nausea and headache among different age groups and these symptoms were reported to be lower (12.2-89.8%) in younger age group than in older age group (90.4-100%). No genderwise difference was observed for any of the symptoms. In clinically diagnosed chikungunya cases higher age group (>35 years) found with higher rate of severity with symptoms of oedema, distaste, nausea and headache when compared with lower age group (1-35 yr). INTERPRETATION & CONCLUSION: Chikungunya invaded Kerala State for the first time in 2006 and continues to be a major vector borne disease in the State. The clinical symptoms in affected cases highlighted high fever, sever myalgia and prolonged arthralgia, with occasional history of skin itch/rash (petechiae).

Desiccated vector mosquitoes used for the surveillance of Japanese encephalitis virus activity in endemic southern India.

To monitor Japanese encephalitis virus (JEV) activity in endemic areas of Tamil Nadu, southern India, desiccated vector mosquitoes were screened for JEV antigen using ELISA, from 1996. A total of 133 233 specimens from eight index villages comprising 2816 pools (mainly Culex vishnui subgroup) were tested. Of these, 59 pools (2.1%) were positive for JEV antigen. Control measures were undertaken in positive villages accordingly. The average annual minimum infection rate was 0.8 at the beginning of the study and remained lower for nearly 8 years. A declining trend in JE cases was recorded.

Natural vertical transmission of dengue viruses by Aedes aegypti in Chennai, Tamil Nadu, India.

BACKGROUND & OBJECTIVE: Dengue viruses are spread and maintained in an Aedes aegypti-human- Ae. aegypti cycle in urban areas of the tropics. Dengue viruses are also maintained in nature by vertical transmission by Ae. aegypti. A study was undertaken in Chennai, a known endemic city in south India, to comprehend the natural vertical transmission dynamics in Ae. aegypti and to assess its epidemiological importance. METHODS: Ae. aegypti males collected in resting and landing collections were tested for dengue virus infection by antigen-capture enzyme-linked immunosorbent assay (ELISA) and further examined by insect bioassay, Toxorhynchites splendens inoculation-indirect immunofluorescence technique (Toxo-IFA) using serotype-specific monoclonal antibodies (Mabs), if found positive by ELISA. RESULTS: Of the 509 pools of Ae. aegypti males (n=5408) screened, 15 pools, collected in April, June- July, November-December in 2003 and March, May in 2004, were found positive for dengue virus infection and the minimum infection rate (MIR) among adult males was high in June 2003 (28.0/ 1000). Three positive pools could be serotyped as dengue-2 (2 pools) and dengue-3 (1 pool). INTERPRETATION & CONCLUSION: Dengue virus isolations from wild caught males of Ae. aegypti indicate the occurrence of transovarial transmission. Vertical transmission was mainly observed in summer months when dengue infections in humans were low suggesting that dengue viruses adopt a novel strategy of surviving adverse climatic conditions.

Comparison of CD4 and CD8 lymphocyte counts in HIV-negative pulmonary TB patients with those in normal blood donors and the effect of antitubercular treatment: hospital-based flow cytometric study.

BACKGROUND: This study was designed to flow cytometrically determine baseline and sequential values of CD4 and CD8 lymphocyte subsets in patients without the human immunodeficiency virus and with pulmonary tuberculosis (TB) and to correlate these values with those obtained from normal male blood donors and with the radiologic extent of disease and response to therapy. METHODS: We studied 39 male patients without the human immunodeficiency virus and with sputum positive for pulmonary TB who had been admitted to Military Hospital (Cardiothoracic Center) in Pune, India. Clinical, laboratory, and radiologic evaluations of these patients were done. Hematologic parameters were assessed by an automated hematology cell counter (AcT*Diff, Coulter), and T-cell subsets (CD4 and CD8) were determined flow cytometrically (EPICS-XL, Coulter). RESULTS: CD4 counts and percentages of CD4 were significantly lower, but CD8 values were normal, in patients with pulmonary TB when compared with values obtained in normal blood donors. The CD4/CD8 ratio was significantly lower in patients with TB. The CD4 counts normalized with antitubercular treatment. The radiologic extent of disease did not correlate well with the immune parameters studied. CONCLUSIONS: TB is a reversible cause of CD4 lymphocytopenia and is associated with normal numbers of CD8 cells. The radiologic extent of disease does not seem to determine the immune response.

Platelet count, platelet aggregation and fibrinogen levels following acute induction to high altitude (3200 and 3771 metres).

Two groups of 20 subjects each were separately exposed to altitudes of 3200 m and 3771 m for 10 days by rapid induction requiring 14 and 16 hours respectively to reach high altitude camps. A statistically significant fall in platelet counts was observed from day 2 at 3200 m and day 3 at 3771 m and counts remained decreased. Platelet aggregation was also decreased initially at both altitudes. Blood fibrinogen decreased only on day 2 at 3771 m with a significant increase over control values by day 10 at both altitudes.

Epidemiology of subperiodic Wuchereria bancrofti infection in the Nicobar Islands, India.

Diurnally subperiodic filariasis due to Wuchereria bancrofti has been reported from tribal populations in the Nancowry group of islands in the Andaman and Nicobar Islands, India. This was confirmed in a survey carried out during the monsoon season in 1993. Microfilariae were detected in the peripheral blood throughout a 24 h period with a peak at 18:00. The microfilaria (mf) rate ranged from 1.2% to 18.7%, with a low disease rate (mean = 1.9%). Incidence of mf was low in children less than 10 years old (3.5%), but increased with increasing age. Culex (Culex) quinquefasciatus was present at a very low density. Aedes (Finlaya) niveus and Aedes (Stegomyia) malayensis were the only species commonly biting man. The former was incriminated as a vector, and found naturally infected with W. bancrofti (infection and infectivity rates 1.1% and 0.9% respectively). After experimental feeding on donors, W. bancrofti developed to L3 stage larvae in A. niveus but failed to develop in A. malayensis and A. aegypti.

Space-spraying with malathion as a supplementary measure for operational malaria control.

Entomological studies showed that due to outdoor resting by the vector Anopheles culicifacies as well as poor spray coverage, indoor residual spraying with malathion was ineffective in malarious villages of the Thenpennai riverine tract in Tamil Nadu. Over a 4 yr period during which residual spraying was supplemented with ground applications of malathion space spraying, the slide positivity among patients with fever fell from 21.04 to 1.1 per cent. In mass blood surveys 0.7 per cent persons surveyed at the beginning of the study were positive for the malarial parasite, but no positives were detected in the last survey, in 1984. There was a rising trend in malaria incidence in riverine villages outside the programme.

Significance of transplant perfusion index in the diagnosis of acute rejection in live related renal allograft recipients.

The study was undertaken to assess the usefulness of transplant perfusion index (TPI) in the differential diagnosis of renal allograft dysfunction with special reference to acute rejection. It was observed that the TPI has a sensitivity of 100 per cent and specificity of 98.1 per cent in the diagnosis of acute rejection. It was also observed that the serial values of TPI provided valuable clues and guide in the management of transplant dysfunction and helped in the immediate and long term follow-up of patients with renal allografts.

Detection of haemagglutination inhibition antibodies against Newcastle disease virus in unvaccinated indigenous chickens in Maiduguri, Borno State, Nigeria.

An examination of 200 serum samples from unvaccinated indigenous (local) chickens in Maiduguri, Borno State (Nigeria) using the haemagglutination inhibition (HI) test showed 73 sera to be positive and 127 to be negative for antibodies against Newcastle disease virus. The highest antibody titre observed was 1:128. The prevalence rate was higher (46.9%) in adult chickens than in young chickens of less than 12 weeks (23%). Presence of HI antibodies in unvaccinated indigenous chickens indicates that these birds had contracted infection and recovered thereafter.

Revalidation and description of Aedes (Finlaya) Pallirostris from northeastern India (Diptera:Culicidae).

Aedes (Finlaya) pallirostris Edwards is resurrected from synonymy with Aedes (Fin.) formosensis Yamada and the female, male, pupa, and 4th-instar larva are described and compared with closely related species. The synonymy of Finlaya khasiana Barraud is transferred from Ae. formosensis to Ae. pallirostris.

Necrobiotic pulmonary nodule leading to pyopneumothorax in a case of rheumatoid arthritis--a rare clinical presentation.

A 49-year-old male patient, an active case of sero positive rheumatoid arthritis involving multiple joints with bilateral necrobiotic pulmonary nodules is presented. Initial symptoms were of progressively increasing dyspnoea. The nodule in the right lung subsequently cavitated leading to pyopneumothorax. The diagnosis of rheumatoid lung was confirmed by post-mortem.

Osler-Rendu-Weber disease presenting as recurrent haemoptysis.

A young adult male with a short history of recurrent haemoptysis due to vascular malformation of right lung is presented. Lesion was not visible in the chest radiograph, nor on bronchography. CT-scan of thorax, however, showed a bunch of circinate opacities in the upper lobe of the right lung. Histopathological examination of the resected lung tissue confirmed the diagnosis.

Verrallina (Neomacleaya) assamensis, a new species from Assam, India.

The adult female, adult male, pupa, and larva of Verrallina (Neomacleaya) assamensis, a new mosquito species, are described from the Dibrugarh District of Assam State, India.

Serum and urinary cation changes on acute induction to high altitude (3200 and 3771 metres).

Twenty subjects each were rapidly inducted by road to 3200 ad 3771 m. Serum and urinary sodium, potassium, calcium, and magnesium were measured during 10 d at high altitude. At 3200 m, only serum potassium increased significantly on the 10th day. At 3771 m, serum potassium did not increase. Serum sodium generally remained low, serum magnesium increased, while calcium decreased significantly. Urinary volume over 24 h decreased more and for longer duration at 3771 m than at 3200 m. Urinary cations did not change significantly at 3200 m. At 3771 m, sodium and potassium excretion decreased on days 1 and 3 later returned towards preinduction levels. Magnesium and calcium decreased throughout the high-altitude stay. Significant changes were noticed in serum and urinary cations on exposure to high altitude when adequate caloric intakes were not ensured.

Pulmonary bullous disease in Marfan syndrome.

Two young adults with marfanoid features who had pulmonary bullous disease are presented. One a young soldier, presented with increasing dyspnoea and an enlarging large pulmonary bulla on the right side. The bulla was under tension and was operated on. The other case was a young housewife who also presented with dyspnoea, and was found to have a cardiac murmur and multiple ectopic beats on initial examination. X-Ray chest revealed bilateral pulmonary bullous emphysema. Both the subjects had many features which are accepted as forme fruste of the Marfan syndrome.

Enlarging pulmonary histoplasmoma associated with pulmonary tuberculosis.

Histoplasmosis is not a frequently reported infection from India. Similarity of its clinical and radiological features with pulmonary tuberculosis, may cause a difficult diagnostic dilemma when the two occur together. We report a case who initially presented with cavitary lesions over right lung responding well to anti tuberculosis chemotherapy but subsequently a small opacity present over the left upper zone showed a relentless increase till it attained a massive size few years later. Operative removal and histopathological examination of the mass confirmed it to be histoplasmoma. She became sputum AFB smear positive and culture negative for a short while during this period and this is explained on the basis of previous reports.